WO2017033653A1 - Rolling bearing unit for wheel support - Google Patents

Rolling bearing unit for wheel support Download PDF

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Publication number
WO2017033653A1
WO2017033653A1 PCT/JP2016/071861 JP2016071861W WO2017033653A1 WO 2017033653 A1 WO2017033653 A1 WO 2017033653A1 JP 2016071861 W JP2016071861 W JP 2016071861W WO 2017033653 A1 WO2017033653 A1 WO 2017033653A1
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WO
WIPO (PCT)
Prior art keywords
outer ring
axial direction
diameter
hole
row
Prior art date
Application number
PCT/JP2016/071861
Other languages
French (fr)
Japanese (ja)
Inventor
真之 田辺
将充 渡部
Original Assignee
日本精工株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2015166818A external-priority patent/JP2016109293A/en
Application filed by 日本精工株式会社 filed Critical 日本精工株式会社
Publication of WO2017033653A1 publication Critical patent/WO2017033653A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/72—Sealings
    • F16C33/76—Sealings of ball or roller bearings
    • F16C33/80—Labyrinth sealings
    • F16C33/805—Labyrinth sealings in addition to other sealings, e.g. dirt guards to protect sealings with sealing lips
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/583—Details of specific parts of races
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/72—Sealings
    • F16C33/76—Sealings of ball or roller bearings
    • F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
    • F16C33/7816—Details of the sealing or parts thereof, e.g. geometry, material
    • F16C33/782—Details of the sealing or parts thereof, e.g. geometry, material of the sealing region
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/002—Sealings comprising at least two sealings in succession
    • F16J15/004—Sealings comprising at least two sealings in succession forming of recuperation chamber for the leaking fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
    • F16J15/3204—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip
    • F16J15/3232—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip having two or more lips
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
    • B60B27/00—Hubs
    • B60B27/0073—Hubs characterised by sealing means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/14—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load
    • F16C19/18—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls
    • F16C19/181—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact
    • F16C19/183—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact with two rows at opposite angles
    • F16C19/184—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact with two rows at opposite angles in O-arrangement
    • F16C19/186—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact with two rows at opposite angles in O-arrangement with three raceways provided integrally on parts other than race rings, e.g. third generation hubs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
    • F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
    • F16C2240/46—Gap sizes or clearances
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2326/00—Articles relating to transporting
    • F16C2326/01—Parts of vehicles in general
    • F16C2326/02—Wheel hubs or castors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/64—Special methods of manufacture
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/72—Sealings
    • F16C33/76—Sealings of ball or roller bearings
    • F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
    • F16C33/7869—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted with a cylindrical portion to the inner surface of the outer race and having a radial portion extending inward
    • F16C33/7873—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted with a cylindrical portion to the inner surface of the outer race and having a radial portion extending inward with a single sealing ring of generally L-shaped cross-section
    • F16C33/7876—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted with a cylindrical portion to the inner surface of the outer race and having a radial portion extending inward with a single sealing ring of generally L-shaped cross-section with sealing lips

Definitions

  • the present invention relates to a wheel bearing rolling bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device.
  • FIG. 11 shows a conventional structure described in Patent Document 1 as a wheel-supporting rolling bearing unit (hereinafter simply referred to as a bearing unit) for rotatably supporting a wheel with respect to an automobile suspension system.
  • a bearing unit for rotatably supporting a wheel with respect to an automobile suspension system.
  • the bearing unit 1 rotatably supports the hub 3 on the inner diameter side of the outer ring 2 via a plurality of balls 4 and 4.
  • the outer ring 2 is made of medium carbon steel.
  • the inner peripheral surface of the outer ring 2 has double-row outer ring raceways 5a and 5b.
  • the outer peripheral surface of the outer ring 2 has a stationary side flange 6. Screw holes 7 are provided at a plurality of locations in the circumferential direction of the stationary flange 6. The outer ring 2 does not rotate because the outer ring 2 is coupled and fixed to the knuckle constituting the suspension device by the bolt screwed into the screw hole 7.
  • the outer peripheral surface of the hub 3 has double-row inner ring raceways 8 a and 8 b and a rotation side flange 9.
  • the hub 3 rotates with a wheel coupled and fixed to the rotation side flange 9.
  • mounting holes 11 that penetrate the rotation side flange 9 in the axial direction are provided at a plurality of locations in the circumferential direction of the rotation side flange 9.
  • the base end portions of a plurality of studs 12 each having a serration portion are press-fitted into each mounting hole 11. Thereby, it is possible to support and fix a braking rotating body such as a disk rotor and a drum brake and a wheel constituting the wheel on the rotation side flange 9.
  • a through hole 13 is provided in a portion of the rotation side flange 9 between the mounting holes 11 adjacent in the circumferential direction.
  • the hub 3 is reduced in weight, and the entire bearing unit 1 is reduced in weight.
  • each through hole 13 is tightened with a bolt screwed into the screw hole 7 of the stationary-side flange 6 (or inserted into the through-hole), and is attached to a suspension device for components constituting the braking device. Etc. can be inserted.
  • the through-hole 13 should be provided as close to the outer diameter portion of the rotation side flange 9 as possible. Is preferred.
  • the diameter D 13 of the inscribed circle at the radially inner end of each through hole 13 centering on the central axis of the bearing unit 1 is set to the outer diameter of the axially outer end of the outer ring 2. It is set to be larger than D 2.
  • the hub 3 is formed by connecting and fixing a hub body 14 and an inner ring 15.
  • the hub body 14 is made of medium carbon steel.
  • a portion near the outer end of the hub body 14 in the axial direction (“outside” in relation to the axial direction is the outer side in the width direction of the vehicle when assembled to the automobile, and is the left side in FIGS. 1 to 5 and 7 to 11.
  • “Inside” is the center side in the width direction of the vehicle, and is the right side of FIGS. 1 to 5 and 7 to 11).
  • the inner ring raceway 8a in the axially outer row of the double row inner ring raceways 8a and 8b is directly provided on the outer circumferential surface of the hub body 14 in the axial direction intermediate portion.
  • the inner ring 15 is made of bearing steel. On the outer peripheral surface of the inner ring 15, the inner ring raceway 8 b in the axially inner row of the double row inner ring raceways 8 a and 8 b is provided.
  • the inner ring 15 is externally fitted and fixed to a small-diameter step portion 16 provided near the axially inner end of the hub body 14.
  • the inner end surface in the axial direction of the inner ring 15 is held down by a caulking portion 17 provided at the inner end portion in the axial direction of the hub body 14.
  • the inner ring 15 is fixedly coupled to the hub body 14.
  • Each ball 4, 4 is made of bearing steel or ceramic.
  • a plurality of balls 4 are freely rollable in each row while being held by cages 10 and 10 between double row outer ring raceways 5a and 5b and double row inner ring raceways 8a and 8b. Is provided.
  • the gap between the inner peripheral surface of the outer end portion of the outer ring 2 in the axial direction and the outer peripheral surface of the intermediate portion of the hub 3 in the axial direction is closed by a seal ring 18 having three seal lips.
  • the tip ends of the three seal lips of the seal ring 18 are in sliding contact with the inner circumferential surface of the rotation side flange 9 or the outer circumferential surface of the hub 3 in the axial direction at the entire circumference. In this way, the seal ring 18 closes the opening on the axially outer end side of the rolling element installation space 19 in which the balls 4 and 4 are installed.
  • the bearing unit 1 has different pitch circle diameters (PCD) of the balls in both rows in order to ensure a large moment rigidity while suppressing an increase in size. That is, the pitch circle diameter of the balls 4, 4 in the axially outer row is made larger than the pitch circle diameter of the balls 4, 4 in the axially inner row.
  • the inner ring raceway 5a in the axially outer row is made larger than the inner diameter of the outer ring raceway 5b in the axially outer row and the inner ring raceway 5a in the axially outer row is made larger. It is larger than the outer diameter of 8b.
  • the seal ring 18 attached to the opening on the axially outer end side of the rolling element installation space 19 may not necessarily exhibit sufficient sealing performance.
  • a gap is provided between the outer end surface in the axial direction of the outer ring 2 and the inner surface in the axial direction of the rotation side flange 9 in order to prevent these two surfaces from contacting each other (metal contact). Then, when traveling on a rough road such as a gravel road, foreign matters such as relatively large sand particles enter through this gap, and this foreign matter slides between the seal lip constituting the seal ring 18 and the axially inner side surface of the rotation side flange 9. If it enters the contact portion, the sliding contact portion may be damaged such as abnormal wear.
  • the present invention provides a wheel support rolling device that can easily discharge foreign matter that has entered through a gap between an axial outer end surface of an outer ring and an axial inner surface of a rotary flange into an external space. Invented to realize the structure of the bearing unit.
  • the wheel support rolling bearing unit of the present disclosure includes an outer ring, a hub, and a plurality of rolling elements.
  • the outer ring has a double-row outer ring raceway on the inner circumferential surface, and is supported by the suspension device in a use state and does not rotate.
  • the hub is disposed coaxially with the outer ring on the inner diameter side of the outer ring, has a double-row inner ring raceway on a portion of the outer peripheral surface facing the double-row outer ring raceway, and an axially outer end portion of the outer ring.
  • a rotation-side flange for coupling and fixing the braking rotator and the wheel is provided at a portion protruding outward in the axial direction.
  • a plurality of rolling elements are provided between the outer ring raceway in the double row and the inner ring raceway in the double row so as to be freely rollable for each row.
  • Foreign matter discharge holes through holes opened on both sides in the axial direction of the rotation side flange) that are opened in at least the inner side surface in the axial direction of both sides in the axial direction of the rotation side flange in one or more circumferential directions of the rotation side flange Or a bottomed hole opened only on the inner side surface in the axial direction is provided.
  • the outer diameter of the outer end surface in the axial direction of the outer ring is larger than the diameter of the inscribed circle at the inner end in the radial direction of the foreign matter discharge hole centered on the central axis of the hub (the central axis of the wheel bearing rolling bearing unit). large.
  • Such foreign matter discharge holes are used, for example, to reduce the weight of the hub, to support the outer ring on the suspension device, or to attach a component constituting a braking device to the suspension device. It is provided to insert a tool.
  • a labyrinth seal is preferably provided between the axially outer end surface of the outer ring and the axially inner side surface of the rotating side flange that face each other.
  • a labyrinth seal is configured as follows, for example. That is, the outer ring side step portion having an inner diameter larger than the portion adjacent to the inner side in the axial direction is provided at the outer end portion in the axial direction of the inner peripheral surface of the outer ring.
  • a thick portion provided at a portion near the base end (base portion) of the rotation side flange, and a thickness (axial thickness) than the thick portion.
  • a thin step portion that is continuous with each other.
  • a notch portion having a crank-shaped cross section is provided at the axially inner end portion of the step portion, and a flange-side step portion having a smaller outer diameter than the portion adjacent to the outside in the axial direction is provided.
  • An axial labyrinth seal is provided between the outer ring side step portion and the flange side step portion by causing the outer ring side step portion and the flange side step portion to face each other in the radial direction.
  • the outer end surface in the axial direction of the outer ring and the inner end surface of the step portion on the flange side are closely opposed to each other.
  • a radial labyrinth seal is provided between the axially outer end surface of the outer ring and the inner end surface of the flange-side stepped portion.
  • the inner peripheral surface of the foreign matter discharge hole is preferably a cylindrical surface whose inner diameter does not change in the axial direction. That is, the foreign matter discharge hole is preferably a cylindrical hole.
  • the inner peripheral surface of the foreign matter discharge hole may be a conical surface inclined in a direction in which the inner diameter becomes smaller toward the outer side in the axial direction. That is, the foreign matter discharge hole can be a conical hole.
  • the inner peripheral surface of the foreign matter discharge hole is a smooth surface whose inner diameter does not repeatedly change in the axial direction.
  • outer ring side recesses are provided in one or more circumferential directions of the outer ring.
  • the outer ring side recess opens to the outer circumferential surface and the outer circumferential surface of the outer ring in the axial direction.
  • Such an outer ring side recess is preferably provided at a lower portion (lower half) in a state where the wheel bearing rolling bearing unit is supported by a vehicle suspension device, and more preferably at the lower end.
  • the diameter of the inscribed circle at the radially inner end of the foreign matter discharge hole centered on the central axis of the hub is also made smaller near the outer diameter of the outer end surface in the axial direction of the outer ring, so that the portion near the inner diameter of the foreign matter discharge hole and the outer ring
  • the outer end face in the axial direction is made to face.
  • FIG. 2 is a schematic diagram corresponding to the YY cross section of FIG. 1, showing a state in which a braking rotator is supported and fixed to a rotation side flange.
  • the figure corresponding to FIG. 2 which shows the 2nd example of embodiment of this invention.
  • the figure equivalent to FIG. 2 which shows the 3rd example of embodiment of this invention.
  • FIG. 6 is a ZZ sectional view of FIG. 5.
  • the figure equivalent to FIG. 2 which shows the 4th example of embodiment of this invention.
  • FIG. 2 which shows the 5th example of embodiment of this invention.
  • the principal part expanded sectional view for demonstrating the method of providing a recessed part.
  • Sectional drawing which shows an example of a conventional structure.
  • a wheel-supporting rolling bearing unit 1a (hereinafter, simply referred to as a bearing unit) of this example includes an outer ring 2a, a hub 3a, and a plurality of balls 4a and 4b, each of which is a rolling element. .
  • Double row outer ring raceways 5c and 5d are provided on the inner peripheral surface of the outer ring 2a.
  • a stationary side flange 6 is provided at the axially intermediate portion of the outer peripheral surface of the outer ring 2a.
  • the inner diameter of the outer ring raceway 5c in the outer row in the axial direction is larger than the inner diameter of the outer ring raceway 5d in the inner row in the axial direction.
  • the inner circumference of the inner circumferential surface of the outer ring 2a inclined toward the axially outer side of the outer ring raceway 5d in the axially inner row is inclined so that the inner diameter becomes smaller toward the inner side in the axial direction.
  • the surface side step part 20 is provided.
  • through holes 36 are provided at a plurality of locations in the circumferential direction of the stationary flange 6.
  • a bolt (not shown) for inserting and fixing the outer ring 2 a to a knuckle constituting the suspension device is inserted into the through hole 36.
  • the hub 3a is a combination of the hub body 14a and the inner ring 15. Near the outer end of the hub 3a in the axial direction, a braking rotator 35 (see FIG. 3) such as a rotor or a drum and a rotation side flange 9a for supporting a wheel are provided. Double-row inner ring raceways 8c and 8d are provided at the axially intermediate portion and inner end portion of the outer peripheral surface of the hub 3a. Of the double row inner ring raceways 8c and 8d, the outer diameter of the inner ring raceway 8c in the axially outer row is larger than the outer diameter of the inner ring raceway 8d in the axially inner row.
  • mounting holes 11 are provided at a plurality of locations in the circumferential direction of the rotation side flange 9a.
  • the base end portion of the stud 12 that supports and fixes the brake rotating body 35 and the wheel is press-fitted into the mounting hole 11 in the rotation side flange 9a.
  • the through-hole 13a which is a foreign material discharge
  • the through hole 13a penetrates the rotation side flange 9a in the axial direction. That is, the through-hole 13a opens on both axial sides of the rotation side flange 9a.
  • each through hole 13a is opposed to the axially outer end surface of the outer ring 2a. That is, as shown in FIG. 2, the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1a, the outer diameter D of the axially outer end face of the outer ring 2a It is smaller than 2a ( D13a ⁇ D2a ).
  • the brake rotating body 35 supported and fixed to the rotation side flange 9a and the size (outer diameter), weight, etc. of the wheel are set as appropriate.
  • each through hole 13a is a cylindrical hole (circular hole) in which the inner diameter of the inner peripheral surface does not change in the axial direction.
  • the outer diameter of the outer peripheral surface of the hub body 14a is slightly closer to the inner side in the axial direction than the inner ring raceway 8c in the axially outer row.
  • An outer peripheral surface side stepped portion 21 is provided to connect an axially inner portion with a small outer diameter and an axially outer portion with a large outer diameter.
  • a small-diameter step portion 16 is provided on the outer peripheral surface of the hub body 14a at a portion closer to the inner end in the axial direction that is closer to the inner side in the axial direction than the step portion 21 on the outer peripheral surface side.
  • An inner ring 15 having an inner ring raceway 8d in the axially inner row provided on the outer peripheral surface is externally fitted to the small diameter step portion 16.
  • the inner ring 15 is pressed against the stepped surface 22 existing at the axially outer end of the small-diameter stepped portion 16 by a caulking portion 17 provided at the axially inner end of the hub body 14a. In this state, the inner ring 15 is coupled and fixed to the hub body 14a.
  • Each ball 4a, 4b is held in the cages 10a, 10b between the double row outer ring raceways 5c, 5d and the double row inner ring raceways 8c, 8d. It is provided so that it can roll freely. In this state, each ball 4a, 4b arranged in a double row is provided with a contact angle of the rear combination type together with the preload.
  • the pitch circle diameters of the balls 4a and 4b in each row differ from each other in accordance with the difference in inner diameter between the double row outer ring raceways 5c and 5d and the difference in outer diameter between the double row inner ring raceways 8c and 8d.
  • the pitch circle diameters of the balls 4a, 4a in the axially outer row are larger than the pitch circle diameters of the balls 4b, 4b in the axially inner row.
  • the diameters of the balls 4a and 4a in the axially outer row are made smaller than the diameters of the balls 4b and 4b in the axially inner row.
  • the diameters of the balls 4a, 4a in the axially outer row and the diameters of the balls 4b, 4b in the axially inner row can be made equal to each other.
  • a tapered roller can be used instead of a ball for one or both of the two rows.
  • a rolling element installation space 19 exists between the inner peripheral surface of the outer ring 2a and the outer peripheral surface of the hub 3a, and the balls 4a and 4b are installed in the rolling element installation space.
  • the axially outer end opening of the rolling element installation space 19 is closed by a seal ring 18 attached to the opening. That is, the three seal lips constituting the seal ring 18 are respectively slidably contacted with the outer peripheral surface of the intermediate portion in the axial direction of the hub body 14a and the inner surface in the axial direction of the rotation side flange 9a over the entire periphery. Yes.
  • the inner end opening in the axial direction of the outer ring 2a is closed by a cover 23 that is mounted on the opening and is formed of a non-magnetic material and has a bottomed cylindrical shape.
  • An encoder 24 is fitted and fixed to the outer peripheral surface of the inner end portion in the axial direction of the inner ring 15. That is, the rotational speed of the wheel coupled and fixed to the hub 3a can be detected by making a speed sensor (not shown) face the detected surface of the encoder 24 via the cover 23.
  • a labyrinth seal 25 is provided between the axially outer end surface of the outer ring 2a and the axially inner surface of the rotation side flange 9a.
  • the labyrinth seal 25 includes a radial labyrinth seal 32, which will be described later, and an axial labyrinth seal 31 that is bent inward in the axial direction from the radial inner end of the radial labyrinth seal 32 as a whole.
  • the cross section is substantially L-shaped.
  • a thicker portion 27 provided in a portion near the base end (root portion) of the rotation side flange 9a and a thickness (axial thickness) than the thick portion 27.
  • a thin step portion 28 is provided, and a step portion 29 is provided.
  • the step surface shape of the step portion 29 is an arc shape or a substantially arc shape.
  • a notch portion having a crank-shaped cross section is provided at the axially inner end portion of the step portion 29, and a flange-side step portion 30 having a smaller outer diameter than the portion adjacent to the outside in the axial direction is provided.
  • An axial labyrinth seal 31 is provided between the outer ring side step part 26 and the flange side step part 30 by causing the outer ring side step part 26 and the flange side step part 30 to face each other in the radial direction.
  • the axially outer end surface of the outer ring 2a and the stepped surface bent at a right angle radially outward from the axially outer end of the flange-side stepped portion 30 are close to each other in the axial direction so that the outer ring 2a
  • a radial labyrinth seal 32 is provided between the axially outer end surface and the stepped surface present at the axially outer end of the flange-side stepped portion 30. That is, by providing the radial labyrinth seal 32 at a position that does not overlap the seal ring 18 in the radial direction (a position that is separated from the seal ring 18 with respect to the axial direction), foreign matter such as muddy water splashed when the vehicle travels is removed.
  • the seal ring 18 is disposed radially inward and axially inward of the labyrinth seal 25, and the seal ring 18 is protected by the labyrinth seal 25.
  • the sum of the axial length and the radial length of the radial labyrinth seal 32) varies depending on the size and weight of the braking rotator 35 and the wheels supported and fixed to the rotation-side flange 9a.
  • the radial width W 31 of the axial labyrinth seal 31 is preferably 0.5 to 1.0 mm, more preferably 0.55 to 0.8 mm, and still more preferably. Is 0.57 to 0.8 mm, and the axial length L 31 of the labyrinth seal 31 in the axial direction is preferably 0.6 mm to 1.4 mm, more preferably 0.7 to 1.3 mm.
  • the axial width W 32 of the radial labyrinth seal 32 is preferably 0.8 to 1.5 mm, more preferably 0.9 to 1.3 mm, and the radial length L of the radial labyrinth seal 32 is set. 32 is preferably 1.5 to 2.6 mm, more preferably 1.9 to 2.5 mm, and still more preferably 1.85 to 2.43 mm.
  • the labyrinth seal 25 there is a possibility that the effect of preventing foreign matter intrusion due to is not sufficiently obtained.
  • the bearing unit 1a is There is a possibility of increasing the size and weight.
  • the length is made larger than the width (L 31 > W 31 , L 32 > W 32 ), and the labyrinth effect is obtained. It is increasing. Further, the length and width of the radial labyrinth seal 32 are made larger than the length and width of the axial labyrinth seal 31 (L 31 > L 32 , W 31 > W 32 ), and the labyrinth seal 25 is placed in the labyrinth seal 25. The invading foreign matter is kept in the radial labyrinth seal 32 as much as possible.
  • the axial labyrinth seal 31 has a constant radial width W 31 in the axial direction.
  • the radial labyrinth seal 32 has a constant axial width W 32 in the radial direction.
  • the effect of preventing foreign matter from entering the rolling element installation space 19 can be maintained well over a long period of time, and the durability can be further improved. That is, in this example, from the radial inner end of the radial labyrinth seal 32 and the radial labyrinth seal 32 between the axial outer end surface of the outer ring 2a and the axial inner surface of the rotation side flange 9a. A labyrinth seal 25 including an axial labyrinth seal 31 bent inward in the axial direction is provided. For this reason, it is difficult for the foreign matter jumped up when the vehicle equipped with the bearing unit 1 a travels to reach the portion where the tip edge of the seal lip constituting the seal ring 18 is in contact. That is, the seal ring 18 can be protected.
  • the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1a smaller than the outer diameter D 2a of the axial outer end surface of the outer ring 2a (D 13a ⁇ D 2a ), the portion closer to the inner diameter of each through hole 13a and the outer end surface in the axial direction of the outer ring 2a are opposed to each other.
  • the portion closer to the inner diameter of each through hole 13a is opened to the portion defining the radial labyrinth seal 32 on the inner side surface in the axial direction of the rotation side flange 9a.
  • each through hole 13a the portion closer to the inner diameter of each through hole 13a and the outer radial half of the radial labyrinth seal 32 are overlapped in the axial direction.
  • the cross-sectional area ⁇ in the rotational direction of the rotation-side flange 9a corresponds to each through hole 13a.
  • each through-hole 13a has the function for inserting a tool when performing various operations, it becomes difficult to insert the tool.
  • the difference between the outer diameter D 2a and diameter D 13a It is regulated to an appropriate range.
  • the foreign matter can hardly reach the portion where the tip edge of the seal lip constituting the seal ring 18 is in contact. Therefore, foreign matter enters the sliding contact portion between the tip edge of the seal lip and the axial inner surface of the rotation side flange 9a, and damage such as abnormal wear occurs in the sliding contact portion over a long period of time. Can be prevented.
  • the effect of preventing foreign matter from entering the rolling element installation space 19 can be maintained well over a long period of time, and the durability of the bearing unit 1a can be further improved.
  • each through-hole 13a which is a foreign matter discharge hole is a cylindrical hole provided in a state where the inner diameter of the inner peripheral surface does not change in the axial direction and penetrates the rotation side flange 9a in the axial direction. . For this reason, with the rotation of the rotation-side flange 9a, the flow of the airflow flowing along the inner peripheral surface of each through hole 13a can be rectified to form a laminar flow.
  • each through-hole 13a which is a foreign material discharge hole
  • the foreign matter discharge hole may be a conical hole. If the inner peripheral surface of the foreign material discharge hole is a conical surface inclined in a direction in which the inner diameter becomes smaller as it goes outward in the axial direction, the velocity of the airflow flowing from the inner side to the outer side in the foreign material discharge hole Can be made faster as it goes outward in the axial direction.
  • the inner peripheral surface of the foreign matter discharge hole is a smooth surface whose inner diameter does not repeatedly change in the axial direction. To do.
  • the foreign matter discharge hole is, for example, a screw hole, that is, when the inner peripheral surface of the foreign matter discharge hole has a shape in which the inner diameter repeatedly changes in the axial direction, the flow of airflow flowing through each foreign matter discharge hole is It becomes turbulent. In this case, the effect of discharging foreign matter due to the action of airflow and pressure generated as the rotation-side flange rotates is not as good as when the foreign matter discharge hole is a cylindrical hole or a conical hole.
  • emission hole can also be made into a bottomed hole opened only to the axial direction inner surface of the rotation side flange. If the foreign matter discharge hole is a bottomed hole, the strength and rigidity of the rotation side flange can be easily ensured as compared with the case where the foreign matter discharge hole is a through hole.
  • FIG. 4 shows a second example of the embodiment of the present invention.
  • the portion positioned at the lower end portion with the bearing unit 1b supported by the suspension device is axially inward in the radial direction (in a state of opening to both inner and outer peripheral surfaces).
  • a concave groove 33 is provided.
  • Such a concave groove 33 is provided at the same time when the outer ring 2b is manufactured by subjecting a metal material such as carbon steel to forging which is plastic processing.
  • the concave groove 33 can also be provided by cutting the axially outer end surface of the outer ring 2b after the outer ring 2b is forged.
  • the phase in the circumferential direction of the portion closer to the inner diameter of the through hole 13a and the groove 33 is the same (the phase in the circumferential direction between the portion closer to the inner diameter of the through hole 13a and the groove 33 is the same.
  • the speed of the air flow generated with the rotation of the rotation side flange 9a can be reduced, and the pressure in the labyrinth seal 25 can be increased.
  • the concave groove 33 is provided in a portion of the outer end surface in the axial direction of the outer ring 2b located at the lower end portion with the bearing unit 1b supported by the suspension device. That is, the direction in which foreign matter is discharged (pushed out) with the increase in pressure in the labyrinth seal 25 based on the presence of the concave groove 33 and the action direction of gravity are made to coincide with each other to further increase the foreign matter discharge effect. Can be improved.
  • the concave groove 33 is provided in a portion positioned at the lower end portion with the bearing unit 1b supported by the suspension device.
  • the concave groove is provided in a portion located below (lower half) with the bearing unit 1b supported by the suspension device, the above-described foreign matter discharge effect is provided to some extent (the portion located at the lower end portion). But not as much as you can).
  • the labyrinth seal (although it cannot obtain the effect of gravity). It is possible to obtain a foreign matter discharging effect due to an increase in the pressure in 25.
  • the concave grooves 33 can also be provided at a plurality of locations in the circumferential direction on the axially outer end surface of the outer ring 2b.
  • the configuration and operation of the other parts are the same as in the first example of the embodiment described above.
  • FIG. 5 to 6 show a third example of the embodiment of the present invention.
  • An outer ring side recess 34 is provided in a portion of the outer peripheral surface of the outer ring 2c in the axial direction that coincides with the through hole 36 (see FIG. 1) provided in the stationary flange 6 in the circumferential direction.
  • the outer ring side recess 34 opens to the axially outer end face of the outer ring 2c and is recessed radially inward.
  • each outer ring side recess 34 is constant in the outer half portion in the axial direction, and is made smaller toward the inner side in the axial direction in the inner half portion in the axial direction. That is, the diameter D 34 of the inscribed circle of the bottom surface of the outer wheel side recess 34 around the central axis of the bearing unit 1c, are larger toward axially inward. And the axial direction inner end edge (back end edge) of each outer ring side recess 34 is positioned outside the axial direction outer end edge of the outer ring raceway 5c (see FIG. 1) in the axial direction outer row in the axial direction. .
  • the shape of the bottom surface at the opening of each outer ring side recess 34 (the shape of the bottom when the opening is viewed from the outside in the axial direction). around the 13a central axis of, and a large arc-shaped in diameter than the inner diameter d 13a of each through hole 13a.
  • the shape of the bottom surface in the opening of each outer ring side recess 34 can be a V shape as shown in FIG. 6B, a linear shape as shown in FIG.
  • the outer ring side recess 34 is provided at the same time when the outer ring 2c is formed by subjecting a metal material such as carbon steel to a forging process which is a plastic process.
  • the outer ring side recess 34 can be provided by cutting the outer ring 2c after the outer ring 2c is made by forging.
  • one of the outer ring side recesses 34 is provided at a portion located at the lower end with the outer ring 2c supported by the vehicle suspension.
  • the pressure in the labyrinth seal 25 is increased based on the presence of the one outer ring side recess 34, and the direction in which foreign matter is discharged (pushed out) and the direction of action of gravity coincide with each other.
  • the diameter D 13a of the inscribed circle at the radially inner end of each through-hole 13a centered on the central axis of the bearing unit 1c is set as the outer ring centered on the central axis of the bearing unit 1c. is made larger than the diameter D 34 of at inscribed circle axially outer end edge of the bottom surface of the side recess 34 (D 13a> D 34) .
  • each through-hole 13a when a tool is inserted into each through-hole 13a, it is possible to prevent the tip of the tool from interfering with the axially outer end surface of the outer ring 2c, and work performed by inserting the tool into each through-hole 13a. It is possible to prevent a decrease in sex. In other words, it is possible to prevent the workability of work such as attaching / detaching the bearing unit 1c to / from the suspension device, and attaching / detaching parts (supports and calipers) constituting the brake device from the suspension device.
  • the bearing unit 1c When the bearing unit 1c is attached to the suspension device, the phase in the circumferential direction of the screw hole provided in the knuckle constituting the suspension device and the through hole 36 of the stationary side flange 6 are made to coincide with each other, and the rotation side flange The phases in the circumferential direction of the through holes 13a of 9a and the through holes 36 are made to coincide with each other.
  • a tool is inserted from the outside in the axial direction of each through hole 13a, and a bolt inserted through each through-hole 36 from the outside in the axial direction is screwed into each screw hole by this tool and further tightened.
  • the stationary side flange 6 is coupled and fixed to the knuckle.
  • the tool is applied from the outside in the axial direction of each through hole 13a in a state where the phases in the circumferential direction of each through hole 13a and each through hole 36 coincide with each other. Is inserted, and the bolts screwed into the screw holes are loosened by inserting the through holes 36 with a tool.
  • the diameter of the outer ring 2c is open to the outer peripheral surface of the outer ring 2c in a portion where the phase in the circumferential direction coincides with each through hole 36.
  • the outer ring side recesses 34 that are recessed inward in the direction are respectively provided, and the diameter D 34 of the inscribed circle at the outer edge in the axial direction of the bottom surface of each outer ring side recess 34 centered on the central axis of the bearing unit 1c, It is smaller than the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1c (D 34 ⁇ D 13a) .
  • the tip of the tool interferes with the axial outer end surface of the outer ring 2c.
  • the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1c is smaller than the outer diameter D 2c of the axially outer end face of the outer ring 2c ( Even in the case of D 13a ⁇ D 2c ), it is possible to prevent the assembling property of the bearing unit 1c from being attached to the knuckle (workability of work performed by inserting a tool into each through hole 13a).
  • the outer ring side recess 34 as described above coincides with a fixing position (mounting hole or the like) of a support or caliper (not shown) that constitutes a braking device together with the brake rotating body 35 (see FIG. 3) in the circumferential direction. It can also be provided.
  • the configuration and operation of the other parts are the same as in the first and second examples of the above-described embodiment.
  • [Fourth Example of Embodiment] 7 and 8 show a fourth example of the embodiment of the present invention.
  • a large-diameter portion 37 having an outer diameter and an inner diameter larger than those adjacent to the inner side in the axial direction is provided at the outer end in the axial direction of the outer ring 2d.
  • shaft of the bearing unit 1d about the outer diameter of the axial direction outer end surface of the large diameter part 37, ie, the axial direction outer end surface of the outer ring
  • the large-diameter portion 37 is formed on one end of the metal material provided in a cylindrical shape (on the outer end in the axial direction of the outer ring 2d) when the outer ring 2d is manufactured by subjecting a metal material such as carbon steel to plastic processing such as forging.
  • the corresponding end portion is provided by plastic deformation so as to expand the left end portion in FIG.
  • a metallic and cylindrical intermediate material 38 is set in a die 39.
  • the inner peripheral surface of the die 39 has a stepped cylindrical shape in which the inner diameter of one end (opening side end) is larger than the inner diameter of the portion adjacent to the other side.
  • the outer diameter of the intermediate portion or the other end portion of the intermediate material 38 is restrained by the die 39.
  • the diameter-enlarging punch 40 is pushed inward from the opening on one end side in the radial direction of the intermediate material 38, and one end portion of the intermediate material 38 is plastically deformed radially outward to increase the outer diameter and inner diameter.
  • a diameter portion 37 is provided.
  • the processing for providing such a large diameter portion 37 can be performed, for example, in the final step of the manufacturing process of the outer ring 2d.
  • a die 39 that can be divided in the circumferential direction is used.
  • the outer diameter of the outer ring 2a (2b, 2c) is increased by increasing the outer diameter of the outer end surface of the outer ring 2a (2b, 2c) in order to improve the foreign matter intrusion effect.
  • the radial thickness of (2b, 2c) increases and the weight increases.
  • the large diameter portion 37 is provided at the axially outer end portion of the outer ring 2d by plastically deforming one end portion of the intermediate material 38 radially outward.
  • the outer diameter of the outer end surface in the axial direction of the portion 37 is made larger than the diameter of the inscribed circle at the inner end portion in the radial direction of each through hole 13a. Therefore, it is possible to maintain a good foreign substance intrusion preventing effect over a long period while suppressing an increase in weight.
  • the bearing unit 1d is a so-called unsprung load provided on the road surface side of the spring constituting the suspension device, the weight reduction makes it possible to improve the running performance centered on ride comfort and running stability. can get.
  • an inclined surface portion 41 is formed on the outer peripheral surface of the outer ring 2d at a continuous portion between the axial middle portion of the outer ring 2d and the large-diameter portion 37 provided at the outer end portion in the axial direction of the outer ring 2d. It is formed.
  • the inclined surface portion 41 can prevent water such as muddy water adhering to the outer peripheral surface of the outer ring 2d from entering the rolling element installation space 19 from the axially outer side opening of the outer ring 2d along the outer peripheral surface of the outer ring 2d (damming. Can do it). Also from this aspect, the effect of preventing foreign matter from entering the rolling element installation space 19 can be improved.
  • Other configurations and operations are the same as those in the first to third examples of the above-described embodiment.
  • FIG. 9 and 10 show a fifth example of the embodiment of the present invention.
  • a concave portion 42 that is recessed inward in the radial direction is provided over the entire circumference at a portion near the outer end in the axial direction of the outer ring 2e.
  • the weight of the outer ring 2e, and hence the increase in unsprung load can be suppressed by providing the recess 42, so that the running performance of the vehicle equipped with the bearing unit 1e can be improved.
  • I can plan.
  • it is a recess that moisture such as muddy water adhering to the outer peripheral surface of the outer ring 2e enters the rolling element installation space 19 (see FIG. 1) from the axially outer opening of the outer ring 2e along the outer peripheral surface of the outer ring 2e. 42 can prevent this.
  • a stepped cylinder made of metal and having an outer diameter at one end (the left end in FIG. 10) smaller than the outer diameter of the portion adjacent to the other.
  • An intermediate material 38a having an outer peripheral surface is set in the die 39a.
  • a portion closer to one end (closer to the opening end) of the inner peripheral surface of the die 39a has a convex portion 43 protruding radially inward over the entire periphery.
  • the diameter-enlarging punch 40a is pushed inward in the radial direction of the intermediate material 38a from the opening on one end side, and one end portion of the intermediate material 38a is plastically deformed radially outward to expand the outer diameter and inner diameter.
  • the recessed part 42 is provided in the part near the axial direction outer end of the outer ring 2e (the part near one end of the intermediate material 38a).
  • the pitch circle diameter of the rolling elements (balls or tapered rollers) in the axially outer row is larger than the pitch circle diameter of the rolling elements in the axially inner row. It can be preferably implemented with a large structure in which the outer diameter of the outer end of the outer ring in the axial direction is large. However, the present invention is applied to a structure in which the pitch circle diameters of the rolling elements in both rows are equal to each other, or a structure in which the pitch circle diameter of the rolling elements in the axially inner row is larger than the pitch circle diameter of the rolling elements in the axially outer row. You can also do it.
  • the present invention is not limited to the bearing unit for the driven wheel as shown in FIGS. 1 and 11, and a spline hole through which the drive shaft is spline-engaged in use in the center portion of the hub body is axially penetrated. It can also be implemented with a bearing unit for driving wheels provided in the state.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rolling Contact Bearings (AREA)

Abstract

A rotary-side flange is provided with a foreign body discharge hole that opens to at least an axial inner side face of the two axial side faces of the rotary-side flange. The outer diameter of an external end face of an outer ring in the axial direction is larger than the diameter of an inscribed circle of the inner end of the foreign body discharge hole in the radial direction with the central axis of a hub serving as the center.

Description

車輪支持用転がり軸受ユニットRolling bearing unit for wheel support
　本発明は、自動車の車輪を懸架装置に対して回転自在に支持する為の車輪支持用転がり軸受ユニットに関する。 The present invention relates to a wheel bearing rolling bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device.
　図１１は、自動車の懸架装置に対して車輪を回転自在に支持する為の車輪支持用転がり軸受ユニット（以後、単に軸受ユニットと呼ぶことがある。）として、特許文献１に記載された従来構造の１例を示している。軸受ユニット１は、外輪２の内径側にハブ３を、複数個の玉４、４を介して、回転自在に支持している。 FIG. 11 shows a conventional structure described in Patent Document 1 as a wheel-supporting rolling bearing unit (hereinafter simply referred to as a bearing unit) for rotatably supporting a wheel with respect to an automobile suspension system. An example is shown. The bearing unit 1 rotatably supports the hub 3 on the inner diameter side of the outer ring 2 via a plurality of balls 4 and 4.
　外輪２は、中炭素鋼製である。外輪２の内周面は複列の外輪軌道５ａ、５ｂを有する。外輪２の外周面は静止側フランジ６を有する。静止側フランジ６の円周方向複数箇所にはねじ孔７が設けられる。ねじ孔７に螺合したボルトにより、外輪２は懸架装置を構成するナックルに結合固定される為、外輪２は回転しない。 The outer ring 2 is made of medium carbon steel. The inner peripheral surface of the outer ring 2 has double-row outer ring raceways 5a and 5b. The outer peripheral surface of the outer ring 2 has a stationary side flange 6. Screw holes 7 are provided at a plurality of locations in the circumferential direction of the stationary flange 6. The outer ring 2 does not rotate because the outer ring 2 is coupled and fixed to the knuckle constituting the suspension device by the bolt screwed into the screw hole 7.
　又、ハブ３の外周面は、複列の内輪軌道８ａ、８ｂと回転側フランジ９とを有する。ハブ３は、使用時に、回転側フランジ９に結合固定した車輪と共に回転する。又、回転側フランジ９の円周方向複数箇所に、回転側フランジ９を軸方向に貫通する取付孔１１を設けている。各取付孔１１に、その一部にセレーション部を有する複数本のスタッド１２の基端部を圧入する。これにより、回転側フランジ９に、ディスクロータやドラムブレーキ等の制動用回転体や、車輪を構成するホイールを支持固定可能としている。又、回転側フランジ９のうち、円周方向に隣り合う取付孔１１同士の間部分に透孔１３を設けている。各透孔１３が設けられることにより、ハブ３が軽量化され、延いては軸受ユニット１全体が軽量化される。また、各透孔１３には、静止側フランジ６のねじ孔７に螺合した（或いは貫通孔に挿通した）ボルトの締め付け作業や、制動装置を構成する部品の懸架装置への取付作業を行う等ための工具が挿入可能である。透孔１３は、ハブ３の慣性モーメントを低減して、加速性能を中心とする走行性能や燃費性能の向上を図る為には、可能な限り、回転側フランジ９の外径寄り部分に設ける事が好ましい。この為、図示の例の場合、軸受ユニット１の中心軸を中心とする各透孔１３の径方向内端部の内接円の直径Ｄ１３を、外輪２の軸方向外端部の外径Ｄ２よりも大きくしている。 The outer peripheral surface of the hub 3 has double-row inner ring raceways 8 a and 8 b and a rotation side flange 9. In use, the hub 3 rotates with a wheel coupled and fixed to the rotation side flange 9. In addition, mounting holes 11 that penetrate the rotation side flange 9 in the axial direction are provided at a plurality of locations in the circumferential direction of the rotation side flange 9. The base end portions of a plurality of studs 12 each having a serration portion are press-fitted into each mounting hole 11. Thereby, it is possible to support and fix a braking rotating body such as a disk rotor and a drum brake and a wheel constituting the wheel on the rotation side flange 9. Further, a through hole 13 is provided in a portion of the rotation side flange 9 between the mounting holes 11 adjacent in the circumferential direction. By providing each through hole 13, the hub 3 is reduced in weight, and the entire bearing unit 1 is reduced in weight. In addition, each through hole 13 is tightened with a bolt screwed into the screw hole 7 of the stationary-side flange 6 (or inserted into the through-hole), and is attached to a suspension device for components constituting the braking device. Etc. can be inserted. In order to reduce the moment of inertia of the hub 3 and improve the driving performance and fuel consumption performance centering on the acceleration performance, the through-hole 13 should be provided as close to the outer diameter portion of the rotation side flange 9 as possible. Is preferred. For this reason, in the case of the illustrated example, the diameter D 13 of the inscribed circle at the radially inner end of each through hole 13 centering on the central axis of the bearing unit 1 is set to the outer diameter of the axially outer end of the outer ring 2. It is set to be larger than D 2.
　又、ハブ３は、ハブ本体１４と内輪１５とを結合固定して成る。ハブ本体１４は、中炭素鋼製である。ハブ本体１４の軸方向外端寄り部分（軸方向に関して「外」とは、自動車への組み付け状態で車両の幅方向外側であり、図１～５、７～１１の左側である。軸方向に関して「内」とは、車両の幅方向中央側であり、図１～５、７～１１の右側である。）の外周面には、回転側フランジ９を直接設けている。ハブ本体１４の軸方向中間部外周面には、複列の内輪軌道８ａ、８ｂのうち軸方向外側列の内輪軌道８ａを、直接設けている。 The hub 3 is formed by connecting and fixing a hub body 14 and an inner ring 15. The hub body 14 is made of medium carbon steel. A portion near the outer end of the hub body 14 in the axial direction ("outside" in relation to the axial direction is the outer side in the width direction of the vehicle when assembled to the automobile, and is the left side in FIGS. 1 to 5 and 7 to 11. “Inside” is the center side in the width direction of the vehicle, and is the right side of FIGS. 1 to 5 and 7 to 11). The inner ring raceway 8a in the axially outer row of the double row inner ring raceways 8a and 8b is directly provided on the outer circumferential surface of the hub body 14 in the axial direction intermediate portion.
　内輪１５は、軸受鋼製である。内輪１５の外周面には、複列の内輪軌道８ａ、８ｂのうち軸方向内側列の内輪軌道８ｂを設けている。内輪１５は、ハブ本体１４の軸方向内端寄り部分に設けられた小径段部１６に外嵌固定している。内輪１５の軸方向内端面は、ハブ本体１４の軸方向内端部に設けたかしめ部１７により抑え付けられている。このように、内輪１５はハブ本体１４に対し結合固定している。 The inner ring 15 is made of bearing steel. On the outer peripheral surface of the inner ring 15, the inner ring raceway 8 b in the axially inner row of the double row inner ring raceways 8 a and 8 b is provided. The inner ring 15 is externally fitted and fixed to a small-diameter step portion 16 provided near the axially inner end of the hub body 14. The inner end surface in the axial direction of the inner ring 15 is held down by a caulking portion 17 provided at the inner end portion in the axial direction of the hub body 14. Thus, the inner ring 15 is fixedly coupled to the hub body 14.
　各玉４、４は、軸受鋼或いはセラミック製である。玉４は、複列の外輪軌道５ａ、５ｂと複列の内輪軌道８ａ、８ｂとの間に、保持器１０、１０に保持された状態で、各列毎に複数個ずつ、転動自在に設けられている。 Each ball 4, 4 is made of bearing steel or ceramic. A plurality of balls 4 are freely rollable in each row while being held by cages 10 and 10 between double row outer ring raceways 5a and 5b and double row inner ring raceways 8a and 8b. Is provided.
　又、外輪２の軸方向外端部内周面とハブ３の軸方向中間部外周面との間の隙間を、３本のシールリップを備えたシールリング１８により塞いでいる。シールリング１８の３本のシールリップの先端部はそれぞれ、回転側フランジ９の軸方向内側面、又はハブ３の軸方向中間部外周面に、全周に亙って摺接する。このようにシールリング１８は、各玉４、４を設置した転動体設置空間１９の軸方向外端側の開口を塞いでいる。 Further, the gap between the inner peripheral surface of the outer end portion of the outer ring 2 in the axial direction and the outer peripheral surface of the intermediate portion of the hub 3 in the axial direction is closed by a seal ring 18 having three seal lips. The tip ends of the three seal lips of the seal ring 18 are in sliding contact with the inner circumferential surface of the rotation side flange 9 or the outer circumferential surface of the hub 3 in the axial direction at the entire circumference. In this way, the seal ring 18 closes the opening on the axially outer end side of the rolling element installation space 19 in which the balls 4 and 4 are installed.
　尚、図示の例の場合、軸受ユニット１は、大型化を抑えつつ、大きなモーメント剛性を確保する為、両列の玉のピッチ円直径（ＰＣＤ）を互いに異ならせている。即ち、軸方向外側列の玉４、４のピッチ円直径を、軸方向内側列の玉４、４のピッチ円直径よりも大きくしている。この為に、軸方向外側列の外輪軌道５ａの内径を軸方向内側列の外輪軌道５ｂの内径よりも大きくすると共に、軸方向外側列の内輪軌道８ａの外径を軸方向内側列の内輪軌道８ｂの外径よりも大きくしている。 In the case of the illustrated example, the bearing unit 1 has different pitch circle diameters (PCD) of the balls in both rows in order to ensure a large moment rigidity while suppressing an increase in size. That is, the pitch circle diameter of the balls 4, 4 in the axially outer row is made larger than the pitch circle diameter of the balls 4, 4 in the axially inner row. For this purpose, the inner ring raceway 5a in the axially outer row is made larger than the inner diameter of the outer ring raceway 5b in the axially outer row and the inner ring raceway 5a in the axially outer row is made larger. It is larger than the outer diameter of 8b.
　上述の様な従来構造の場合、使用条件が厳しくなると、転動体設置空間１９の軸方向外端側開口部に装着したシールリング１８が、必ずしも十分なシール性能を発揮できなくなる可能性がある。即ち、外輪２の軸方向外端面と回転側フランジ９の軸方向内側面との間には、これら両面同士が接触（金属接触）する事を防止する為に隙間を設けている。そして、砂利道等の悪路走行時に、この隙間から比較的大きな砂粒等の異物が侵入し、この異物が、シールリング１８を構成するシールリップと回転側フランジ９の軸方向内側面との摺接部に入り込むと、この摺接部に、異常摩耗等の損傷を発生する可能性がある。 In the case of the conventional structure as described above, if the use conditions become severe, the seal ring 18 attached to the opening on the axially outer end side of the rolling element installation space 19 may not necessarily exhibit sufficient sealing performance. In other words, a gap is provided between the outer end surface in the axial direction of the outer ring 2 and the inner surface in the axial direction of the rotation side flange 9 in order to prevent these two surfaces from contacting each other (metal contact). Then, when traveling on a rough road such as a gravel road, foreign matters such as relatively large sand particles enter through this gap, and this foreign matter slides between the seal lip constituting the seal ring 18 and the axially inner side surface of the rotation side flange 9. If it enters the contact portion, the sliding contact portion may be damaged such as abnormal wear.
日本国特開２００７－１００７１５号公報Japanese Laid-Open Patent Publication No. 2007-1000071
　本発明は、上述の様な事情に鑑みて、外輪の軸方向外端面と回転側フランジの軸方向内側面との間の隙間から侵入した異物を外部空間に排出し易くできる、車輪支持用転がり軸受ユニットの構造を実現すべく発明したものである。 In view of the circumstances as described above, the present invention provides a wheel support rolling device that can easily discharge foreign matter that has entered through a gap between an axial outer end surface of an outer ring and an axial inner surface of a rotary flange into an external space. Invented to realize the structure of the bearing unit.
　本開示の車輪支持用転がり軸受ユニットは、外輪と、ハブと、複数個の転動体と、を備える。
　前記外輪は、内周面に複列の外輪軌道を有し、使用状態で懸架装置に支持されて回転しない。
　前記ハブは、前記外輪の内径側にこの外輪と同軸に配置され、外周面のうち前記複列の外輪軌道に対向する部分に複列の内輪軌道を有し、前記外輪の軸方向外端部よりも軸方向外方に突出した部分に制動用回転体及び車輪を結合固定する為の回転側フランジを有する。
　前記転動体は、前記複列の外輪軌道と前記複列の内輪軌道との間に、各列毎に複数個ずつ転動自在に設けられている。
　前記回転側フランジの円周方向１乃至複数箇所に、回転側フランジの軸方向両側面のうちの少なくとも軸方向内側面に開口する異物排出孔（回転側フランジの軸方向両側面に開口した貫通孔又は軸方向内側面のみに開口した有底孔を含む）が設けられている。
　前記外輪の軸方向外端面の外径が、前記ハブの中心軸（車輪支持用転がり軸受ユニットの中心軸）を中心とする前記異物排出孔の径方向内端部の内接円の直径よりも大きい。
　尚、この様な異物排出孔は、例えば、前記ハブの軽量化の為や、前記外輪を前記懸架装置に支持したり、懸架装置に制動装置を構成する部品を取り付けたりする作業を行う際に工具を挿入する為に設けられるものである。 The wheel support rolling bearing unit of the present disclosure includes an outer ring, a hub, and a plurality of rolling elements.
The outer ring has a double-row outer ring raceway on the inner circumferential surface, and is supported by the suspension device in a use state and does not rotate.
The hub is disposed coaxially with the outer ring on the inner diameter side of the outer ring, has a double-row inner ring raceway on a portion of the outer peripheral surface facing the double-row outer ring raceway, and an axially outer end portion of the outer ring. In addition, a rotation-side flange for coupling and fixing the braking rotator and the wheel is provided at a portion protruding outward in the axial direction.
A plurality of rolling elements are provided between the outer ring raceway in the double row and the inner ring raceway in the double row so as to be freely rollable for each row.
Foreign matter discharge holes (through holes opened on both sides in the axial direction of the rotation side flange) that are opened in at least the inner side surface in the axial direction of both sides in the axial direction of the rotation side flange in one or more circumferential directions of the rotation side flange Or a bottomed hole opened only on the inner side surface in the axial direction is provided.
The outer diameter of the outer end surface in the axial direction of the outer ring is larger than the diameter of the inscribed circle at the inner end in the radial direction of the foreign matter discharge hole centered on the central axis of the hub (the central axis of the wheel bearing rolling bearing unit). large.
Such foreign matter discharge holes are used, for example, to reduce the weight of the hub, to support the outer ring on the suspension device, or to attach a component constituting a braking device to the suspension device. It is provided to insert a tool.
　上述の様な本開示の車輪支持用転がり軸受ユニットを実施する場合に好ましくは、互いに対向する、前記外輪の軸方向外端面と前記回転側フランジの軸方向内側面との間にラビリンスシールを設ける。
　この様なラビリンスシールは、具体的には、例えば次の様に構成する。
　即ち、前記外輪の内周面の軸方向外端部に、軸方向内側に隣接する部分よりも内径が大きな外輪側段差部を設ける。又、前記回転側フランジの軸方向内側面には、前記回転側フランジの基端寄り部分（根元部分）に設けられた厚肉部と、前記厚肉部よりも肉厚（軸方向厚さ）の小さい薄肉部と、を連続する段部が設けられる。前記段部の軸方向内端部に、断面クランク形の切り欠き部を設け、軸方向外側に隣接する部分よりも外径が小さなフランジ側段差部を設ける。そして、前記外輪側段差部と前記フランジ側段差部とを径方向に近接対向させる事により、前記外輪側段差部と前記フランジ側段差部との間に軸方向のラビリンスシールを設ける。これと共に、前記外輪の軸方向外端面と前記フランジ側段差部の奥端面（このフランジ側段差部の軸方向外端部から径方向外方に直角に折れ曲がった段差面）とを近接対向させる事により、前記外輪の軸方向外端面と前記フランジ側段差部の奥端面との間に径方向のラビリンスシールを設ける。 When implementing the rolling bearing unit for supporting a wheel according to the present disclosure as described above, a labyrinth seal is preferably provided between the axially outer end surface of the outer ring and the axially inner side surface of the rotating side flange that face each other. .
Specifically, such a labyrinth seal is configured as follows, for example.
That is, the outer ring side step portion having an inner diameter larger than the portion adjacent to the inner side in the axial direction is provided at the outer end portion in the axial direction of the inner peripheral surface of the outer ring. Further, on the inner side surface in the axial direction of the rotation side flange, a thick portion provided at a portion near the base end (base portion) of the rotation side flange, and a thickness (axial thickness) than the thick portion. And a thin step portion that is continuous with each other. A notch portion having a crank-shaped cross section is provided at the axially inner end portion of the step portion, and a flange-side step portion having a smaller outer diameter than the portion adjacent to the outside in the axial direction is provided. An axial labyrinth seal is provided between the outer ring side step portion and the flange side step portion by causing the outer ring side step portion and the flange side step portion to face each other in the radial direction. At the same time, the outer end surface in the axial direction of the outer ring and the inner end surface of the step portion on the flange side (the step surface bent at a right angle radially outward from the outer end portion in the axial direction of the flange side step portion) are closely opposed to each other. Thus, a radial labyrinth seal is provided between the axially outer end surface of the outer ring and the inner end surface of the flange-side stepped portion.
　上述の様な本開示の車輪支持用転がり軸受ユニットを実施する場合に好ましくは、前記異物排出孔の内周面を、軸方向に関して内径が変化しない円筒面とする事が好ましい。即ち、前記異物排出孔を円筒孔とする事が好ましい。但し、前記異物排出孔の内周面を、軸方向外方に向かう程内径が小さくなる方向に傾斜した円すい面状とする事もできる。即ち、前記異物排出孔を円すい孔とする事もできる。何れにしても、前記異物排出孔の内周面を、軸方向に関して内径が大小に繰り返し変化しない滑らかな面とする事が好ましい。 When implementing the wheel support rolling bearing unit of the present disclosure as described above, the inner peripheral surface of the foreign matter discharge hole is preferably a cylindrical surface whose inner diameter does not change in the axial direction. That is, the foreign matter discharge hole is preferably a cylindrical hole. However, the inner peripheral surface of the foreign matter discharge hole may be a conical surface inclined in a direction in which the inner diameter becomes smaller toward the outer side in the axial direction. That is, the foreign matter discharge hole can be a conical hole. In any case, it is preferable that the inner peripheral surface of the foreign matter discharge hole is a smooth surface whose inner diameter does not repeatedly change in the axial direction.
　又、上述の様な本開示の車輪支持用転がり軸受ユニットを実施する場合に好ましくは、前記外輪の円周方向１乃至複数箇所に外輪側凹部を設ける。外輪側凹部は、前記外輪の軸方向外端面と外周面とに開口する。
　この様な外輪側凹部は、前記車輪支持用転がり軸受ユニットを車両の懸架装置に支持した状態で下方に位置する部分（下半部）に設ける事が好ましく、より好ましくは下端部に設ける。 Further, when the wheel support rolling bearing unit of the present disclosure as described above is implemented, preferably, outer ring side recesses are provided in one or more circumferential directions of the outer ring. The outer ring side recess opens to the outer circumferential surface and the outer circumferential surface of the outer ring in the axial direction.
Such an outer ring side recess is preferably provided at a lower portion (lower half) in a state where the wheel bearing rolling bearing unit is supported by a vehicle suspension device, and more preferably at the lower end.
　上述の様な本開示の車輪支持用転がり軸受ユニットによれば、外輪の軸方向外端面と回転側フランジの軸方向内側面との間の隙間から侵入した異物を外部空間に排出し易くできる。
　即ち、車両の走行時に跳ね上げられた異物が、外輪の軸方向外端面と回転側フランジの軸方向内側面との間に侵入すると、この異物は、回転側フランジの回転に伴って外輪の軸方向外端面と回転側フランジの軸方向内側面との間に発生する気流により、ベルヌーイの定理からも明らかな通り、速度が速く圧力が低い、回転側フランジ側に引き寄せられる。
　ハブの中心軸を中心とする異物排出孔の径方向内端部の内接円の直径を、外輪の軸方向外端面の外径寄りも小さくして、異物排出孔の内径寄り部分と外輪の軸方向外端面とを対向させている。異物排出孔の内径寄り部分と外輪の軸方向外端面とが対向する部分では、気流の速度が小さく（遅く）なり、外輪の軸方向外端面と回転側フランジの軸方向内側面との間の隙間内の圧力も大きくなる。従って、回転側フランジ側に引き寄せられた異物は、気流及び圧力の作用により、異物排出孔内に排出される（異物排出孔側に引き寄せられる）。その後、遠心力の作用により外部空間に排出される。この結果、外輪の内周面とハブの外周面との間に存在する転動体設置空間内への異物の侵入を防止する事ができて、車輪支持用転がり軸受ユニットの耐久性を向上する事ができる。 According to the wheel support rolling bearing unit of the present disclosure as described above, foreign matter that has entered from the gap between the outer end surface in the axial direction of the outer ring and the inner surface in the axial direction of the rotation side flange can be easily discharged to the external space.
In other words, if foreign matter bounced up when the vehicle travels enters between the outer end surface in the axial direction of the outer ring and the inner side surface in the axial direction of the rotation side flange, the foreign matter will move along the axis of the outer ring along with the rotation of the rotation side flange. As is apparent from Bernoulli's theorem, the air flow generated between the outer end surface in the direction and the inner side surface in the axial direction of the rotating flange attracts the rotating flange at a higher speed and lower pressure.
The diameter of the inscribed circle at the radially inner end of the foreign matter discharge hole centered on the central axis of the hub is also made smaller near the outer diameter of the outer end surface in the axial direction of the outer ring, so that the portion near the inner diameter of the foreign matter discharge hole and the outer ring The outer end face in the axial direction is made to face. At the portion where the outer diameter portion of the foreign matter discharge hole and the outer end surface in the axial direction of the outer ring face each other, the speed of the airflow is reduced (slow), and the space between the outer end surface in the axial direction of the outer ring and the inner side surface in the axial direction of the rotary flange The pressure in the gap also increases. Accordingly, the foreign matter drawn toward the rotation side flange is discharged into the foreign matter discharge hole by the action of airflow and pressure (drawn toward the foreign matter discharge hole side). Then, it is discharged to the external space by the action of centrifugal force. As a result, foreign matter can be prevented from entering the rolling element installation space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub, and the durability of the wheel bearing rolling bearing unit can be improved. Can do.
本発明の実施形態の第１例を示す断面図。Sectional drawing which shows the 1st example of embodiment of this invention. 図１のＸ部拡大図。The X section enlarged view of FIG. 回転側フランジに制動回転体を支持固定した状態で示す、図１のＹ－Ｙ断面に相当する模式図。FIG. 2 is a schematic diagram corresponding to the YY cross section of FIG. 1, showing a state in which a braking rotator is supported and fixed to a rotation side flange. 本発明の実施形態の第２例を示す、図２に相当する図。The figure corresponding to FIG. 2 which shows the 2nd example of embodiment of this invention. 本発明の実施形態の第第３例を示す、図２に相当する図。The figure equivalent to FIG. 2 which shows the 3rd example of embodiment of this invention. 図５のＺ－Ｚ断面図。FIG. 6 is a ZZ sectional view of FIG. 5. 本発明の実施形態の第４例を示す、図２に相当する図。The figure equivalent to FIG. 2 which shows the 4th example of embodiment of this invention. 大径部を設ける方法を説明する為の要部拡大断面図。The principal part expanded sectional view for demonstrating the method of providing a large diameter part. 本発明の実施形態の第５例を示す、図２に相当する図。The figure equivalent to FIG. 2 which shows the 5th example of embodiment of this invention. 凹部を設ける方法を説明する為の要部拡大断面図。The principal part expanded sectional view for demonstrating the method of providing a recessed part. 従来構造の１例を示す断面図。Sectional drawing which shows an example of a conventional structure.
　［実施形態の第１例］
　図１～３は、本発明の実施形態の第１例を示している。本例の車輪支持用転がり軸受ユニット１ａ（以後、単に軸受ユニットと呼ぶことがある。）は、外輪２ａと、ハブ３ａと、それぞれが転動体である複数個の玉４ａ、４ｂと、を備える。 [First Example of Embodiment]
1 to 3 show a first example of an embodiment of the present invention. A wheel-supporting rolling bearing unit 1a (hereinafter, simply referred to as a bearing unit) of this example includes an outer ring 2a, a hub 3a, and a plurality of balls 4a and 4b, each of which is a rolling element. .
　外輪２ａ内周面には複列の外輪軌道５ｃ、５ｄが設けられる。外輪２ａの外周面の軸方向中間部には、静止側フランジ６が設けられる。複列の外輪軌道５ｃ、５ｄのうち、軸方向外側の列の外輪軌道５ｃの内径は、軸方向内側列の外輪軌道５ｄの内径よりも大きい。この為に、外輪２ａの軸方向中間部内周面において軸方向内側列の外輪軌道５ｄよりも軸方向外側に寄った部分に、軸方向内側に向かう程内径が小さくなる方向に傾斜した、内周面側段差部２０を設けている。又、静止側フランジ６の円周方向複数箇所に、貫通孔３６をそれぞれ設けている。貫通孔３６には、外輪２ａを懸架装置を構成するナックルに結合固定する為のボルト（図示省略）が挿通される。 Double row outer ring raceways 5c and 5d are provided on the inner peripheral surface of the outer ring 2a. A stationary side flange 6 is provided at the axially intermediate portion of the outer peripheral surface of the outer ring 2a. Among the double row outer ring raceways 5c and 5d, the inner diameter of the outer ring raceway 5c in the outer row in the axial direction is larger than the inner diameter of the outer ring raceway 5d in the inner row in the axial direction. For this reason, the inner circumference of the inner circumferential surface of the outer ring 2a inclined toward the axially outer side of the outer ring raceway 5d in the axially inner row is inclined so that the inner diameter becomes smaller toward the inner side in the axial direction. The surface side step part 20 is provided. In addition, through holes 36 are provided at a plurality of locations in the circumferential direction of the stationary flange 6. A bolt (not shown) for inserting and fixing the outer ring 2 a to a knuckle constituting the suspension device is inserted into the through hole 36.
　又、ハブ３ａは、ハブ本体１４ａと内輪１５とを組み合わせて成る。ハブ３ａの外周面の軸方向外端寄り部分には、ロータ又はドラム等の制動用回転体３５（図３参照）及び車輪を支持する為の回転側フランジ９ａが設けられる。ハブ３ａの外周面の軸方向中間部及び内端部には、複列の内輪軌道８ｃ、８ｄが設けられる。複列の内輪軌道８ｃ、８ｄのうち、軸方向外側列の内輪軌道８ｃの外径は、軸方向内側列の内輪軌道８ｄの外径よりも大きい。 The hub 3a is a combination of the hub body 14a and the inner ring 15. Near the outer end of the hub 3a in the axial direction, a braking rotator 35 (see FIG. 3) such as a rotor or a drum and a rotation side flange 9a for supporting a wheel are provided. Double-row inner ring raceways 8c and 8d are provided at the axially intermediate portion and inner end portion of the outer peripheral surface of the hub 3a. Of the double row inner ring raceways 8c and 8d, the outer diameter of the inner ring raceway 8c in the axially outer row is larger than the outer diameter of the inner ring raceway 8d in the axially inner row.
　又、回転側フランジ９ａの円周方向複数箇所に、取付孔１１を設けている。取付孔１１には、回転側フランジ９ａに制動用回転体３５及び車輪を支持固定するスタッド１２の基端部が圧入される。そして、回転側フランジ９ａのうち、円周方向に隣り合う取付孔１１同士の間部分のうちの少なくとも１箇所に、異物排出孔である透孔１３ａを設けている。透孔１３ａは、回転側フランジ９ａを軸方向に貫通する。即ち、透孔１３ａは、回転側フランジ９ａの軸方向両側面に開口する。 In addition, mounting holes 11 are provided at a plurality of locations in the circumferential direction of the rotation side flange 9a. The base end portion of the stud 12 that supports and fixes the brake rotating body 35 and the wheel is press-fitted into the mounting hole 11 in the rotation side flange 9a. And the through-hole 13a which is a foreign material discharge | emission hole is provided in at least one place of the part between the attachment holes 11 adjacent to the circumference direction among the rotation side flanges 9a. The through hole 13a penetrates the rotation side flange 9a in the axial direction. That is, the through-hole 13a opens on both axial sides of the rotation side flange 9a.
　本例の場合、各透孔１３ａの径方向内寄り部分を、外輪２ａの軸方向外端面に対向させている。即ち、図２に示すように、軸受ユニット１ａの中心軸を中心とする各透孔１３ａの径方向内端部の内接円の直径Ｄ１３ａを、外輪２ａの軸方向外端面の外径Ｄ２ａよりも小さくしている（Ｄ１３ａ＜Ｄ２ａ）。尚、各透孔１３ａの内径、及び、上記外径Ｄ２ａを上記直径Ｄ１３ａよりも大きくする量｛上記外径Ｄ２ａと上記直径Ｄ１３ａとの差（＝Ｄ２ａ－Ｄ１３ａ）｝は、回転側フランジ９ａに支持固定する制動用回転体３５及び車輪の大きさ（外径）や重量等に応じて適宜設定される。例えば、一般的な自動車用の軸受ユニットの場合で、各透孔１３ａの内径を２０～３０ｍｍ程度とし、上記外径Ｄ２ａと上記直径Ｄ１３ａとの差（＝Ｄ２ａ－Ｄ１３ａ）を１～８ｍｍ程度とする。又、本例の場合、各透孔１３ａを、内周面の内径が軸方向に関して変化しない、円筒孔（円孔）としている。 In the case of this example, the radially inward portion of each through hole 13a is opposed to the axially outer end surface of the outer ring 2a. That is, as shown in FIG. 2, the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1a, the outer diameter D of the axially outer end face of the outer ring 2a It is smaller than 2a ( D13a < D2a ). The inner diameter of each through hole 13a, and, {difference between the outer diameter D 2a and the diameter D 13a (= D 2a -D 13a )} amount larger than the diameter D 13a of the outer diameter D 2a is The brake rotating body 35 supported and fixed to the rotation side flange 9a and the size (outer diameter), weight, etc. of the wheel are set as appropriate. For example, in the case of a general automobile bearing unit, the inner diameter of each through hole 13a is about 20 to 30 mm, and the difference (= D 2a −D 13a ) between the outer diameter D 2a and the diameter D 13a is 1 About 8 mm. In the case of this example, each through hole 13a is a cylindrical hole (circular hole) in which the inner diameter of the inner peripheral surface does not change in the axial direction.
　複列の内輪軌道８ｃ、８ｄの外径を異ならせる為に、ハブ本体１４ａの軸方向中間部外周面において軸方向外側列の内輪軌道８ｃよりも少し軸方向内側に寄った部分に、外径が小さい軸方向内側部分と外径が大きい軸方向外側部分とを連続させる、外周面側段差部２１を設けている。又、ハブ本体１４ａの外周面に、外周面側段差部２１よりも軸方向内側に寄った軸方向内端寄り部分に、小径段部１６を設けている。小径段部１６に、外周面に軸方向内側列の内輪軌道８ｄを設けた、内輪１５を外嵌する。内輪１５は、ハブ本体１４ａの軸方向内端部に設けたかしめ部１７により、小径段部１６の軸方向外端部に存在する段差面２２に向け抑え付けられている。この状態で内輪１５をハブ本体１４ａに対し結合固定している。 In order to make the outer diameters of the double-row inner ring raceways 8c and 8d different, the outer diameter of the outer peripheral surface of the hub body 14a is slightly closer to the inner side in the axial direction than the inner ring raceway 8c in the axially outer row. An outer peripheral surface side stepped portion 21 is provided to connect an axially inner portion with a small outer diameter and an axially outer portion with a large outer diameter. Further, a small-diameter step portion 16 is provided on the outer peripheral surface of the hub body 14a at a portion closer to the inner end in the axial direction that is closer to the inner side in the axial direction than the step portion 21 on the outer peripheral surface side. An inner ring 15 having an inner ring raceway 8d in the axially inner row provided on the outer peripheral surface is externally fitted to the small diameter step portion 16. The inner ring 15 is pressed against the stepped surface 22 existing at the axially outer end of the small-diameter stepped portion 16 by a caulking portion 17 provided at the axially inner end of the hub body 14a. In this state, the inner ring 15 is coupled and fixed to the hub body 14a.
　各玉４ａ、４ｂは、複列の外輪軌道５ｃ、５ｄと、複列の内輪軌道８ｃ、８ｄとの間に、保持器１０ａ、１０ｂに保持された状態で、両列毎に複数個ずつ、転動自在に設けている。この状態で、複列に配置された各玉４ａ、４ｂには、予圧と共に背面組み合わせ型の接触角を付与している。又、これら各列の玉４ａ、４ｂのピッチ円直径は、複列の外輪軌道５ｃ、５ｄの内径の差及び複列の内輪軌道８ｃ、８ｄの外径の差に応じて互いに異なっている。即ち、軸方向外側列の玉４ａ、４ａのピッチ円直径が、軸方向内側列の玉４ｂ、４ｂのピッチ円直径よりも大きくなっている。尚、本例の場合、軸方向外側列の玉４ａ、４ａの直径を、軸方向内側列の玉４ｂ、４ｂの直径よりも小さくしている。但し、これら軸方向外側列の玉４ａ、４ａの直径と軸方向内側列の玉４ｂ、４ｂの直径とを互いに等しくする事もできる。又、重量が嵩む軸受ユニットの場合、両列のうちの一方又は双方の列に関して、玉に代えて円すいころを使用する事もできる。 Each ball 4a, 4b is held in the cages 10a, 10b between the double row outer ring raceways 5c, 5d and the double row inner ring raceways 8c, 8d. It is provided so that it can roll freely. In this state, each ball 4a, 4b arranged in a double row is provided with a contact angle of the rear combination type together with the preload. The pitch circle diameters of the balls 4a and 4b in each row differ from each other in accordance with the difference in inner diameter between the double row outer ring raceways 5c and 5d and the difference in outer diameter between the double row inner ring raceways 8c and 8d. That is, the pitch circle diameters of the balls 4a, 4a in the axially outer row are larger than the pitch circle diameters of the balls 4b, 4b in the axially inner row. In the case of this example, the diameters of the balls 4a and 4a in the axially outer row are made smaller than the diameters of the balls 4b and 4b in the axially inner row. However, the diameters of the balls 4a, 4a in the axially outer row and the diameters of the balls 4b, 4b in the axially inner row can be made equal to each other. Further, in the case of a bearing unit that increases in weight, a tapered roller can be used instead of a ball for one or both of the two rows.
　又、本例の場合、外輪２ａの内周面とハブ３ａの外周面との間には転動体設置空間１９が存在し、当該転動体設置空間に各玉４ａ、４ｂが設置される。この転動体設置空間１９の軸方向外端開口部を、この開口部分に装着したシールリング１８により塞いでいる。即ち、このシールリング１８を構成する３本のシールリップを、それぞれハブ本体１４ａの軸方向中間部外周面と回転側フランジ９ａの軸方向内側面とに、全周に亙って摺接させている。又、外輪２ａの軸方向内端開口を、この開口部分に装着した、非磁性材により有底円筒状に構成したカバー２３により塞ぐ。内輪１５の軸方向内端部外周面に、エンコーダ２４を外嵌固定している。即ち、図示しない速度センサとこのエンコーダ２４の被検出面とを、カバー２３を介して対向させる事により、ハブ３ａに結合固定した車輪の回転速度を検出可能としている。 In the case of this example, a rolling element installation space 19 exists between the inner peripheral surface of the outer ring 2a and the outer peripheral surface of the hub 3a, and the balls 4a and 4b are installed in the rolling element installation space. The axially outer end opening of the rolling element installation space 19 is closed by a seal ring 18 attached to the opening. That is, the three seal lips constituting the seal ring 18 are respectively slidably contacted with the outer peripheral surface of the intermediate portion in the axial direction of the hub body 14a and the inner surface in the axial direction of the rotation side flange 9a over the entire periphery. Yes. Also, the inner end opening in the axial direction of the outer ring 2a is closed by a cover 23 that is mounted on the opening and is formed of a non-magnetic material and has a bottomed cylindrical shape. An encoder 24 is fitted and fixed to the outer peripheral surface of the inner end portion in the axial direction of the inner ring 15. That is, the rotational speed of the wheel coupled and fixed to the hub 3a can be detected by making a speed sensor (not shown) face the detected surface of the encoder 24 via the cover 23.
　更に、本例の場合、外輪２ａの軸方向外端面と回転側フランジ９ａの軸方向内側面との間にラビリンスシール２５を設けている。ラビリンスシール２５は、後述する径方向のラビリンスシール３２と、径方向のラビリンスシール３２の径方向内端部から軸方向内方に向けて折れ曲がった軸方向のラビリンスシール３１と、から成り、全体として断面略Ｌ字形状である。 Furthermore, in the case of this example, a labyrinth seal 25 is provided between the axially outer end surface of the outer ring 2a and the axially inner surface of the rotation side flange 9a. The labyrinth seal 25 includes a radial labyrinth seal 32, which will be described later, and an axial labyrinth seal 31 that is bent inward in the axial direction from the radial inner end of the radial labyrinth seal 32 as a whole. The cross section is substantially L-shaped.
　外輪２ａの軸方向外端部内周面に、軸方向内側に隣接する部分（シールリング１８を内嵌固定した部分）よりも内径が大きな外輪側段差部２６を設けている。 An outer ring-side stepped portion 26 having a larger inner diameter than the portion adjacent to the inner side in the axial direction (the portion where the seal ring 18 is fitted and fixed) is provided on the inner peripheral surface of the outer ring 2a in the axial direction.
　又、回転側フランジ９ａの軸方向内側面には、回転側フランジ９ａの基端寄り部分（根元部分）に設けられた厚肉部２７と厚肉部２７よりも肉厚（軸方向厚さ）の小さい薄肉部２８と、を連続する段部２９が設けられる。段部２９の段面形状は、円弧形若しくは略円弧形である。段部２９の軸方向内端部には、断面クランク形の切り欠き部を設け、軸方向外側に隣接する部分よりも外径が小さなフランジ側段差部３０を設けている。 Further, on the inner side surface in the axial direction of the rotation side flange 9a, a thicker portion 27 provided in a portion near the base end (root portion) of the rotation side flange 9a and a thickness (axial thickness) than the thick portion 27. A thin step portion 28 is provided, and a step portion 29 is provided. The step surface shape of the step portion 29 is an arc shape or a substantially arc shape. A notch portion having a crank-shaped cross section is provided at the axially inner end portion of the step portion 29, and a flange-side step portion 30 having a smaller outer diameter than the portion adjacent to the outside in the axial direction is provided.
　外輪側段差部２６とフランジ側段差部３０とを径方向に近接対向させる事により、外輪側段差部２６とフランジ側段差部３０との間に軸方向のラビリンスシール３１を設けている。 An axial labyrinth seal 31 is provided between the outer ring side step part 26 and the flange side step part 30 by causing the outer ring side step part 26 and the flange side step part 30 to face each other in the radial direction.
　これと共に、外輪２ａの軸方向外端面と、フランジ側段差部３０の軸方向外端部から径方向外方に直角に折れ曲がった段差面と、を軸方向に近接対向させる事により、外輪２ａの軸方向外端面と、フランジ側段差部３０の軸方向外端部に存在する段差面と、の間に径方向のラビリンスシール３２を設けている。即ち、この径方向のラビリンスシール３２を、シールリング１８と径方向に重ならない位置（軸方向に関してシールリング１８から外れた位置）に設ける事により、車両走行時に跳ね上げられた泥水等の異物が、径方向のラビリンスシール３２内に径方向に侵入し、この径方向のラビリンスシール３２内を通過して直接シールリング１８まで達するのを防止している。換言すれば、シールリング１８をラビリンスシール２５よりも径方向内側で且つ軸方向内側に配置して、ラビリンスシール２５によりシールリング１８を保護している。 At the same time, the axially outer end surface of the outer ring 2a and the stepped surface bent at a right angle radially outward from the axially outer end of the flange-side stepped portion 30 are close to each other in the axial direction so that the outer ring 2a A radial labyrinth seal 32 is provided between the axially outer end surface and the stepped surface present at the axially outer end of the flange-side stepped portion 30. That is, by providing the radial labyrinth seal 32 at a position that does not overlap the seal ring 18 in the radial direction (a position that is separated from the seal ring 18 with respect to the axial direction), foreign matter such as muddy water splashed when the vehicle travels is removed. In the radial labyrinth seal 32, it is prevented from entering the radial labyrinth seal 32 and passing through the radial labyrinth seal 32 and reaching the seal ring 18 directly. In other words, the seal ring 18 is disposed radially inward and axially inward of the labyrinth seal 25, and the seal ring 18 is protected by the labyrinth seal 25.
　尚、断面形状がＬ字形であるラビリンスシール２５の幅（軸方向のラビリンスシール３１の径方向幅、及び、径方向のラビリンスシール３２の軸方向幅）及び長さ（軸方向のラビリンスシール３１の軸方向長さと、径方向のラビリンスシール３２の径方向長さとの合計）は、回転側フランジ９ａに支持固定する制動用回転体３５及び車輪の大きさや重量等に応じて異なる。 The width (the radial width of the axial labyrinth seal 31 and the axial width of the radial labyrinth seal 32) and the length (length of the axial labyrinth seal 31) of the labyrinth seal 25 whose cross-sectional shape is L-shaped. The sum of the axial length and the radial length of the radial labyrinth seal 32) varies depending on the size and weight of the braking rotator 35 and the wheels supported and fixed to the rotation-side flange 9a.
　例えば、一般的な自動車用の軸受ユニットの場合、軸方向のラビリンスシール３１の径方向幅Ｗ３１を、好ましくは０．５～１．０ｍｍ、より好ましくは０．５５～０．８ｍｍ、更に好ましくは０．５７～０．８ｍｍとし、軸方向のラビリンスシール３１の軸方向長さＬ３１を、好ましくは０．６ｍｍ～１．４ｍｍ、より好ましくは０．７～１．３ｍｍとする。一方、径方向のラビリンスシール３２の軸方向幅Ｗ３２を、好ましくは０．８～１．５ｍｍ、より好ましくは０．９～１．３ｍｍとし、径方向のラビリンスシール３２の径方向長さＬ３２を、好ましくは１．５～２．６ｍｍ、より好ましくは１．９～２．５ｍｍ、更に好ましくは１．８５～２．４３ｍｍとする。 For example, in the case of a general automobile bearing unit, the radial width W 31 of the axial labyrinth seal 31 is preferably 0.5 to 1.0 mm, more preferably 0.55 to 0.8 mm, and still more preferably. Is 0.57 to 0.8 mm, and the axial length L 31 of the labyrinth seal 31 in the axial direction is preferably 0.6 mm to 1.4 mm, more preferably 0.7 to 1.3 mm. On the other hand, the axial width W 32 of the radial labyrinth seal 32 is preferably 0.8 to 1.5 mm, more preferably 0.9 to 1.3 mm, and the radial length L of the radial labyrinth seal 32 is set. 32 is preferably 1.5 to 2.6 mm, more preferably 1.9 to 2.5 mm, and still more preferably 1.85 to 2.43 mm.
　軸方向のラビリンスシール３１の径方向幅Ｗ３１を０．５ｍｍより小さくしたり、径方向のラビリンスシール３２の軸方向幅Ｗ３２を０．８ｍｍよりも小さくすると、車輪が縁石に乗り上げる等した場合に、外輪２ａの軸方向外端部と、回転側フランジ９ａとが接触（衝突）する可能性がある。一方、軸方向のラビリンスシール３１の径方向幅Ｗ３１を１．０ｍｍより大きくしたり、径方向のラビリンスシール３２の軸方向幅Ｗ３２を１．５ｍｍよりも大きくすると、ラビリンスシール２５による異物侵入防止効果を十分に得られない可能性がある。又、軸方向のラビリンスシール３１の軸方向長さＬ３１を０．６ｍｍより小さくしたり、径方向のラビリンスシール３２の径方向長さＬ３２を１．５ｍｍよりも小さくすると、このラビリンスシール２５による異物侵入防止効果を十分に得られない可能性がある。一方、軸方向のラビリンスシール３１の軸方向長さＬ３１を１．４ｍｍより大きくしたり、径方向のラビリンスシール３２の径方向長さＬ３２を２．６ｍｍよりも大きくすると、軸受ユニット１ａが大型・重量化する可能性がある。 When the radial width W 31 of the axial labyrinth seal 31 is smaller than 0.5 mm, or when the axial width W 32 of the radial labyrinth seal 32 is smaller than 0.8 mm, the wheel rides on the curb, etc. In addition, there is a possibility that the axially outer end portion of the outer ring 2a and the rotation side flange 9a come into contact (collision). On the other hand, when the radial width W 31 of the axial labyrinth seal 31 is made larger than 1.0 mm or the axial width W 32 of the radial labyrinth seal 32 is made larger than 1.5 mm, foreign matter intrusion by the labyrinth seal 25 occurs. The prevention effect may not be obtained sufficiently. Also, or less than 0.6mm and the axial length L 31 in the axial direction of the labyrinth seal 31, when the radial length L 32 of the radial labyrinth seal 32 is smaller than 1.5 mm, the labyrinth seal 25 There is a possibility that the effect of preventing foreign matter intrusion due to is not sufficiently obtained. On the other hand, if greater than 1.4mm and the axial length L 31 in the axial direction of the labyrinth seal 31, when the radial length L 32 of the radial labyrinth seal 32 is greater than 2.6 mm, the bearing unit 1a is There is a possibility of increasing the size and weight.
　但し、軸方向のラビリンスシール３１と径方向のラビリンスシール３２との何れのラビリンスシールにおいても、長さを幅よりも大きくして（Ｌ３１＞Ｗ３１、Ｌ３２＞Ｗ３２）、ラビリンス効果を高めている。又、径方向のラビリンスシール３２の長さ及び幅を、軸方向のラビリンスシール３１の長さ及び幅よりも大きくして（Ｌ３１＞Ｌ３２、Ｗ３１＞Ｗ３２）、ラビリンスシール２５内に侵入した異物を、可能な限り径方向のラビリンスシール３２内に留められる様にしている。これにより、後述する様に、各透孔１３ａの存在及び回転側フランジ９ａの回転に伴う気流の作用により、ラビリンスシール２５内に侵入した異物を外部空間に排出し易くしている。尚、軸方向のラビリンスシール３１は、径方向幅Ｗ３１を軸方向に関して一定としている。同様に、径方向のラビリンスシール３２は、軸方向幅Ｗ３２を径方向に関して一定としている。 However, in any of the labyrinth seals of the axial labyrinth seal 31 and the radial labyrinth seal 32, the length is made larger than the width (L 31 > W 31 , L 32 > W 32 ), and the labyrinth effect is obtained. It is increasing. Further, the length and width of the radial labyrinth seal 32 are made larger than the length and width of the axial labyrinth seal 31 (L 31 > L 32 , W 31 > W 32 ), and the labyrinth seal 25 is placed in the labyrinth seal 25. The invading foreign matter is kept in the radial labyrinth seal 32 as much as possible. As a result, as will be described later, foreign substances that have entered the labyrinth seal 25 are easily discharged into the external space by the presence of each through-hole 13a and the action of an air flow accompanying the rotation of the rotation-side flange 9a. The axial labyrinth seal 31 has a constant radial width W 31 in the axial direction. Similarly, the radial labyrinth seal 32 has a constant axial width W 32 in the radial direction.
　上述の様な本例の軸受ユニット１ａによれば、転動体設置空間１９への異物侵入防止効果を長期間に亙り良好に維持して、耐久性をより向上させる事ができる。即ち、本例の場合、外輪２ａの軸方向外端面と回転側フランジ９ａの軸方向内側面との間に、径方向のラビリンスシール３２と、径方向のラビリンスシール３２の径方向内端部から軸方向内方に向けて折れ曲がった軸方向のラビリンスシール３１と、から成るラビリンスシール２５を設けている。この為、軸受ユニット１ａを搭載した車両の走行時に跳ね上げられた異物が、シールリング１８を構成するシールリップの先端縁が当接している部分に達し難くできる。即ち、シールリング１８を保護する事ができる。 According to the bearing unit 1a of the present example as described above, the effect of preventing foreign matter from entering the rolling element installation space 19 can be maintained well over a long period of time, and the durability can be further improved. That is, in this example, from the radial inner end of the radial labyrinth seal 32 and the radial labyrinth seal 32 between the axial outer end surface of the outer ring 2a and the axial inner surface of the rotation side flange 9a. A labyrinth seal 25 including an axial labyrinth seal 31 bent inward in the axial direction is provided. For this reason, it is difficult for the foreign matter jumped up when the vehicle equipped with the bearing unit 1 a travels to reach the portion where the tip edge of the seal lip constituting the seal ring 18 is in contact. That is, the seal ring 18 can be protected.
　又、仮に、異物がラビリンスシール２５（軸方向のラビリンスシール３１）内に侵入した場合であっても、この異物は、回転側フランジ９ａの回転に伴ってラビリンスシール２５（径方向のラビリンスシール３２）内に発生する気流により、ベルヌーイの定理からも明らかな通り、速度が速く圧力が低い、回転側フランジ９ａ側に引き寄せられる。 Even if foreign matter enters the labyrinth seal 25 (axial labyrinth seal 31), the foreign matter is caused by the labyrinth seal 25 (radial labyrinth seal 32) as the rotary flange 9a rotates. ), The air flow generated in the cylinder 9 is pulled toward the rotating flange 9a where the speed is high and the pressure is low, as is clear from Bernoulli's theorem.
　ここで、軸受ユニット１ａの中心軸を中心とする各透孔１３ａの径方向内端部の内接円の直径Ｄ１３ａを、外輪２ａの軸方向外端面の外径Ｄ２ａよりも小さく（Ｄ１３ａ＜Ｄ２ａ）して、各透孔１３ａの内径寄り部分と外輪２ａの軸方向外端面とを対向させている。換言すれば、各透孔１３ａの内径寄り部分を、回転側フランジ９ａの軸方向内側面のうち、径方向のラビリンスシール３２を画成する部分に開口させている。 Here, the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1a, smaller than the outer diameter D 2a of the axial outer end surface of the outer ring 2a (D 13a <D 2a ), the portion closer to the inner diameter of each through hole 13a and the outer end surface in the axial direction of the outer ring 2a are opposed to each other. In other words, the portion closer to the inner diameter of each through hole 13a is opened to the portion defining the radial labyrinth seal 32 on the inner side surface in the axial direction of the rotation side flange 9a.
　これにより、各透孔１３ａの内径寄り部分と、径方向のラビリンスシール３２の径方向外半部と、を軸方向に重ねている。各透孔１３ａの内径寄り部分と外輪２ａの軸方向外端面とが対向する部分では、各透孔１３ａの分だけ、断面積｛回転側フランジ９ａの回転方向（図３の矢印α参照）に直交する仮想平面に関する断面積｝が大きくなるので、ベルヌーイの定理からも明らかな通り、回転側フランジ９ａの回転に伴って発生する気流の速度が小さく（遅く）なり、ラビリンスシール２５内の圧力も大きくなる。 Thus, the portion closer to the inner diameter of each through hole 13a and the outer radial half of the radial labyrinth seal 32 are overlapped in the axial direction. In the portion where the inner diameter portion of each through hole 13a and the outer end surface in the axial direction of the outer ring 2a face each other, the cross-sectional area {in the rotational direction of the rotation-side flange 9a (see arrow α in FIG. 3)] corresponds to each through hole 13a. Since the cross-sectional area of the orthogonal virtual plane} is increased, as is clear from Bernoulli's theorem, the velocity of the air flow generated with the rotation of the rotation-side flange 9a is reduced (slow), and the pressure in the labyrinth seal 25 is also increased. growing.
　この圧力の増加は、異物を外部空間に排出する為の排出力となる。従って、回転側フランジ９ａ側に引き寄せられた異物は、この回転側フランジ９ａの回転に伴って発生する気流及び圧力の作用により、各透孔１３ａ内に排出される（透孔１３ａ側に引き寄せられる）。その後、異物は、遠心力の作用により径方向外方に移動させられて、各透孔１３ａの開口部のうち、外輪２ａの軸方向外端面の外周縁よりも径方向外側に位置する部分から外部空間に排出される。 This increase in pressure becomes a discharging force for discharging foreign matter to the external space. Accordingly, the foreign matter attracted to the rotation side flange 9a side is discharged into each through hole 13a by the action of the airflow and pressure generated by the rotation of the rotation side flange 9a (it is attracted to the through hole 13a side). ). Thereafter, the foreign matter is moved radially outward by the action of centrifugal force, and from the portion located on the radially outer side of the outer peripheral edge of the axially outer end surface of the outer ring 2a in the opening of each through hole 13a. It is discharged to the external space.
　特に本例の場合、外輪２ａの外径Ｄ２ａと、各透孔１３ａの径方向内端部の内接円の直径Ｄ１３ａとの差（＝Ｄ２ａ－Ｄ１３ａ）を、１～８ｍｍ程度としている為、異物を各透孔１３ａ内に排出し易くできる。即ち、差を１ｍｍより小さくすると、ラビリンスシール２５内の圧力を十分大きくする事ができず、排出力を十分に得られない可能性がある。一方、差を８ｍｍよりも大きくすると、軸受ユニット１ａが大型・重量化したり、径方向のラビリンスシール３２の径方向長さを確保し難くなったりする可能性がある。又、各透孔１３ａが、各種作業を行う際に工具を挿入する為の機能を併せ持っている場合には、この工具を挿入し難くなる。これに対し、本例の軸受ユニット１ａの場合には、各透孔１３ａの内径寄り部分とこの外輪２ａの軸方向外端面とを対向させると共に、外径Ｄ２ａと直径Ｄ１３ａとの差を適切な範囲に規制している。これにより、異物が、シールリング１８を構成するシールリップの先端縁が当接している部分に達し難くできる。従って、異物が、シールリップの先端縁と回転側フランジ９ａの軸方向内側面との摺接部に入り込む事により、摺接部に異常摩耗等の損傷が発生する事を長期間に亙って防止できる。この結果、転動体設置空間１９への異物侵入防止効果を長期間に亙り良好に維持する事ができて、軸受ユニット１ａの耐久性をより向上させる事ができる。 Especially in the case of this embodiment, the outer diameter D 2a of the outer ring 2a, the difference between the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a of the (= D 2a -D 13a), about 1 ~ 8 mm Therefore, foreign matter can be easily discharged into each through hole 13a. That is, if the difference is smaller than 1 mm, the pressure in the labyrinth seal 25 cannot be sufficiently increased, and there is a possibility that the exhaust force cannot be obtained sufficiently. On the other hand, if the difference is larger than 8 mm, the bearing unit 1a may be increased in size and weight, or it may be difficult to secure the radial length of the radial labyrinth seal 32. Moreover, when each through-hole 13a has the function for inserting a tool when performing various operations, it becomes difficult to insert the tool. In contrast, in the case of the bearing unit 1a of the present embodiment, along with to face the inner diameter near portion of each through hole 13a and the axially outer end face of the outer ring 2a, the difference between the outer diameter D 2a and diameter D 13a It is regulated to an appropriate range. Thereby, the foreign matter can hardly reach the portion where the tip edge of the seal lip constituting the seal ring 18 is in contact. Therefore, foreign matter enters the sliding contact portion between the tip edge of the seal lip and the axial inner surface of the rotation side flange 9a, and damage such as abnormal wear occurs in the sliding contact portion over a long period of time. Can be prevented. As a result, the effect of preventing foreign matter from entering the rolling element installation space 19 can be maintained well over a long period of time, and the durability of the bearing unit 1a can be further improved.
　更に、本例の場合、異物排出孔である各透孔１３ａを、内周面の内径が軸方向に関して変化せず、回転側フランジ９ａを軸方向に貫通する状態で設けられた円筒孔としている。この為、回転側フランジ９ａの回転に伴い、各透孔１３ａの内周面に沿って流れる気流の流れを整流して、層流とする事ができる。 Furthermore, in the case of this example, each through-hole 13a which is a foreign matter discharge hole is a cylindrical hole provided in a state where the inner diameter of the inner peripheral surface does not change in the axial direction and penetrates the rotation side flange 9a in the axial direction. . For this reason, with the rotation of the rotation-side flange 9a, the flow of the airflow flowing along the inner peripheral surface of each through hole 13a can be rectified to form a laminar flow.
　尚、本発明を実施する場合、異物排出孔である各透孔１３ａの内周面を、軸方向外方に向かう程内径が小さくなる方向に傾斜した円すい面状としても良い。即ち、異物排出孔を円すい孔としても良い。異物排出孔の内周面を、軸方向外方に向かう程内径が小さくなる方向に傾斜した円すい面状にすれば、異物排出孔内を軸方向内方から外方に向けて流れる気流の速度を、軸方向外方に向かうに従って速くする事ができる。この為、回転側フランジの回転に伴い、異物排出孔内に排出された異物を、異物排出孔の軸方向外側開口部から外部空間に排出し易くできる。異物排出孔として、円筒孔と円すい孔とのうちの何れの構造を採用する場合でも、この異物排出孔の内周面は、軸方向に関して内径が大小に繰り返し変化する事がない滑らかな面とする。 In addition, when implementing this invention, it is good also considering the internal peripheral surface of each through-hole 13a which is a foreign material discharge hole as a conical surface shape inclined in the direction where an internal diameter becomes small, so that it goes to an axial direction outward. That is, the foreign matter discharge hole may be a conical hole. If the inner peripheral surface of the foreign material discharge hole is a conical surface inclined in a direction in which the inner diameter becomes smaller as it goes outward in the axial direction, the velocity of the airflow flowing from the inner side to the outer side in the foreign material discharge hole Can be made faster as it goes outward in the axial direction. For this reason, the foreign matter discharged into the foreign matter discharge hole along with the rotation of the rotation side flange can be easily discharged from the axially outer opening of the foreign matter discharge hole to the external space. Regardless of the structure of the cylindrical hole or the conical hole used as the foreign matter discharge hole, the inner peripheral surface of the foreign matter discharge hole is a smooth surface whose inner diameter does not repeatedly change in the axial direction. To do.
　一方、異物排出孔を例えばねじ孔等とした場合、即ち、異物排出孔の内周面が軸方向に関して内径が大小に繰り返し変化する形状である場合、各異物排出孔内を流れる気流の流れが乱流となってしまう。この場合、回転側フランジの回転に伴って発生する気流及び圧力の作用による異物の排出効果を、異物排出孔を円筒孔や円すい孔とした場合に比べて、良好には得られない。 On the other hand, when the foreign matter discharge hole is, for example, a screw hole, that is, when the inner peripheral surface of the foreign matter discharge hole has a shape in which the inner diameter repeatedly changes in the axial direction, the flow of airflow flowing through each foreign matter discharge hole is It becomes turbulent. In this case, the effect of discharging foreign matter due to the action of airflow and pressure generated as the rotation-side flange rotates is not as good as when the foreign matter discharge hole is a cylindrical hole or a conical hole.
　又、本発明を実施する場合には、異物排出孔を、回転側フランジの軸方向内側面にのみ開口した有底孔とする事もできる。異物排出孔を有底孔とすれば、回転側フランジの強度及び剛性を、異物排出孔を貫通孔とした場合と比較して、確保し易くできる。 Moreover, when implementing this invention, a foreign material discharge | emission hole can also be made into a bottomed hole opened only to the axial direction inner surface of the rotation side flange. If the foreign matter discharge hole is a bottomed hole, the strength and rigidity of the rotation side flange can be easily ensured as compared with the case where the foreign matter discharge hole is a through hole.
　［実施形態の第２例］
　図４は、本発明の実施形態の第２例を示している。外輪２ｂの軸方向外端面のうち、軸受ユニット１ｂを懸架装置に支持した状態で下端部に位置する部分に、径方向に亙って（内外両周面に開口する状態で）軸方向内方に凹んだ凹溝３３を設けている。この様な凹溝３３は、外輪２ｂを、炭素鋼等の金属材料に塑性加工である鍛造加工を施して造るのと同時に設ける。但し、凹溝３３を、外輪２ｂを鍛造加工により造った後で、外輪２ｂの軸方向外端面に切削加工を施す事により設ける事もできる。 [Second Example of Embodiment]
FIG. 4 shows a second example of the embodiment of the present invention. Of the outer end surface of the outer ring 2b in the axial direction, the portion positioned at the lower end portion with the bearing unit 1b supported by the suspension device is axially inward in the radial direction (in a state of opening to both inner and outer peripheral surfaces). A concave groove 33 is provided. Such a concave groove 33 is provided at the same time when the outer ring 2b is manufactured by subjecting a metal material such as carbon steel to forging which is plastic processing. However, the concave groove 33 can also be provided by cutting the axially outer end surface of the outer ring 2b after the outer ring 2b is forged.
　上述の様な本例によれば、透孔１３ａの内径寄り部分と凹溝３３とが対向する部分に於いて（透孔１３ａの内径寄り部分と凹溝３３との円周方向に関する位相が一致した状態で）、回転側フランジ９ａの回転に伴って発生する気流の速度をより小さくでき、ラビリンスシール２５内の圧力をより大きくできる。 According to the present example as described above, the phase in the circumferential direction of the portion closer to the inner diameter of the through hole 13a and the groove 33 is the same (the phase in the circumferential direction between the portion closer to the inner diameter of the through hole 13a and the groove 33 is the same. In this state, the speed of the air flow generated with the rotation of the rotation side flange 9a can be reduced, and the pressure in the labyrinth seal 25 can be increased.
　更に本例の場合、凹溝３３を、外輪２ｂの軸方向外端面のうちで、軸受ユニット１ｂを懸架装置に支持した状態で下端部に位置する部分に設けている。即ち、凹溝３３の存在に基づいてラビリンスシール２５内の圧力が大きくなる事に伴い異物が排出される（押し出される）方向と、重力の作用方向と、を一致させて、異物排出効果をより向上させる事ができる。 Further, in the case of this example, the concave groove 33 is provided in a portion of the outer end surface in the axial direction of the outer ring 2b located at the lower end portion with the bearing unit 1b supported by the suspension device. That is, the direction in which foreign matter is discharged (pushed out) with the increase in pressure in the labyrinth seal 25 based on the presence of the concave groove 33 and the action direction of gravity are made to coincide with each other to further increase the foreign matter discharge effect. Can be improved.
　尚、上述の様な異物排出効果を考慮すれば、凹溝３３は、軸受ユニット１ｂを懸架装置に支持した状態で下端部に位置する部分に設ける事が最も好ましい。但し、凹溝を、軸受ユニット１ｂを懸架装置に支持した状態で下方（下半部）に位置する部分に設ければ、上述の様な異物排出効果をある程度（下端部に位置する部分に設けた場合程ではないにしろ）得る事ができる。 In consideration of the foreign matter discharging effect as described above, it is most preferable that the concave groove 33 is provided in a portion positioned at the lower end portion with the bearing unit 1b supported by the suspension device. However, if the concave groove is provided in a portion located below (lower half) with the bearing unit 1b supported by the suspension device, the above-described foreign matter discharge effect is provided to some extent (the portion located at the lower end portion). But not as much as you can).
　又、凹溝３３を、軸受ユニット１ｂを懸架装置に支持した状態で上方（上半部）に位置する部分に設けた場合にも、（重力による作用効果を得る事はできないが、）ラビリンスシール２５内の圧力が増大する事による異物排出効果を得る事はできる。 Also, when the concave groove 33 is provided in the upper (upper half) portion of the bearing unit 1b supported by the suspension device, the labyrinth seal (although it cannot obtain the effect of gravity). It is possible to obtain a foreign matter discharging effect due to an increase in the pressure in 25.
　又、凹溝３３は、外輪２ｂの軸方向外端面の円周方向複数箇所に設ける事もできる。
　その他の部分の構成及び作用は、上述した実施形態の第１例と同様である。 The concave grooves 33 can also be provided at a plurality of locations in the circumferential direction on the axially outer end surface of the outer ring 2b.
The configuration and operation of the other parts are the same as in the first example of the embodiment described above.
　［実施形態の第３例］
　図５～６は、本発明の実施形態の第３例を示している。外輪２ｃの軸方向外端部外周面のうちで、円周方向に関する位相が静止側フランジ６に設けた貫通孔３６（図１参照）と一致する部分に、外輪側凹部３４を設けている。外輪側凹部３４は、外輪２ｃの軸方向外端面に開口し、径方向内方に凹んでいる。 [Third example of embodiment]
5 to 6 show a third example of the embodiment of the present invention. An outer ring side recess 34 is provided in a portion of the outer peripheral surface of the outer ring 2c in the axial direction that coincides with the through hole 36 (see FIG. 1) provided in the stationary flange 6 in the circumferential direction. The outer ring side recess 34 opens to the axially outer end face of the outer ring 2c and is recessed radially inward.
　各外輪側凹部３４の径方向深さを、軸方向外半部で一定とし、軸方向内半部で軸方向内方に向かうに従って小さくしている。即ち、軸受ユニット１ｃの中心軸を中心とする各外輪側凹部３４の底面の内接円の直径Ｄ３４を、軸方向内方に向かうに従って大きくしている。そして、これら各外輪側凹部３４の軸方向内端縁（奥端縁）が、軸方向に関して、軸方向外側列の外輪軌道５ｃ（図１参照）の軸方向外端縁よりも外側に位置する。この為、各外輪側凹部３４を設けた場合でも、外輪２ｃのうち軸方向外側列の外輪軌道５ｃを設けた部分の剛性の低下を防止できる。従って、静止側フランジ６を懸架装置を構成するナックルに結合固定した状態で、軸方向外側列の外輪軌道５ｃの真円度が悪化するのを防止できる。 The radial depth of each outer ring side recess 34 is constant in the outer half portion in the axial direction, and is made smaller toward the inner side in the axial direction in the inner half portion in the axial direction. That is, the diameter D 34 of the inscribed circle of the bottom surface of the outer wheel side recess 34 around the central axis of the bearing unit 1c, are larger toward axially inward. And the axial direction inner end edge (back end edge) of each outer ring side recess 34 is positioned outside the axial direction outer end edge of the outer ring raceway 5c (see FIG. 1) in the axial direction outer row in the axial direction. . For this reason, even when each outer ring side recess 34 is provided, it is possible to prevent a decrease in rigidity of a portion of the outer ring 2c provided with the outer ring raceway 5c in the outer row in the axial direction. Accordingly, it is possible to prevent the roundness of the outer ring raceway 5c in the outer row in the axial direction from deteriorating in a state where the stationary flange 6 is coupled and fixed to the knuckle constituting the suspension device.
　各外輪側凹部３４の開口部に於ける底面の形状（この開口部を軸方向外側から見た底面の形状）を、図６（Ａ）に示す様に、回転側フランジ９ａに設けた透孔１３ａの中心軸を中心とし、各透孔１３ａの内径ｄ１３ａよりも直径が大きい円弧形としている。但し、各外輪側凹部３４の開口部に於ける底面の形状は、図６（Ｂ）に示す様なＶ字形や、図６（Ｃ）に示す様な直線状等とする事もできる。何れにしても、各透孔１３ａの中心軸を中心とする各外輪側凹部３４の開口部に於ける底面の内接円ｄ３４の直径を、これら各透孔１３ａの内径ｄ１３ａよりも大きくする。 Through holes provided in the rotation side flange 9a as shown in FIG. 6 (A), the shape of the bottom surface at the opening of each outer ring side recess 34 (the shape of the bottom when the opening is viewed from the outside in the axial direction). around the 13a central axis of, and a large arc-shaped in diameter than the inner diameter d 13a of each through hole 13a. However, the shape of the bottom surface in the opening of each outer ring side recess 34 can be a V shape as shown in FIG. 6B, a linear shape as shown in FIG. In any case, the diameter of the inscribed circle d 34 of at the bottom to the opening of the outer concave portion 34 around the central axis of each through hole 13a, larger than the inner diameter d 13a of each through hole 13a To do.
　外輪側凹部３４は、外輪２ｃを、炭素鋼等の金属材料に塑性加工である鍛造加工を施して造るのと同時に設ける。但し、外輪２ｃを鍛造加工により造った後で、外輪２ｃに切削加工を施す事により、外輪側凹部３４を設ける事もできる。 The outer ring side recess 34 is provided at the same time when the outer ring 2c is formed by subjecting a metal material such as carbon steel to a forging process which is a plastic process. However, the outer ring side recess 34 can be provided by cutting the outer ring 2c after the outer ring 2c is made by forging.
　尚、本例の場合には、各外輪側凹部３４のうちの１つの外輪側凹部３４を、外輪２ｃを車両の懸架装置に支持した状態で下端部に位置する部分に設けている。これにより、この１つの外輪側凹部３４の存在に基づいてラビリンスシール２５内の圧力を大きくし、異物が排出される（押し出される）方向と、重力の作用方向と、を一致させている。 In the case of this example, one of the outer ring side recesses 34 is provided at a portion located at the lower end with the outer ring 2c supported by the vehicle suspension. Thereby, the pressure in the labyrinth seal 25 is increased based on the presence of the one outer ring side recess 34, and the direction in which foreign matter is discharged (pushed out) and the direction of action of gravity coincide with each other.
　又、本例の場合、軸受ユニット１ｃの中心軸を中心とする各透孔１３ａの径方向内端部の内接円の直径Ｄ１３ａを、この軸受ユニット１ｃの中心軸を中心とする各外輪側凹部３４の底面の軸方向外端縁に於ける内接円の直径Ｄ３４よりも大きくしている（Ｄ１３ａ＞Ｄ３４）。 In the case of this example, the diameter D 13a of the inscribed circle at the radially inner end of each through-hole 13a centered on the central axis of the bearing unit 1c is set as the outer ring centered on the central axis of the bearing unit 1c. is made larger than the diameter D 34 of at inscribed circle axially outer end edge of the bottom surface of the side recess 34 (D 13a> D 34) .
　従って、各透孔１３ａに工具を挿入する際に、この工具の先端部と外輪２ｃの軸方向外端面とが干渉する事を防止でき、各透孔１３ａに工具を挿入して行う作業の作業性の低下を防止できる。即ち、軸受ユニット１ｃを懸架装置に取り付けたり取り外したりする作業や、制動装置を構成する部品（サポートやキャリパ）を懸架装置に取り付けたり取り外したりする等の作業の作業性の低下防止できる。 Accordingly, when a tool is inserted into each through-hole 13a, it is possible to prevent the tip of the tool from interfering with the axially outer end surface of the outer ring 2c, and work performed by inserting the tool into each through-hole 13a. It is possible to prevent a decrease in sex. In other words, it is possible to prevent the workability of work such as attaching / detaching the bearing unit 1c to / from the suspension device, and attaching / detaching parts (supports and calipers) constituting the brake device from the suspension device.
　軸受ユニット１ｃを懸架装置に取り付ける場合には、懸架装置を構成するナックルに設けたねじ孔と、静止側フランジ６の貫通孔３６と、の円周方向に関する位相を互いに一致させると共に、回転側フランジ９ａの透孔１３ａと、各貫通孔３６と、の円周方向に関する位相を互いに一致させる。この状態で、各透孔１３ａの軸方向外側から工具を挿入し、この工具により各貫通孔３６を軸方向外側から挿通したボルトを各ねじ孔に螺合し、更に締め付ける。これにより、静止側フランジ６をナックルに結合固定する。又、軸受ユニット１ｃを懸架装置から取り外す場合も、各透孔１３ａと、各貫通孔３６と、の円周方向に関する位相とを互いに一致させた状態で、各透孔１３ａの軸方向外側から工具を挿入し、工具により各貫通孔３６を挿通し各ねじ孔に螺合したボルトを緩める。 When the bearing unit 1c is attached to the suspension device, the phase in the circumferential direction of the screw hole provided in the knuckle constituting the suspension device and the through hole 36 of the stationary side flange 6 are made to coincide with each other, and the rotation side flange The phases in the circumferential direction of the through holes 13a of 9a and the through holes 36 are made to coincide with each other. In this state, a tool is inserted from the outside in the axial direction of each through hole 13a, and a bolt inserted through each through-hole 36 from the outside in the axial direction is screwed into each screw hole by this tool and further tightened. Thereby, the stationary side flange 6 is coupled and fixed to the knuckle. Further, when the bearing unit 1c is removed from the suspension device, the tool is applied from the outside in the axial direction of each through hole 13a in a state where the phases in the circumferential direction of each through hole 13a and each through hole 36 coincide with each other. Is inserted, and the bolts screwed into the screw holes are loosened by inserting the through holes 36 with a tool.
　本例の場合には、外輪２ｃの軸方向外端部外周面のうちで、円周方向に関する位相が各貫通孔３６と一致する部分に、外輪２ｃの軸方向外端面に開口する状態で径方向内方に凹んだ外輪側凹部３４をそれぞれ設け、軸受ユニット１ｃの中心軸を中心とするこれら各外輪側凹部３４の底面の軸方向外端縁に於ける内接円の直径Ｄ３４を、軸受ユニット１ｃの中心軸を中心とする各透孔１３ａの径方向内端部の内接円の直径Ｄ１３ａよりも小さくしている（Ｄ３４＜Ｄ１３ａ）。 In the case of this example, in the outer peripheral surface of the outer ring 2c in the axial direction, the diameter of the outer ring 2c is open to the outer peripheral surface of the outer ring 2c in a portion where the phase in the circumferential direction coincides with each through hole 36. The outer ring side recesses 34 that are recessed inward in the direction are respectively provided, and the diameter D 34 of the inscribed circle at the outer edge in the axial direction of the bottom surface of each outer ring side recess 34 centered on the central axis of the bearing unit 1c, It is smaller than the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1c (D 34 <D 13a) .
　この為、ボルトを締め付ける或いは緩める作業に際して、工具を各透孔１３ａの軸方向外側から挿入する際に、この工具の先端部と外輪２ｃの軸方向外端面とが干渉（衝合）するのを防止できる。従って、軸受ユニット１ｃの中心軸を中心とする各透孔１３ａの径方向内端部の内接円の直径Ｄ１３ａが外輪２ｃの軸方向外端面の外径Ｄ２ｃよりも小さくなっている（Ｄ１３ａ＜Ｄ２ｃ）場合でも、軸受ユニット１ｃの懸架装置のナックルへの組み付け性（各透孔１３ａに工具を挿入して行う作業の作業性）が損なわれる事を防止できる。更に、本例の場合には、各外輪側凹部３４の底面の内接円の直径Ｄ３４を軸方向内方に向かう程大きくしている（外周面からの深さを小さくしている）為、工具がこれら各外輪側凹部３４に引っ掛かる事を防止して、軸方向内方に案内する事ができる。 For this reason, when the tool is inserted from the outside in the axial direction of each through hole 13a during the operation of tightening or loosening the bolt, the tip of the tool interferes with the axial outer end surface of the outer ring 2c. Can be prevented. Accordingly, the diameter D 13a of the inscribed circle of the radially inner end of each through hole 13a around the center axis of the bearing unit 1c is smaller than the outer diameter D 2c of the axially outer end face of the outer ring 2c ( Even in the case of D 13a <D 2c ), it is possible to prevent the assembling property of the bearing unit 1c from being attached to the knuckle (workability of work performed by inserting a tool into each through hole 13a). Further, in the case of this example, (and to reduce the depth from the outer peripheral surface) more greatly to that toward the diameter D 34 axially inwardly of the inscribed circle of the bottom surface of the outer ring recess 34 for The tool can be guided inward in the axial direction by preventing the tool from being caught in the outer ring side recesses 34.
　尚、上述の様な外輪側凹部３４は、円周方向に関して制動用回転体３５（図３参照）と共に制動装置を構成する図示しないサポート又はキャリパの固定位置（取付孔等）と一致する部分に設ける事もできる。
　その他の部分の構成及び作用は、上述した実施形態の第１～２例と同様である。 The outer ring side recess 34 as described above coincides with a fixing position (mounting hole or the like) of a support or caliper (not shown) that constitutes a braking device together with the brake rotating body 35 (see FIG. 3) in the circumferential direction. It can also be provided.
The configuration and operation of the other parts are the same as in the first and second examples of the above-described embodiment.
　［実施形態の第４例］
　図７、８は、本発明の実施形態の第４例を示している。外輪２ｄの軸方向外端部に、軸方向内側に隣接する部分よりも外径及び内径が大きい大径部３７を設けている。そして、大径部３７の軸方向外端面、即ち、外輪２ｄの軸方向外端面の外径を、軸受ユニット１ｄの中心軸を中心とする、回転側フランジ９ａに設けられた透孔１３ａの径方向内端部の内接円の直径よりも大きくしている。大径部３７は、炭素鋼等の金属材料に鍛造加工等の塑性加工を施して外輪２ｄを造る際に、円筒状に設けられた金属材料の一端部（外輪２ｄの軸方向外端部に相当する端部であって、図８の左端部）を押し広げる様に塑性変形させる事により設ける。 [Fourth Example of Embodiment]
7 and 8 show a fourth example of the embodiment of the present invention. A large-diameter portion 37 having an outer diameter and an inner diameter larger than those adjacent to the inner side in the axial direction is provided at the outer end in the axial direction of the outer ring 2d. And the diameter of the through-hole 13a provided in the rotation side flange 9a centering on the center axis | shaft of the bearing unit 1d about the outer diameter of the axial direction outer end surface of the large diameter part 37, ie, the axial direction outer end surface of the outer ring | wheel 2d. It is larger than the diameter of the inscribed circle at the inner end in the direction. The large-diameter portion 37 is formed on one end of the metal material provided in a cylindrical shape (on the outer end in the axial direction of the outer ring 2d) when the outer ring 2d is manufactured by subjecting a metal material such as carbon steel to plastic processing such as forging. The corresponding end portion is provided by plastic deformation so as to expand the left end portion in FIG.
　即ち、図８に示す様に、金属製で円筒状の中間素材３８を、ダイス３９内にセットする。ダイス３９の内周面は、一端部（開口側端部）の内径が、他方側に隣接する部分の内径よりも大きい段付円筒状である。このように、中間素材３８の中間部乃至他端部の外径をダイス３９によって拘束する。この状態で、拡径パンチ４０を、中間素材３８の径方向内側に一端側開口から押し込み、この中間素材３８の一端部を径方向外方に塑性変形させ、外径及び内径を拡げる事により大径部３７を設ける。この様な大径部３７を設ける加工は、例えば外輪２ｄの製造工程のうちの最終工程で行う事ができる。又、好ましくは、ダイス３９として、円周方向に分割可能なものを使用する。 That is, as shown in FIG. 8, a metallic and cylindrical intermediate material 38 is set in a die 39. The inner peripheral surface of the die 39 has a stepped cylindrical shape in which the inner diameter of one end (opening side end) is larger than the inner diameter of the portion adjacent to the other side. In this way, the outer diameter of the intermediate portion or the other end portion of the intermediate material 38 is restrained by the die 39. In this state, the diameter-enlarging punch 40 is pushed inward from the opening on one end side in the radial direction of the intermediate material 38, and one end portion of the intermediate material 38 is plastically deformed radially outward to increase the outer diameter and inner diameter. A diameter portion 37 is provided. The processing for providing such a large diameter portion 37 can be performed, for example, in the final step of the manufacturing process of the outer ring 2d. Preferably, a die 39 that can be divided in the circumferential direction is used.
　上述の様な本例によれば、転動体設置空間１９（図１参照）への異物侵入防止効果を長期間に亙り良好に維持できる構造を採用した場合でも、重量が増大するのを抑える事ができる。即ち、前述の実施形態の第１～３例の構造の場合、異物侵入効果を良好にすべく、外輪２ａ（、２ｂ、２ｃ）の軸方向外端面の外径を大きくした分、この外輪２ａ（、２ｂ、２ｃ）の径方向厚さが大きくなって重量が増大する可能性がある。これに対し、本例の軸受ユニット１ｄの場合、中間素材３８の一端部を径方向外方に塑性変形させる事で、外輪２ｄの軸方向外端部に大径部３７を設け、この大径部３７の軸方向外端面の外径を、各透孔１３ａの径方向内端部の内接円の直径よりも大きくしている。そのため、重量の増大を抑えつつ、異物侵入防止効果を長期間に亙り良好に維持する事ができる。 According to the present example as described above, even when a structure that can satisfactorily maintain the foreign object intrusion effect into the rolling element installation space 19 (see FIG. 1) over a long period of time is adopted, an increase in weight can be suppressed. Can do. That is, in the structures of the first to third examples of the above-described embodiment, the outer diameter of the outer ring 2a (2b, 2c) is increased by increasing the outer diameter of the outer end surface of the outer ring 2a (2b, 2c) in order to improve the foreign matter intrusion effect. There is a possibility that the radial thickness of (2b, 2c) increases and the weight increases. On the other hand, in the case of the bearing unit 1d of the present example, the large diameter portion 37 is provided at the axially outer end portion of the outer ring 2d by plastically deforming one end portion of the intermediate material 38 radially outward. The outer diameter of the outer end surface in the axial direction of the portion 37 is made larger than the diameter of the inscribed circle at the inner end portion in the radial direction of each through hole 13a. Therefore, it is possible to maintain a good foreign substance intrusion preventing effect over a long period while suppressing an increase in weight.
　尚、軸受ユニット１ｄは、懸架装置を構成するばねよりも路面側に設けられる、所謂ばね下荷重であるから、軽量化により、乗り心地や走行安定性を中心とする走行性能を向上させる効果を得られる。 Since the bearing unit 1d is a so-called unsprung load provided on the road surface side of the spring constituting the suspension device, the weight reduction makes it possible to improve the running performance centered on ride comfort and running stability. can get.
　又、本例の場合、外輪２ｄの外周面には、外輪２ｄの軸方向中間部と、外輪２ｄの軸方向外端部に設けられた大径部３７と、の連続部に傾斜面部４１が形成される。傾斜面部４１により、外輪２ｄの外周面に付着した泥水等の水分が、外輪２ｄの外周面を伝って外輪２ｄの軸方向外側開口から転動体設置空間１９に侵入する事を防止できる（堰き止める事ができる）。この面からもこの転動体設置空間１９への異物侵入防止効果の向上を図れる。
　その他の部分の構成及び作用は、上述した実施形態の第１～３例と同様である。 In the case of this example, an inclined surface portion 41 is formed on the outer peripheral surface of the outer ring 2d at a continuous portion between the axial middle portion of the outer ring 2d and the large-diameter portion 37 provided at the outer end portion in the axial direction of the outer ring 2d. It is formed. The inclined surface portion 41 can prevent water such as muddy water adhering to the outer peripheral surface of the outer ring 2d from entering the rolling element installation space 19 from the axially outer side opening of the outer ring 2d along the outer peripheral surface of the outer ring 2d (damming. Can do it). Also from this aspect, the effect of preventing foreign matter from entering the rolling element installation space 19 can be improved.
Other configurations and operations are the same as those in the first to third examples of the above-described embodiment.
　［実施形態の第５例］
　図９、１０は、本発明の実施形態の第５例を示している。外輪２ｅの軸方向外端寄り部分に、径方向内方に凹んだ凹部４２を全周に亙って設けている。この様な本例によれば、凹部４２を設けた分、外輪２ｅの重量、延いては、ばね下荷重の増大を抑える事ができて、軸受ユニット１ｅを搭載した車両の走行性能の向上を図れる。又、外輪２ｅの外周面に付着した泥水等の水分が、外輪２ｅの外周面を伝ってこの外輪２ｅの軸方向外側開口から転動体設置空間１９（図１参照）に侵入する事を、凹部４２により防止できる。 [Fifth Example of Embodiment]
9 and 10 show a fifth example of the embodiment of the present invention. A concave portion 42 that is recessed inward in the radial direction is provided over the entire circumference at a portion near the outer end in the axial direction of the outer ring 2e. According to this example, the weight of the outer ring 2e, and hence the increase in unsprung load, can be suppressed by providing the recess 42, so that the running performance of the vehicle equipped with the bearing unit 1e can be improved. I can plan. Further, it is a recess that moisture such as muddy water adhering to the outer peripheral surface of the outer ring 2e enters the rolling element installation space 19 (see FIG. 1) from the axially outer opening of the outer ring 2e along the outer peripheral surface of the outer ring 2e. 42 can prevent this.
　上述の様な外輪２ｅを造るには、図１０に示した様に、金属製で、一端部（図１０の左端部）の外径が他方に隣接する部分の外径よりも小さい段付円筒状の外周面を有する中間素材３８ａを、ダイス３９ａ内にセットする。ダイス３９ａの内周面の一端寄り（開口端寄り）部分は、全周に亙って径方向内方に突出する凸部４３を有する。このように、中間素材３８ａの中間部乃至他端部の外径をダイス３９ａによって拘束する。この状態で、拡径パンチ４０ａを、中間素材３８ａの径方向内側に一端側開口から押し込み、中間素材３８ａの一端部を径方向外方に塑性変形させ、外径及び内径を拡げる。これにより、外輪２ｅの軸方向外端寄り部分（中間素材３８ａの一端寄り部分）に凹部４２を設ける。
　その他の構成及び作用は、上述した実施形態の第１～４例と同様である。 In order to manufacture the outer ring 2e as described above, as shown in FIG. 10, a stepped cylinder made of metal and having an outer diameter at one end (the left end in FIG. 10) smaller than the outer diameter of the portion adjacent to the other. An intermediate material 38a having an outer peripheral surface is set in the die 39a. A portion closer to one end (closer to the opening end) of the inner peripheral surface of the die 39a has a convex portion 43 protruding radially inward over the entire periphery. Thus, the outer diameter of the intermediate | middle part thru | or other end part of the intermediate | middle raw material 38a is restrained by the die | dye 39a. In this state, the diameter-enlarging punch 40a is pushed inward in the radial direction of the intermediate material 38a from the opening on one end side, and one end portion of the intermediate material 38a is plastically deformed radially outward to expand the outer diameter and inner diameter. Thereby, the recessed part 42 is provided in the part near the axial direction outer end of the outer ring 2e (the part near one end of the intermediate material 38a).
Other configurations and operations are the same as those in the first to fourth examples of the above-described embodiment.
　本出願は、２０１５年８月２６日出願の日本特許出願２０１５－１６６８１８及び２０１６年５月３１日出願の日本特許出願２０１６－１０８５５４に基づくものであり、その内容はここに参照として取り込まれる。 This application is based on Japanese Patent Application No. 2015-166818 filed on August 26, 2015 and Japanese Patent Application No. 2016-108554 filed on May 31, 2016, the contents of which are incorporated herein by reference.
　本発明は、上述した実施形態の第１例の図１の様に、軸方向外側列の転動体（玉又は円すいころ）のピッチ円直径が軸方向内側列の転動体のピッチ円直径よりも大きく、外輪の軸方向外端部の外径が大きい構造で好ましく実施できる。但し、本発明は、両列の転動体のピッチ円直径が互いに等しい構造や、軸方向内側列の転動体のピッチ円直径が軸方向外側列の転動体のピッチ円直径よりも大きい構造に適用する事もできる。
　又、本発明は、図１、１１に示す様な従動輪用の軸受ユニットに限らず、ハブ本体の中心部に、使用時に駆動軸をスプライン係合させる為のスプライン孔を軸方向に貫通する状態で設けた、駆動輪用の軸受ユニットで実施する事もできる。 In the present invention, as shown in FIG. 1 of the first example of the embodiment described above, the pitch circle diameter of the rolling elements (balls or tapered rollers) in the axially outer row is larger than the pitch circle diameter of the rolling elements in the axially inner row. It can be preferably implemented with a large structure in which the outer diameter of the outer end of the outer ring in the axial direction is large. However, the present invention is applied to a structure in which the pitch circle diameters of the rolling elements in both rows are equal to each other, or a structure in which the pitch circle diameter of the rolling elements in the axially inner row is larger than the pitch circle diameter of the rolling elements in the axially outer row. You can also do it.
In addition, the present invention is not limited to the bearing unit for the driven wheel as shown in FIGS. 1 and 11, and a spline hole through which the drive shaft is spline-engaged in use in the center portion of the hub body is axially penetrated. It can also be implemented with a bearing unit for driving wheels provided in the state.
　　１、１ａ～１ｅ　車輪支持用転がり軸受ユニット
　　２、２ａ～２ｅ　外輪
　　３、３ａ　ハブ
　　４、４ａ、４ｂ　玉
　　５ａ～５ｄ　外輪軌道
　　６　　静止側フランジ
　　７　　ねじ孔
　　８ａ～８ｄ　内輪軌道
　　９、９ａ　回転側フランジ
　１０、１０ａ、１０ｂ　保持器
　１１　　取付孔
　１２　　スタッド
　１３、１３ａ　透孔
　１４、１４ａ　ハブ本体
　１５　　内輪
　１６　　小径段部
　１７　　かしめ部
　１８　　シールリング
　１９　　転動体設置空間
　２０　　内周面側段差部
　２１　　外周面側段差部
　２２　　段差面
　２３　　カバー
　２４　　エンコーダ
　２５　　ラビリンスシール
　２６　　外輪側段差部
　２７　　厚肉部
　２８　　薄肉部
　２９　　段部
　３０　　フランジ側段差部
　３１　　軸方向のラビリンスシール
　３２　　径方向のラビリンスシール
　３３　　凹溝
　３４　　外輪側凹部
　３５　　制動用回転体
　３６　　貫通孔
　３７　　大径部
　３８、３８ａ　　中間素材
　３９、３９ａ　　ダイス
　４０、４０ａ　　拡径パンチ
　４１　　傾斜面部
　４２　　凹部
　４３　　凸部 1, 1a to 1e Wheel bearing rolling bearing unit 2, 2a to 2e Outer ring 3, 3a Hub 4, 4a, 4b Ball 5a to 5d Outer ring raceway 6 Stationary side flange 7 Screw hole 8a to 8d Inner ring raceway 9, 9a Rotation side flange DESCRIPTION OF SYMBOLS 10, 10a, 10b Cage 11 Mounting hole 12 Stud 13, 13a Through- hole 14, 14a Hub main body 15 Inner ring 16 Small diameter step part 17 Caulking part 18 Seal ring 19 Rolling body installation space 20 Inner peripheral surface side step part 21 Outer peripheral surface side Stepped portion 22 Stepped surface 23 Cover 24 Encoder 25 Labyrinth seal 26 Outer ring side stepped portion 27 Thick portion 28 Thinned portion 29 Stepped portion 30 Flange side stepped portion 31 Axial labyrinth seal 32 Radial direction labyrinth seal 33 Concave groove 34 Outer ring side Concave part 35 Rotating body for braking 36 Through hole 37 Large diameter part 38, 38a Intermediate material 39, 39a Dice 40, 40a Diameter expansion punch 41 Inclined surface part 42 Concave part 43 Convex part

Claims (1)

  1. 　内周面に複列の外輪軌道を有し、使用状態で懸架装置に支持されて回転しない外輪と、
    　前記外輪の内径側に前記外輪と同軸に配置されるハブであって、外周面のうち前記複列の外輪軌道に対向する部分に複列の内輪軌道を有し、前記外輪の軸方向外端部よりも軸方向外方に突出した部分に制動用回転体及び車輪を結合固定する為の回転側フランジを有する前記ハブと、
    　前記複列の外輪軌道と前記複列の内輪軌道との間に、各列毎に複数個ずつ転動自在に設けられた転動体と、
    を備え、
    　前記回転側フランジに、前記回転側フランジの軸方向両側面のうちの少なくとも軸方向内側面に開口する異物排出孔が設けられている、
    車輪支持用転がり軸受ユニットに於いて、
    　前記外輪の軸方向外端面の外径が、前記ハブの中心軸を中心とする前記異物排出孔の径方向内端部の内接円の直径よりも大きい、車輪支持用転がり軸受ユニット。     An outer ring which has a double row outer ring raceway on the inner peripheral surface and which is supported by a suspension device in a use state and does not rotate;
    A hub disposed coaxially with the outer ring on the inner diameter side of the outer ring, the outer ring having a double-row inner ring raceway in a portion facing the double-row outer ring raceway, and an outer end in the axial direction of the outer ring The hub having a rotating side flange for coupling and fixing a braking rotator and a wheel to a portion protruding axially outward from the portion;
    Between the double row outer ring raceway and the double row inner ring raceway, a plurality of rolling elements provided so as to be freely rollable for each row,
    With
    The rotation side flange is provided with a foreign matter discharge hole that opens on at least an axial inner side surface of both side surfaces in the axial direction of the rotation side flange.
    In the wheel bearing rolling bearing unit,
    A wheel bearing rolling bearing unit in which an outer diameter of an outer end surface in the axial direction of the outer ring is larger than a diameter of an inscribed circle at a radially inner end portion of the foreign matter discharge hole centered on a central axis of the hub.
PCT/JP2016/071861 2015-08-26 2016-07-26 Rolling bearing unit for wheel support WO2017033653A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2015166818A JP2016109293A (en) 2014-12-04 2015-08-26 Rolling bearing unit for wheel support
JP2015-166818 2015-08-26
JP2016108554A JP6610441B2 (en) 2014-12-04 2016-05-31 Rolling bearing unit for wheel support
JP2016-108554 2016-05-31

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000094902A (en) * 1998-09-25 2000-04-04 Nsk Ltd Hub unit for automobile and assembly method therefor
JP2008274993A (en) * 2007-04-25 2008-11-13 Nsk Ltd Wheel supporting bearing unit
JP2009002369A (en) * 2007-06-19 2009-01-08 Ntn Corp Bearing device for wheel
JP2009090826A (en) * 2007-10-09 2009-04-30 Honda Motor Co Ltd Pump for air supply
JP2016109183A (en) * 2014-12-04 2016-06-20 日本精工株式会社 Outer ring for rolling bearing unit, and rolling bearing unit for supporting wheel
JP2016109293A (en) * 2014-12-04 2016-06-20 日本精工株式会社 Rolling bearing unit for wheel support

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000094902A (en) * 1998-09-25 2000-04-04 Nsk Ltd Hub unit for automobile and assembly method therefor
JP2008274993A (en) * 2007-04-25 2008-11-13 Nsk Ltd Wheel supporting bearing unit
JP2009002369A (en) * 2007-06-19 2009-01-08 Ntn Corp Bearing device for wheel
JP2009090826A (en) * 2007-10-09 2009-04-30 Honda Motor Co Ltd Pump for air supply
JP2016109183A (en) * 2014-12-04 2016-06-20 日本精工株式会社 Outer ring for rolling bearing unit, and rolling bearing unit for supporting wheel
JP2016109293A (en) * 2014-12-04 2016-06-20 日本精工株式会社 Rolling bearing unit for wheel support

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