WO2018074375A1 - Cooling structure for bearing device - Google Patents

Cooling structure for bearing device Download PDF

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Publication number
WO2018074375A1
WO2018074375A1 PCT/JP2017/037246 JP2017037246W WO2018074375A1 WO 2018074375 A1 WO2018074375 A1 WO 2018074375A1 JP 2017037246 W JP2017037246 W JP 2017037246W WO 2018074375 A1 WO2018074375 A1 WO 2018074375A1
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WO
WIPO (PCT)
Prior art keywords
ring spacer
outer ring
cooling structure
lubricating fluid
peripheral surface
Prior art date
Application number
PCT/JP2017/037246
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French (fr)
Japanese (ja)
Inventor
惠介 那須
真人 吉野
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Ntn株式会社
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Publication of WO2018074375A1 publication Critical patent/WO2018074375A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q11/00—Accessories fitted to machine tools for keeping tools or parts of the machine in good working condition or for cooling work; Safety devices specially combined with or arranged in, or specially adapted for use in connection with, machine tools
    • B23Q11/12—Arrangements for cooling or lubricating parts of the machine
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/66—Special parts or details in view of lubrication
    • 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
    • F16C37/00—Cooling of bearings

Definitions

  • the present invention relates to a cooling structure for a bearing device, for example, a main shaft of a machine tool and a cooling structure for a bearing incorporated in the main shaft.
  • an annular recess is provided on the peripheral surface of the outer ring spacer facing the inner ring spacer, an outlet is provided in the recess, an air nozzle is provided, and cooling air is directed toward the peripheral surface of the inner ring spacer.
  • a cooling structure for discharging is proposed (Patent Document 2).
  • the outer ring spacer is provided with lubricating fluid discharge means for supplying lubricating air oil to the rolling bearings on both sides. According to this configuration, the compressed air is adiabatically expanded by being discharged at a stroke from the narrow nozzle hole into the space formed by the recess. As a result, the flow rate of compressed air increases and the temperature decreases. Therefore, the rotating side spacer is efficiently cooled.
  • JP 2000-161375 A Japanese Patent Laying-Open No. 2015-183738
  • the cooling structure of the bearing device of Patent Document 2 provides an excellent cooling function.
  • the configuration is such that two rows of rolling bearings are similarly cooled, and in the arrangement of bearings arranged in three or more rows, the cooling function for each rolling bearing cannot be individually adjusted.
  • the temperature rise of the rolling bearing differs depending on the drive system and the bearing arrangement. Therefore, in order to use limited compressed air efficiently, the bearing temperature is high (the temperature of the inner ring and the outer ring). It is necessary to intensively cool the areas where the difference is large.
  • the cooling structure of the bearing device of Patent Document 2 it is possible to apply the cooling structure of the bearing device of Patent Document 2 to two adjacent rolling bearings. In that case, the temperature of each two rolling bearings Therefore, it is difficult to adjust the cooling function according to the arrangement location of the rolling bearings.
  • the object of the present invention is that it is possible to adjust the cooling function according to the arrangement location of the rolling bearings for the rolling bearings arranged in three or more rows, and the rolling bearing which is the main cooling purpose can be efficiently cooled, It is another object of the present invention to provide a cooling structure for a bearing device that can alleviate a mixed flow of a lubricating fluid and compressed air.
  • the cooling structure for a bearing device is a cooling structure for a bearing device in which an outer ring spacer and an inner ring spacer are interposed between outer rings and inner rings of adjacent rolling bearings in an arrangement of rolling bearings arranged in three or more rows in the axial direction.
  • Lubricating fluid discharge means for supplying a lubricating fluid containing air and lubricating oil to a rolling bearing on the corresponding side of the rolling bearing adjacent to the outer ring spacer is adjacent to the outer ring spacer.
  • a portion of the annular space on the supply side of the lubrication fluid (the side on which the lubrication fluid discharge means is provided) with respect to the central axis of the air nozzle is a non-supply side (the lubrication fluid discharge means is provided). It is characterized by having a larger volume than the part on the non-side.
  • the annular space between the outer ring spacer and the inner ring spacer has a larger volume on the supply side of the lubricating fluid than the non-supply side portion with respect to the central axis of the air nozzle. Since the compressed air discharged to the side tends to flow toward the space part having a large volume, the compressed air easily flows to the rolling bearing on the supply side of the lubricating fluid. Therefore, this rolling bearing can be effectively cooled. Further, since the amount of compressed air flowing into the opposite rolling bearing is reduced, the mixed flow of the lubricating fluid and the compressed air supplied from the other outer ring spacer in the opposite rolling bearing is alleviated.
  • the rolling bearing that is the main cooling purpose can be efficiently cooled.
  • the compressed air discharged from the narrow air nozzle is discharged at a stretch into a wide annular space, so that the compressed air is adiabatically expanded.
  • the flow rate of compressed air increases and the temperature decreases. Therefore, the inner ring spacer is efficiently cooled, the temperature of the compressed air flowing into the rolling bearing is low, and the rolling bearing is also efficiently cooled.
  • the lubricating fluid is, for example, air oil or oil mist.
  • the said annular space may be formed only by the said recessed part provided in the internal peripheral surface of the said outer ring
  • the annular space is formed only by the recessed portion of the outer ring spacer, the inner ring spacer has a simple shape, and the processing of the spacer is easy.
  • the said annular space may be formed by the said recessed part provided in the inner peripheral surface of the said outer ring spacer, and the said recessed part provided in the outer peripheral surface of the said inner ring spacer.
  • the recessed portion is formed in both the outer ring spacer and the inner ring spacer, a large volume of the annular space can be obtained, and the adiabatic expansion effect can be enhanced.
  • the axial length of the portion on the supply side of the lubricating fluid may be longer than the axial length of the portion on the non-supply side.
  • the annular space is difficult to vary in size in the radial direction due to limitations on the thickness of the inner ring spacer and outer ring spacer, but it is easy to change the size in the axial direction. .
  • the length of the gap between the outer ring spacer and the inner ring spacer in the axial direction is shortened on the large volume side, and the flow resistance is reduced. . Therefore, the compressed air is more likely to flow to the rolling bearing on the supply side of the lubricating fluid.
  • the lubricating fluid discharge means continues to the outer ring spacer provided for only one of the rolling bearings adjacent to the outer ring spacer on the side where the lubricating fluid discharge means is not provided.
  • An air nozzle that discharges compressed air to an annular space between the outer ring spacer and the corresponding inner ring spacer is provided in an outer ring spacer between two rolling bearings arranged in parallel, and the lubricating fluid discharge means is disposed between the outer rings. It may be provided for both rolling bearings adjacent to the seat.
  • one outer ring spacer has two fluid discharge means for lubrication to be supplied to the rolling bearings on both sides and to supply compressed air to the rolling bearings on both sides,
  • the number of outer ring spacers having the lubricating fluid discharge means and the air nozzle can be reduced. Cooling adjustment is performed in the same manner for both rolling bearings. However, only one of the rolling bearings described above has lubricating fluid discharge means, and compressed air is concentrated on one of the rolling bearings. Since it is combined with the outer ring spacer to be fed, the cooling function can be adjusted according to the arrangement location of the rolling bearings.
  • the annular space between the outer ring spacer and the inner ring spacer in which the lubricating fluid discharge means is provided for both rolling bearings adjacent to the outer ring spacer is the outer ring. It is good also as a structure formed by the cyclic
  • the outer ring spacer provided with the two fluid discharge means for lubrication also provides an increase in the flow rate of compressed air and a decrease in temperature due to the adiabatic expansion by providing the recess and expanding the annular space.
  • the lubricating fluid discharge means has a flange protruding so as to cover the outer peripheral surface of the inner ring in the rolling bearing on the side corresponding to the lubricating fluid discharge means, and an opening in the inner peripheral surface of the flange And a lubricating nozzle for discharging the lubricating fluid.
  • a cooling structure for a bearing device according to a first embodiment of the present invention will be described with reference to FIGS.
  • the cooling structure of the bearing device of this example is applied to a front-side bearing device in a spindle device of a machine tool. However, it is not limited only to the spindle device of the machine tool.
  • the bearing device J includes three or more rolling bearings 1 arranged in the axial direction, in the illustrated example, four rolling bearings 1, and between the outer rings 2 and 2 of the adjacent rolling bearings 1, 1 and the inner rings 3, 3.
  • An outer ring spacer 4 and an inner ring spacer 5 are interposed therebetween.
  • the subscript “I” is attached to the rolling bearings 1 in the center two rows
  • the subscript “O” is attached to the rolling bearings 1 at the end. ".
  • the outer ring 2 and the outer ring spacer 4 are installed in the housing 6, and the inner ring 3 and the inner ring spacer 5 are fitted to the main shaft 7.
  • the rolling bearing 1 is an angular ball bearing, and a plurality of rolling elements 8 are interposed between the raceways of the inner ring 3 and the outer ring 2. Each rolling element 8 is held at equal intervals in the circumferential direction by a cage 9.
  • the two center rolling bearings 1 I and 1 I are arranged in a rear combination, and each of the two rolling bearings 1 O and 1 O at both ends is arranged in the same direction as the adjacent rolling bearing 1 I.
  • the outer ring spacer 4 and the inner ring spacer 5 are provided with a difference in width, whereby the initial preload of each rolling bearing 1 is set and used.
  • the outer ring 2 and the outer ring spacer 4 are, for example, a clearance fit with respect to the housing 6, and are positioned in the axial direction by the step portion 6 a of the housing 6 and the end surface cover 40.
  • the inner ring 3 and the inner ring spacer 5 of the rolling bearing 1 are, for example, an interference fit with respect to the main shaft 7 and are positioned in the axial direction by the positioning spacers 41 and 42 on both sides. Note that the positioning spacer 42 on the left side of the figure is fixed by a nut 43 screwed onto the main shaft 7.
  • Each rolling bearing 1 is an inner ring rotation.
  • FIG. 2 shows a partially enlarged view between the rolling bearings 1 I and 1 I in the center two rows of FIG.
  • the outer ring spacer 4 includes an outer ring spacer main body 11 and ring-shaped flanges 12 and 12 made of different members from the outer ring spacer main body 11.
  • the flange 12 constitutes a lubricating fluid discharge means 30 described later.
  • the outer ring spacer main body 11 has a substantially T-shaped cross section, and the flanges 12 and 12 are fixed symmetrically on both sides of the outer ring spacer main body 11 in the axial direction.
  • the inner diameter dimension of the outer ring spacer main body 11 is larger than the inner diameter dimension of the flange portions 12 and 12.
  • the recessed part 13 comprised by the inner peripheral surface of the outer ring spacer main body 11 and the side surface of the collar parts 12 and 12 following this inner peripheral surface is formed in the inner peripheral surface of the outer ring spacer 4.
  • the recess 13 is an annular groove having a rectangular cross section.
  • An annular space 14 is formed between the outer ring 2 and the inner ring 3 by the recess 13.
  • the inner peripheral surface of the outer ring spacer 4 other than the recessed portion 13, that is, the inner peripheral surfaces of the flange portions 12 and 12, and the outer peripheral surface of the inner ring spacer 5 are opposed to each other via a minute radial clearance ⁇ a.
  • annular space 14 whose radial direction width is wider than others is formed.
  • the annular space 14 and the radial clearance ⁇ a on both sides thereof constitute a both-side exhaust path 58.
  • the outer ring spacer main body 11 is provided with an air nozzle 15 for discharging compressed air A for cooling toward the outer peripheral surface of the inner ring spacer 5.
  • the outlet 15 a of the air nozzle 15 opens in the recess 13 on the inner peripheral surface of the outer ring spacer 4.
  • a plurality of (for example, three) air nozzles 15 are arranged at equal intervals in the circumferential direction (see FIG. 3).
  • each air nozzle 15 is inclined forward in the rotational direction of the inner ring spacer 5. That is, the position is offset from an arbitrary radial straight line L in a cross section perpendicular to the axis of the outer ring spacer 4 in a direction orthogonal to the straight line L.
  • the reason for offsetting the air nozzle 15 is to improve the cooling effect by causing the compressed air A to act as a swirling flow in the rotation direction of the inner ring spacer 5.
  • the outer ring spacer 4 is indicated by a cross section passing through the center line of the air nozzle 15.
  • an introduction groove 16 for introducing the compressed air A into each air nozzle 15 from the outside of the bearing is formed in the outer peripheral surface of the outer ring spacer main body 11.
  • the introduction groove 16 is provided in an intermediate portion in the axial direction on the outer peripheral surface of the outer ring spacer 4 and is formed in an arc shape communicating with each air nozzle 15.
  • the introduction groove 16 is provided on the outer peripheral surface of the outer ring spacer main body 11 over an angular range ⁇ indicating most of the circumferential direction except a circumferential position where an air oil supply path (not shown) described later is provided. .
  • a compressed air introduction path 45 is provided in the housing 6, and the introduction groove 16 communicates with the compressed air introduction path 45.
  • An air supply device (not shown) for supplying the compressed air A to the compressed air introduction hole 45 is provided outside the housing 6.
  • FIG. 4 shows an enlarged view of the rolling bearing 1 O at the right end of FIG. 1 and the adjacent spacer.
  • the rolling bearing 1 O at the left end of FIG. 1 and the adjacent spacer are the same as those in FIG.
  • the rolling bearings 1 O at the end and the spacers adjacent thereto are the same as the rolling bearings 1 I and 1 I in the middle two rows and the spacers therebetween except for matters to be specifically described.
  • the outer ring spacer 4 of the end rolling bearing 1 O is provided only on one side where the flange portion 12 of the lubricating fluid supply means 30 is provided with the end rolling bearing 1 O serving as a main cooling purpose. Is provided.
  • the portion of the inner peripheral surface of the outer ring spacer 4 opposite to the flange portion 12 is a small diameter portion 2 a that is close to the outer peripheral surface of the inner ring spacer 5, similar to the flange portion 12.
  • An annular recess 13A is formed by the side surface of the small-diameter portion 2a, the side surface of the flange portion 12, and the inner peripheral surface of the central portion in the width direction of the outer ring spacer 4, and the recess 13A forms the annular ring recess 4A.
  • An annular space 14 ⁇ / b> A is formed between the inner peripheral surface and the outer peripheral surface of the inner ring spacer 5.
  • the side surface of the small diameter portion 2a on the annular space 14A side is an inclined surface in which the inner diameter side approaches the end portion in the spacer width direction.
  • the annular space 14A and the radial clearance ⁇ a on one side thereof constitute a one-side exhaust path 59.
  • Said annular space 14A is relative to the center axis O 15 of the air nozzle 15, the rolling bearing 1 O-side portion 14A1 of the end portion as a main purpose of the cooling, with larger volume than the portion 14A2 of the center of the rolling bearing 1 I side Thus, it is formed in an asymmetric shape in the axial direction. Specifically, the axial length of the portion 14A1 of the annular space 14A is longer than the axial length of the portion 14A2.
  • the ratio of the volume of both portions 14A1,14A2 of the annular space 14A for example 6: 4, 7: 3 and the like, are designed appropriately, the portion 14A2 of the smaller, distance from the center axis O 15 from the opening edge of the air nozzle 15
  • a range from the center axis O 15 to the rolling bearing 1 I in the direction to 1/5 of the outer ring spacer width is preferable, and more preferably the center axis O 15 to the rolling bearing 1 between the outer rings in the I side direction.
  • the range is up to 1/10 of the seat width.
  • each outer ring spacer 4 includes the flange portion 12 (FIGS. 2 and 4) as a means constituting a lubricating fluid discharge means 30.
  • Each flange 12 protrudes into the bearing and faces the outer peripheral surface of the inner ring 3 via an air oil passage annular clearance ⁇ b.
  • the flange portion 12 is disposed so as to enter the bearing so as to cover the outer peripheral surface of the inner ring 3. Further, the distal end portion of the flange portion 12 is disposed radially inward from the inner peripheral surface of the cage 9.
  • a lubrication nozzle 31 is provided for supplying, for example, air oil, which is opened to the annular clearance ⁇ b and serves as a lubrication fluid.
  • the lubricating nozzle 31 is inclined so as to reach the inner diameter side toward the bearing side, and an outlet is opened at an inner peripheral surface portion of the flange portion 12 facing the inner ring 3. Air oil is supplied to the lubricating nozzle 31 through a lubricating fluid supply path (not shown) provided in the housing 6 and the outer ring spacer body 11.
  • An annular recess 3 a is provided at a location on the extended line of the lubricating nozzle 31 on the outer peripheral surface of the inner ring 3.
  • the oil of the air oil discharged from the lubricating nozzle 31 of the collar portion 12 is accumulated in the annular recess 3a, and this oil is along the outer peripheral surface of the inner ring 3 which is an inclined surface by the centrifugal force accompanying the rotation of the inner ring 3. Guided to the bearing center side.
  • the bearing device J is provided with an exhaust path 46 for exhausting compressed air for cooling and air oil that is a lubricating fluid for lubrication.
  • the exhaust passage 46 includes an exhaust groove 47 provided in a part of the outer ring spacer body 11 in the circumferential direction, a radial exhaust hole 48 provided in the housing 6 and communicating with the exhaust groove 47, and an axial exhaust hole 49.
  • the exhaust groove 47 of the outer ring spacer body 11 is formed over a circumferential position diagonal to the position where the lubricating fluid supply path is provided.
  • the cooling structure of the bearing apparatus which consists of the said structure.
  • the cooling structure of this bearing device includes four rows of rolling bearings 2, and compressed air is branched and discharged from one air nozzle 15 for the two central rolling bearings 1 I and 1 I.
  • compressed air is individually discharged from the air nozzles 15 and 15. Therefore, the cooling function of each rolling bearing 1 can be adjusted according to the arrangement location of these rolling bearings 1. Moreover, about the cooling of each rolling bearing 1, it can cool efficiently as follows.
  • Compressed air A for cooling is blown toward the outer peripheral surface of the inner ring spacer 5 from the air nozzle 15 of each outer ring spacer 4 shown in FIGS.
  • the compressed air A is adiabatically expanded by being discharged from the narrow air nozzle 15 into the wide annular spaces 14 and 14A.
  • the volume of the compressed air in the air nozzle 15 is V1
  • the temperature is T1
  • the volume of the compressed air in the annular spaces 14, 14A is V2
  • the temperature is T2
  • the flow rate of the compressed air A increases.
  • the inner ring spacer 5 is efficiently cooled by blowing the compressed air A at a low temperature and high speed onto the inner ring spacer 5.
  • the compressed air A discharged from the air nozzle 15 flows in the axial direction while turning along the outer peripheral surface of the inner ring spacer 5. , And is discharged to the outside of the bearing through the exhaust passage 46. Since the compressed air A turns, the time during which the compressed air A is in contact with the outer peripheral surface of the inner ring spacer 5 is longer than when the straight air flows in the axial direction, and the inner ring spacer 5 can be cooled more efficiently. it can.
  • the inner ring spacer 5 is efficiently cooled, so that the inner ring 3 and the main shaft 7 of the rolling bearing 1 can be effectively cooled via the inner ring spacer 5. Since this cooling structure can improve cooling efficiency only by providing an annular recess 13, 13A on the inner peripheral surface of the outer ring spacer 4 and inclining the air nozzle 15, the cooling efficiency can be improved. It is not necessary to increase the output of the air supply device that supplies air A, and power consumption can be suppressed.
  • the compressed air A discharged into the annular spaces 14 and 14A between the recesses 13 and 13A and the inner ring spacer 5 passes through the radial clearance ⁇ a between the outer ring spacer 4 and the inner ring spacer 5 to the outside of the bearing. Is discharged. At that time, at least a part of the compressed air A flows into the bearing.
  • the flow velocity of each portion of the compressed air A flowing in the radial clearance ⁇ a in the circumferential direction is made uniform, and the flow velocity of the compressed air A flowing into the bearing is reduced. It becomes uniform. Thereby, the collision sound between the compressed air A and the rotating rolling element 9 can be reduced.
  • FIG. 5 the flow of compressed air is indicated by the outline line thickness arrow, and the flow of the lubricating fluid is indicated by the bold line arrow, and is discharged from the air nozzle 15 of the outer ring spacer 4 adjacent to the rolling bearing 1 O at the end.
  • compressed air passes through the gap between the outer ring spacer 4 and the inner ring spacer 5, enters the inner rolling bearing 1 I on the center side of the adjacent, to mixed flow to the flow of lubricating fluid.
  • the annular space 14A of the outer ring spacer 4 adjacent to the end rolling bearing 1 O is a portion of the end portion of the air nozzle 15 on the side of the rolling bearing 1 O with respect to the central axis O 15 .
  • 14A1 is, so that it has a greater volume than the portion 14A2 of the center of the rolling bearing 1 I side, are formed axially asymmetrical. That is, the annular space 14A is the center axis O 15 of the air nozzle 15, the portion 14A1 is non-supply side of the supply side of the lubricating fluid (lubricating side fluid discharge means is provided) (lubricating fluid delivery means It has a larger volume than the portion 14A2 on the side not provided.
  • the annular space 14B defined between the outer ring spacer 4 and the inner ring spacer 5 adjacent to the rolling bearing 1 O end is formed on the inner peripheral surface of the outer ring spacer 4 It is formed by a recess 13 a and the recess 13 b formed on the outer peripheral surface of the inner ring spacer 5.
  • the shape of the inner ring spacer 5 is a simple shape without unevenness. And it is easy to manufacture.
  • the annular space 14 ⁇ / b> B is formed by a recess 13 a formed in the outer ring spacer 4 and a recess 13 b formed in the inner ring spacer 5. If so, the volume of the annular space 14B can be increased, and the compressed air discharged from the air nozzle 15 can be sufficiently adiabatically expanded to enhance the cooling effect.
  • FIG. 8 is a cross-sectional view showing an outline of the entire spindle device of the machine tool to which each of the embodiments is applied.
  • the main shaft 7 has a front portion supported by the bearing device J according to any one of the above embodiments, and a rear portion supported by another rolling bearing 61.
  • An outer tube cooling type liquid cooling device 62 is provided on the outer periphery of the housing 6.
  • the rear end of the main shaft 7 is connected to an electric motor 63 outside the housing 6.
  • FIG. 9 shows another example of a spindle device of a machine tool to which the bearing device is applied, and is a built-in motor type.
  • An electric motor 63 ⁇ / b> A is provided between the front bearing device J and the rear bearing 61 in the housing 6.
  • the electric motor 63 ⁇ / b> A is a built-in motor including a stator 64 provided on the inner periphery of the housing 6 and a rotor 65 provided on the outer periphery of the main shaft 7.
  • the cooling structure of the bearing device of the present invention can be effectively applied to both the external motor type and the built-in motor type main shaft devices.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rolling Contact Bearings (AREA)
  • Auxiliary Devices For Machine Tools (AREA)
  • Turning (AREA)
  • Mounting Of Bearings Or Others (AREA)

Abstract

In this cooling structure for a bearing device, an annular space (14A) is provided between an outer ring spacer (4) and an inner ring spacer (5), and an air nozzle (15) which is open to the annular space (14A) and discharges compressed air is provided to the outer ring spacer (4). The outer ring spacer (4) has, provided therein for only one side of a plurality of roller bearings (1) adjacent to the outer ring spacer (4), a lubricating fluid discharge means (12) for supplying a lubricating fluid such as air oil to the roller bearing (1) at the corresponding side among the roller bearings (1) adjacent to the outer ring spacer (4). The annular space (14A) has a greater volume in a section (14A1) on the side where the lubricating fluid is supplied, than in a section (14A2) at the side where the lubricating fluid is not supplied, with respect to the central axis (O15) of the air nozzle (15).

Description

軸受装置の冷却構造Cooling structure of bearing device 関連出願Related applications
　本出願は、２０１６年１０月１７日出願の特願２０１６－２０３３３６の優先権を主張するものであり、それらの全体を参照により本願の一部をなすものとして引用する。 This application claims the priority of Japanese Patent Application No. 2016-203336 filed on Oct. 17, 2016, which is incorporated herein by reference in its entirety.
　この発明は、軸受装置の冷却構造に関し、例えば、工作機械の主軸および主軸に組み込まれる軸受の冷却構造に関する。 The present invention relates to a cooling structure for a bearing device, for example, a main shaft of a machine tool and a cooling structure for a bearing incorporated in the main shaft.
　工作機械の主軸装置では、加工精度を確保するために、装置の温度上昇は小さく抑える必要がある。しかしながら最近の工作機械では、加工能率を向上させるため高速化の傾向にあり、主軸を支持する軸受からの発熱も高速化と共に大きくなってきている。また、装置内部に駆動用のモータを組込んだいわゆるモータビルトインタイプが多くなってきており、装置の発熱要因ともなってきている。 In the spindle device of a machine tool, it is necessary to keep the temperature rise of the device small to ensure machining accuracy. However, recent machine tools have a tendency to increase the speed in order to improve the processing efficiency, and the heat generated from the bearing supporting the main shaft is also increasing as the speed increases. In addition, so-called motor built-in types in which a driving motor is incorporated in the apparatus are becoming more and more a cause of heat generation of the apparatus.
　発熱による軸受の温度上昇は、予圧の増加をもたらす結果となり、主軸の高速化、高精度化を考えると極力抑えたい。主軸装置の温度上昇を抑える方法として、冷却用の圧縮エアを軸受に送り、軸と軸受の冷却を行う方法がある（例えば、特許文献１）。なお、特許文献１では、２つの軸受間の空間に冷風を、回転方向に角度を付けて噴射して旋回流とすることで、軸と軸受の冷却を行っている。 ¡The temperature rise of the bearing due to heat generation results in an increase in the preload, and we want to suppress it as much as possible considering the speed and accuracy of the spindle. As a method of suppressing the temperature rise of the main shaft device, there is a method of cooling the shaft and the bearing by sending compressed air for cooling to the bearing (for example, Patent Document 1). In Patent Document 1, the shaft and the bearing are cooled by injecting cold air into the space between the two bearings at an angle in the rotational direction to form a swirling flow.
　また、外輪間座の内輪間座と対向する周面に環状の凹み部を設け、この凹み部に出口を開口させてエアノズルを設け、冷却用の圧縮エアを内輪間座の周面に向けて吐出する冷却構造が提案されている（特許文献２）。前記外輪間座には、潤滑用のエアオイルを供給する潤滑用流体吐出手段が、両側の転がり軸受に対して設けられている。
　この構成によると、狭いノズル孔から前記凹み部で形成される空間へ圧縮エアが一気に吐出されることにより、圧縮エアが断熱膨張する。そのため、圧縮エアの流速が増し、また温度が下がる。そのため、回転側間座が効率良く冷却される。 In addition, an annular recess is provided on the peripheral surface of the outer ring spacer facing the inner ring spacer, an outlet is provided in the recess, an air nozzle is provided, and cooling air is directed toward the peripheral surface of the inner ring spacer. A cooling structure for discharging is proposed (Patent Document 2). The outer ring spacer is provided with lubricating fluid discharge means for supplying lubricating air oil to the rolling bearings on both sides.
According to this configuration, the compressed air is adiabatically expanded by being discharged at a stroke from the narrow nozzle hole into the space formed by the recess. As a result, the flow rate of compressed air increases and the temperature decreases. Therefore, the rotating side spacer is efficiently cooled.
特開２０００－１６１３７５号公報JP 2000-161375 A 特開２０１５－１８３７３８号公報Japanese Patent Laying-Open No. 2015-183738
　特許文献２の軸受装置の冷却構造は、優れた冷却機能が得られる。しかし、２列の転がり軸受を同様に冷却する構成であり、３列以上並ぶ軸受の配列において、各転がり軸受に対する冷却機能を個別に調整することができない。 The cooling structure of the bearing device of Patent Document 2 provides an excellent cooling function. However, the configuration is such that two rows of rolling bearings are similarly cooled, and in the arrangement of bearings arranged in three or more rows, the cooling function for each rolling bearing cannot be individually adjusted.
　３列以上並ぶ軸受の配列では、駆動方式、軸受配列により、転がり軸受の温度上昇が相違するため、限られた圧縮エアを効率良く使用するためには、軸受温度が高い（内輪と外輪の温度差が大きい）箇所を重点的に冷却する必要がある。
　例えば、４列の転がり軸受の配列において、特許文献２の軸受装置の冷却構造を隣合う２つずつの転がり軸受に適用することは可能であるが、その場合、２つずつの転がり軸受の温度をまとめて調整せざるを得ず、転がり軸受の配列場所に応じた冷却機能の調整を行うことが難しい。 In the arrangement of bearings arranged in three or more rows, the temperature rise of the rolling bearing differs depending on the drive system and the bearing arrangement. Therefore, in order to use limited compressed air efficiently, the bearing temperature is high (the temperature of the inner ring and the outer ring). It is necessary to intensively cool the areas where the difference is large.
For example, in the arrangement of four rows of rolling bearings, it is possible to apply the cooling structure of the bearing device of Patent Document 2 to two adjacent rolling bearings. In that case, the temperature of each two rolling bearings Therefore, it is difficult to adjust the cooling function according to the arrangement location of the rolling bearings.
　そこで、特許文献２の軸受装置の冷却構造を適用した２列の転がり軸受の隣に、特許文献２の冷却構造と同様の凹み部およびエアノズルを有するが、一つの転がり軸受のみに対してエアオイル等の潤滑用流体を供給する外輪間座を設け、その潤滑用流体供給側の転がり軸受の冷却および潤滑を行わせることを試みた。
　この構成の場合、エアノズルから吐出された圧縮エアは、外輪間座と内輪間座の間の隙間から両側へ分岐して流れ、内輪間座を冷却すると共に、前記潤滑用流体を供給する側の転がり軸受内に流入してその転がり軸受の冷却を行う。 Therefore, next to the two rows of rolling bearings to which the cooling structure of the bearing device of Patent Document 2 is applied, there are recesses and air nozzles similar to those of the cooling structure of Patent Document 2, but air oil or the like for only one rolling bearing. An outer ring spacer for supplying the lubricating fluid was provided, and an attempt was made to cool and lubricate the rolling bearing on the lubricating fluid supply side.
In this configuration, the compressed air discharged from the air nozzle branches and flows to both sides from the gap between the outer ring spacer and the inner ring spacer, cools the inner ring spacer, and supplies the lubricating fluid. It flows into the rolling bearing and cools the rolling bearing.
　しかし、圧縮エアが両側へ分岐して流れるため、主な冷却目的とする潤滑用流体供給側の転がり軸受への圧縮エアの流入量が十分でなく、目的とする転がり軸受を効率良く冷却することができない。そのため、転がり軸受の配列場所に応じた冷却機能を調整することが難しい。
　また、反対側の転がり軸受に流入した圧縮エアは、その転がり軸受内に他方の外輪間座から供給されて転がり軸受内を流れる潤滑用流体と混流し、潤滑用流体の転がり軸受内での適正な流れを阻害する。 However, because compressed air branches and flows to both sides, the amount of compressed air flowing into the rolling bearing on the lubrication fluid supply side, which is the main cooling purpose, is not sufficient, and the intended rolling bearing can be efficiently cooled. I can't. For this reason, it is difficult to adjust the cooling function according to the arrangement location of the rolling bearings.
The compressed air that has flowed into the opposite rolling bearing is mixed with the lubricating fluid that is supplied from the other outer ring spacer into the rolling bearing and flows through the rolling bearing. Obstruct the flow.
　この発明の目的は、３列以上並ぶ転がり軸受に対して、転がり軸受の配列場所に応じた冷却機能の調整が可能であり、主な冷却目的となる転がり軸受を効率良く冷却することができ、また潤滑用流体と圧縮エアとの混流を緩和することができる軸受装置の冷却構造を提供することである。 The object of the present invention is that it is possible to adjust the cooling function according to the arrangement location of the rolling bearings for the rolling bearings arranged in three or more rows, and the rolling bearing which is the main cooling purpose can be efficiently cooled, It is another object of the present invention to provide a cooling structure for a bearing device that can alleviate a mixed flow of a lubricating fluid and compressed air.
　この発明の軸受装置の冷却構造は、軸方向に３列以上に並ぶ転がり軸受の配列における隣合う転がり軸受の外輪間および内輪間に外輪間座および内輪間座がそれぞれ介在する軸受装置の冷却構造において、
　前記外輪間座および内輪間座のいずれかの組における前記外輪間座と前記内輪間座との間に、前記外輪間座の内周面と前記内輪間座の外周面とのいずれか一方または両方に設けられた環状の凹み部により形成される環状空間があり、この環状空間に開口して圧縮エアを吐出するエアノズルが前記外輪間座に設けられ、
　前記外輪間座に、当該外輪間座に隣合う転がり軸受のうち対応する側の転がり軸受へエアおよび潤滑油を含む潤滑用流体を供給する潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の一方のみに対して設けられ、
　前記環状空間における、前記エアノズルの中心軸に対して前記潤滑用流体の供給側（前記潤滑用流体吐出手段が設けられた側）の部分が、非供給側（前記潤滑用流体吐出手段が設けられていない側）の部分よりも大きな容積を持つことを特徴とする。 The cooling structure for a bearing device according to the present invention is a cooling structure for a bearing device in which an outer ring spacer and an inner ring spacer are interposed between outer rings and inner rings of adjacent rolling bearings in an arrangement of rolling bearings arranged in three or more rows in the axial direction. In
Between the outer ring spacer and the inner ring spacer in any set of the outer ring spacer and the inner ring spacer, either the inner peripheral surface of the outer ring spacer or the outer peripheral surface of the inner ring spacer, or There is an annular space formed by annular recesses provided on both, and an air nozzle that opens into this annular space and discharges compressed air is provided in the outer ring spacer,
Lubricating fluid discharge means for supplying a lubricating fluid containing air and lubricating oil to a rolling bearing on the corresponding side of the rolling bearing adjacent to the outer ring spacer is adjacent to the outer ring spacer. Provided for only one of the bearings,
A portion of the annular space on the supply side of the lubrication fluid (the side on which the lubrication fluid discharge means is provided) with respect to the central axis of the air nozzle is a non-supply side (the lubrication fluid discharge means is provided). It is characterized by having a larger volume than the part on the non-side.
　この構成によると、外輪間座と内輪間座間の環状空間は、エアノズルの中心軸に対し、潤滑用流体の供給側の部分が非供給側の部分よりも大きな容積を持つが、前記環状空間内に吐出された圧縮エアは、容積の大きい空間部分側へ流れやすいため、前記潤滑用流体の供給側の転がり軸受へ流れやすい。そのため、この転がり軸受を効果的に冷却することができる。また反対側の転がり軸受への圧縮エアの流入量が減るため、反対側の転がり軸受内での、他の外輪間座から供給された潤滑用流体と圧縮エアとの混流が緩和される。
　また、上記のように潤滑用流体の供給側となる片方の転がり軸受を重点的に冷却するこができるため、主な冷却目的となる転がり軸受を効率良く冷却することができる。
　さらに、狭いエアノズルから吐出された圧縮エアが、広い環状空間に一気に吐出されることにより、圧縮エアが断熱膨張する。そのため、圧縮エアの流速が増し、また温度が下がる。そのため、内輪間座が効率良く冷却され、転がり軸受内に流入する圧縮エアの温度も低く、転がり軸受も効率的に冷却される。
　なお、前記潤滑用流体は、例えばエアオイルまたはオイルミストである。 According to this configuration, the annular space between the outer ring spacer and the inner ring spacer has a larger volume on the supply side of the lubricating fluid than the non-supply side portion with respect to the central axis of the air nozzle. Since the compressed air discharged to the side tends to flow toward the space part having a large volume, the compressed air easily flows to the rolling bearing on the supply side of the lubricating fluid. Therefore, this rolling bearing can be effectively cooled. Further, since the amount of compressed air flowing into the opposite rolling bearing is reduced, the mixed flow of the lubricating fluid and the compressed air supplied from the other outer ring spacer in the opposite rolling bearing is alleviated.
In addition, since one of the rolling bearings on the supply side of the lubricating fluid can be intensively cooled as described above, the rolling bearing that is the main cooling purpose can be efficiently cooled.
Furthermore, the compressed air discharged from the narrow air nozzle is discharged at a stretch into a wide annular space, so that the compressed air is adiabatically expanded. As a result, the flow rate of compressed air increases and the temperature decreases. Therefore, the inner ring spacer is efficiently cooled, the temperature of the compressed air flowing into the rolling bearing is low, and the rolling bearing is also efficiently cooled.
The lubricating fluid is, for example, air oil or oil mist.
　この発明において、前記環状空間が、前記外輪間座の内周面に設けられた前記凹み部のみで形成されても良い。
　前記環状空間を外輪間座の凹み部のみで形成する場合は、内輪間座が単純な形状で済み、間座の加工が簡単である。 In this invention, the said annular space may be formed only by the said recessed part provided in the internal peripheral surface of the said outer ring | wheel spacer.
When the annular space is formed only by the recessed portion of the outer ring spacer, the inner ring spacer has a simple shape, and the processing of the spacer is easy.
　この発明において、前記環状空間が、前記外輪間座の内周面に設けられた前記凹み部と、前記内輪間座の外周面に設けられた前記凹み部とで形成されても良い。
　外輪間座と内輪間座との両方に前記凹み部が形成されていると、前記環状空間の容積が大きく得られ、前記断熱膨張の効果を高めることができる。 In this invention, the said annular space may be formed by the said recessed part provided in the inner peripheral surface of the said outer ring spacer, and the said recessed part provided in the outer peripheral surface of the said inner ring spacer.
When the recessed portion is formed in both the outer ring spacer and the inner ring spacer, a large volume of the annular space can be obtained, and the adiabatic expansion effect can be enhanced.
　この発明において、前記環状空間は、前記潤滑用流体の供給側の部分の軸方向長さが、非供給側の部分の軸方向長さよりも長くても良い。
　前記環状空間は、径方向には、内輪間座および外輪間座の厚さ上の制限から、大きさに差を持たせることが難しいが、軸方向には大きさを変えることは容易である。また、軸方向に大きさを変える場合、結果的に外輪間座と内輪間座との間の隙間の軸方向長さにつき、容積の大きな部分側の長さが短くなり、流路抵抗が減る。そのため、潤滑用流体の供給側の転がり軸受へ、圧縮エアがより流れやすくなる。 In the present invention, in the annular space, the axial length of the portion on the supply side of the lubricating fluid may be longer than the axial length of the portion on the non-supply side.
The annular space is difficult to vary in size in the radial direction due to limitations on the thickness of the inner ring spacer and outer ring spacer, but it is easy to change the size in the axial direction. . Further, when the size is changed in the axial direction, as a result, the length of the gap between the outer ring spacer and the inner ring spacer in the axial direction is shortened on the large volume side, and the flow resistance is reduced. . Therefore, the compressed air is more likely to flow to the rolling bearing on the supply side of the lubricating fluid.
　この発明において、前記潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の一方のみに対して設けられた前記外輪間座に対して前記潤滑用流体吐出手段が設けられていない側に続いて並ぶ２つの転がり軸受間の外輪間座に、この外輪間座と対応する内輪間座との間の環状空間へ圧縮エアを吐出するエアノズルが設けられ、前記潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の両方に対して設けられても良い。
　１つの外輪間座が、両側の転がり軸受へ供給する２つの潤滑用流体吐出手段を持つようにし、また両側の転がり軸受へ圧縮エアを供給するようにした場合、多数配列される転がり軸受に対して、潤滑用流体吐出手段およびエアノズルを有する外輪間座の個数が少なくて済む。冷却の調整は、両側の転がり軸受を同様に行うことになるが、前述した、一方の転がり軸受のみに対して潤滑用流体吐出手段を有し、また一方の転がり軸受に重点的に圧縮エアを送る外輪間座と組み合わせられるため、転がり軸受の配列場所に応じた冷却機能の調整が可能である。 In this invention, the lubricating fluid discharge means continues to the outer ring spacer provided for only one of the rolling bearings adjacent to the outer ring spacer on the side where the lubricating fluid discharge means is not provided. An air nozzle that discharges compressed air to an annular space between the outer ring spacer and the corresponding inner ring spacer is provided in an outer ring spacer between two rolling bearings arranged in parallel, and the lubricating fluid discharge means is disposed between the outer rings. It may be provided for both rolling bearings adjacent to the seat.
When one outer ring spacer has two fluid discharge means for lubrication to be supplied to the rolling bearings on both sides and to supply compressed air to the rolling bearings on both sides, Thus, the number of outer ring spacers having the lubricating fluid discharge means and the air nozzle can be reduced. Cooling adjustment is performed in the same manner for both rolling bearings. However, only one of the rolling bearings described above has lubricating fluid discharge means, and compressed air is concentrated on one of the rolling bearings. Since it is combined with the outer ring spacer to be fed, the cooling function can be adjusted according to the arrangement location of the rolling bearings.
　この構成の場合に、前記潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の両方に対して設けられた前記外輪間座と前記内輪間座との間の前記環状空間が、前記外輪間座の内周面と前記内輪間座の外周面とのいずれか一方または両方に設けられた環状の凹み部により形成される構成としても良い。
　前述したように２つの潤滑用流体吐出手段が設けられた外輪間座についても、前記凹み部を設けて環状空間を広げることで、前記断熱膨張による圧縮エアの流速増、温度低下が得られる。 In this configuration, the annular space between the outer ring spacer and the inner ring spacer in which the lubricating fluid discharge means is provided for both rolling bearings adjacent to the outer ring spacer is the outer ring. It is good also as a structure formed by the cyclic | annular recessed part provided in any one or both of the inner peripheral surface of a spacer and the outer peripheral surface of the said inner ring | wheel spacer.
As described above, the outer ring spacer provided with the two fluid discharge means for lubrication also provides an increase in the flow rate of compressed air and a decrease in temperature due to the adiabatic expansion by providing the recess and expanding the annular space.
　この発明において、前記潤滑用流体吐出手段が、当該潤滑用流体吐出手段が対応する側の転がり軸受における前記内輪の外周面に被さるように突出する鍔部と、この鍔部の内周面に開口して前記潤滑用流体を吐出する潤滑用ノズルとを有するようにしても良い。
　このように内輪の外周面に被さる鍔部に潤滑用ノズルを設けた場合、潤滑用流体の転がり軸受内への供給が効果的に行われる。 In this invention, the lubricating fluid discharge means has a flange protruding so as to cover the outer peripheral surface of the inner ring in the rolling bearing on the side corresponding to the lubricating fluid discharge means, and an opening in the inner peripheral surface of the flange And a lubricating nozzle for discharging the lubricating fluid.
In this way, when the lubricating nozzle is provided on the flange portion covering the outer peripheral surface of the inner ring, the lubricating fluid is effectively supplied into the rolling bearing.
　請求の範囲および／または明細書および／または図面に開示された少なくとも２つの構成のどのような組合せも、本発明に含まれる。特に、請求の範囲の各請求項の２つ以上のどのような組合せも、本発明に含まれる。 Any combination of at least two configurations disclosed in the claims and / or the specification and / or drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the present invention.
　この発明は、添付の図面を参考にした以下の好適な実施形態の説明からより明瞭に理解されるであろう。しかしながら、実施形態および図面は単なる図示および説明のためのものであり、この発明の範囲を定めるために利用されるべきでない。この発明の範囲は添付の請求の範囲によって定まる。添付図面において、複数の図面における同一の部品番号は、同一部分を示す。
この発明の第１の実施形態に係る軸受装置の冷却構造を適用した工作機械の主軸装置における軸受装置部分の断面図である。 同軸受装置の中央２列の転がり軸受における冷却構造の部分拡大断面図である。 同軸受装置の間座部分の横断面図である。 同軸受装置の端部の転がり軸受における冷却構造の部分拡大断面図である。 同軸受装置の冷却構造における各部の潤滑用流体と圧縮エアの流れを示すイメージ図である。 この発明の第２の実施形態に係る軸受装置の冷却構造の部分断面図である。 同軸受装置の冷却構造の部分拡大断面図である。 前記各実施形態に係る軸受装置の冷却構造を適用する工作機械の主軸装置の一例を示す概略断面図である。 前記各実施形態に係る軸受装置の冷却構造を適用する工作機械の主軸装置の他の例を示す概略断面図である。 The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and description and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same part number in a plurality of drawings indicates the same part.
It is sectional drawing of the bearing apparatus part in the main axis | shaft apparatus of the machine tool to which the cooling structure of the bearing apparatus which concerns on 1st Embodiment of this invention is applied. It is a partial expanded sectional view of the cooling structure in the rolling bearing of the center two rows of the same bearing device. It is a cross-sectional view of the spacer part of the bearing device. It is a partial expanded sectional view of the cooling structure in the rolling bearing of the edge part of the same bearing device. It is an image figure which shows the fluid for lubrication of each part in the cooling structure of the said bearing apparatus, and the flow of compressed air. It is a fragmentary sectional view of the cooling structure of the bearing device concerning a 2nd embodiment of this invention. It is a partial expanded sectional view of the cooling structure of the bearing device. It is a schematic sectional drawing which shows an example of the main axis | shaft apparatus of the machine tool to which the cooling structure of the bearing apparatus which concerns on each said embodiment is applied. It is a schematic sectional drawing which shows the other example of the main axis | shaft apparatus of the machine tool to which the cooling structure of the bearing apparatus which concerns on each said embodiment is applied.
　この発明の第１の実施形態に係る軸受装置の冷却構造を図１ないし図５と共に説明する。この例の軸受装置の冷却構造は、工作機械の主軸装置におけるフロント側の軸受装置に適用されている。ただし、工作機械の主軸装置だけに限定されるものではない。 A cooling structure for a bearing device according to a first embodiment of the present invention will be described with reference to FIGS. The cooling structure of the bearing device of this example is applied to a front-side bearing device in a spindle device of a machine tool. However, it is not limited only to the spindle device of the machine tool.
　図１は、図の左側が主軸のフロント側、右側がリア側である。同図に示すように、軸受装置Ｊは、軸方向に並ぶ３つ以上、図示の例では４つの転がり軸受１を備え、隣合う転がり軸受１，１の外輪２，２間および内輪３，３間に、外輪間座４および内輪間座５がそれぞれ介在している。なお、中央２列の転がり軸受１については、添字「Ｉ」を、端部の転がり軸受１については添字「Ｏ」を付しているが、特に区別を要しない場合は、単に「転がり軸受１」と称す。外輪２および外輪間座４がハウジング６に設置され、内輪３および内輪間座５が主軸７に嵌合している。転がり軸受１はアンギュラ玉軸受であり、内輪３と外輪２の軌道面間に複数の転動体８が介在している。各転動体８は、保持器９により円周方向に等間隔で保持される。中央２つの転がり軸受１Ｉ，１Ｉは背面組合せで配置されており、両端の二つの転がり軸受１Ｏ，１Ｏのそれぞれは、その隣の転がり軸受１Ｉと同じ向きに配置されている。外輪間座４と内輪間座５とは幅寸法に差が設けられ、これにより各転がり軸受１の初期予圧が設定されて使用される。 In FIG. 1, the left side of the figure is the front side of the main shaft, and the right side is the rear side. As shown in the figure, the bearing device J includes three or more rolling bearings 1 arranged in the axial direction, in the illustrated example, four rolling bearings 1, and between the outer rings 2 and 2 of the adjacent rolling bearings 1, 1 and the inner rings 3, 3. An outer ring spacer 4 and an inner ring spacer 5 are interposed therebetween. In addition, the subscript “I” is attached to the rolling bearings 1 in the center two rows, and the subscript “O” is attached to the rolling bearings 1 at the end. ". The outer ring 2 and the outer ring spacer 4 are installed in the housing 6, and the inner ring 3 and the inner ring spacer 5 are fitted to the main shaft 7. The rolling bearing 1 is an angular ball bearing, and a plurality of rolling elements 8 are interposed between the raceways of the inner ring 3 and the outer ring 2. Each rolling element 8 is held at equal intervals in the circumferential direction by a cage 9. The two center rolling bearings 1 I and 1 I are arranged in a rear combination, and each of the two rolling bearings 1 O and 1 O at both ends is arranged in the same direction as the adjacent rolling bearing 1 I. The outer ring spacer 4 and the inner ring spacer 5 are provided with a difference in width, whereby the initial preload of each rolling bearing 1 is set and used.
　外輪２および外輪間座４は、例えばハウジング６に対してすきま嵌めとされ、ハウジング６の段部６ａと端面蓋４０とにより軸方向の位置決めがされる。また、転がり軸受１の内輪３および内輪間座５は、例えば主軸７に対して締まり嵌めとされ、両側の位置決め間座４１，４２により軸方向の位置決めがされる。なお、図の左側の位置決め間座４２は、主軸７に螺着されたナット４３により固定される。各転がり軸受１は内輪回転となる。 The outer ring 2 and the outer ring spacer 4 are, for example, a clearance fit with respect to the housing 6, and are positioned in the axial direction by the step portion 6 a of the housing 6 and the end surface cover 40. The inner ring 3 and the inner ring spacer 5 of the rolling bearing 1 are, for example, an interference fit with respect to the main shaft 7 and are positioned in the axial direction by the positioning spacers 41 and 42 on both sides. Note that the positioning spacer 42 on the left side of the figure is fixed by a nut 43 screwed onto the main shaft 7. Each rolling bearing 1 is an inner ring rotation.
　冷却構造について説明する。
　図１の中央２列の転がり軸受１Ｉ，１Ｉ間の部分拡大図を図２に示す。外輪間座４は、外輪間座本体１１と、この外輪間座本体１１とは別部材からなるリング状の鍔部１２，１２とを有する。鍔部１２は、後述の潤滑用流体吐出手段３０を構成する。外輪間座本体１１は断面略Ｔ字形状に形成され、この外輪間座本体１１の軸方向両側に鍔部１２，１２が対称配置で固定されている。外輪間座本体１１の内径寸法は、鍔部１２，１２の内径寸法よりも大きい。これにより、外輪間座４の内周面に、外輪間座本体１１の内周面と、この内周面に続く鍔部１２，１２の側面とで構成される凹み部１３が形成されている。この凹み部１３は、断面長方形の環状溝である。前記凹み部１３によって、外輪２と内輪３との間に環状空間１４が構成されている。外輪間座４の凹み部１３以外の内周面、すなわち鍔部１２，１２の内周面と、内輪間座５の外周面とは、微小な径方向すきまδａを介して対向している。これにより、前記凹み部１３と内輪間座５の外周面との間に、他よりも径方向幅の広い環状空間１４が形成されている。前記環状空間１４とその両側の前記径方向すきまδａとで、両側排気経路５８が構成される。 The cooling structure will be described.
FIG. 2 shows a partially enlarged view between the rolling bearings 1 I and 1 I in the center two rows of FIG. The outer ring spacer 4 includes an outer ring spacer main body 11 and ring-shaped flanges 12 and 12 made of different members from the outer ring spacer main body 11. The flange 12 constitutes a lubricating fluid discharge means 30 described later. The outer ring spacer main body 11 has a substantially T-shaped cross section, and the flanges 12 and 12 are fixed symmetrically on both sides of the outer ring spacer main body 11 in the axial direction. The inner diameter dimension of the outer ring spacer main body 11 is larger than the inner diameter dimension of the flange portions 12 and 12. Thereby, the recessed part 13 comprised by the inner peripheral surface of the outer ring spacer main body 11 and the side surface of the collar parts 12 and 12 following this inner peripheral surface is formed in the inner peripheral surface of the outer ring spacer 4. . The recess 13 is an annular groove having a rectangular cross section. An annular space 14 is formed between the outer ring 2 and the inner ring 3 by the recess 13. The inner peripheral surface of the outer ring spacer 4 other than the recessed portion 13, that is, the inner peripheral surfaces of the flange portions 12 and 12, and the outer peripheral surface of the inner ring spacer 5 are opposed to each other via a minute radial clearance δa. Thereby, between the said recessed part 13 and the outer peripheral surface of the inner ring | wheel spacer 5, the annular space 14 whose radial direction width is wider than others is formed. The annular space 14 and the radial clearance δa on both sides thereof constitute a both-side exhaust path 58.
　前記外輪間座本体１１には、内輪間座５の外周面に向けて冷却用の圧縮エアＡを吐出するエアノズル１５が設けられている。エアノズル１５の出口１５ａは、外輪間座４の内周面の前記凹み部１３に開口している。この例では、複数個（例えば３個）のエアノズル１５が、円周方向に等間隔で配置されている（図３参照）。 The outer ring spacer main body 11 is provided with an air nozzle 15 for discharging compressed air A for cooling toward the outer peripheral surface of the inner ring spacer 5. The outlet 15 a of the air nozzle 15 opens in the recess 13 on the inner peripheral surface of the outer ring spacer 4. In this example, a plurality of (for example, three) air nozzles 15 are arranged at equal intervals in the circumferential direction (see FIG. 3).
　図３に示すように、各エアノズル１５は、内輪間座５の回転方向の前方へ傾斜させてある。つまり、外輪間座４の軸心に垂直な断面における任意の半径方向の直線Ｌから、この直線Ｌと直交する方向にオフセットした位置にある。エアノズル１５をオフセットさせる理由は、圧縮エアＡを内輪間座５の回転方向に旋回流として作用させて、冷却効果を向上させるためである。なお、図１、図２では、外輪間座４を、エアノズル１５の中心線を通る断面で表示している。 As shown in FIG. 3, each air nozzle 15 is inclined forward in the rotational direction of the inner ring spacer 5. That is, the position is offset from an arbitrary radial straight line L in a cross section perpendicular to the axis of the outer ring spacer 4 in a direction orthogonal to the straight line L. The reason for offsetting the air nozzle 15 is to improve the cooling effect by causing the compressed air A to act as a swirling flow in the rotation direction of the inner ring spacer 5. In FIGS. 1 and 2, the outer ring spacer 4 is indicated by a cross section passing through the center line of the air nozzle 15.
　外輪間座本体１１の外周面には、軸受外部から各エアノズル１５に圧縮エアＡを導入するための導入溝１６が形成されている。この導入溝１６は、外輪間座４の外周面における軸方向中間部に設けられ、各エアノズル１５に連通する円弧状に形成されている。導入溝１６は、外輪間座本体１１の外周面において、後述のエアオイル供給経路（図示せず）が設けられる円周方向位置を除く円周方向の大部分を示す角度範囲αにわたって設けられている。図１のように、ハウジング６に圧縮エア導入経路４５が設けられ、この圧縮エア導入経路４５に導入溝１６が連通するように構成されている。ハウジング６の外部には、圧縮エア導入孔４５に圧縮エアＡを供給するエア供給装置（図示せず）が設けられている。 In the outer peripheral surface of the outer ring spacer main body 11, an introduction groove 16 for introducing the compressed air A into each air nozzle 15 from the outside of the bearing is formed. The introduction groove 16 is provided in an intermediate portion in the axial direction on the outer peripheral surface of the outer ring spacer 4 and is formed in an arc shape communicating with each air nozzle 15. The introduction groove 16 is provided on the outer peripheral surface of the outer ring spacer main body 11 over an angular range α indicating most of the circumferential direction except a circumferential position where an air oil supply path (not shown) described later is provided. . As shown in FIG. 1, a compressed air introduction path 45 is provided in the housing 6, and the introduction groove 16 communicates with the compressed air introduction path 45. An air supply device (not shown) for supplying the compressed air A to the compressed air introduction hole 45 is provided outside the housing 6.
　図１の右側の端部の転がり軸受１Ｏおよびその隣の間座の拡大図を図４に示す。図１の左側の端部の転がり軸受１Ｏおよびその隣の間座については、左右対称である点を除いて図４と同様であるため、説明を省略する。また、端部の転がり軸受１Ｏおよびその隣の間座は、特に説明する事項を除き、中央２列の転がり軸受１Ｉ，１Ｉおよびその間の間座と同じである。 FIG. 4 shows an enlarged view of the rolling bearing 1 O at the right end of FIG. 1 and the adjacent spacer. The rolling bearing 1 O at the left end of FIG. 1 and the adjacent spacer are the same as those in FIG. Further, the rolling bearings 1 O at the end and the spacers adjacent thereto are the same as the rolling bearings 1 I and 1 I in the middle two rows and the spacers therebetween except for matters to be specifically described.
　図４において、端部の転がり軸受１Ｏの外輪間座４は、前記潤滑用流体供給手段３０の鍔部１２が、主な冷却目的となる端部の転がり軸受１Ｏの存在する一方だけに設けられている。外輪間座４の内周面における前記鍔部１２と反対側の部分は、鍔部１２と同様に内輪間座５の外周面に近接する小径部２ａとなる。この小径部２ａの側面と、鍔部１２の側面と、外輪間座４の幅方向中央部分の内周面とで、環状の凹み部１３Ａが形成され、この凹み部１３Ａにより外輪間座４の内周面と内輪間座５の外周面との間の環状空間１４Ａが構成される。前記小径部２ａの環状空間１４Ａ側の側面は、内径側が間座幅方向の端部に近づく傾斜面となっている。前記環状空間１４Ａとその片側の径方向すきまδａとで、片側排気経路５９が構成される。 In FIG. 4, the outer ring spacer 4 of the end rolling bearing 1 O is provided only on one side where the flange portion 12 of the lubricating fluid supply means 30 is provided with the end rolling bearing 1 O serving as a main cooling purpose. Is provided. The portion of the inner peripheral surface of the outer ring spacer 4 opposite to the flange portion 12 is a small diameter portion 2 a that is close to the outer peripheral surface of the inner ring spacer 5, similar to the flange portion 12. An annular recess 13A is formed by the side surface of the small-diameter portion 2a, the side surface of the flange portion 12, and the inner peripheral surface of the central portion in the width direction of the outer ring spacer 4, and the recess 13A forms the annular ring recess 4A. An annular space 14 </ b> A is formed between the inner peripheral surface and the outer peripheral surface of the inner ring spacer 5. The side surface of the small diameter portion 2a on the annular space 14A side is an inclined surface in which the inner diameter side approaches the end portion in the spacer width direction. The annular space 14A and the radial clearance δa on one side thereof constitute a one-side exhaust path 59.
　前記環状空間１４Ａは、エアノズル１５の中心軸Ｏ１５に対する、冷却の主目的となる端部の転がり軸受１Ｏ側の部分１４Ａ１が、中央の転がり軸受１Ｉ側の部分１４Ａ２よりも大きな容積を持つように、軸方向に非対称形状に形成されている。具体的には、前記環状空間１４Ａの前記部分１４Ａ１の軸方向長さが、前記部分１４Ａ２の軸方向長さよりも長くなっている。前記環状空間１４Ａの前記両部分１４Ａ１，１４Ａ２の容積の割合は、例えば６：４、７：３等、適宜に設計され、小さい方の部分１４Ａ２は、エアノズル１５の開口縁から中心軸Ｏ１５までの範囲としても良いが、中心軸Ｏ１５～ 転がり軸受１Ｉ側方向に外輪間座幅の1/5までの範囲が好ましく、より好ましくは中心軸Ｏ１５　～　転がり軸受１Ｉ側方向に外輪間座幅の1/10までの範囲である。 Said annular space 14A is relative to the center axis O 15 of the air nozzle 15, the rolling bearing 1 O-side portion 14A1 of the end portion as a main purpose of the cooling, with larger volume than the portion 14A2 of the center of the rolling bearing 1 I side Thus, it is formed in an asymmetric shape in the axial direction. Specifically, the axial length of the portion 14A1 of the annular space 14A is longer than the axial length of the portion 14A2. Wherein the ratio of the volume of both portions 14A1,14A2 of the annular space 14A, for example 6: 4, 7: 3 and the like, are designed appropriately, the portion 14A2 of the smaller, distance from the center axis O 15 from the opening edge of the air nozzle 15 However, a range from the center axis O 15 to the rolling bearing 1 I in the direction to 1/5 of the outer ring spacer width is preferable, and more preferably the center axis O 15 to the rolling bearing 1 between the outer rings in the I side direction. The range is up to 1/10 of the seat width.
　潤滑構造について説明する。
　図１に示すように、各外輪間座４は、潤滑用流体吐出手段３０を構成する手段として、前記鍔部１２（図２、図４）を有する。各鍔部１２は、軸受内に突出して内輪３の外周面との間でエアオイル通過用の環状すきまδｂを介して対向する。鍔部１２は、内輪３の外周面に被さるように軸受内に進入して配置される。また、鍔部１２の先端部は、保持器９の内周面よりも半径方向の内方に配置されている。 The lubrication structure will be described.
As shown in FIG. 1, each outer ring spacer 4 includes the flange portion 12 (FIGS. 2 and 4) as a means constituting a lubricating fluid discharge means 30. Each flange 12 protrudes into the bearing and faces the outer peripheral surface of the inner ring 3 via an air oil passage annular clearance δb. The flange portion 12 is disposed so as to enter the bearing so as to cover the outer peripheral surface of the inner ring 3. Further, the distal end portion of the flange portion 12 is disposed radially inward from the inner peripheral surface of the cage 9.
　図２に示す外輪間座４に２つ設けられる鍔部１２、および図４に示す外輪間座４に１つ設けられる鍔部１２のいずれも、この鍔部１２と内輪３の外周面間の前記環状すきまδｂに開口して潤滑用流体となる例えばエアオイルを供給する潤滑用ノズル３１が設けられている。この潤滑用ノズル３１は、軸受側に向かうに従い内径側に至るように傾斜し、鍔部１２における内輪３と対向する内周面部分に出口が開口している。潤滑用ノズル３１には、ハウジング６および外輪間座本体１１に設けられた潤滑用流体供給経路（図示せず）を通ってエアオイルが供給される。内輪３の外周面における潤滑用ノズル３１の延長線上の箇所には、環状凹み部３ａが設けられている。
　鍔部１２の潤滑用ノズル３１から吐出されたエアオイルの油が前記環状凹み部３ａに溜り、この油が、内輪３の回転に伴う遠心力により、傾斜面である内輪３の外周面に沿って軸受中心側へと導かれる。 Each of the two flanges 12 provided on the outer ring spacer 4 shown in FIG. 2 and the one flange 12 provided on the outer ring spacer 4 shown in FIG. 4 is between the flange 12 and the outer peripheral surface of the inner ring 3. A lubrication nozzle 31 is provided for supplying, for example, air oil, which is opened to the annular clearance δb and serves as a lubrication fluid. The lubricating nozzle 31 is inclined so as to reach the inner diameter side toward the bearing side, and an outlet is opened at an inner peripheral surface portion of the flange portion 12 facing the inner ring 3. Air oil is supplied to the lubricating nozzle 31 through a lubricating fluid supply path (not shown) provided in the housing 6 and the outer ring spacer body 11. An annular recess 3 a is provided at a location on the extended line of the lubricating nozzle 31 on the outer peripheral surface of the inner ring 3.
The oil of the air oil discharged from the lubricating nozzle 31 of the collar portion 12 is accumulated in the annular recess 3a, and this oil is along the outer peripheral surface of the inner ring 3 which is an inclined surface by the centrifugal force accompanying the rotation of the inner ring 3. Guided to the bearing center side.
　排気構造について説明する。
　図１に示すように、この軸受装置Ｊには、冷却用の圧縮エアおよび潤滑用の潤滑用流体であるエアオイルを排気する排気経路４６が設けられている。排気経路４６は、外輪間座本体１１における円周方向の一部に設けられた排気溝４７と、ハウジング６に設けられ前記排気溝４７に連通する径方向排気孔４８および軸方向排気孔４９とを有する。前記外輪間座本体１１の排気溝４７は、潤滑用流体供給経路が設けられる位置とは対角の円周方向位置にわたって形成されている。 The exhaust structure will be described.
As shown in FIG. 1, the bearing device J is provided with an exhaust path 46 for exhausting compressed air for cooling and air oil that is a lubricating fluid for lubrication. The exhaust passage 46 includes an exhaust groove 47 provided in a part of the outer ring spacer body 11 in the circumferential direction, a radial exhaust hole 48 provided in the housing 6 and communicating with the exhaust groove 47, and an axial exhaust hole 49. Have The exhaust groove 47 of the outer ring spacer body 11 is formed over a circumferential position diagonal to the position where the lubricating fluid supply path is provided.
　上記構成からなる軸受装置の冷却構造の作用について説明する。
　この軸受装置の冷却構造は、図１に示すように、４列の転がり軸受２からなり、中央２つの転がり軸受１Ｉ，１Ｉについては、１つのエアノズル１５から圧縮エアが分岐して吐出されるが、両端の転がり軸受１Ｏ，１Ｏについては、個別にエアノズル１５，１５から圧縮エアが吐出される。そのため、各転がり軸受１の冷却機能を、これら転がり軸受１の配置場所に応じて調整することができる。また、個々の転がり軸受１の冷却について、次のように効率良く冷却することができる。 The effect | action of the cooling structure of the bearing apparatus which consists of the said structure is demonstrated.
As shown in FIG. 1, the cooling structure of this bearing device includes four rows of rolling bearings 2, and compressed air is branched and discharged from one air nozzle 15 for the two central rolling bearings 1 I and 1 I. However, with respect to the rolling bearings 1 O and 1 O at both ends, compressed air is individually discharged from the air nozzles 15 and 15. Therefore, the cooling function of each rolling bearing 1 can be adjusted according to the arrangement location of these rolling bearings 1. Moreover, about the cooling of each rolling bearing 1, it can cool efficiently as follows.
　図２および図４に示す各外輪間座４のエアノズル１５より、冷却用の圧縮エアＡが内輪間座５の外周面に向けて吹き付けられる。このとき、圧縮エアＡが狭いエアノズル１５内から広い環状空間１４，１４Ａに吐出されることで、圧縮エアＡが断熱膨張する。エアノズル１５内における圧縮エアの体積をＶ１、温度をＴ１とし、環状空間１４，１４Ａでの圧縮エアの体積をＶ２、温度をＴ２とした場合、気体の状態方程式、熱力学の第１法則より、Ｖ１＜Ｖ２、Ｔ１＞Ｔ２となる。すなわち、環状空間１４，１４Ａでは、圧縮エアＡの温度が下がると共に、体積が増加する。体積が増加することで、圧縮エアＡの流速が増大する。このように、低温で高速の圧縮エアＡを内輪間座５に吹き付けることで、内輪間座５を効率良く冷却する。 Compressed air A for cooling is blown toward the outer peripheral surface of the inner ring spacer 5 from the air nozzle 15 of each outer ring spacer 4 shown in FIGS. At this time, the compressed air A is adiabatically expanded by being discharged from the narrow air nozzle 15 into the wide annular spaces 14 and 14A. When the volume of the compressed air in the air nozzle 15 is V1, the temperature is T1, the volume of the compressed air in the annular spaces 14, 14A is V2, and the temperature is T2, the gas equation of state, the first law of thermodynamics, V1 <V2 and T1> T2. That is, in the annular spaces 14, 14A, the temperature of the compressed air A decreases and the volume increases. As the volume increases, the flow rate of the compressed air A increases. Thus, the inner ring spacer 5 is efficiently cooled by blowing the compressed air A at a low temperature and high speed onto the inner ring spacer 5.
　また、エアノズル１５が内輪間座５の回転方向の前方へ傾斜しているため、エアノズル１５から吐出された圧縮エアＡは、内輪間座５の外周面に沿って旋回しながら軸方向に流れて、前記排気経路４６を通って軸受外部へ排出される。圧縮エアＡが旋回するため、軸方向にまっすぐ流れる場合と比べて、圧縮エアＡが内輪間座５の外周面と接している時間が長く、内輪間座５をより一層効率良く冷却することができる。 In addition, since the air nozzle 15 is inclined forward in the rotational direction of the inner ring spacer 5, the compressed air A discharged from the air nozzle 15 flows in the axial direction while turning along the outer peripheral surface of the inner ring spacer 5. , And is discharged to the outside of the bearing through the exhaust passage 46. Since the compressed air A turns, the time during which the compressed air A is in contact with the outer peripheral surface of the inner ring spacer 5 is longer than when the straight air flows in the axial direction, and the inner ring spacer 5 can be cooled more efficiently. it can.
　このように、内輪間座５が効率良く冷却されることで、この内輪間座５を介して転がり軸受１の内輪３および主軸７を効果的に冷却することができる。この冷却構造は、外輪間座４の内周面に環状の凹み部１３，１３Ａを設け、かつエアノズル１５を傾斜させるという構造的な工夫を施すだけで冷却効率を向上させることができるため、圧縮エアＡを供給するエア供給装置の出力を大きくしなくてもよく、消費電力を抑えることができる。 As described above, the inner ring spacer 5 is efficiently cooled, so that the inner ring 3 and the main shaft 7 of the rolling bearing 1 can be effectively cooled via the inner ring spacer 5. Since this cooling structure can improve cooling efficiency only by providing an annular recess 13, 13A on the inner peripheral surface of the outer ring spacer 4 and inclining the air nozzle 15, the cooling efficiency can be improved. It is not necessary to increase the output of the air supply device that supplies air A, and power consumption can be suppressed.
　加えて、外輪間座４の内周面に凹み部１３，１３Ａが設けられていると、次のような効果もある。すなわち、凹み部１３，１３Ａと内輪間座５の間の環状空間１４，１４Ａに吐出された圧縮エアＡは、外輪間座４と内輪間座５の間の径方向すきまδａを通って軸受外部へ排出される。その際、少なくとも一部の圧縮エアＡは軸受内へ流入する。環状空間１４，１４Ａよりも径方向すきまδａが狭まっているため、径方向すきまδａを流れる圧縮エアＡの周方向の各部での流速が均一化され、軸受内に流入する圧縮エアＡの流速が均一になる。それにより、圧縮エアＡと回転中の転動体９との衝突音を小さくすることができる。 In addition, if the recessed portions 13 and 13A are provided on the inner peripheral surface of the outer ring spacer 4, the following effects are also obtained. In other words, the compressed air A discharged into the annular spaces 14 and 14A between the recesses 13 and 13A and the inner ring spacer 5 passes through the radial clearance δa between the outer ring spacer 4 and the inner ring spacer 5 to the outside of the bearing. Is discharged. At that time, at least a part of the compressed air A flows into the bearing. Since the radial clearance δa is narrower than the annular spaces 14 and 14A, the flow velocity of each portion of the compressed air A flowing in the radial clearance δa in the circumferential direction is made uniform, and the flow velocity of the compressed air A flowing into the bearing is reduced. It becomes uniform. Thereby, the collision sound between the compressed air A and the rotating rolling element 9 can be reduced.
　次に、一方の転がり軸受１への重点的な圧縮エアの供給およびその反対側の転がり軸受１における潤滑用流体と圧縮エアとの混流の防止につき説明する。図５に、圧縮エアの流れを外形線太さの矢印で、潤滑用流体の流れを太線の矢印で示すように、端部の転がり軸受１Ｏに隣接する外輪間座４のエアノズル１５から吐出された圧縮エアは、外輪間座４と内輪間座５との間の隙間を通って、その隣の中央側の転がり軸受１Ｉに内に進入し、潤滑用流体の流れに混流する。 Next, a description will be given of the supply of compressed air to one of the rolling bearings 1 and prevention of mixed flow of the lubricating fluid and the compressed air in the rolling bearing 1 on the opposite side. In FIG. 5, the flow of compressed air is indicated by the outline line thickness arrow, and the flow of the lubricating fluid is indicated by the bold line arrow, and is discharged from the air nozzle 15 of the outer ring spacer 4 adjacent to the rolling bearing 1 O at the end. compressed air passes through the gap between the outer ring spacer 4 and the inner ring spacer 5, enters the inner rolling bearing 1 I on the center side of the adjacent, to mixed flow to the flow of lubricating fluid.
　しかし、この実施形態では、前述のように、端部の転がり軸受１Ｏに隣接する外輪間座４の環状空間１４Ａは、エアノズル１５の中心軸Ｏ１５に対する端部の転がり軸受１Ｏ側の部分１４Ａ１が、中央の転がり軸受１Ｉ側の部分１４Ａ２よりも大きな容積を持つように、軸方向に非対称形状に形成されている。
　すなわち、前記環状空間１４Ａは、エアノズル１５の中心軸Ｏ１５に対し、潤滑用流体の供給側（潤滑用流体吐出手段が設けられた側）の部分１４Ａ１が非供給側（潤滑用流体吐出手段が設けられていない側）の部分１４Ａ２よりも大きな容積を持つ。前記環状空間１４Ａ内に吐出された圧縮エアは、容積の大きい空間部分１４Ａ１側へ流れやすいため、前記潤滑用流体の供給側となる端部の転がり軸受１Ｏへ流れやすい。そのため、反対側の転がり軸受１Ｉへの圧縮エアの流入量が減るため、反対側の転がり軸受１Ｉ内での、他の外輪間座４から供給された潤滑用流体と圧縮エアとの混流が緩和される。 However, in this embodiment, as described above, the annular space 14A of the outer ring spacer 4 adjacent to the end rolling bearing 1 O is a portion of the end portion of the air nozzle 15 on the side of the rolling bearing 1 O with respect to the central axis O 15 . 14A1 is, so that it has a greater volume than the portion 14A2 of the center of the rolling bearing 1 I side, are formed axially asymmetrical.
That is, the annular space 14A is the center axis O 15 of the air nozzle 15, the portion 14A1 is non-supply side of the supply side of the lubricating fluid (lubricating side fluid discharge means is provided) (lubricating fluid delivery means It has a larger volume than the portion 14A2 on the side not provided. Compressed air discharged into the annular space 14A, in order easily flows into the large space portion 14A1 side of the volume, easily flows into the rolling bearing 1 O end the supply side of the lubricating fluid. Therefore, since the flow rate of compressed air into the rolling bearing 1 I on the opposite side is reduced, at the opposite side of the rolling bearing in 1 I, mixed flow of the lubricating fluid supplied from between the other of the outer ring seat 4 and the compressed air Is alleviated.
　図６，７は、この発明の第２の実施形態を示す。この実施形態において、特に説明する事項の他は、図１～図５と共に説明した第１の実施形態と同様である。この実施形態では、端部の転がり軸受１Ｏに隣接する外輪間座４と内輪間座５との間に形成される環状空間１４Ｂが、前記外輪間座４の内周面に形成された前記凹み部１３ａと、前記内輪間座５の外周面に形成された前記凹み部１３ｂとで形成されている。
　図４の例のように、前記環状空間１４Ａが、外輪間座４の内周面に形成された凹み部１３Ａのみで構成される場合は、内輪間座５の形状が単純な凹凸のない形状で良く、製造が簡単である。しかし、外輪間座４の径方向寸法の制限から、環状空間１４Ａの容積を十分に得ることが難しい場合がある。しかし、図６，７に示す第２の実施形態のように、環状空間１４Ｂが、外輪間座４に形成された凹み部１３ａと内輪間座５に形成された凹み部１３ｂとで形成されている場合は、環状空間１４Ｂの容積を大きく得て、エアノズル１５から吐出される圧縮エアの断熱膨張を十分に行わせ、冷却効果を高めることができる。 6 and 7 show a second embodiment of the present invention. This embodiment is the same as the first embodiment described with reference to FIGS. 1 to 5 except for matters to be specifically described. In this embodiment, the annular space 14B defined between the outer ring spacer 4 and the inner ring spacer 5 adjacent to the rolling bearing 1 O end is formed on the inner peripheral surface of the outer ring spacer 4 It is formed by a recess 13 a and the recess 13 b formed on the outer peripheral surface of the inner ring spacer 5.
When the annular space 14A is configured by only the recessed portion 13A formed on the inner peripheral surface of the outer ring spacer 4 as in the example of FIG. 4, the shape of the inner ring spacer 5 is a simple shape without unevenness. And it is easy to manufacture. However, it may be difficult to obtain a sufficient volume of the annular space 14A due to the limitation of the radial dimension of the outer ring spacer 4. However, as in the second embodiment shown in FIGS. 6 and 7, the annular space 14 </ b> B is formed by a recess 13 a formed in the outer ring spacer 4 and a recess 13 b formed in the inner ring spacer 5. If so, the volume of the annular space 14B can be increased, and the compressed air discharged from the air nozzle 15 can be sufficiently adiabatically expanded to enhance the cooling effect.
　図８は、前記各実施形態が適用される工作機械の主軸装置の全体の概略を示す断面図である。主軸７は、前記いずれかの実施形態の軸受装置Ｊでフロント部が支持され、リア部が他の転がり軸受６１で支持されている。ハウジング６の外周には、外筒冷却型の液冷装置６２が設けられている。主軸７の後端は、ハウジング６の外部の電動モータ６３に連結されている。 FIG. 8 is a cross-sectional view showing an outline of the entire spindle device of the machine tool to which each of the embodiments is applied. The main shaft 7 has a front portion supported by the bearing device J according to any one of the above embodiments, and a rear portion supported by another rolling bearing 61. An outer tube cooling type liquid cooling device 62 is provided on the outer periphery of the housing 6. The rear end of the main shaft 7 is connected to an electric motor 63 outside the housing 6.
　図９は、前記軸受装置が適用される工作機械の主軸装置の他の例を示し、ビルトインモータ型とされている。ハウジング６内におけるフロント側の軸受装置Ｊとリア側の軸受６１と間に、電動モータ６３Ａが設けられている。この電動モータ６３Ａは、ハウジング６の内周に設けられたステータ６４と、主軸７の外周に設けられたロータ６５とでなるビルトインモータである。
　これら図８、図９の各例に示すように、外部モータ型およびビルトインモータ型のいずれの主軸装置においても、この発明の軸受装置の冷却構造を効果的に適用することができる。 FIG. 9 shows another example of a spindle device of a machine tool to which the bearing device is applied, and is a built-in motor type. An electric motor 63 </ b> A is provided between the front bearing device J and the rear bearing 61 in the housing 6. The electric motor 63 </ b> A is a built-in motor including a stator 64 provided on the inner periphery of the housing 6 and a rotor 65 provided on the outer periphery of the main shaft 7.
As shown in the examples of FIGS. 8 and 9, the cooling structure of the bearing device of the present invention can be effectively applied to both the external motor type and the built-in motor type main shaft devices.
　以上のとおり、図面を参照しながら好適な実施例を説明したが、当業者であれば、本件明細書を見て、自明な範囲内で種々の変更および修正を容易に想定するであろう。したがって、そのような変更および修正は、添付の請求の範囲から定まるこの発明の範囲内のものと解釈される。 As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily assume various changes and modifications within the obvious scope by looking at the present specification. Accordingly, such changes and modifications are to be construed as within the scope of the present invention as defined by the appended claims.
１，１Ｏ，１Ｉ…転がり軸受
２…外輪
３…内輪
４…外輪間座
５…内輪間座
６…ハウジング
７…主軸
８…転動体
１１…外輪間座本体
１２…鍔部
１３，１３Ａ，１３ａ，１３ｂ…凹み部
１４，１４Ａ，１４Ｂ…環状空間
１４Ａ１，１４Ａ２……環状空間の部分
１５…エアノズル
３０…潤滑用流体吐出手段
３１…潤滑用ノズル
４５…圧縮エア導入経路
４６…排気経路
Ａ…圧縮エア
Ｏ１５…中心軸 DESCRIPTION OF SYMBOLS 1,1 O , 1 I ... Rolling bearing 2 ... Outer ring 3 ... Inner ring 4 ... Outer ring spacer 5 ... Inner ring spacer 6 ... Housing 7 ... Main shaft 8 ... Rolling body 11 ... Outer ring spacer main body 12 ... Eaves 13, 13A, 13a, 13b ... depressions 14, 14A, 14B ... annular space 14A1, 14A2 ... annular space portion 15 ... air nozzle 30 ... lubrication fluid discharge means 31 ... lubrication nozzle 45 ... compressed air introduction path 46 ... exhaust path A ... Compressed air O 15 ... central axis

Claims (7)

  1. 　軸方向に３列以上に並ぶ転がり軸受の配列における隣合う転がり軸受の外輪間および内輪間に外輪間座および内輪間座がそれぞれ介在する軸受装置の冷却構造において、
    　前記外輪間座および内輪間座のいずれかの組における前記外輪間座と前記内輪間座との間に、前記外輪間座の内周面と前記内輪間座の外周面とのいずれか一方または両方に設けられた環状の凹み部により形成される環状空間があり、この環状空間に開口して圧縮エアを吐出するエアノズルが前記外輪間座に設けられ、
    　前記外輪間座に、当該外輪間座に隣合う転がり軸受のうち対応する側の転がり軸受へエアおよび潤滑油を含む潤滑用流体を供給する潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の一方のみに対して設けられ、
    　前記環状空間における、前記エアノズルの中心軸に対して前記潤滑用流体の供給側の部分が、非供給側の部分よりも大きな容積を持つ軸受装置の冷却構造。     In a cooling structure for a bearing device in which an outer ring spacer and an inner ring spacer are interposed between outer rings and inner rings of adjacent rolling bearings in an array of rolling bearings arranged in three or more rows in the axial direction,
    Between the outer ring spacer and the inner ring spacer in any set of the outer ring spacer and the inner ring spacer, either the inner peripheral surface of the outer ring spacer or the outer peripheral surface of the inner ring spacer, or There is an annular space formed by annular recesses provided on both, and an air nozzle that opens into this annular space and discharges compressed air is provided in the outer ring spacer,
    Lubricating fluid discharge means for supplying a lubricating fluid containing air and lubricating oil to a rolling bearing on the corresponding side of the rolling bearing adjacent to the outer ring spacer is adjacent to the outer ring spacer. Provided for only one of the bearings,
    The bearing structure cooling structure in which the portion on the supply side of the lubricating fluid has a larger volume than the portion on the non-supply side with respect to the central axis of the air nozzle in the annular space.
  2. 　請求項１に記載の軸受装置の冷却構造において、前記環状空間が、前記外輪間座の内周面に設けられた前記凹み部のみで形成される軸受装置の冷却構造。 2. The cooling structure for a bearing device according to claim 1, wherein the annular space is formed only by the recessed portion provided on an inner peripheral surface of the outer ring spacer.
  3. 　請求項１に記載の軸受装置の冷却構造において、前記環状空間が、前記外輪間座の内周面に設けられた前記凹み部と、前記内輪間座の外周面に設けられた前記凹み部とで形成される軸受装置の冷却構造。 2. The cooling structure for a bearing device according to claim 1, wherein the annular space includes the recessed portion provided on an inner peripheral surface of the outer ring spacer, and the recessed portion provided on an outer peripheral surface of the inner ring spacer. The cooling structure of the bearing device formed by.
  4. 　請求項１ないし請求項３のいずれか１項に記載の軸受装置の冷却構造において、前記環状空間は、前記潤滑用流体の供給側の部分の軸方向長さが、非供給側の部分の軸方向長さよりも長い軸受装置の冷却構造。 4. The cooling structure for a bearing device according to claim 1, wherein the annular space has an axial length of a portion on a supply side of the lubricating fluid, and an axis of a portion on a non-supply side. Cooling structure of bearing device longer than the direction length.
  5. 　請求項１ないし請求項４のいずれか１項に記載の軸受装置の冷却構造において、前記潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の一方のみに対して設けられた前記外輪間座に対して前記潤滑用流体吐出手段が設けられていない側に続いて並ぶ２つの転がり軸受間の外輪間座に、この外輪間座と対応する内輪間座との間の環状空間へ圧縮エアを吐出するエアノズルが設けられ、前記潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の両方に対して設けられた軸受装置の冷却構造。 5. The cooling structure for a bearing device according to claim 1, wherein the lubricating fluid discharge means is provided between only one of the rolling bearings adjacent to the outer ring spacer. 5. Compressed air into the annular space between the outer ring spacer and the corresponding inner ring spacer between the outer ring spacers between the two rolling bearings arranged next to the side where the lubricating fluid discharge means is not provided with respect to the seat A cooling structure for a bearing device in which an air nozzle for discharging the oil is provided and the fluid discharge means for lubrication is provided for both of the rolling bearings adjacent to the outer ring spacer.
  6. 　請求項５に記載の軸受装置の冷却構造において、前記潤滑用流体吐出手段が当該外輪間座に隣合う転がり軸受の両方に対して設けられた前記外輪間座と前記内輪間座との間の前記環状空間が、前記外輪間座の内周面と前記内輪間座の外周面とのいずれか一方または両方に設けられた環状の凹み部により形成される軸受装置の冷却構造。 6. The cooling structure for a bearing device according to claim 5, wherein said lubricating fluid discharge means is provided between said outer ring spacer and said inner ring spacer provided for both rolling bearings adjacent to said outer ring spacer. The bearing structure cooling structure in which the annular space is formed by an annular recess provided in one or both of an inner peripheral surface of the outer ring spacer and an outer peripheral surface of the inner ring spacer.
  7. 　請求項１ないし請求項６のいずれか１項に記載の軸受装置の冷却構造において、前記潤滑用流体吐出手段が、当該潤滑用流体吐出手段が対応する側の転がり軸受における前記内輪の外周面に被さるように突出する鍔部と、この鍔部の内周面に開口して前記潤滑用流体を吐出する潤滑用ノズルとを有する軸受装置の冷却構造。 The cooling structure for a bearing device according to any one of claims 1 to 6, wherein the lubricating fluid discharge means is disposed on an outer peripheral surface of the inner ring in a rolling bearing on a side corresponding to the lubricating fluid discharge means. A cooling structure for a bearing device, comprising: a flange portion that protrudes so as to be covered; and a lubricating nozzle that opens to an inner peripheral surface of the flange portion and discharges the lubricating fluid.
PCT/JP2017/037246 2016-10-17 2017-10-13 Cooling structure for bearing device WO2018074375A1 (en)

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Cited By (1)

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CN114850962A (en) * 2022-06-09 2022-08-05 珠海格力电器股份有限公司 Cooling system and electric spindle

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JP2014062620A (en) * 2012-09-24 2014-04-10 Ntn Corp Cooling structure for bearing device
JP2014062617A (en) * 2012-09-24 2014-04-10 Ntn Corp Cooling structure of bearing device
JP2015117820A (en) * 2013-11-18 2015-06-25 Ntn株式会社 Cooling structure of bearing device
JP2016089975A (en) * 2014-11-06 2016-05-23 Ntn株式会社 Cooling structure of bearing device

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JP2007303528A (en) * 2006-05-10 2007-11-22 Jtekt Corp Rolling bearing
JP2008164080A (en) * 2006-12-28 2008-07-17 Ntn Corp Angular ball bearing device
JP2014062620A (en) * 2012-09-24 2014-04-10 Ntn Corp Cooling structure for bearing device
JP2014062617A (en) * 2012-09-24 2014-04-10 Ntn Corp Cooling structure of bearing device
JP2015117820A (en) * 2013-11-18 2015-06-25 Ntn株式会社 Cooling structure of bearing device
JP2016089975A (en) * 2014-11-06 2016-05-23 Ntn株式会社 Cooling structure of bearing device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114850962A (en) * 2022-06-09 2022-08-05 珠海格力电器股份有限公司 Cooling system and electric spindle

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