WO2015147245A1 - Bearing device for wheel - Google Patents

Bearing device for wheel Download PDF

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Publication number
WO2015147245A1
WO2015147245A1 PCT/JP2015/059562 JP2015059562W WO2015147245A1 WO 2015147245 A1 WO2015147245 A1 WO 2015147245A1 JP 2015059562 W JP2015059562 W JP 2015059562W WO 2015147245 A1 WO2015147245 A1 WO 2015147245A1
Authority
WO
WIPO (PCT)
Prior art keywords
wheel
diameter
bearing device
rolling
screw hole
Prior art date
Application number
PCT/JP2015/059562
Other languages
French (fr)
Japanese (ja)
Inventor
慎介 平野
慎太朗 石川
恭大 有竹
佳祐 森井
Original Assignee
Ntn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
Application filed by Ntn株式会社 filed Critical Ntn株式会社
Publication of WO2015147245A1 publication Critical patent/WO2015147245A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
    • B60B27/00—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
    • F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/04—Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
    • F16C35/06—Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
    • B60B27/00—Hubs
    • B60B27/0005—Hubs with ball bearings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
    • B60B27/00—Hubs
    • B60B27/0094—Hubs one or more of the bearing races are formed by the hub
    • 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
    • F16C2226/00—Joining parts; Fastening; Assembling or mounting parts
    • F16C2226/50—Positive connections
    • F16C2226/52—Positive connections with plastic deformation, e.g. caulking or staking
    • 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
    • F16C2226/00—Joining parts; Fastening; Assembling or mounting parts
    • F16C2226/50—Positive connections
    • F16C2226/60—Positive connections with threaded parts, e.g. bolt and nut connections
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
    • Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction 

Definitions

  • the present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like, and in particular, to increase the bearing rigidity while reducing the weight and size, and to suppress the stress generated in the outer member and to ensure accuracy.
  • the present invention relates to a wheel bearing device that extends the service life of the wheel.
  • wheel bearing devices that support wheels of automobiles and the like support a hub wheel for mounting a wheel rotatably via a rolling bearing, and there are a drive wheel and a driven wheel.
  • an inner ring rotation method is generally used for driving wheels
  • an inner ring rotation method and an outer ring rotation method are generally used for driven wheels.
  • a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used.
  • this double row angular contact ball bearing a plurality of balls are interposed between a fixed ring and a rotating ring, and a predetermined contact angle is given to the balls so as to contact the fixed ring and the rotating ring.
  • the left and right rows of bearings have the same specifications, so that they have sufficient rigidity when stationary, but optimal rigidity is always obtained when the vehicle turns. Absent. That is, the position of the vehicle weight when stationary is determined so that it acts on the approximate center of the double row rolling bearing, but when turning, the opposite side of the turning direction (when turning right, the vehicle Larger radial load or axial load is applied to the left axle. Therefore, at the time of turning, it is effective to increase the rigidity of the outer bearing row rather than the inner bearing row.
  • the “outer side” refers to the side closer to the outer side of the vehicle when assembled to the vehicle, and the “inner side” refers to the side closer to the center.
  • the wheel bearing device 50 includes an inner member 51, an outer member 52, and double-row balls 53, 53 accommodated between the members 51, 52 so as to roll freely.
  • the inner member 51 includes a hub ring 54 and an inner ring 55 that is press-fitted into the hub ring 54 through a predetermined shimiro.
  • the hub wheel 54 integrally has a wheel mounting flange 56 for mounting a wheel (not shown) at one end, an outer side inner rolling surface 54a on the outer periphery, and an axial direction from the inner rolling surface 54a.
  • a small-diameter step portion 54b is formed via a step portion 57 that extends in an inclined manner.
  • Hub bolts 56a are planted on the wheel mounting flange 56 at equal intervals in the circumferential direction.
  • the inner ring 55 has an inner-side inner rolling surface 55a formed on the outer periphery, is press-fitted into the small-diameter step portion 54b of the hub ring 54, and is formed by plastically deforming an end portion of the small-diameter step portion 54b. Thus, the inner ring 55 is fixed in the axial direction.
  • the outer member 52 does not have a vehicle body mounting flange to be attached to a knuckle (not shown) on the outer periphery, has an attachment surface 52c, and has an outer side facing the inner rolling surface 54a of the hub wheel 54 on the inner periphery.
  • An outer side rolling surface 52a and an inner side outer side rolling surface 52b facing the inner side rolling surface 55a of the inner ring 55 are integrally formed via a stepped portion 58 that extends from the outer side rolling surface 52a so as to be inclined in the axial direction.
  • Double-row balls 53 and 53 are accommodated between these rolling surfaces, and are held by rollers 59 and 60 so as to be freely rollable.
  • seals 61 and 62 are attached to the opening portion of the annular space formed between the outer member 52 and the inner member 51, and leakage of grease sealed inside the bearing to the outside and rainwater from the outside. And dust are prevented from entering the bearing.
  • the pitch circle diameter PCDo of the outer side ball 53 is set to be larger than the pitch circle diameter PCDi of the inner side ball 53.
  • the double-row balls 53 and 53 have the same size, but due to the difference in pitch circle diameters PCDo and PCDi, the number of outer-side balls 53 is set larger than the number of inner-side balls 53. .
  • the outer shape of the hub wheel 54 continues from the groove bottom portion of the inner rolling surface 54a to the stepped portion 57 and the small diameter stepped portion 54b through the shoulder portion 57a against which the inner ring 55 is abutted. Further, a mortar-shaped recess 63 is formed at the outer end of the hub wheel 54.
  • the outer side outer rolling surface 52a is formed with a larger diameter than the inner side outer rolling surface 52b in accordance with the difference in pitch circle diameters PCDo and PCDi. From the shoulder 64 of the running surface 52a to the shoulder 65 on the small diameter side via the stepped portion 58, it reaches the outer rolling surface 52b on the inner side.
  • the bearing space can be effectively utilized to increase the bearing rigidity of the outer side portion compared to the inner side, and the life of the bearing can be extended.
  • the recess 63 is formed in the end portion of the hub wheel 54 along the outer shape, and the end portion on the outer side of the hub wheel 54 is set to have a uniform wall thickness. The conflicting problem of rigidity can be solved.
  • the outer peripheral surface of the outer member 52 is gradually formed to have a smaller diameter from the outer cylindrical outer surface AA toward the inner cylindrical outer surface BB. ing.
  • four attachment parts 66 are formed in the vicinity of the outer peripheral surface BB on the inner side at equal intervals in the circumferential direction, and an attachment surface 52 c parallel to the end face of the outer member 52 is formed on the attachment part 66.
  • the attachment portion 66 is formed to protrude radially outward from the outer peripheral surface BB on the inner side, and a screw hole 67 extending in the axial direction is formed in the attachment surface 52c.
  • the knuckle is fitted to the outer peripheral surface BB on the inner side, joined to the mounting surface 52c, and the outer member 52 is fastened to the knuckle via a fixing bolt (not shown).
  • the outer peripheral surface of the outer member 52 does not include a general vehicle body mounting flange fastened to the knuckle, and is formed with a gradually decreasing diameter from the outer side toward the inner side, and at the inner side end.
  • the part is provided with a mounting part 66 extending radially outward. Since the mounting surface 52c is formed in the mounting portion 66 and the outer member 52 is fastened to the knuckle by a fixing bolt that is screwed into the screw hole 67, the weight is reduced and the bearing rigidity is increased. Thus, it is possible to provide a wheel bearing device that extends the life of the bearing (see, for example, Patent Document 1).
  • the bearing mounting plate and the knuckle constituting the suspension device are joined by welding, the surface accuracy of the bearing mounting plate is low.
  • the bearing mounting plate is formed from a steel plate by pressing, it is conceivable that the surface accuracy of the mounting surface is further lowered.
  • tensile stress is generated in the fastening part of the knuckle bolt, which induces deterioration of the roundness of the outer rolling surface of the outer member.
  • the bearing life may be reduced.
  • Patent Document 2 discloses that a strain (tensile stress) generated based on an uneven contact state between the fixed flange and the knuckle is a true of the outer rolling surface of the outer member.
  • the structure of a wheel bearing device that prevents the influence of circularity from being described is described.
  • a mounting hole 73 is formed in the large-diameter portion 71.
  • a groove 74 is formed on the entire inner surface of the inner side surface (side surface facing the knuckle) 69 of the large-diameter portion 71 and the small-diameter portion 72 in a continuous state over the entire circumference. Is formed.
  • the radially outer edge of the concave groove 74 formed in the large diameter portion 71 is located at the same position as the outer edge of the concave groove 74 formed in the small diameter portion 72 or radially outward from it. ing.
  • the concave groove 74 is away from the inner side surface 69 of the vehicle body mounting flange 68 with respect to the outer side surface 75a of the opposing knuckle 75 (FIG. 9). It is formed in a state of being recessed in the left direction). Further, the deepest portion 76 of the concave groove 74 exists in both the large diameter portion 71 and the small diameter portion 72.
  • the side surface 69 on the inner side of the vehicle body mounting flange 68 and the side surface 75a on the outer side of the knuckle 75 abut only at a portion other than the groove 74. That is, the concave groove 74 is also formed on the inner side surface of the small diameter portion 72. Therefore, the small diameter portion 72 does not contact the outer side surface 75 a of the knuckle 75, and only the peripheral portion of the mounting hole 73 of the large diameter portion 71 contacts the outer side surface 75 a of the knuckle 75.
  • the contact area between the vehicle body mounting flange 68 and the knuckle 75 can be reduced, and even if the finishing accuracy of the outer side surface 75a of the knuckle 75 is not good, the degree to which the outer member 70 is affected by this accuracy. Can be small.
  • the large diameter portion 71 and the concave groove 74 formed continuously over the entire circumference of the base end side portion of the inner side surface 69 of the small diameter portion 72 are not provided in the large diameter portion 71.
  • the circular diameter is large, the effect of absorbing the distortion due to the concave groove 74 cannot be expected.
  • the present invention has been made in view of such circumstances, and while increasing the rigidity of the bearing while reducing the weight and size, suppressing the stress generated in the outer member to ensure accuracy and extending the life of the bearing. It is an object of the present invention to provide a wheel bearing device.
  • the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel attachment for attaching a wheel to one end.
  • a hub ring having a flange integrally formed with a small-diameter step portion extending in the axial direction on the outer periphery, and an inward rotation that is press-fitted into the small-diameter step portion of the hub ring and faces the outer surface of the double row on the outer periphery.
  • An inner member composed of at least one inner ring on which a running surface is formed, and a double row rolling element that is rotatably accommodated between the inner member and the outer member.
  • a vehicle body mounting flange having an outer peripheral surface in which a large diameter portion and a small diameter portion are alternately arranged in the circumferential direction is provided on the inner side of the outer member, and on the inner side of the vehicle body mounting flange.
  • a mounting surface is formed and extends in the axial direction on the mounting surface of the large diameter portion.
  • a fixing bolt is formed in which a hole is formed and a concave groove is formed in the vicinity of the radially inner side of the screw hole, and a knuckle constituting a suspension device is joined to the mounting surface and screwed into the screw hole.
  • the outer member is fastened through.
  • the vehicle body mounting flange including the outer peripheral surface in which the large diameter portion and the small diameter portion are alternately arranged in the circumferential direction on the inner side of the outer member.
  • a mounting surface is formed on the inner side of the vehicle body mounting flange, a screw hole extending in the axial direction is formed on the mounting surface of the large-diameter portion, and a groove is formed near the radially inner side of the screw hole.
  • the knuckle that forms the suspension device is joined to the mounting surface and the outer member is fastened via a fixing bolt that is screwed into the screw hole. It is possible to provide a wheel bearing device that absorbs and prevents deformation of the mounting surface to prevent the roundness of the outer rolling surface close to the mounting surface from deteriorating, ensuring accuracy and extending the life of the bearing.
  • the structure is inexpensive, the structure is simple and the cost can be reduced, and the mounting surface of the suspension device is machined such as grinding. Even if is eliminated and the surface accuracy is low, the accuracy of the bearing portion can be ensured.
  • the groove width W1 in the radial direction of the concave groove is smaller than the minimum contact width W0-W1 on the inner diameter side from the opening edge of the screw hole (W1 ⁇ W0 ⁇ ).
  • W1 If set, it is possible to prevent the pressure receiving area from decreasing with respect to the axial force applied to the vehicle body mounting flange, and to prevent the strength and durability from being lowered due to the increase in surface pressure.
  • the groove width W1 in the radial direction of the concave groove is set to be larger than the groove depth H, and the minimum contact width between the screw hole and the concave groove If W2 is set to be larger than 1 ⁇ 2 of the screw diameter E of the screw hole (W2 ⁇ E / 2), the rigidity of the vehicle body mounting flange is ensured, the deformation of the mounting surface is prevented, and misalignment is performed. It is possible to suppress the deterioration of the roundness of the outer rolling surface and to ensure accuracy.
  • the concave groove is formed into an eyebrow shape by forging, it is not necessary to form the concave groove by machining, and the number of processing steps can be reduced and the cost can be reduced. Can be achieved.
  • an annular relief continuous over the entire circumference at the outer peripheral surface of the outer member to which the suspension device is fitted and the corner of the mounting surface of the vehicle body mounting flange. If the groove is formed, it is possible to prevent misalignment from occurring due to interference of the corners of the suspension device.
  • the pitch circle diameter of the outer side rolling elements of the double row rolling elements is set to be larger than the pitch circle diameter of the inner side rolling elements.
  • the outer member has an outer peripheral surface formed with a gradually decreasing diameter from the outer peripheral surface on the outer side toward the outer peripheral surface on the inner side, and on the outer side of the outer rolling surface of the double row.
  • the inner side outer rolling surface is integrally formed through a stepped portion extending in an axial direction from the rolling surface, and a shoulder is formed on each of the double row outer rolling surfaces.
  • these shoulder portions are formed to a predetermined groove depth by turning, and at least the stepped portion between both shoulder portions is not turned and remains forged, the groove depth of the outer rolling surface Are severely regulated, and edge loading occurs when riding on the shoulder Can be prevented, it is possible to reduce the material losses reduce the site to be deleted in a turning as much as possible.
  • the wheel bearing device integrally has an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for mounting the wheel on one end, and on the outer periphery.
  • a hub wheel having a small-diameter step portion extending in the axial direction, and at least one inner rolling surface that is press-fitted into the small-diameter step portion of the hub wheel and that faces the outer rolling surface of the double row on the outer periphery.
  • the wheel bearing device comprising: an inner member comprising an inner ring; and a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member.
  • a vehicle body mounting flange having an outer peripheral surface in which large diameter portions and small diameter portions are alternately arranged in the circumferential direction, and a mounting surface is formed on the inner side of the vehicle body mounting flange.
  • a screw hole extending in the axial direction is formed on the mounting surface of the A concave groove is formed near the radially inner side of the screw hole, and the outer member is fastened via a fixing bolt that is joined to the mounting surface by a knuckle constituting a suspension device and screwed into the screw hole.
  • the tensile stress generated at the time of bolt fastening is absorbed by the concave groove, the deformation of the mounting surface is suppressed, and the roundness of the outer rolling surface near the mounting surface is prevented from deteriorating, ensuring accuracy and length of the bearing. It is possible to provide a wheel bearing device with a long life.
  • FIG. 1 It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is the side view seen from the inner side of the bearing apparatus for wheels of FIG. It is a principal part enlarged view of the III section of the wheel bearing apparatus of FIG. (A) is a principal part enlarged view which shows the modification of FIG. 3, (b) is a principal part enlarged view which shows the modification of (a). It is a side view which shows the modification of the outward member of FIG. It is a side view which shows the modification of the outward member of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a side view which shows the outward member of the other conventional wheel bearing apparatus. (A) is principal part sectional drawing which shows the small diameter part of the outward member of FIG. 8, (B) is principal part sectional drawing which shows the large diameter part of the outward member of FIG.
  • An outer member having a double row outer rolling surface integrally formed on the inner periphery and a wheel mounting flange for mounting a wheel on one end are integrally formed, and one of the outer rolling surfaces of the double row is formed on the outer periphery.
  • the outer peripheral surface of the outer member is alternately arranged with a large diameter portion and a small diameter portion in the circumferential direction. It is formed in the shape of a petal that protrudes radially outward from the small-diameter portion.
  • a plurality of screws are formed in a circumferentially equidistant manner, a mounting surface is formed on the inner side of the vehicle body mounting flange, a screw hole extending in the axial direction on the mounting surface, and a radially inner side of the screw hole A concave groove is formed in the vicinity, and a knuckle that constitutes a suspension device is joined to the mounting surface, and the outer member is fastened through a fixing bolt that is screwed into the screw hole.
  • FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention
  • FIG. 2 is a side view of the wheel bearing device shown in FIG. 1 viewed from the inner side
  • FIG. 3 is a wheel of FIG.
  • FIG. 4A is an enlarged view of a main part showing a modification of FIG. 3
  • FIG. 4B is an enlarged view of a main part showing a modification of FIG. 5
  • FIG. 6 is a side view showing a modification of the outer member in FIG.
  • This wheel bearing device is for a driven wheel referred to as a third generation, and is a double row rolling element housed in a freely rollable manner between the inner member 1 and the outer member 2, and both members 1 and 2. (Balls) 3 and 3.
  • the inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4 through a predetermined shimiro.
  • the hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface.
  • a small-diameter step portion 4b is formed via a step portion 7 that extends from the surface 4a while being inclined in the axial direction.
  • Hub bolts 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction.
  • the inner ring 5 is formed by forming the other (inner side) inner rolling surface 5a on the outer periphery, press-fitted into the small-diameter step portion 4b of the hub wheel 4, and plastically deforming the end portion of the small-diameter step portion 4b.
  • the inner ring 5 is fixed in the axial direction by the fastening portion 8.
  • the inner ring 5 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching.
  • the rolling element 3 is made of high carbon chrome steel such as SUJ2 as in the case of the inner ring 5, and is hardened in the range of 62 to 67 HRC up to the core part by quenching.
  • the hub wheel 4 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway surface 4a and the inner side base portion 6b of the wheel mounting flange 6 to the small diameter step portion 4b.
  • the surface hardness is set to a range of 58 to 64 HRC by induction hardening.
  • the caulking portion 8 is kept in the surface hardness after forging.
  • the hub wheel 4 is formed by forging from a bar material as a raw material, and the inner rolling surface 4a, the shoulder portion 7a, and the small-diameter step portion 4b including the base portion 6b that becomes the land portion of the outer seal 12 are turned by turning.
  • the stepped portion 7 is formed with a tapered surface having a predetermined inclination angle. That is, the stepped portion 7 is left as a forged surface without being turned.
  • the groove depth of the inner rolling surface 4a is strictly regulated, and it is possible to prevent the occurrence of edge load due to shoulder climbing, and to reduce material loss by reducing the number of parts to be deleted by turning as much as possible. Therefore, cost reduction can be achieved.
  • the hub wheel 4 is hardened by induction hardening after turning.
  • the stepped portion remains as a forged skin if the stepped portion 7 is removed by shot blasting before grinding.
  • the scale adhering to the surface of 7 is removed, and burrs at each corner are also removed at the same time and rounded smoothly, ensuring abnormal noise, abnormal vibration, and rotation failure due to scale dropout. Can prevent and improve product quality.
  • a compressive residual stress is formed on the surface of the stepped portion 7, and the strength and durability can be improved against a moment load or the like applied to the hub wheel 4.
  • the outer member 2 has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) on the outer periphery, and an outer outer rolling surface 2a facing the inner rolling surface 4a of the hub wheel 4 on the inner periphery. And the inner side outer side rolling surface 2b which opposes the inner side rolling surface 5a of the inner ring
  • the outer member 2 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 2a and 2b have a surface hardness in the range of 58 to 64HRC by induction hardening. Has been cured.
  • a seal 12 is attached to the outer opening of both sides of the annular space formed between the outer member 2 and the inner member 1, and a cover (see FIG. (Not shown) is installed to prevent leakage of grease enclosed in the bearing to the outside and intrusion of rainwater and dust from the outside into the bearing.
  • the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated here, it is not restricted to this,
  • the double row tapered roller bearing which used the tapered roller for the rolling element 3 may consist of.
  • the pitch circle diameter PCDo of the outer side rolling element 3 is set to be larger than the pitch circle diameter PCDi of the inner side rolling element 3 (PCDo> PCDi). Further, the outer diameter do of the outer rolling element 3 is set to be smaller than the outer diameter di of the inner rolling element 3 (do ⁇ di). Due to the difference in size between the pitch circle diameters PCDo and PCDi and the rolling elements 3, the number Zo of the outer rolling elements 3 is set to be larger than the number Zi of the inner rolling elements 3. As a result, the bearing space can be effectively utilized to increase the bearing rigidity of the outer side portion compared to the inner side, and the life of the bearing can be extended.
  • the outer ring of the hub wheel 4 is formed in a shape that continues from the groove bottom part of the inner rolling surface 4a to the step part 7 and the small diameter step part 4b through the shoulder part 7a with which the inner ring 5 is abutted.
  • a mortar-shaped recess 14 is formed at the outer end of the hub wheel 4.
  • the depth of the recess 14 is the depth from the outer end surface of the hub wheel 4 to the vicinity of the axial center of the stepped portion 7 beyond the axial position corresponding to the groove bottom of the inner rolling surface 4a.
  • the outer end of the hub wheel 4 has a substantially uniform thickness.
  • the abbreviation "substantially uniform" here is, for example, a design target value that is substantially free of wall thickness difference, that is, a wall thickness difference caused by a processing error or the like should be allowed. It is.
  • the outer side outer rolling surface 2a is formed with a larger diameter than the inner side outer rolling surface 2b due to the difference in pitch circle diameters PCDo and PCDi, and the outer side outer rolling surface 2b is formed. From the shoulder 15 of the running surface 2a to the shoulder 16 on the small diameter side through the step portion 11, the outer rolling surface 2b on the inner side is reached.
  • the outer member 2 is formed by a forging process from a bar material as a raw material, and includes an outer peripheral surface BB on the inner side on which both ends and a knuckle (not shown) are fitted, and a fitting on which a seal and a cover are attached.
  • the mating surfaces, the double row outer rolling surfaces 2a and 2b, the large-diameter shoulder 15 and the small-diameter shoulder 16 are forged while leaving a predetermined turning allowance.
  • the shoulder portion 15 on the large diameter side and the shoulder portion 16 on the small diameter side are formed to a predetermined groove depth by turning, and the step portion 11 between the shoulder portions 15 and 16 is a taper having a predetermined inclination angle. It is formed with a surface.
  • the stepped portion 11 is left as a forged surface without being turned.
  • the groove depth of the outer rolling surfaces 2a, 2b is strictly regulated, and it is possible to prevent the occurrence of edge loading due to shoulder climbing and to reduce the material loss by reducing the number of parts to be deleted by turning as much as possible. The cost can be reduced.
  • the outer member 2 is hardened by induction hardening after turning, but the stepped portion 11 between the outer rolling surfaces 2a and 2b of the double row is not hardened, and the outer rolling surfaces 2a and 2b are not hardened.
  • the curing process is discontinuous. Thereby, the work time of induction hardening can be shortened and cost reduction can be achieved.
  • the step portion 11 is shot blasted before the grinding process, the scale attached to the surface of the step portion 11 is removed, and burrs and the like at the respective corner portions are also removed at the same time. Smooth rounding prevents abnormal noise during operation, abnormal vibration, and rotation failure due to scale dropout, and can improve product quality. Further, this shot blasting process forms a compressive residual stress on the surface of the stepped portion 11 and can improve strength and durability.
  • the outer peripheral surface of the outer member 2 is formed to have a substantially uniform thickness in accordance with the size difference between the pitch circle diameters PCDo and PCDi and the rolling elements 3 and 3. Specifically, it is formed in a shape that gradually decreases in diameter from the cylindrical outer peripheral surface AA on the outer side to the cylindrical outer peripheral surface BB on the inner side through the step portion 13.
  • the step portion 13 is formed as a tapered surface having a predetermined inclination angle corresponding to the shape of the step portion 11 on the inner peripheral surface, and is left as a forged skin without being turned.
  • the outer peripheral surface of the outer member 2 is formed into a petal shape in which the large diameter portions 17 and the small diameter portions 18 are alternately arranged in the circumferential direction, and radially outward from the small diameter portions 18.
  • a plurality (four in this case) of vehicle body mounting flanges 2c are formed in a circumferentially equidistant manner.
  • a mounting surface 19 parallel to the end surface of the outer member 2 is formed on the inner side of the vehicle body mounting flange 2c, and a non-through screw hole 20 extending in the axial direction is formed in the mounting surface 19.
  • a knuckle (not shown) is fitted to the outer peripheral surface BB on the inner side, joined to the mounting surface 19, and the outer member 2 is fastened to the knuckle via a fixing bolt (not shown).
  • a concave groove 22 is formed by turning in the vicinity of the radially inner side of the screw hole 20 of the mounting surface 19.
  • the groove bottom of the annular groove 22 is formed in an arc shape, and the minimum inner diameter D1 of the opening edge of the groove 22 is set larger than the outer diameter D2 of the small diameter portion 18 (D1 ⁇ D2).
  • the concave groove 22 is not continuous but is formed in a discontinuous state on the mounting surface 19 of the vehicle body mounting flange 2c.
  • the “near” here is the radially inner side of the screw hole 20 of the mounting surface 19 and the outer peripheral surface BB of the outer member 2 to which the suspension device is fitted and the vehicle body mounting flange. It is between the corners of the mounting surface 19 of 2c.
  • the concave groove 22 has a radial groove width W1 that is a minimum contact width with a knuckle (not shown) on the inner diameter side from the opening edge of the screw hole 20, that is, It is set smaller than the minimum contact width W0-W1 among the contact widths on the inner diameter side from the opening edge of the screw hole 20 (W1 ⁇ W0-W1).
  • the groove width W1 of the concave groove 22 is set larger than the groove depth H (W1 ⁇ H), and the distance between the screw hole 20 and the concave groove 22 which is a part of the contact surface of the knuckle, that is, The minimum contact width W2 between the screw hole 20 and the concave groove 22 is set to be larger than 1 ⁇ 2 of the screw diameter E of the screw hole 20 (W2 ⁇ E / 2).
  • FIGS. 4A and 4B are modifications of the above-described embodiment (FIG. 3).
  • This embodiment is basically different from the above-described embodiment only in the shape of the concave groove 22, and the same parts and parts having the same functions or parts having the same functions are denoted by the same reference numerals for detailed description. Omitted.
  • a non-penetrating screw hole 20 is formed in the mounting surface 19 of the vehicle body mounting flange 2c, and an annular concave groove 23 is formed near the radially inner side of the screw hole 20.
  • the concave groove 23 has a rectangular cross section, a flat groove bottom, and a circular arc corner.
  • the groove width W1 and groove depth H in the radial direction of the recessed groove 23, or the minimum contact width W2 between the recessed groove 23 and the screw hole 20 are set as described above.
  • a non-penetrating screw hole 20 is formed in the mounting surface 19 of the vehicle body mounting flange 2c, and an annular concave groove 24 is formed in the vicinity of the radially inner side of the screw hole 20.
  • the groove 24 has a triangular cross section and a circular arc tip.
  • the groove width W1 and groove depth H in the radial direction of the recessed groove 24 or the minimum contact width W2 between the recessed groove 24 and the screw hole 20 are set as described above.
  • Such a shape of the concave grooves 23 and 24 increases the degree of freedom in design, secures the rigidity of the vehicle body mounting flange 2c, and secures the roundness of the outer rolling surface 2b after assembly.
  • FIG. 5 is a modification of the above-described embodiment (FIG. 2).
  • This embodiment is basically different from the above-described embodiment only in the configuration of the vehicle body mounting flange 2c and the concave groove 22, and the same reference numerals are given to the same parts or parts having the same function. Detailed description is omitted.
  • a vehicle body mounting flange 26 is formed on the outer periphery on the inner side of the outer member 25 so as to protrude radially outward.
  • the vehicle body mounting flange 26 is formed in a rectangular shape in which the large diameter portions 27 and the small diameter portions 28 are alternately arranged in the circumferential direction, and the large diameter portions 27 and the small diameter portions 28 are smoothly connected.
  • a mounting surface 29 with which a knuckle (not shown) abuts is formed on the inner side of the vehicle body mounting flange 26, and a non-penetrating screw hole 20 is formed at a corner of the mounting surface 29.
  • a concave groove 30 is formed in the vicinity of the radially inner side of the screw hole 20 by a cutting process such as a lathe.
  • the minimum inner diameter D1 of the opening edge of the concave groove 30 is set larger than the outer diameter D3 of the outer peripheral surface BB (D1 ⁇ D3), and the concave groove 30 is formed in a continuous annular shape. Accordingly, the concave groove 30 can be processed by continuous cutting, and the occurrence of damage to the cutting tool is suppressed as compared with the so-called intermittent cutting in which the cutting state and the non-cutting state occur alternately. As the workability is improved, the life of the cutting tool is extended and the cost can be reduced.
  • FIG. 6 is a modification of the above-described embodiment (FIG. 5). This embodiment basically differs from the above-described embodiment only in the configuration of the vehicle body mounting flange 26 and the recessed groove 30, and the same reference numerals are given to the same parts or parts having the same function. Detailed description is omitted.
  • a vehicle body mounting flange 32 is formed on the outer periphery on the inner side of the outer member 31 so as to protrude radially outward.
  • the vehicle body mounting flange 32 is formed in a triangular shape in which the large diameter portions 33 and the small diameter portions 34 are alternately arranged in the circumferential direction, and the large diameter portions 33 and the small diameter portions 34 are smoothly connected.
  • a mounting surface 35 with which a knuckle (not shown) abuts is formed on the inner side of the vehicle body mounting flange 32, and a non-penetrating screw hole 20 is formed at a corner of the mounting surface 35.
  • a concave groove 36 is formed in the vicinity of the radially inner side of the screw hole 20 by forging.
  • the concave groove 36 is formed on the radially outer side with respect to the outer diameter D3 of the outer peripheral surface BB, and the concave groove 36 is formed in an eyebrow shape that is discontinuous.
  • the wheel bearing device according to the present invention can be applied to a wheel bearing device having a second or third generation structure.

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

Abstract

Provided is a bearing device for a wheel, the bearing device being configured so as to be lightweight and compact and have increased bearing rigidity and so as to reduce stress occurring in an outer member to thereby ensure accuracy and extend the life of the bearing. A bearing device for a wheel is affixed to a torsion beam suspension. The outer peripheral surface of an outer member (2) is formed in a petal shape, in which large-diameter sections (17) and small-diameter sections (18) are circumferentially alternately arranged. Vehicle body mounting flanges (2c) are formed protruding radially outward from the small-diameter sections (18). Mounting surfaces (19) are formed on the inner side of the vehicle body mounting flanges (2c), axially extending threaded holes (20) are formed in the mounting surfaces (19), and grooves (22) are formed near the threaded holes (20) at positions on the inside radially of the threaded holes (20). The outer member (2) is fastened to a suspension device by means of fastening bolts engaged with the threaded holes (20). As a result of this configuration, tensile stress generated when the bolts are tightened are absorbed by the grooves (22) to prevent the deformation of the mounting surfaces (19), thereby preventing a deterioration in the roundness of an outer rolling surface (2b).

Description

車輪用軸受装置Wheel bearing device
　本発明は、自動車等の車輪を回転自在に支承する車輪用軸受装置、特に、軽量・コンパクト化を図りつつ軸受剛性を増大させると共に、外方部材に発生する応力を抑制して精度確保と軸受の長寿命化を図った車輪用軸受装置に関するものである。 The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like, and in particular, to increase the bearing rigidity while reducing the weight and size, and to suppress the stress generated in the outer member and to ensure accuracy. The present invention relates to a wheel bearing device that extends the service life of the wheel.
　従来から自動車等の車輪を支持する車輪用軸受装置は、車輪を取り付けるためのハブ輪を転がり軸受を介して回転自在に支承するもので、駆動輪用と従動輪用とがある。構造上の理由から、駆動輪用では内輪回転方式が、従動輪用では内輪回転と外輪回転の両方式が一般的に採用されている。この車輪用軸受装置には、所望の軸受剛性を有し、ミスアライメントに対しても耐久性を発揮すると共に、燃費向上の観点から回転トルクが小さい複列アンギュラ玉軸受が多用されている。この複列アンギュラ玉軸受は、固定輪と回転輪との間に複数のボールを介在させ、このボールに所定の接触角を付与して固定輪および回転輪に接触させている。 2. Description of the Related Art Conventionally, wheel bearing devices that support wheels of automobiles and the like support a hub wheel for mounting a wheel rotatably via a rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used. In this double row angular contact ball bearing, a plurality of balls are interposed between a fixed ring and a rotating ring, and a predetermined contact angle is given to the balls so as to contact the fixed ring and the rotating ring.
　こうした複列の転がり軸受で構成された車輪用軸受装置において、従来は左右両列の軸受が同一仕様のため、静止時には充分な剛性を有するが、車両の旋回時には必ずしも最適な剛性が得られていない。すなわち、静止時の車重は複列の転がり軸受の略中央に作用するように車輪との位置関係が決められているが、旋回時には、旋回方向の反対側（右旋回の場合は車両の左側）の車軸に、より大きなラジアル荷重やアキシアル荷重が負荷される。したがって、旋回時には、インナー側の軸受列よりもアウター側の軸受列の剛性を高めることが有効とされている。なお、「アウター側」とは、車両に組み付けた状態で車両の外側寄りとなる側を言い、「インナー側」とは、中央寄り側を言う。 In wheel bearing devices composed of such double-row rolling bearings, the left and right rows of bearings have the same specifications, so that they have sufficient rigidity when stationary, but optimal rigidity is always obtained when the vehicle turns. Absent. That is, the position of the vehicle weight when stationary is determined so that it acts on the approximate center of the double row rolling bearing, but when turning, the opposite side of the turning direction (when turning right, the vehicle Larger radial load or axial load is applied to the left axle. Therefore, at the time of turning, it is effective to increase the rigidity of the outer bearing row rather than the inner bearing row. The “outer side” refers to the side closer to the outer side of the vehicle when assembled to the vehicle, and the “inner side” refers to the side closer to the center.
　近年、小型自動車のリア側に、廉価で構造がシンプルなトーションビーム式サスペンションが採用される傾向がある。そこで、装置を大型化させることなく高剛性化を図った車輪用軸受装置として、図７に示すものが知られている。 In recent years, there is a tendency to use a torsion beam type suspension that is inexpensive and has a simple structure on the rear side of a small car. Then, what is shown in FIG. 7 is known as a wheel bearing apparatus which achieved high rigidity without enlarging an apparatus.
　この車輪用軸受装置５０は、内方部材５１と外方部材５２、および両部材５１、５２間に転動自在に収容された複列のボール５３、５３とを備えている。内方部材５１は、ハブ輪５４と、このハブ輪５４に所定のシメシロを介して圧入された内輪５５とからなる。 The wheel bearing device 50 includes an inner member 51, an outer member 52, and double- row balls 53, 53 accommodated between the members 51, 52 so as to roll freely. The inner member 51 includes a hub ring 54 and an inner ring 55 that is press-fitted into the hub ring 54 through a predetermined shimiro.
　ハブ輪５４は、一端部に車輪（図示せず）を取り付けるための車輪取付フランジ５６を一体に有し、外周にアウター側の内側転走面５４ａと、この内側転走面５４ａから軸方向に傾斜して延びる段差部５７を介して小径段部５４ｂが形成されている。車輪取付フランジ５６にはハブボルト５６ａが周方向等配に植設されている。 The hub wheel 54 integrally has a wheel mounting flange 56 for mounting a wheel (not shown) at one end, an outer side inner rolling surface 54a on the outer periphery, and an axial direction from the inner rolling surface 54a. A small-diameter step portion 54b is formed via a step portion 57 that extends in an inclined manner. Hub bolts 56a are planted on the wheel mounting flange 56 at equal intervals in the circumferential direction.
　内輪５５は、外周にインナー側の内側転走面５５ａが形成され、ハブ輪５４の小径段部５４ｂに圧入されると共に、小径段部５４ｂの端部を塑性変形させて形成した加締部５４ｃによって内輪５５が軸方向に固定されている。 The inner ring 55 has an inner-side inner rolling surface 55a formed on the outer periphery, is press-fitted into the small-diameter step portion 54b of the hub ring 54, and is formed by plastically deforming an end portion of the small-diameter step portion 54b. Thus, the inner ring 55 is fixed in the axial direction.
　外方部材５２は、外周にナックル（図示せず）に取り付けられるための車体取付フランジはなく、取付面５２ｃを有し、内周にハブ輪５４の内側転走面５４ａに対向するアウター側の外側転走面５２ａと、この外側転走面５２ａから軸方向に傾斜して延びる段差部５８を介して内輪５５の内側転走面５５ａに対向するインナー側の外側転走面５２ｂが一体に形成されている。これら両転走面間に複列のボール５３、５３が収容され、保持器５９、６０によって転動自在に保持されている。 The outer member 52 does not have a vehicle body mounting flange to be attached to a knuckle (not shown) on the outer periphery, has an attachment surface 52c, and has an outer side facing the inner rolling surface 54a of the hub wheel 54 on the inner periphery. An outer side rolling surface 52a and an inner side outer side rolling surface 52b facing the inner side rolling surface 55a of the inner ring 55 are integrally formed via a stepped portion 58 that extends from the outer side rolling surface 52a so as to be inclined in the axial direction. Has been. Double- row balls 53 and 53 are accommodated between these rolling surfaces, and are held by rollers 59 and 60 so as to be freely rollable.
　また、外方部材５２と内方部材５１との間に形成される環状空間の開口部にはシール６１、６２が装着され、軸受内部に封入されたグリースの外部への漏洩と、外部から雨水やダスト等が軸受内部に侵入するのを防止している。 Further, seals 61 and 62 are attached to the opening portion of the annular space formed between the outer member 52 and the inner member 51, and leakage of grease sealed inside the bearing to the outside and rainwater from the outside. And dust are prevented from entering the bearing.
　ここでは、アウター側のボール５３のピッチ円直径ＰＣＤｏがインナー側のボール５３のピッチ円直径ＰＣＤｉよりも大径に設定されている。そして、複列のボール５３、５３のサイズは同じであるが、このピッチ円直径ＰＣＤｏ、ＰＣＤｉの違いにより、アウター側のボール５３の個数がインナー側のボール５３の個数よりも多く設定されている。 Here, the pitch circle diameter PCDo of the outer side ball 53 is set to be larger than the pitch circle diameter PCDi of the inner side ball 53. The double- row balls 53 and 53 have the same size, but due to the difference in pitch circle diameters PCDo and PCDi, the number of outer-side balls 53 is set larger than the number of inner-side balls 53. .
　ハブ輪５４の外郭形状は、内側転走面５４ａの溝底部から段差部５７と、内輪５５が突き合わされる肩部５７ａを介して小径段部５４ｂに続いている。また、ハブ輪５４のアウター側の端部にすり鉢状の凹所６３が形成されている。 The outer shape of the hub wheel 54 continues from the groove bottom portion of the inner rolling surface 54a to the stepped portion 57 and the small diameter stepped portion 54b through the shoulder portion 57a against which the inner ring 55 is abutted. Further, a mortar-shaped recess 63 is formed at the outer end of the hub wheel 54.
　一方、外方部材５２において、ピッチ円直径ＰＣＤｏ、ＰＣＤｉの違いに伴い、アウター側の外側転走面５２ａがインナー側の外側転走面５２ｂよりも拡径して形成され、アウター側の外側転走面５２ａの肩部６４から段差部５８を介して小径側の肩部６５に続き、インナー側の外側転走面５２ｂに到っている。 On the other hand, in the outer member 52, the outer side outer rolling surface 52a is formed with a larger diameter than the inner side outer rolling surface 52b in accordance with the difference in pitch circle diameters PCDo and PCDi. From the shoulder 64 of the running surface 52a to the shoulder 65 on the small diameter side via the stepped portion 58, it reaches the outer rolling surface 52b on the inner side.
　こうした従来の車輪用軸受装置５０では、有効に軸受スペースを活用してインナー側に比べアウター側部分の軸受剛性を増大させることができ、軸受の長寿命化を図ることができる。さらに、ハブ輪５４の端部に凹所６３が外郭形状に沿って形成され、ハブ輪５４のアウター側の端部が均一な肉厚に設定されているので、装置の軽量・コンパクト化と高剛性化という、相反する課題を解決することができる。 In such a conventional wheel bearing device 50, the bearing space can be effectively utilized to increase the bearing rigidity of the outer side portion compared to the inner side, and the life of the bearing can be extended. Further, the recess 63 is formed in the end portion of the hub wheel 54 along the outer shape, and the end portion on the outer side of the hub wheel 54 is set to have a uniform wall thickness. The conflicting problem of rigidity can be solved.
　ここで、ピッチ円直径ＰＣＤｏ、ＰＣＤｉの違いに伴い、外方部材５２の外周面が、アウター側の円筒状の外周面ＡＡからインナー側の円筒状の外周面ＢＢに向って漸次小径に形成されている。そして、インナー側の外周面ＢＢの近傍に、周方向等配に４箇所の取付部６６が形成され、この取付部６６に外方部材５２の端面と平行な取付面５２ｃが形成されている。取付部６６は、インナー側の外周面ＢＢから径方向外方に突出して形成され、取付面５２ｃには軸方向に延びるねじ孔６７が形成されている。ナックルは、インナー側の外周面ＢＢに嵌合されると共に、この取付面５２ｃに接合され、固定ボルト（図示せず）を介して外方部材５２がナックルに締結される。 Here, with the difference in pitch circle diameters PCDo and PCDi, the outer peripheral surface of the outer member 52 is gradually formed to have a smaller diameter from the outer cylindrical outer surface AA toward the inner cylindrical outer surface BB. ing. And four attachment parts 66 are formed in the vicinity of the outer peripheral surface BB on the inner side at equal intervals in the circumferential direction, and an attachment surface 52 c parallel to the end face of the outer member 52 is formed on the attachment part 66. The attachment portion 66 is formed to protrude radially outward from the outer peripheral surface BB on the inner side, and a screw hole 67 extending in the axial direction is formed in the attachment surface 52c. The knuckle is fitted to the outer peripheral surface BB on the inner side, joined to the mounting surface 52c, and the outer member 52 is fastened to the knuckle via a fixing bolt (not shown).
　このように、外方部材５２の外周面が、ナックルに締結される一般的な車体取付フランジを備えておらず、アウター側からインナー側に向って漸次小径に形成されると共に、インナー側の端部に径方向外方に延びる取付部６６を備えている。そして、この取付部６６に取付面５２ｃが形成され、ねじ孔６７に螺着される固定ボルトによって外方部材５２がナックルに締結されているので、軽量・コンパクト化を図ると共に、軸受剛性を増大させ、軸受の長寿命化を図った車輪用軸受装置を提供することができる（例えば、特許文献１参照。）。 As described above, the outer peripheral surface of the outer member 52 does not include a general vehicle body mounting flange fastened to the knuckle, and is formed with a gradually decreasing diameter from the outer side toward the inner side, and at the inner side end. The part is provided with a mounting part 66 extending radially outward. Since the mounting surface 52c is formed in the mounting portion 66 and the outer member 52 is fastened to the knuckle by a fixing bolt that is screwed into the screw hole 67, the weight is reduced and the bearing rigidity is increased. Thus, it is possible to provide a wheel bearing device that extends the life of the bearing (see, for example, Patent Document 1).
　トーションビーム式サスペンションでは、軸受取付プレートと懸架装置を構成するナックルとを溶接により接合しているため、軸受取付プレートの面精度が低い。特に、軸受取付プレートが鋼板からプレス加工によって形成されている場合は、その取付面の面精度が一層低下することが考えられる。このような軸受取付プレートに車輪用軸受装置を締結する場合、ナックルボルトの締結部に引張応力が発生し、外方部材の外側転走面の真円度劣化を誘発させるため、軸受精度の劣化と共に軸受寿命低下に繋がる恐れがある。 In the torsion beam type suspension, since the bearing mounting plate and the knuckle constituting the suspension device are joined by welding, the surface accuracy of the bearing mounting plate is low. In particular, when the bearing mounting plate is formed from a steel plate by pressing, it is conceivable that the surface accuracy of the mounting surface is further lowered. When fastening a wheel bearing device to such a bearing mounting plate, tensile stress is generated in the fastening part of the knuckle bolt, which induces deterioration of the roundness of the outer rolling surface of the outer member. At the same time, the bearing life may be reduced.
　このような事情に対応して、特許文献２には、固定側フランジとナックルとの不均等な当接状態に基づいて発生する歪み（引張応力）が、外方部材の外側転走面の真円度に影響を及ぼすことの防止を図った車輪用軸受装置の構造が記載されている。この構造の場合、図８に示すように、固定側の車体取付フランジ６８として、外方部材７０の円周方向に関して大径部７１と小径部７２とを交互に配置した非円形状のものを使用し、このうち大径部７１に取付孔７３が形成されている。そして、大径部７１と小径部７２のインナー側の側面（ナックルと対向する側面）６９の基端側部分（径方向内側部分）の全面に、全周に亙り連続した状態で凹溝７４が形成されている。なお、大径部７１に形成された凹溝７４の径方向外端縁は、小径部７２に形成された凹溝７４の外端縁と同じ位置か、それよりも径方向外方に位置している。 Corresponding to such circumstances, Patent Document 2 discloses that a strain (tensile stress) generated based on an uneven contact state between the fixed flange and the knuckle is a true of the outer rolling surface of the outer member. The structure of a wheel bearing device that prevents the influence of circularity from being described is described. In the case of this structure, as shown in FIG. 8, a non-circular one in which large-diameter portions 71 and small-diameter portions 72 are alternately arranged in the circumferential direction of the outer member 70 as the vehicle body mounting flange 68 on the fixed side. Of these, a mounting hole 73 is formed in the large-diameter portion 71. A groove 74 is formed on the entire inner surface of the inner side surface (side surface facing the knuckle) 69 of the large-diameter portion 71 and the small-diameter portion 72 in a continuous state over the entire circumference. Is formed. The radially outer edge of the concave groove 74 formed in the large diameter portion 71 is located at the same position as the outer edge of the concave groove 74 formed in the small diameter portion 72 or radially outward from it. ing.
　この凹溝７４は、図９（Ａ）、（Ｂ）に示すように、車体取付フランジ６８のインナー側の側面６９から、対向するナックル７５のアウター側の側面７５ａに対して離れる方向（図９の左方向）に凹んだ状態で形成されている。また、凹溝７４の最深部７６は、大径部７１と小径部７２の何れにも存在している。 As shown in FIGS. 9A and 9B, the concave groove 74 is away from the inner side surface 69 of the vehicle body mounting flange 68 with respect to the outer side surface 75a of the opposing knuckle 75 (FIG. 9). It is formed in a state of being recessed in the left direction). Further, the deepest portion 76 of the concave groove 74 exists in both the large diameter portion 71 and the small diameter portion 72.
　この状態で、車体取付フランジ６８のインナー側の側面６９と、ナックル７５のアウター側の側面７５ａとは、凹溝７４以外の部分のみで当接する。すなわち、この凹溝７４は、小径部７２のインナー側の側面にも形成されている。このため、小径部７２がナックル７５のアウター側の側面７５ａと当接することはなく、大径部７１の取付孔７３の周辺部分のみがナックル７５のアウター側の側面７５ａに当接することになるため、車体取付フランジ６８とナックル７５との当接面積を小さくすることができ、ナックル７５のアウター側の側面７５ａの仕上げ精度が良くない場合でも、外方部材７０がこの精度の影響を受ける度合いを小さくすることができる。 In this state, the side surface 69 on the inner side of the vehicle body mounting flange 68 and the side surface 75a on the outer side of the knuckle 75 abut only at a portion other than the groove 74. That is, the concave groove 74 is also formed on the inner side surface of the small diameter portion 72. Therefore, the small diameter portion 72 does not contact the outer side surface 75 a of the knuckle 75, and only the peripheral portion of the mounting hole 73 of the large diameter portion 71 contacts the outer side surface 75 a of the knuckle 75. The contact area between the vehicle body mounting flange 68 and the knuckle 75 can be reduced, and even if the finishing accuracy of the outer side surface 75a of the knuckle 75 is not good, the degree to which the outer member 70 is affected by this accuracy. Can be small.
　また、車体取付フランジ６８のインナー側の側面６９と、ナックル７５のアウター側の側面７５ａとの不均等な当接状態に起因する歪みが発生した場合でも、車体取付フランジ６８の基端部に形成された凹溝７４部分は他の部分と比べて弾性変形し易いため、この歪みを吸収することができる。その結果、この歪みが、外方部材７０の外側転走面（図示せず）の、真円度を含む形状精度に悪影響を及ぼすのを防止することができる。 Further, even when a distortion due to an uneven contact state between the inner side surface 69 of the vehicle body mounting flange 68 and the outer side surface 75a of the knuckle 75 occurs, it is formed at the base end portion of the vehicle body mounting flange 68. Since the recessed groove 74 portion is more easily elastically deformed than the other portions, this distortion can be absorbed. As a result, it is possible to prevent this distortion from adversely affecting the shape accuracy including the roundness of the outer rolling surface (not shown) of the outer member 70.
特開２０１２－２１９８５５号公報JP 2012-211985 A 特開２０１２－２２８９０９号公報JP 2012-228909 A
　然しながら、こうした従来の車輪用軸受装置では、大径部７１と小径部７２のインナー側の側面６９の基端側部分の全周に亙り連続して形成された凹溝７４は、大径部７１と小径部７２の基端側部分とナックル７５の角部との干渉を回避する、所謂逃げ溝を兼ねた凹溝７４であるため、小径部７２の外径寸法に対して取付孔７３のピッチ円直径が大きくなるような仕様では、凹溝７４による歪みを吸収する効果が期待できない。この場合、小径部７２の外径を大きくするか、凹溝７４の溝幅を大きくすることも考えられるが、これでは、軽量・コンパクト化が阻害されると共に、車体取付フランジ６８自体の強度・耐久性が低下する恐れがあり、こうした凹溝７４によって外方部材７０における外側転走面の真円度を含む形状精度に悪影響を及ぼすのを防止するには限界があった。 However, in such a conventional wheel bearing device, the large diameter portion 71 and the concave groove 74 formed continuously over the entire circumference of the base end side portion of the inner side surface 69 of the small diameter portion 72 are not provided in the large diameter portion 71. And a groove 74 that also serves as a so-called escape groove that avoids interference between the proximal end portion of the small diameter portion 72 and the corner portion of the knuckle 75, and therefore the pitch of the mounting hole 73 with respect to the outer diameter of the small diameter portion 72. In the specification in which the circular diameter is large, the effect of absorbing the distortion due to the concave groove 74 cannot be expected. In this case, it is conceivable to increase the outer diameter of the small-diameter portion 72 or to increase the groove width of the concave groove 74. However, this impedes weight and downsizing, and reduces the strength of the vehicle body mounting flange 68 itself. Durability may be reduced, and there is a limit in preventing such concave grooves 74 from adversely affecting the shape accuracy including the roundness of the outer rolling surface of the outer member 70.
　本発明は、このような事情に鑑みてなされたもので、軽量・コンパクト化を図りつつ軸受剛性を増大させると共に、外方部材に発生する応力を抑制して精度確保と軸受の長寿命化を図った車輪用軸受装置を提供することを目的としている。 The present invention has been made in view of such circumstances, and while increasing the rigidity of the bearing while reducing the weight and size, suppressing the stress generated in the outer member to ensure accuracy and extending the life of the bearing. It is an object of the present invention to provide a wheel bearing device.
　係る目的を達成すべく、本発明のうち請求項１記載の発明は、内周に複列の外側転走面が一体に形成された外方部材と、一端部に車輪を取り付けるための車輪取付フランジを一体に有し、外周に軸方向に延びる小径段部が形成されたハブ輪、およびこのハブ輪の小径段部に圧入され、外周に前記複列の外側転走面に対向する内側転走面が形成された少なくとも一つの内輪からなる内方部材と、この内方部材と前記外方部材の両転走面間に転動自在に収容された複列の転動体と、を備えた車輪用軸受装置において、前記外方部材のインナー側に、円周方向に関して大径部と小径部とが交互に配置された外周面からなる車体取付フランジを備え、この車体取付フランジのインナー側に取付面が形成され、前記大径部の取付面に軸方向に延びるねじ孔が形成されると共に、このねじ孔の径方向内方側の近傍に凹溝が形成され、前記取付面に懸架装置を構成するナックルが接合されて前記ねじ孔に螺着される固定ボルトを介して前記外方部材が締結されている。 In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel attachment for attaching a wheel to one end. A hub ring having a flange integrally formed with a small-diameter step portion extending in the axial direction on the outer periphery, and an inward rotation that is press-fitted into the small-diameter step portion of the hub ring and faces the outer surface of the double row on the outer periphery. An inner member composed of at least one inner ring on which a running surface is formed, and a double row rolling element that is rotatably accommodated between the inner member and the outer member. In the wheel bearing device, a vehicle body mounting flange having an outer peripheral surface in which a large diameter portion and a small diameter portion are alternately arranged in the circumferential direction is provided on the inner side of the outer member, and on the inner side of the vehicle body mounting flange. A mounting surface is formed and extends in the axial direction on the mounting surface of the large diameter portion. A fixing bolt is formed in which a hole is formed and a concave groove is formed in the vicinity of the radially inner side of the screw hole, and a knuckle constituting a suspension device is joined to the mounting surface and screwed into the screw hole. The outer member is fastened through.
　このように、第２または第３世代構造の車輪用軸受装置において、外方部材のインナー側に、円周方向に関して大径部と小径部とが交互に配置された外周面からなる車体取付フランジを備え、この車体取付フランジのインナー側に取付面が形成され、大径部の取付面に軸方向に延びるねじ孔が形成されると共に、このねじ孔の径方向内方側の近傍に凹溝が形成され、取付面に懸架装置を構成するナックルが接合されてねじ孔に螺着される固定ボルトを介して外方部材が締結されているので、ボルト締結時に発生する引張応力を凹溝で吸収し、取付面の変形を抑制して取付面に近い外側転走面の真円度劣化を防止し、精度確保と軸受の長寿命化を図った車輪用軸受装置を提供することができる。 Thus, in the wheel bearing device of the second or third generation structure, the vehicle body mounting flange including the outer peripheral surface in which the large diameter portion and the small diameter portion are alternately arranged in the circumferential direction on the inner side of the outer member. A mounting surface is formed on the inner side of the vehicle body mounting flange, a screw hole extending in the axial direction is formed on the mounting surface of the large-diameter portion, and a groove is formed near the radially inner side of the screw hole. The knuckle that forms the suspension device is joined to the mounting surface and the outer member is fastened via a fixing bolt that is screwed into the screw hole. It is possible to provide a wheel bearing device that absorbs and prevents deformation of the mounting surface to prevent the roundness of the outer rolling surface close to the mounting surface from deteriorating, ensuring accuracy and extending the life of the bearing.
　好ましくは、請求項２に記載の発明のように、前記懸架装置がトーションビーム式サスペンションであれば、廉価で構造がシンプルになってコスト低減ができると共に、懸架装置の取付面が研削等の機械加工が廃止されて面精度が低くても、軸受部の精度を確保することができる。 Preferably, if the suspension device is a torsion beam suspension as in the invention described in claim 2, the structure is inexpensive, the structure is simple and the cost can be reduced, and the mounting surface of the suspension device is machined such as grinding. Even if is eliminated and the surface accuracy is low, the accuracy of the bearing portion can be ensured.
　また、請求項３に記載の発明のように、前記凹溝の径方向の溝幅Ｗ１が、前記ねじ孔の開口縁より内径側の最小当接幅Ｗ０－Ｗ１よりも小さく（Ｗ１≦Ｗ０－Ｗ１）設定されていれば、車体取付フランジに負荷される軸力に対して、受圧面積が減少し、面圧上昇に伴う強度・耐久性が低下するのを防止することができる。 As in the third aspect of the invention, the groove width W1 in the radial direction of the concave groove is smaller than the minimum contact width W0-W1 on the inner diameter side from the opening edge of the screw hole (W1 ≦ W0−). W1) If set, it is possible to prevent the pressure receiving area from decreasing with respect to the axial force applied to the vehicle body mounting flange, and to prevent the strength and durability from being lowered due to the increase in surface pressure.
　また、請求項４に記載の発明のように、前記凹溝の径方向の溝幅Ｗ１が溝深さＨよりも大きく設定されると共に、前記ねじ孔と凹溝との間の最小当接幅Ｗ２が、当該ねじ孔のねじ径Ｅの１／２よりも大きく（Ｗ２≧Ｅ／２）設定されていれば、車体取付フランジの剛性を確保し、取付面の変形を防止してミスアライメントを抑制し、外側転走面の真円度劣化を防止して精度確保を図ることができる。 Further, as in the invention described in claim 4, the groove width W1 in the radial direction of the concave groove is set to be larger than the groove depth H, and the minimum contact width between the screw hole and the concave groove If W2 is set to be larger than ½ of the screw diameter E of the screw hole (W2 ≧ E / 2), the rigidity of the vehicle body mounting flange is ensured, the deformation of the mounting surface is prevented, and misalignment is performed. It is possible to suppress the deterioration of the roundness of the outer rolling surface and to ensure accuracy.
　また、請求項５に記載の発明のように、前記凹溝が鍛造加工によってまゆ型形状に形成されていれば、凹溝を機械加工で形成する必要がなく、加工工数が低減できて低コスト化を図ることができる。 Further, as in the invention described in claim 5, if the concave groove is formed into an eyebrow shape by forging, it is not necessary to form the concave groove by machining, and the number of processing steps can be reduced and the cost can be reduced. Can be achieved.
　また、請求項６に記載の発明のように、前記懸架装置が嵌合される前記外方部材の外周面と前記車体取付フランジの取付面の隅部に、全周に亙り連続した環状の逃げ溝が形成されていれば、懸架装置の角部が干渉してミスアライメントが生じるのを防止することができる。 According to a sixth aspect of the present invention, an annular relief continuous over the entire circumference at the outer peripheral surface of the outer member to which the suspension device is fitted and the corner of the mounting surface of the vehicle body mounting flange. If the groove is formed, it is possible to prevent misalignment from occurring due to interference of the corners of the suspension device.
　また、請求項７に記載の発明のように、前記複列の転動体のうちアウター側の転動体のピッチ円直径がインナー側の転動体のピッチ円直径よりも大径に設定され、このピッチ円直径の違いに伴い、前記外方部材が、アウター側の外周面からインナー側の外周面に向って漸次小径に形成された外周面と、前記複列の外側転走面のうちアウター側の転走面から軸方向に傾斜して延びる段差部を介してインナー側の外側転走面が一体に形成された内周面を備え、前記複列の外側転走面にそれぞれ肩部が形成されると共に、これら肩部が旋削加工によって所定の溝深さに形成され、少なくとも両肩部間の段差部が旋削加工されずに鍛造肌のままとされていれば、外側転走面の溝深さが厳しく規制され、肩乗り上げによってエッジロードが発生するのが防止できると共に、旋削加工によって削除される部位を可及的に減少させてマテリアルロスの削減を図ることができる。 Further, as in the invention according to claim 7, the pitch circle diameter of the outer side rolling elements of the double row rolling elements is set to be larger than the pitch circle diameter of the inner side rolling elements. Along with the difference in circular diameter, the outer member has an outer peripheral surface formed with a gradually decreasing diameter from the outer peripheral surface on the outer side toward the outer peripheral surface on the inner side, and on the outer side of the outer rolling surface of the double row. The inner side outer rolling surface is integrally formed through a stepped portion extending in an axial direction from the rolling surface, and a shoulder is formed on each of the double row outer rolling surfaces. In addition, if these shoulder portions are formed to a predetermined groove depth by turning, and at least the stepped portion between both shoulder portions is not turned and remains forged, the groove depth of the outer rolling surface Are severely regulated, and edge loading occurs when riding on the shoulder Can be prevented, it is possible to reduce the material losses reduce the site to be deleted in a turning as much as possible.
　本発明に係る車輪用軸受装置は、内周に複列の外側転走面が一体に形成された外方部材と、一端部に車輪を取り付けるための車輪取付フランジを一体に有し、外周に軸方向に延びる小径段部が形成されたハブ輪、およびこのハブ輪の小径段部に圧入され、外周に前記複列の外側転走面に対向する内側転走面が形成された少なくとも一つの内輪からなる内方部材と、この内方部材と前記外方部材の両転走面間に転動自在に収容された複列の転動体と、を備えた車輪用軸受装置において、前記外方部材のインナー側に、円周方向に関して大径部と小径部とが交互に配置された外周面からなる車体取付フランジを備え、この車体取付フランジのインナー側に取付面が形成され、前記大径部の取付面に軸方向に延びるねじ孔が形成されると共に、このねじ孔の径方向内方側の近傍に凹溝が形成され、前記取付面に懸架装置を構成するナックルが接合されて前記ねじ孔に螺着される固定ボルトを介して前記外方部材が締結されているので、ボルト締結時に発生する引張応力を凹溝で吸収し、取付面の変形を抑制して取付面に近い外側転走面の真円度劣化を防止し、精度確保と軸受の長寿命化を図った車輪用軸受装置を提供することができる。 The wheel bearing device according to the present invention integrally has an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for mounting the wheel on one end, and on the outer periphery. A hub wheel having a small-diameter step portion extending in the axial direction, and at least one inner rolling surface that is press-fitted into the small-diameter step portion of the hub wheel and that faces the outer rolling surface of the double row on the outer periphery. In the wheel bearing device, comprising: an inner member comprising an inner ring; and a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member. Provided on the inner side of the member is a vehicle body mounting flange having an outer peripheral surface in which large diameter portions and small diameter portions are alternately arranged in the circumferential direction, and a mounting surface is formed on the inner side of the vehicle body mounting flange. A screw hole extending in the axial direction is formed on the mounting surface of the A concave groove is formed near the radially inner side of the screw hole, and the outer member is fastened via a fixing bolt that is joined to the mounting surface by a knuckle constituting a suspension device and screwed into the screw hole. As a result, the tensile stress generated at the time of bolt fastening is absorbed by the concave groove, the deformation of the mounting surface is suppressed, and the roundness of the outer rolling surface near the mounting surface is prevented from deteriorating, ensuring accuracy and length of the bearing. It is possible to provide a wheel bearing device with a long life.
本発明に係る車輪用軸受装置の一実施形態を示す縦断面図である。It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. 図１の車輪用軸受装置のインナー側から見た側面図である。It is the side view seen from the inner side of the bearing apparatus for wheels of FIG. 図１の車輪用軸受装置のＩＩＩ部の要部拡大図である。It is a principal part enlarged view of the III section of the wheel bearing apparatus of FIG. （ａ）は、図３の変形例を示す要部拡大図、（ｂ）は、（ａ）の変形例を示す要部拡大図である。(A) is a principal part enlarged view which shows the modification of FIG. 3, (b) is a principal part enlarged view which shows the modification of (a). 図１の外方部材の変形例を示す側面図である。It is a side view which shows the modification of the outward member of FIG. 図５の外方部材の変形例を示す側面図である。It is a side view which shows the modification of the outward member of FIG. 従来の車輪用軸受装置を示す縦断面図である。It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. 従来の他の車輪用軸受装置の外方部材を示す側面図である。It is a side view which shows the outward member of the other conventional wheel bearing apparatus. （Ａ）は、図８の外方部材の小径部を示す要部断面図、（Ｂ）は、図８の外方部材の大径部を示す要部断面図である。(A) is principal part sectional drawing which shows the small diameter part of the outward member of FIG. 8, (B) is principal part sectional drawing which shows the large diameter part of the outward member of FIG.
　内周に複列の外側転走面が一体に形成された外方部材と、一端部に車輪を取り付けるための車輪取付フランジを一体に有し、外周に前記複列の外側転走面の一方に対向する内側転走面と、この内側転走面から軸方向に傾斜して延びる段差部を介して小径段部が形成されたハブ輪、およびこのハブ輪の小径段部に圧入され、外周に前記複列の外側転走面の他方に対向する内側転走面が形成された内輪からなる内方部材と、この内方部材と前記外方部材の両転走面間に転動自在に収容された複列の転動体と、を備えたトーションビーム式サスペンションに固定される車輪用軸受装置において、前記外方部材の外周面が、円周方向に関して大径部と小径部とを交互に配置した花弁形状に形成され、前記小径部から径方向外方に突出して車体取付フランジが周方向等配に複数個形成されると共に、前記車体取付フランジのインナー側に取付面が形成され、この取付面に軸方向に延びるねじ孔と、このねじ孔の径方向内方側の近傍に凹溝が形成され、前記取付面に懸架装置を構成するナックルが接合されて前記ねじ孔に螺着される固定ボルトを介して前記外方部材が締結される。 An outer member having a double row outer rolling surface integrally formed on the inner periphery and a wheel mounting flange for mounting a wheel on one end are integrally formed, and one of the outer rolling surfaces of the double row is formed on the outer periphery. A hub ring having a small-diameter step portion formed through an inner rolling surface opposite to the inner rolling surface and a stepped portion extending in an axial direction from the inner rolling surface, and the outer periphery is press-fitted into the small-diameter step portion of the hub ring. An inner member formed of an inner ring formed with an inner rolling surface facing the other of the outer rolling surfaces of the double row, and freely rollable between both rolling surfaces of the inner member and the outer member. In a wheel bearing device fixed to a torsion beam suspension having a double row rolling element accommodated therein, the outer peripheral surface of the outer member is alternately arranged with a large diameter portion and a small diameter portion in the circumferential direction. It is formed in the shape of a petal that protrudes radially outward from the small-diameter portion. A plurality of screws are formed in a circumferentially equidistant manner, a mounting surface is formed on the inner side of the vehicle body mounting flange, a screw hole extending in the axial direction on the mounting surface, and a radially inner side of the screw hole A concave groove is formed in the vicinity, and a knuckle that constitutes a suspension device is joined to the mounting surface, and the outer member is fastened through a fixing bolt that is screwed into the screw hole.
　以下、本発明の実施の形態を図面に基づいて詳細に説明する。
　図１は、本発明に係る車輪用軸受装置の一実施形態を示す縦断面図、図２は、図１の車輪用軸受装置のインナー側から見た側面図、図３は、図１の車輪用軸受装置のＩＩＩ部の要部拡大図、図４（ａ）は、図３の変形例を示す要部拡大図、（ｂ）は、（ａ）の変形例を示す要部拡大図、図５は、図１の外方部材の変形例を示す側面図、図６は、図５の外方部材の変形例を示す側面図である。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is a side view of the wheel bearing device shown in FIG. 1 viewed from the inner side, and FIG. 3 is a wheel of FIG. FIG. 4A is an enlarged view of a main part showing a modification of FIG. 3, and FIG. 4B is an enlarged view of a main part showing a modification of FIG. 5 is a side view showing a modification of the outer member in FIG. 1, and FIG. 6 is a side view showing a modification of the outer member in FIG.
　この車輪用軸受装置は第３世代と呼称される従動輪用であって、内方部材１と外方部材２、および両部材１、２間に転動自在に収容された複列の転動体（ボール）３、３とを備えている。内方部材１は、ハブ輪４と、このハブ輪４に所定のシメシロを介して圧入された内輪５とからなる。 This wheel bearing device is for a driven wheel referred to as a third generation, and is a double row rolling element housed in a freely rollable manner between the inner member 1 and the outer member 2, and both members 1 and 2. (Balls) 3 and 3. The inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4 through a predetermined shimiro.
　ハブ輪４は、アウター側の端部に車輪（図示せず）を取り付けるための車輪取付フランジ６を一体に有し、外周に一方（アウター側）の内側転走面４ａと、この内側転走面４ａから軸方向に傾斜して延びる段差部７を介して小径段部４ｂが形成されている。車輪取付フランジ６にはハブボルト６ａが周方向等配に植設されている。 The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface. A small-diameter step portion 4b is formed via a step portion 7 that extends from the surface 4a while being inclined in the axial direction. Hub bolts 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction.
　内輪５は、外周に他方（インナー側）の内側転走面５ａが形成され、ハブ輪４の小径段部４ｂに圧入されると共に、小径段部４ｂの端部を塑性変形させて形成した加締部８によって内輪５が軸方向に固定されている。なお、内輪５はＳＵＪ２等の高炭素クロム鋼で形成され、ズブ焼入れによって芯部まで５８～６４ＨＲＣの範囲に硬化処理されている。また、転動体３は内輪５と同様、ＳＵＪ２等の高炭素クロム鋼で形成され、ズブ焼入れによって芯部まで６２～６７ＨＲＣの範囲に硬化処理されている。 The inner ring 5 is formed by forming the other (inner side) inner rolling surface 5a on the outer periphery, press-fitted into the small-diameter step portion 4b of the hub wheel 4, and plastically deforming the end portion of the small-diameter step portion 4b. The inner ring 5 is fixed in the axial direction by the fastening portion 8. The inner ring 5 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching. The rolling element 3 is made of high carbon chrome steel such as SUJ2 as in the case of the inner ring 5, and is hardened in the range of 62 to 67 HRC up to the core part by quenching.
　ハブ輪４はＳ５３Ｃ等の炭素０．４０～０．８０ｗｔ％を含む中高炭素鋼で形成され、内側転走面４ａをはじめ、車輪取付フランジ６のインナー側の基部６ｂから小径段部４ｂに亙って高周波焼入れによって表面硬さを５８～６４ＨＲＣの範囲に硬化処理されている。なお、加締部８は鍛造加工後の表面硬さのままとされている。これにより、車輪取付フランジ６に負荷される回転曲げ荷重に対して充分な機械的強度を有し、内輪５の嵌合部となる小径段部４ｂの耐フレッティング性が向上すると共に、微小なクラック等の発生がなく加締部８の塑性加工をスムーズに行うことができる。 The hub wheel 4 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway surface 4a and the inner side base portion 6b of the wheel mounting flange 6 to the small diameter step portion 4b. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. The caulking portion 8 is kept in the surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 6, the fretting resistance of the small-diameter step portion 4b serving as the fitting portion of the inner ring 5 is improved, and the minute There is no occurrence of cracks and the like, and the plastic working of the caulking portion 8 can be performed smoothly.
　ハブ輪４は、素材となるバー材から鍛造加工により形成され、アウター側のシール１２のランド部となる基部６ｂをはじめ、内側転走面４ａと肩部７ａおよび小径段部４ｂが旋削加工によって所定の寸法に形成されると共に、段差部７が所定の傾斜角からなるテーパ面で形成されている。すなわち、この段差部７は旋削加工されずに鍛造肌のままとされている。これにより、内側転走面４ａの溝深さが厳しく規制され、肩乗り上げによってエッジロードが発生するのが防止できると共に、旋削加工によって削除される部位を可及的に減少させてマテリアルロスの削減ができ、低コスト化を図ることができる。 The hub wheel 4 is formed by forging from a bar material as a raw material, and the inner rolling surface 4a, the shoulder portion 7a, and the small-diameter step portion 4b including the base portion 6b that becomes the land portion of the outer seal 12 are turned by turning. In addition to being formed with a predetermined dimension, the stepped portion 7 is formed with a tapered surface having a predetermined inclination angle. That is, the stepped portion 7 is left as a forged surface without being turned. As a result, the groove depth of the inner rolling surface 4a is strictly regulated, and it is possible to prevent the occurrence of edge load due to shoulder climbing, and to reduce material loss by reducing the number of parts to be deleted by turning as much as possible. Therefore, cost reduction can be achieved.
　ハブ輪４は、旋削加工後に高周波焼入れによって硬化処理が施されるが、好ましくは、研削加工の前に、段差部７がショットブラスト加工によってスケールが除去されれば、鍛造肌のままの段差部７の表面に付着したスケールが除去されると共に、それぞれの角部のバリ等も同時に除去されて滑らかに丸められ、スケールの脱落に起因する運転時の異音、異常振動、回転不調を確実に防止し、製品品質の向上を図ることができる。また、段差部７の表面に圧縮残留応力が形成され、ハブ輪４に負荷されるモーメント荷重等に対して強度・耐久性を向上させることができる。 The hub wheel 4 is hardened by induction hardening after turning. Preferably, the stepped portion remains as a forged skin if the stepped portion 7 is removed by shot blasting before grinding. The scale adhering to the surface of 7 is removed, and burrs at each corner are also removed at the same time and rounded smoothly, ensuring abnormal noise, abnormal vibration, and rotation failure due to scale dropout. Can prevent and improve product quality. Further, a compressive residual stress is formed on the surface of the stepped portion 7, and the strength and durability can be improved against a moment load or the like applied to the hub wheel 4.
　外方部材２は、外周にナックル（図示せず）に取り付けられるための車体取付フランジ２ｃを有し、内周にハブ輪４の内側転走面４ａに対向するアウター側の外側転走面２ａと、この外側転走面２ａから軸方向に傾斜して延びる段差部１１を介して内輪５の内側転走面５ａに対向するインナー側の外側転走面２ｂが一体に形成されている。これら両転走面間に複列の転動体３、３が収容され、保持器９、１０によって転動自在に保持されている。 The outer member 2 has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) on the outer periphery, and an outer outer rolling surface 2a facing the inner rolling surface 4a of the hub wheel 4 on the inner periphery. And the inner side outer side rolling surface 2b which opposes the inner side rolling surface 5a of the inner ring | wheel 5 through the level | step-difference part 11 which inclines in the axial direction from this outer side rolling surface 2a is integrally formed. Double- row rolling elements 3 and 3 are accommodated between these rolling surfaces and are held by the cages 9 and 10 so as to roll freely.
　外方部材２はＳ５３Ｃ等の炭素０．４０～０．８０ｗｔ％を含む中高炭素鋼で形成され、少なくとも複列の外側転走面２ａ、２ｂが高周波焼入れによって表面硬さを５８～６４ＨＲＣの範囲に硬化処理されている。また、外方部材２と内方部材１との間に形成される環状空間の両側開口部のうちアウター側の開口部にシール１２が装着されると共に、インナー側の開口部にはカバー（図示せず）が装着され、軸受内部に封入されたグリースの外部への漏洩と、外部から雨水やダスト等が軸受内部に侵入するのを防止している。なお、ここでは、転動体３にボールを使用した複列アンギュラ玉軸受で構成された車輪用軸受装置を例示したが、これに限らず、転動体３に円錐ころを使用した複列円錐ころ軸受で構成されていても良い。 The outer member 2 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 2a and 2b have a surface hardness in the range of 58 to 64HRC by induction hardening. Has been cured. In addition, a seal 12 is attached to the outer opening of both sides of the annular space formed between the outer member 2 and the inner member 1, and a cover (see FIG. (Not shown) is installed to prevent leakage of grease enclosed in the bearing to the outside and intrusion of rainwater and dust from the outside into the bearing. In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated here, it is not restricted to this, The double row tapered roller bearing which used the tapered roller for the rolling element 3 It may consist of.
　本実施形態では、アウター側の転動体３のピッチ円直径ＰＣＤｏがインナー側の転動体３のピッチ円直径ＰＣＤｉよりも大径に設定されている（ＰＣＤｏ＞ＰＣＤｉ）。また、アウター側の転動体３の外径ｄｏがインナー側の転動体３の外径ｄｉよりも小径に設定されている（ｄｏ＜ｄｉ）。こうしたピッチ円直径ＰＣＤｏ、ＰＣＤｉと転動体３のサイズの違いにより、アウター側の転動体３の個数Ｚｏがインナー側の転動体３の個数Ｚｉよりも多く設定されている。これにより、有効に軸受スペースを活用してインナー側に比べアウター側部分の軸受剛性を増大させることができ、軸受の長寿命化を図ることができる。 In this embodiment, the pitch circle diameter PCDo of the outer side rolling element 3 is set to be larger than the pitch circle diameter PCDi of the inner side rolling element 3 (PCDo> PCDi). Further, the outer diameter do of the outer rolling element 3 is set to be smaller than the outer diameter di of the inner rolling element 3 (do <di). Due to the difference in size between the pitch circle diameters PCDo and PCDi and the rolling elements 3, the number Zo of the outer rolling elements 3 is set to be larger than the number Zi of the inner rolling elements 3. As a result, the bearing space can be effectively utilized to increase the bearing rigidity of the outer side portion compared to the inner side, and the life of the bearing can be extended.
　ハブ輪４の外郭は、内側転走面４ａの溝底部から段差部７と、内輪５が突き合わされる肩部７ａを介して小径段部４ｂに続く形状に形成されている。また、ハブ輪４のアウター側の端部にはすり鉢状の凹所１４が形成されている。この凹所１４の深さは、ハブ輪４のアウター側の端面から内側転走面４ａの溝底に対応する軸方向位置を越えて段差部７の軸方向中央部付近までの深さとされ、ハブ輪４のアウター側の端部が略均一な肉厚となっている。なお、ここでいう「略均一」の略とは、例えば、設計の狙い値であって実質的に肉厚差がない状態、すなわち、加工誤差等によって生じる肉厚差は当然許容されるべきものである。 The outer ring of the hub wheel 4 is formed in a shape that continues from the groove bottom part of the inner rolling surface 4a to the step part 7 and the small diameter step part 4b through the shoulder part 7a with which the inner ring 5 is abutted. A mortar-shaped recess 14 is formed at the outer end of the hub wheel 4. The depth of the recess 14 is the depth from the outer end surface of the hub wheel 4 to the vicinity of the axial center of the stepped portion 7 beyond the axial position corresponding to the groove bottom of the inner rolling surface 4a. The outer end of the hub wheel 4 has a substantially uniform thickness. The abbreviation "substantially uniform" here is, for example, a design target value that is substantially free of wall thickness difference, that is, a wall thickness difference caused by a processing error or the like should be allowed. It is.
　一方、外方部材２において、ピッチ円直径ＰＣＤｏ、ＰＣＤｉの違いに伴い、アウター側の外側転走面２ａがインナー側の外側転走面２ｂよりも拡径して形成され、アウター側の外側転走面２ａの肩部１５から段差部１１を介して小径側の肩部１６に続き、インナー側の外側転走面２ｂに到っている。 On the other hand, in the outer member 2, the outer side outer rolling surface 2a is formed with a larger diameter than the inner side outer rolling surface 2b due to the difference in pitch circle diameters PCDo and PCDi, and the outer side outer rolling surface 2b is formed. From the shoulder 15 of the running surface 2a to the shoulder 16 on the small diameter side through the step portion 11, the outer rolling surface 2b on the inner side is reached.
　外方部材２は、素材となるバー材から鍛造加工により形成され、両端面をはじめ、ナックル（図示せず）が外嵌されるインナー側の外周面ＢＢと、シールおよびカバーが装着される嵌合面と、複列の外側転走面２ａ、２ｂと、大径側の肩部１５と小径側の肩部１６が所定の旋削取代を残した状態で鍛造加工されている。 The outer member 2 is formed by a forging process from a bar material as a raw material, and includes an outer peripheral surface BB on the inner side on which both ends and a knuckle (not shown) are fitted, and a fitting on which a seal and a cover are attached. The mating surfaces, the double row outer rolling surfaces 2a and 2b, the large-diameter shoulder 15 and the small-diameter shoulder 16 are forged while leaving a predetermined turning allowance.
　また、大径側の肩部１５と小径側の肩部１６が旋削加工によって所定の溝深さに形成されると共に、両肩部１５、１６間の段差部１１が所定の傾斜角からなるテーパ面で形成されている。すなわち、この段差部１１は旋削加工されずに鍛造肌のままとされている。これにより、外側転走面２ａ、２ｂの溝深さが厳しく規制され、肩乗り上げによってエッジロードが発生するのが防止できると共に、旋削加工によって削除される部位を可及的に減少させてマテリアルロスの削減ができ、低コスト化を図ることができる。 Further, the shoulder portion 15 on the large diameter side and the shoulder portion 16 on the small diameter side are formed to a predetermined groove depth by turning, and the step portion 11 between the shoulder portions 15 and 16 is a taper having a predetermined inclination angle. It is formed with a surface. In other words, the stepped portion 11 is left as a forged surface without being turned. As a result, the groove depth of the outer rolling surfaces 2a, 2b is strictly regulated, and it is possible to prevent the occurrence of edge loading due to shoulder climbing and to reduce the material loss by reducing the number of parts to be deleted by turning as much as possible. The cost can be reduced.
　外方部材２が旋削加工後に高周波焼入れによって硬化処理が施されるが、複列の外側転走面２ａ、２ｂ間の段差部１１が硬化処理されず、それぞれの外側転走面２ａ、２ｂの硬化処理が非連続とされている。これにより、高周波焼入れの作業時間を短縮することができ、低コスト化を図ることができる。 The outer member 2 is hardened by induction hardening after turning, but the stepped portion 11 between the outer rolling surfaces 2a and 2b of the double row is not hardened, and the outer rolling surfaces 2a and 2b are not hardened. The curing process is discontinuous. Thereby, the work time of induction hardening can be shortened and cost reduction can be achieved.
　さらに、好ましくは、研削加工の前に、段差部１１がショットブラスト加工されていれば、段差部１１の表面に付着したスケールが除去されると共に、それぞれの角部のバリ等も同時に除去されて滑らかに丸められ、スケールの脱落に起因する運転時の異音、異常振動、回転不調を防止し、製品品質の向上を図ることができる。また、このショットブラスト加工により段差部１１の表面に圧縮残留応力が形成され、強度・耐久性を向上させることができる。 Further, preferably, if the step portion 11 is shot blasted before the grinding process, the scale attached to the surface of the step portion 11 is removed, and burrs and the like at the respective corner portions are also removed at the same time. Smooth rounding prevents abnormal noise during operation, abnormal vibration, and rotation failure due to scale dropout, and can improve product quality. Further, this shot blasting process forms a compressive residual stress on the surface of the stepped portion 11 and can improve strength and durability.
　本実施形態では、ピッチ円直径ＰＣＤｏ、ＰＣＤｉと転動体３、３のサイズの違いに伴い、外方部材２の外周面が略均一な肉厚に形成されている。具体的には、アウター側の円筒状の外周面ＡＡから段差部１３を介してインナー側の円筒状の外周面ＢＢに向って漸次縮径する形状に形成されている。この段差部１３は内周面の段差部１１の形状に対応して所定の傾斜角からなるテーパ面で形成され、旋削加工されずに鍛造肌のままとされている。これにより、軽量化を図ると共に、旋削加工によって削除される部位を可及的に減少させてマテリアルロスの削減ができ、低コスト化を図ることができる。 In the present embodiment, the outer peripheral surface of the outer member 2 is formed to have a substantially uniform thickness in accordance with the size difference between the pitch circle diameters PCDo and PCDi and the rolling elements 3 and 3. Specifically, it is formed in a shape that gradually decreases in diameter from the cylindrical outer peripheral surface AA on the outer side to the cylindrical outer peripheral surface BB on the inner side through the step portion 13. The step portion 13 is formed as a tapered surface having a predetermined inclination angle corresponding to the shape of the step portion 11 on the inner peripheral surface, and is left as a forged skin without being turned. Thereby, while lightening, while reducing the part deleted by turning as much as possible, material loss can be reduced and cost reduction can be achieved.
　そして、外方部材２の外周面は、図２に示すように、円周方向に関して大径部１７と小径部１８とを交互に配置した花弁形状に形成され、小径部１８から径方向外方に突出して車体取付フランジ２ｃが周方向等配に複数個（ここでは、４個）形成されている。また、この車体取付フランジ２ｃのインナー側に外方部材２の端面と平行な取付面１９が形成され、この取付面１９に軸方向に延びる非貫通のねじ孔２０が形成されている。そして、図示しないナックルは、インナー側の外周面ＢＢに嵌合されると共に、この取付面１９に接合され、固定ボルト（図示せず）を介して外方部材２がナックルに締結される。 As shown in FIG. 2, the outer peripheral surface of the outer member 2 is formed into a petal shape in which the large diameter portions 17 and the small diameter portions 18 are alternately arranged in the circumferential direction, and radially outward from the small diameter portions 18. A plurality (four in this case) of vehicle body mounting flanges 2c are formed in a circumferentially equidistant manner. A mounting surface 19 parallel to the end surface of the outer member 2 is formed on the inner side of the vehicle body mounting flange 2c, and a non-through screw hole 20 extending in the axial direction is formed in the mounting surface 19. A knuckle (not shown) is fitted to the outer peripheral surface BB on the inner side, joined to the mounting surface 19, and the outer member 2 is fastened to the knuckle via a fixing bolt (not shown).
　また、ナックルが嵌合されるパイロット部としてのインナー側の外周面ＢＢと取付面１９との隅部には、ナックルの角部が干渉してミスアライメント（取付誤差）が生じないよう、全周に亙り連続した逃げ溝２１が形成されている。 In addition, the corners of the outer peripheral surface BB on the inner side as the pilot portion into which the knuckle is fitted and the mounting surface 19 are prevented from causing misalignment (mounting error) due to interference of corner portions of the knuckle. A continuous relief groove 21 is formed.
　ここで、取付面１９のねじ孔２０の径方向内方側の近傍に旋削加工によって凹溝２２が形成されている。本実施形態では、この環状の凹溝２２の溝底が円弧状に形成され、凹溝２２の開口縁の最小内径Ｄ１が小径部１８の外径Ｄ２よりも大径（Ｄ１≧Ｄ２）に設定されている。すなわち、凹溝２２は連続ではなく車体取付フランジ２ｃの取付面１９に不連続の状態で形成されている。ここでいう「近傍」とは、具体的には、取付面１９のねじ孔２０の径方向内方側であって、懸架装置が嵌合される外方部材２の外周面ＢＢと車体取付フランジ２ｃの取付面１９の隅部との間のことをいう。 Here, a concave groove 22 is formed by turning in the vicinity of the radially inner side of the screw hole 20 of the mounting surface 19. In the present embodiment, the groove bottom of the annular groove 22 is formed in an arc shape, and the minimum inner diameter D1 of the opening edge of the groove 22 is set larger than the outer diameter D2 of the small diameter portion 18 (D1 ≧ D2). Has been. That is, the concave groove 22 is not continuous but is formed in a discontinuous state on the mounting surface 19 of the vehicle body mounting flange 2c. Specifically, the “near” here is the radially inner side of the screw hole 20 of the mounting surface 19 and the outer peripheral surface BB of the outer member 2 to which the suspension device is fitted and the vehicle body mounting flange. It is between the corners of the mounting surface 19 of 2c.
　こうした凹溝２２を取付面１９のねじ孔２０の径方向内方の近傍に形成することにより、ボルト締結時に発生する引張応力をこの凹溝２２で吸収し、ボルト締結に伴う取付面１９の変形を抑制して取付面１９に近い外側転走面２ｂの真円度劣化を防止し、精度確保と軸受の長寿命化を図った車輪用軸受装置を提供することができる。 By forming such a concave groove 22 in the vicinity of the inside of the mounting surface 19 in the radial direction of the screw hole 20, the tensile stress generated at the time of bolt fastening is absorbed by the concave groove 22, and the mounting surface 19 is deformed due to bolt fastening. Thus, it is possible to provide a wheel bearing device that prevents the deterioration of the roundness of the outer rolling surface 2b close to the mounting surface 19 and that ensures accuracy and extends the life of the bearing.
　また、凹溝２２は、図３に拡大して示すように、径方向の溝幅Ｗ１は、ねじ孔２０の開口縁より内径側のナックル（図示せず）との最小当接幅、すなわち、ねじ孔２０の開口縁より内径側の当接幅のうち最小の当接幅Ｗ０－Ｗ１よりも小さく設定されている（Ｗ１≦Ｗ０－Ｗ１）。これにより、車体取付フランジ２ｃに負荷される軸力に対して、受圧面積が減少し、面圧上昇に伴う強度・耐久性が低下するのを防止することができる。 Further, as shown in an enlarged view of FIG. 3, the concave groove 22 has a radial groove width W1 that is a minimum contact width with a knuckle (not shown) on the inner diameter side from the opening edge of the screw hole 20, that is, It is set smaller than the minimum contact width W0-W1 among the contact widths on the inner diameter side from the opening edge of the screw hole 20 (W1 ≦ W0-W1). As a result, the pressure receiving area is reduced with respect to the axial force applied to the vehicle body mounting flange 2c, and it is possible to prevent the strength and durability associated with the increase in surface pressure from being reduced.
　また、凹溝２２の溝幅Ｗ１は溝深さＨよりも大きく設定されると共に（Ｗ１≧Ｈ）、ナックルの当接面の一部であるねじ孔２０と凹溝２２との距離、すなわち、ねじ孔２０と凹溝２２との間の最小当接幅Ｗ２が、ねじ孔２０のねじ径Ｅの１／２よりも大きく設定されている（Ｗ２≧Ｅ／２）。これにより、車体取付フランジ２ｃの剛性を確保し、取付面１９の変形を防止してミスアライメントを抑制し、外側転走面２ｂの真円度劣化を防止して精度確保を図ることができる。 Further, the groove width W1 of the concave groove 22 is set larger than the groove depth H (W1 ≧ H), and the distance between the screw hole 20 and the concave groove 22 which is a part of the contact surface of the knuckle, that is, The minimum contact width W2 between the screw hole 20 and the concave groove 22 is set to be larger than ½ of the screw diameter E of the screw hole 20 (W2 ≧ E / 2). Thereby, the rigidity of the vehicle body mounting flange 2c can be ensured, the deformation of the mounting surface 19 can be prevented, misalignment can be suppressed, and the roundness of the outer rolling surface 2b can be prevented from being deteriorated to ensure accuracy.
　図４（ａ）、（ｂ）は、前述した実施形態（図３）の変形例である。この実施形態は、前述した実施形態と基本的には凹溝２２の形状が異なるだけで、その他同一部品同一部位あるいは同様の機能を有する部品や部位には同じ符合を付して詳細な説明を省略する。 FIGS. 4A and 4B are modifications of the above-described embodiment (FIG. 3). This embodiment is basically different from the above-described embodiment only in the shape of the concave groove 22, and the same parts and parts having the same functions or parts having the same functions are denoted by the same reference numerals for detailed description. Omitted.
　図４（ａ）に示すように、車体取付フランジ２ｃの取付面１９に非貫通のねじ孔２０が形成され、このねじ孔２０の径方向内方側の近傍に環状の凹溝２３が形成されている。この凹溝２３は断面が矩形状に形成され、溝底がフラットで隅部が円弧状に形成されている。そして、凹溝２３の径方向の溝幅Ｗ１や溝深さＨ、あるいは凹溝２３とねじ孔２０との間の最小当接幅Ｗ２が前述した関係に設定されている。 As shown in FIG. 4A, a non-penetrating screw hole 20 is formed in the mounting surface 19 of the vehicle body mounting flange 2c, and an annular concave groove 23 is formed near the radially inner side of the screw hole 20. ing. The concave groove 23 has a rectangular cross section, a flat groove bottom, and a circular arc corner. The groove width W1 and groove depth H in the radial direction of the recessed groove 23, or the minimum contact width W2 between the recessed groove 23 and the screw hole 20 are set as described above.
　図４（ｂ）に示すように、車体取付フランジ２ｃの取付面１９に非貫通のねじ孔２０が形成され、このねじ孔２０の径方向内方側の近傍に環状の凹溝２４が形成されている。この凹溝２４は断面が三角形状に形成され、先端部が円弧状に形成されている。そして、凹溝２４の径方向の溝幅Ｗ１や溝深さＨ、あるいは凹溝２４とねじ孔２０との間の最小当接幅Ｗ２が前述した関係に設定されている。こうした凹溝２３、２４の形状により、設計自由度が拡大すると共に、車体取付フランジ２ｃの剛性を確保し、組み付け後の外側転走面２ｂの真円度を確保することができる。 As shown in FIG. 4B, a non-penetrating screw hole 20 is formed in the mounting surface 19 of the vehicle body mounting flange 2c, and an annular concave groove 24 is formed in the vicinity of the radially inner side of the screw hole 20. ing. The groove 24 has a triangular cross section and a circular arc tip. The groove width W1 and groove depth H in the radial direction of the recessed groove 24 or the minimum contact width W2 between the recessed groove 24 and the screw hole 20 are set as described above. Such a shape of the concave grooves 23 and 24 increases the degree of freedom in design, secures the rigidity of the vehicle body mounting flange 2c, and secures the roundness of the outer rolling surface 2b after assembly.
　図５は、前述した実施形態（図２）の変形例である。この実施形態は、前述した実施形態と基本的には車体取付フランジ２ｃと凹溝２２の構成が異なるだけで、その他同一部品同一部位あるいは同様の機能を有する部品や部位には同じ符合を付して詳細な説明を省略する。 FIG. 5 is a modification of the above-described embodiment (FIG. 2). This embodiment is basically different from the above-described embodiment only in the configuration of the vehicle body mounting flange 2c and the concave groove 22, and the same reference numerals are given to the same parts or parts having the same function. Detailed description is omitted.
　外方部材２５のインナー側の外周に径方向外方に突出して車体取付フランジ２６が形成されている。この車体取付フランジ２６は、円周方向に関して大径部２７と小径部２８とが交互に配置され、これら大径部２７と小径部２８が滑らかに繋がる矩形状に形成されている。そして、車体取付フランジ２６のインナー側にナックル（図示せず）が当接する取付面２９が形成され、この取付面２９の角部に非貫通のねじ孔２０が形成されている。 A vehicle body mounting flange 26 is formed on the outer periphery on the inner side of the outer member 25 so as to protrude radially outward. The vehicle body mounting flange 26 is formed in a rectangular shape in which the large diameter portions 27 and the small diameter portions 28 are alternately arranged in the circumferential direction, and the large diameter portions 27 and the small diameter portions 28 are smoothly connected. A mounting surface 29 with which a knuckle (not shown) abuts is formed on the inner side of the vehicle body mounting flange 26, and a non-penetrating screw hole 20 is formed at a corner of the mounting surface 29.
　ここで、ねじ孔２０の径方向内方側の近傍に旋盤等の切削加工によって凹溝３０が形成されている。本実施形態では、この凹溝３０の開口縁の最小内径Ｄ１が外周面ＢＢの外径Ｄ３よりも大径（Ｄ１≧Ｄ３）に設定され、凹溝３０は連続した環状に形成されている。これにより、凹溝３０の加工を連続切削加工により行うことができ、切削状態と非切削状態とが交互に発生する、所謂断続切削加工の場合に比べて切削工具の損傷が発生するのを抑え、加工性の向上と共に切削工具の寿命が延び、低コスト化を図ることができる。 Here, a concave groove 30 is formed in the vicinity of the radially inner side of the screw hole 20 by a cutting process such as a lathe. In the present embodiment, the minimum inner diameter D1 of the opening edge of the concave groove 30 is set larger than the outer diameter D3 of the outer peripheral surface BB (D1 ≧ D3), and the concave groove 30 is formed in a continuous annular shape. Accordingly, the concave groove 30 can be processed by continuous cutting, and the occurrence of damage to the cutting tool is suppressed as compared with the so-called intermittent cutting in which the cutting state and the non-cutting state occur alternately. As the workability is improved, the life of the cutting tool is extended and the cost can be reduced.
　図６は、前述した実施形態（図５）の変形例である。この実施形態は、前述した実施形態と基本的には車体取付フランジ２６と凹溝３０の構成が異なるだけで、その他同一部品同一部位あるいは同様の機能を有する部品や部位には同じ符合を付して詳細な説明を省略する。 FIG. 6 is a modification of the above-described embodiment (FIG. 5). This embodiment basically differs from the above-described embodiment only in the configuration of the vehicle body mounting flange 26 and the recessed groove 30, and the same reference numerals are given to the same parts or parts having the same function. Detailed description is omitted.
　外方部材３１のインナー側の外周に径方向外方に突出して車体取付フランジ３２が形成されている。この車体取付フランジ３２は、円周方向に関して大径部３３と小径部３４とが交互に配置され、これら大径部３３と小径部３４が滑らかに繋がる三角形状に形成されている。そして、車体取付フランジ３２のインナー側にナックル（図示せず）が当接する取付面３５が形成され、この取付面３５の角部に非貫通のねじ孔２０が形成されている。 A vehicle body mounting flange 32 is formed on the outer periphery on the inner side of the outer member 31 so as to protrude radially outward. The vehicle body mounting flange 32 is formed in a triangular shape in which the large diameter portions 33 and the small diameter portions 34 are alternately arranged in the circumferential direction, and the large diameter portions 33 and the small diameter portions 34 are smoothly connected. A mounting surface 35 with which a knuckle (not shown) abuts is formed on the inner side of the vehicle body mounting flange 32, and a non-penetrating screw hole 20 is formed at a corner of the mounting surface 35.
　ここで、ねじ孔２０の径方向内方側の近傍に鍛造加工によって凹溝３６が形成されている。本実施形態では、この凹溝３６が外周面ＢＢの外径Ｄ３よりも径方向外方側に形成され、凹溝３６は不連続となるまゆ型形状に形成されている。これにより、凹溝３６を機械加工で形成する必要がなく、加工工数が低減できて低コスト化を図ることができる。 Here, a concave groove 36 is formed in the vicinity of the radially inner side of the screw hole 20 by forging. In the present embodiment, the concave groove 36 is formed on the radially outer side with respect to the outer diameter D3 of the outer peripheral surface BB, and the concave groove 36 is formed in an eyebrow shape that is discontinuous. Thereby, it is not necessary to form the concave groove 36 by machining, the number of processing steps can be reduced, and the cost can be reduced.
　以上、本発明の実施の形態について説明を行ったが、本発明はこうした実施の形態に何等限定されるものではなく、あくまで例示であって、本発明の要旨を逸脱しない範囲内において、さらに種々なる形態で実施し得ることは勿論のことであり、本発明の範囲は、特許請求の範囲の記載によって示され、さらに特許請求の範囲に記載の均等の意味、および範囲内のすべての変更を含む。 The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.
　本発明に係る車輪用軸受装置は、第２または第３世代構造の車輪用軸受装置に適用することができる。 The wheel bearing device according to the present invention can be applied to a wheel bearing device having a second or third generation structure.
１　内方部材
２、２５、３１　外方部材
２ａ、２ｂ　外側転走面
２ｃ、２６、３２　車体取付フランジ
３　転動体
４　ハブ輪
４ａ、５ａ　内側転走面
４ｂ　小径段部
５　内輪
６　車輪取付フランジ
６ａ　ハブボルト
６ｂ　車輪取付フランジのインナー側の基部
７、１１、１３　段差部
７ａ　ハブ輪の肩部
８　加締部
９、１０　保持器
１２　アウター側のシール
１４　凹所
１５　大径側の肩部
１６　小径側の肩部
１７、２７、３３　外方部材の大径部
１８、２８、３４　外方部材の小径部
１９、２９、３５　車体取付フランジの取付面
２０　ねじ孔
２１　逃げ溝
２２、２３、２４、３０、３６　凹溝
５０　車輪用軸受装置
５１　内方部材
５２、７０　外方部材
５２ａ　アウター側の外側転走面
５２ｂ　インナー側の外側転走面
５２ｃ　取付面
５３　ボール
５４　ハブ輪
５４ａ、５５ａ　内側転走面
５４ｂ　小径段部
５４ｃ　加締部
５５　内輪
５６　車輪取付フランジ
５６ａ　ハブボルト
５７、５８　段差部
５７ａ、６４、６５　肩部
５９、６０　保持器
６１、６２　シール
６３　凹所
６６　取付部
６７　ねじ孔
６８　車体取付フランジ
６９　車体取付フランジのインナー側の側面
７１　大径部
７２　小径部
７３　取付孔
７４　凹溝
７５　ナックル
７５ａ　ナックルのアウター側の側面
７６　凹溝の最深部
ＡＡ　外方部材のアウター側の外周面
ＢＢ　外方部材のインナー側の外周面
ｄｉ　インナー側の転動体の外径
ｄｏ　アウター側の転動体の外径
Ｄ１　凹溝の開口縁の最小内径
Ｄ２　小径部の外径
Ｄ３　外方部材の外周面の外径
Ｅ　ねじ孔のねじ径
Ｈ　凹溝の溝深さ
ＰＣＤｉ　インナー側の転動体のピッチ円直径
ＰＣＤｏ　アウター側の転動体のピッチ円直径
Ｗ０　ねじ孔の開口縁より内径側の最小当接幅
Ｗ１　凹溝の径方向の溝幅
Ｗ２　ねじ孔と凹溝との間の最小当接幅
Ｚｉ　インナー側の転動体の個数
Ｚｏ　アウター側の転動体の個数 DESCRIPTION OF SYMBOLS 1 Inner member 2, 25, 31 Outer member 2a, 2b Outer rolling surface 2c, 26, 32 Car body mounting flange 3 Rolling element 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step part 5 Inner ring 6 Wheel mounting flange 6a Hub bolt 6b Base portion 7, 11, 13 on inner side of wheel mounting flange Stepped portion 7a Shoulder portion 8 of hub wheel Clamping portion 9, 10, Cage 12 Seal on outer side 14 Recess 15 Shoulder portion 16 on large diameter side Small diameter Side shoulder portions 17, 27, 33 Outer member large diameter portions 18, 28, 34 Outer member small diameter portions 19, 29, 35 Body mounting flange mounting surface 20 Screw hole 21 Escape grooves 22, 23, 24, 30, 36 Groove 50 Wheel bearing device 51 Inner member 52, 70 Outer member 52a Outer outer rolling surface 52b Inner outer rolling surface 52c Mounting surface 53 Ball 54 Hub wheels 54a, 55a Inner rolling 54b Small diameter step portion 54c Caulking portion 55 Inner ring 56 Wheel mounting flange 56a Hub bolt 57, 58 Step portion 57a, 64, 65 Shoulder portion 59, 60 Cage 61, 62 Seal 63 Recess 66 Mounting portion 67 Screw hole 68 Car body mounting flange 69 Inner side surface 71 of the vehicle body mounting flange Large diameter portion 72 Small diameter portion 73 Mounting hole 74 Concave groove 75 Knuckle 75a Outer side surface 76 of the knuckle Deepest portion AA of the concave groove Outer outer peripheral surface BB of the outer member Inner side outer peripheral surface di Inner side rolling element outer diameter do Outer side rolling element outer diameter D1 Groove opening edge minimum inner diameter D2 Small diameter outer diameter D3 Outer member outer diameter outer diameter E Screw diameter of screw hole H Groove depth of concave groove PCDi Pitch circle diameter of inner side rolling element PCDo Pitch circle diameter of outer side rolling element W0 From opening edge of screw hole Minimum contact width W1 on the inner diameter side Groove width W2 in the radial direction of the recessed groove Minimum contact width Zi between the screw hole and the recessed groove Zi Number of rolling elements on the inner side Zo Number of rolling elements on the outer side

Claims (7)

  1. 　内周に複列の外側転走面が一体に形成された外方部材と、
    　一端部に車輪を取り付けるための車輪取付フランジを一体に有し、外周に軸方向に延びる小径段部が形成されたハブ輪、およびこのハブ輪の小径段部に圧入され、外周に前記複列の外側転走面に対向する内側転走面が形成された少なくとも一つの内輪からなる内方部材と、
    　この内方部材と前記外方部材の両転走面間に転動自在に収容された複列の転動体と、を備えた車輪用軸受装置において、
    　前記外方部材のインナー側に、円周方向に関して大径部と小径部とが交互に配置された外周面からなる車体取付フランジを備え、この車体取付フランジのインナー側に取付面が形成され、前記大径部の取付面に軸方向に延びるねじ孔が形成されると共に、このねじ孔の径方向内方側の近傍に凹溝が形成され、前記取付面に懸架装置を構成するナックルが接合されて前記ねじ孔に螺着される固定ボルトを介して前記外方部材が締結されていることを特徴とする車輪用軸受装置。     An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
    A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end, a small diameter step portion extending in the axial direction on the outer periphery, and a small diameter step portion of the hub wheel are press-fitted, and the double row is disposed on the outer periphery. An inner member composed of at least one inner ring formed with an inner rolling surface facing the outer rolling surface of
    In the wheel bearing device comprising the inner member and the double row rolling elements accommodated so as to roll between both rolling surfaces of the outer member,
    Provided on the inner side of the outer member is a vehicle body mounting flange having an outer peripheral surface in which large diameter portions and small diameter portions are alternately arranged in the circumferential direction, and a mounting surface is formed on the inner side of the vehicle body mounting flange. A screw hole extending in the axial direction is formed on the mounting surface of the large diameter portion, and a concave groove is formed in the vicinity of the radially inner side of the screw hole, and a knuckle constituting a suspension device is joined to the mounting surface. The outer bearing member is fastened via a fixing bolt that is screwed into the screw hole.
  2. 　前記懸架装置がトーションビーム式サスペンションである請求項１に記載の車輪用軸受装置。 The wheel bearing device according to claim 1, wherein the suspension device is a torsion beam suspension.
  3. 　前記凹溝の径方向の溝幅Ｗ１が、前記ねじ孔の開口縁より内径側の最小当接幅Ｗ０－Ｗ１よりも小さく（Ｗ１≦Ｗ０－Ｗ１）設定されている請求項１に記載の車輪用軸受装置。 The wheel according to claim 1, wherein a groove width W1 in the radial direction of the concave groove is set to be smaller than a minimum contact width W0-W1 closer to an inner diameter side than an opening edge of the screw hole (W1≤W0-W1). Bearing device.
  4. 　前記凹溝の径方向の溝幅Ｗ１が溝深さＨよりも大きく設定されると共に、前記ねじ孔と凹溝との間の最小当接幅Ｗ２が、当該ねじ孔のねじ径Ｅの１／２よりも大きく（Ｗ２≧Ｅ／２）設定されている請求項１に記載の車輪用軸受装置。 The groove width W1 in the radial direction of the concave groove is set larger than the groove depth H, and the minimum contact width W2 between the screw hole and the concave groove is 1 / of the screw diameter E of the screw hole. The wheel bearing device according to claim 1, wherein the wheel bearing device is set to be larger than 2 (W2 ≧ E / 2).
  5. 　前記凹溝が鍛造加工によってまゆ型形状に形成されている請求項１、３および請求項４いずれかに記載の車輪用軸受装置。 The wheel bearing device according to any one of claims 1, 3 and 4, wherein the concave groove is formed into an eyebrow shape by forging.
  6. 　前記懸架装置が嵌合される前記外方部材の外周面と前記車体取付フランジの取付面の隅部に、全周に亙り連続した環状の逃げ溝が形成されている請求項１に記載の車輪用軸受装置。 The wheel according to claim 1, wherein an annular relief groove that is continuous over the entire circumference is formed at an outer peripheral surface of the outer member to which the suspension device is fitted and a corner of the mounting surface of the vehicle body mounting flange. Bearing device.
  7. 　前記複列の転動体のうちアウター側の転動体のピッチ円直径がインナー側の転動体のピッチ円直径よりも大径に設定され、このピッチ円直径の違いに伴い、前記外方部材が、アウター側の外周面からインナー側の外周面に向って漸次小径に形成された外周面と、前記複列の外側転走面のうちアウター側の転走面から軸方向に傾斜して延びる段差部を介してインナー側の外側転走面が一体に形成された内周面を備え、前記複列の外側転走面にそれぞれ肩部が形成されると共に、これら肩部が旋削加工によって所定の溝深さに形成され、少なくとも両肩部間の段差部が旋削加工されずに鍛造肌のままとされている請求項１に記載の車輪用軸受装置。 Among the double row rolling elements, the pitch circle diameter of the outer side rolling elements is set to be larger than the pitch circle diameter of the inner side rolling elements, and with the difference in pitch circle diameter, the outer member is An outer peripheral surface formed with a gradually decreasing diameter from the outer peripheral surface of the outer side toward the outer peripheral surface of the inner side, and a stepped portion extending in an axially inclined manner from the outer rolling surface of the double row outer rolling surfaces. The inner side outer rolling surface is formed integrally with the inner circumferential surface, and shoulders are formed on the outer rolling surfaces of the double row, respectively, and these shoulders are turned into predetermined grooves by turning. The wheel bearing device according to claim 1, wherein the wheel bearing device is formed to a depth, and at least a step portion between both shoulder portions is left as a forged surface without being turned.
PCT/JP2015/059562 2014-03-28 2015-03-27 Bearing device for wheel WO2015147245A1 (en)

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JP7098913B2 (en) * 2017-11-13 2022-07-12 日本精工株式会社 Hub unit bearing and hub unit bearing with rotating body for braking

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012219855A (en) * 2011-04-05 2012-11-12 Ntn Corp Bearing device for wheel
JP2012228909A (en) * 2011-04-25 2012-11-22 Nsk Ltd Hub unit for supporting wheel
JP2013006488A (en) * 2011-06-23 2013-01-10 Ntn Corp Bearing device for wheel

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012219855A (en) * 2011-04-05 2012-11-12 Ntn Corp Bearing device for wheel
JP2012228909A (en) * 2011-04-25 2012-11-22 Nsk Ltd Hub unit for supporting wheel
JP2013006488A (en) * 2011-06-23 2013-01-10 Ntn Corp Bearing device for wheel

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