JP2008240756A - Thrust roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust roller bearing capable of improving oil passing properties of lubricating oil. <P>SOLUTION: The thrust roller bearing 21a is provided with an outer ring 22a, an inner ring 22a, a plurality of rollers 31 arranged between the outer ring 22a and the inner ring 22b, and an annular retainer 11 retaining the rollers 31. A first clearance 30a to which lubricating oil is supplied and a second clearance 30b from which lubricating oil is discharged are formed between the outer ring 22a and the inner ring 22b. The second clearance 30b is wider than the first clearance 30a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thrust roller bearing, and more particularly to a thrust roller bearing in which lubricating oil is supplied.

  In an automatic transmission for an automobile, a thrust roller bearing that supports the thrust load is disposed at a portion to which the thrust load is applied. Recently, thrust roller bearings are required to have low torque from the viewpoint of reducing fuel consumption, as well as reducing the risk of damage to thrust roller bearings and preventing heat generation.

  A thrust roller bearing is generally composed of a bearing ring such as an outer ring or an inner ring, a plurality of rollers, and a cage that holds the rollers. Here, the structure of the conventional thrust roller bearing will be described. FIG. 11 is a cross-sectional view showing a part of a conventional thrust roller bearing. Referring to FIG. 11, thrust roller bearing 101 holds outer ring 102a, inner ring 102b, a plurality of needle rollers 103 arranged between outer ring 102a and inner ring 102b, and a plurality of needle rollers 103. Device 104. The cage 104 that holds the needle rollers 103 is bent a plurality of times in the direction of the rotation axis of the cage 104 so that the cross-section thereof becomes a W shape. A cage 104 that holds the needle rollers 103 is disposed between the outer ring 102a and the inner ring 102b.

  Japanese Patent Application Laid-Open No. 2006-170369 (Patent Document 1), Japanese Patent Application Laid-Open No. 2006-170370 (Patent Document 2), Japanese Patent Application Laid-Open No. 2006-170371 (Patent Document 3) ). According to Patent Document 1, Patent Document 2, and Patent Document 3, the thrust roller bearing includes a pair of race rings, needle rollers disposed between the race rings, and a cage that holds the needle rollers. The cage is bent in the axial direction a plurality of times and formed into a W-shaped cross section. And the friction at the time of radial contact is reduced by reducing the contact area between the outer ring collar part and the cage, and the torque is reduced.

Further, according to Japanese Patent Application Laid-Open No. 2006-118562 (Patent Document 4) and Japanese Patent Application Laid-Open No. 2006-189133 (Patent Document 5), the cage provided in the thrust roller bearing has a U-shaped cross section and is entirely annular. A pair of manufactured elements is combined in the middle. Also in Patent Document 4, the contact area in the radial direction between the race and the cage is reduced to reduce friction and reduce torque. In Patent Document 5, an excellent surface hardening process such as wear resistance is applied to the contact portion to reduce wear.
JP 2006-170369 A JP 2006-170370 A JP 2006-170371 A JP 2006-118562 A JP 2006-189133 A

Lubricating oil is supplied to the thrust roller bearing 101. The lubricating oil is supplied from, for example, the inner diameter side of the thrust roller bearing 101 on which the rotating shaft is disposed. The supplied lubricating oil passes through the thrust roller bearing 101 and is discharged from the outer diameter side. Specifically, with reference again to FIG. 11, the lubricating oil is supplied from the inner diameter side of the gap 106a between the outer ring 102a and the inner ring 102b in the direction indicated by the arrow _{Z 1} in FIG. Lubricating oil passes through the thrust roller bearing 101, is discharged from the gap 106b in the outer diameter side between the outer ring 102a and the inner ring 102b in the direction indicated by arrow _{Z 2} in FIG. In this way, the lubricating oil is supplied into the thrust roller bearing 101.

  Here, if the lubricating oil stays in the thrust roller bearing 101 for a long time, heat generation of the thrust roller bearing 101 may not be prevented. Moreover, the stirring resistance of the lubricating oil increases, making it difficult to reduce the torque.

  According to Patent Document 1, Patent Document 2, and Patent Document 3, the cage has a shape obtained by bending a thin plate-like member a plurality of times so as to have a W-shaped cross section. Further, according to Patent Document 4 and Patent Document 5, the cage is composed of elements on two thin plates bent in the axial direction. Since the cages having such shapes are complicated in shape, the lubricating oil tends to stay in the cage more easily. If it does so, an above-mentioned problem will become remarkable.

  An object of the present invention is to provide a thrust roller bearing capable of improving the oil permeability of a lubricating oil.

  A thrust roller bearing according to the present invention includes a pair of race rings, a plurality of rollers disposed between the pair of race rings, and an annular cage that holds the rollers. Between the pair of raceways, a first gap to which the lubricating oil is supplied and a second gap from which the lubricating oil is discharged are formed. Here, the second gap is wider than the first gap.

  With this configuration, since the gap on the side from which the lubricating oil is discharged is wider than the gap on the side from which the lubricating oil is supplied, the lubricating oil can be discharged smoothly. If it does so, the residence in the thrust roller bearing of the lubricating oil supplied in the thrust roller bearing can be reduced. Therefore, the oil permeability of the lubricating oil can be improved.

  Preferably, each raceway ring includes a disc portion having a raceway surface on the surface thereof and extending in the radial direction, and a flange portion extending in the rotational axis direction from a radial end portion of the disc portion. Here, the disc portion included in one of the race rings and the flange portion included in the other race ring form a first gap, and are included in the flange portion and the other race ring included in one of the race rings. The disc portion forms a second gap.

  More preferably, the length in the radial direction of one disk part involved in the formation of the second gap is shorter than the length in the radial direction of the other disk part involved in the formation of the first gap. By carrying out like this, the length of the radial direction of the disc part contained in each track ring can be adjusted, and the 2nd crevice can be made wider than the 1st crevice. Therefore, the retention of the lubricating oil can be reduced more reliably.

  More preferably, the length in the rotation axis direction of one flange part involved in the formation of the second gap is shorter than the length in the rotation axis direction of the other flange part involved in the formation of the first gap. By carrying out like this, the length of the rotating shaft direction of the collar part contained in each track ring can be adjusted, and a 2nd clearance gap can be made wider than a 1st clearance gap. Therefore, the retention of the lubricating oil can be reduced more reliably.

  More preferably, the first gap is located on the inner diameter side, and the second gap is located on the outer diameter side. By doing so, the lubricating oil can be efficiently discharged using the centrifugal force or the like in the operating state of the thrust roller bearing. Therefore, the retention of lubricating oil can be further reduced.

  According to the present invention, since the gap on the side from which the lubricating oil is discharged is wider than the gap on the side from which the lubricating oil is supplied, the lubricating oil can be discharged smoothly. If it does so, the residence in the thrust roller bearing of the lubricating oil supplied in the thrust roller bearing can be reduced. Therefore, the oil permeability of the lubricating oil can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. First, the configuration of an outer ring as a bearing ring provided in a thrust roller bearing according to an embodiment of the present invention will be described. FIG. 2 is a view of an outer ring provided in a thrust roller bearing according to an embodiment of the present invention as viewed from the thickness direction. 3 is a cross-sectional view of the outer ring 22a shown in FIG. 2 taken along the line III-III in FIG.

  Referring to FIGS. 2 and 3, outer ring 22 a as a raceway has a through hole 28 at the center thereof and has an annular shape. The outer ring 22a includes an outer ring disc part 23a having an outer ring raceway surface 24a on the surface thereof, and an outer ring flange part 25a extending in the rotational axis direction from an outer diameter side end of the outer ring disk part 23a. In the operating state of the thrust roller bearing, the outer ring 22a rotates around the rotation axis 20a. The outer ring flange portion 25a includes a staking portion 27a in which an end portion in the rotation axis direction is slightly bent toward the inner diameter side. Four staking portions 27a are provided at intervals of about 90 degrees in the circumferential direction. The staking portion 27a prevents the constituent members constituting the thrust roller bearing 21a from being separated.

  Next, the structure of the cage provided in the thrust roller bearing according to the embodiment of the present invention will be described. FIG. 4 is a view of the cage provided in the thrust roller bearing according to the embodiment of the present invention as seen from the thickness direction. FIG. 5 is a side view of the cage shown in FIG. FIG. 6 is an enlarged view of the pocket portion indicated by VI in FIG. 4 in the cage shown in FIG. 7 is a cross-sectional view of the cage shown in FIG. 4 taken along the VII-VII cross section in FIG. FIG. 8 is a cross-sectional view when the pocket portion of the cage shown in FIG. 6 is cut along the VIII-VIII cross section in FIG. FIG. 9 is a cross-sectional view when the pocket portion of the cage shown in FIG. 6 is cut along the IX-IX cross section in FIG.

  With reference to FIGS. 4-9, the structure of the holder | retainer with which the thrust roller bearing which concerns on one Embodiment of this invention is equipped is demonstrated. As shown in FIGS. 4 and 5, the cage 11 of the thrust roller bearing is not bent in the plate thickness direction but is annular. The cage 11 has a through hole 12 penetrating in the thickness direction at the center. The cage 11 has a plurality of pockets 14 for accommodating rollers. The pockets 14 are arranged substantially radially. The cage 11 includes a plurality of annular portions having different diameters, here, an annular portion 13a on the outer diameter side and an annular portion 13b on the inner diameter side, and a plurality of annular portions 13a and 13b that connect the annular portions 13a and 13b so as to form a pocket 14. Column part 15. In the operating state of the thrust roller bearing, the cage 11 rotates around the rotation axis 20b.

  The cage 11 is provided with first and second roller stoppers 16a and 16b for preventing the rollers accommodated in the pocket 14 from dropping off, and first and second roller guides 17a and 17b for guiding the rollers. It has been. The first roller stopper 16a prevents the roller from dropping in the direction opposite to the direction indicated by the arrow A in FIG. The second roller stopper 16b prevents the roller from dropping in the direction indicated by the arrow A in FIG.

  The cage 11 is guided by the first and second roller guide portions 17a and 17b. The first and second roller guide portions 17a and 17b have an arc shape in cross section (see FIGS. 8 and 9). The first and second roller stoppers 16a and 16b and the first and second roller guides 17a and 17b are provided by coining using a jig or the like.

  In the cross section shown in FIG. 7, that is, the cross section cut along a plane parallel to the rotation axis 20b of the cage 11 and including the rotation axis 20b, the outer diameter side end surface and the inner diameter side end surface of the cage 11 protrude in the radial direction. Convex portions 18a and 18b. The convex-shaped parts 18a and 18b have a substantially arc shape. In this case, the whole convex-shaped part 18a, 18b is a substantially circular arc shape.

  Next, a configuration of a thrust roller bearing including the outer ring 22a and the cage 11 described above and according to an embodiment of the present invention will be described. A thrust roller bearing according to an embodiment of the present invention is disposed, for example, at a location where a thrust load is applied in an automatic transmission of an automobile. FIG. 1 is a cross-sectional view showing a part of a thrust roller bearing according to an embodiment of the present invention, and corresponds to a portion indicated by I in FIG.

  1 to 9, a thrust roller bearing 21a includes an outer ring 22a, an inner ring 22b, a plurality of rollers 31 disposed between the outer ring 22a and the inner ring 22b, and a cage that holds the plurality of rollers 31. 11. The thrust roller bearing 21 a supports a thrust load applied in the plate thickness direction of the cage 11. In the operating state of the thrust roller bearing 21a, lubricating oil is supplied to the thrust roller bearing 21a.

  The inner ring 22b as a bearing ring has a through hole at the center thereof and has an annular shape. The inner ring 22b includes an inner ring disc portion 23b having an inner ring raceway surface 24b on the surface thereof, and an inner ring flange portion 25b extending in the rotation axis direction from the inner diameter side end portion of the inner ring disc portion 23b. The inner ring collar portion 25b is also provided with a staking portion (not shown) in which the end portion in the rotation axis direction is slightly bent toward the outer diameter side.

  The rollers 31 roll on the outer ring raceway surface 24a and the inner ring raceway surface 24b. The cage 11 containing the rollers 31 in the pocket 14 is disposed between the outer ring 22a and the inner ring 22b. In this case, the outer ring flange portion 25a of the outer ring 22a is located on the radially outer side of the cage 11, and the inner ring flange portion 25b of the inner ring 22b is located on the radially inner side.

  Between the outer ring 22a and the inner ring 22b, a first gap 30a to which lubricating oil is supplied and a second gap 30b from which the lubricating oil is discharged are formed. Specifically, a first gap 30a is formed between the inner ring flange portion 25b and the outer ring disc portion 23a, and a second gap 30b is formed between the outer ring flange portion 25a and the inner ring disc portion 23b. That is, the inner ring flange portion 25b and the outer ring disc portion 23a are involved in the formation of the first gap 30a, and the outer ring flange portion 25a and the inner ring disc portion 23b are involved in the formation of the second gap 30b. Lubricating oil is supplied into the thrust roller bearing 21a using the first gap 30a, and lubricating oil is discharged out of the thrust roller bearing 21a using the second gap 30b. Here, the lubricating oil is supplied in the direction indicated by the arrow C in FIG. 1 from the first gap 30a on the inner diameter side. And lubricating oil is discharged | emitted from the 2nd clearance gap 30b used as an outer-diameter side in the direction shown by the arrow D in FIG. In this way, the lubricating oil passes through the thrust roller bearing 21a.

Here, the second gap 30b is configured wider than the first gap 30a. Specifically, the cross-section shown in FIG. 1, i.e., in the cross section including the rotation axis 20a which is parallel to the rotational axis 20a of the outer ring 22a, the length of the first gap 30a and L _1, the second gap 30b Let L ₂ be L ₂ longer than L ₁ . In this case, the length L ₃ radially of the inner ring disc portion 23b that is involved in the formation of the second gap 30b, the radial length of the outer ring disk portion 23a involved in the formation of the first gap 30a L _Shorter than ₄ .

  With this configuration, the second gap 30b on the side from which the lubricant is discharged can be made wider than the first gap 30a on the side to which the lubricant is supplied. Can be discharged. If it does so, the residence in the thrust roller bearing 21a of the lubricating oil supplied in the thrust roller bearing 21a can be reduced. Therefore, the oil permeability of the lubricating oil can be improved.

In this case, the length L ₃ radially of the inner ring disc portion 23b that is involved in the formation of the second gap 30b, the radial length of the outer ring disk portion 23a involved in the formation of the first gap 30a L ₄ because it is shorter than, by adjusting the radial dimension of the outer ring circular part 23a and the inner ring disc portion 23b, it is possible to widen the second gap 30b than the first gap 30a. Therefore, the retention of the lubricating oil can be reduced more reliably.

  Further, since the first gap 30a is located on the inner diameter side and the second gap 30b is located on the outer diameter side, lubrication is efficiently performed using centrifugal force or the like in the operating state of the thrust roller bearing 21a. Oil can be drained. Therefore, the retention of lubricating oil can be further reduced.

  Furthermore, the retainer 11 provided in the thrust roller bearing 21a is not bent in the plate thickness direction and has a simple shape, so that retention of lubricating oil in the retainer 11 can be reduced. If it does so, the thrust roller bearing 21a provided with such a holder | retainer 11 can flow lubricating oil smoothly. Therefore, the retention of lubricating oil can be further reduced.

  Moreover, since the convex-shaped parts 18a and 18b of the holder | retainer 11 are substantially circular arc shapes, when lubricating oil passes the convex-shaped parts 18a and 18b, lubricating oil can be poured smoothly. Therefore, the retention of lubricating oil can be further reduced.

  During the operation of the thrust roller bearing 21a, the cage 11 comes into contact with the outer ring 22a or the inner ring 22b, and a load is applied from the outer ring 22a or the inner ring 22b in the radial direction, that is, in the direction of the arrow B in FIG. May be loaded. However, when the outer ring 22a or the inner ring 22b is in contact with the retainer 11, specifically, the inner diameter side surface 26a of the outer ring flange portion 25a or the outer diameter side surface 26b of the inner ring flange portion 25b is in contact with the retainer 11. Even in this case, since the outer diameter side and inner diameter side end faces of the cage 11 include convex portions 18a and 18b having substantially arc shapes projecting in the radial direction, the contact area between the outer ring 22a or the inner ring 22b and the cage 11 is increased. Can be small. If it does so, the friction which generate | occur | produces in a contact state can be made small, and it can be set as a low torque. Therefore, the cage 11 having such a configuration can reduce the risk of breakage and reduce the torque. In this case, since the convex-shaped parts 18a and 18b are substantially circular arc shape, when the outer ring | wheel 22a or the inner ring | wheel 22b and the holder | retainer 11 contact, line contact will be carried out. Therefore, since the contact area can be further reduced, the torque can be reduced.

  Here, about the roller 31 with which the thrust roller bearing 21a is equipped, you may make it the structure containing the convex curved surface which protrudes in the axial direction of the roller 31 about the end surface. Specifically, for example, the end surfaces 32 a and 32 b of the roller 31 are round surfaces protruding in the axial direction of the roller 31. By doing so, when the lubricating oil passes through the end faces 32a and 32b of the roller 31 in the operating state of the thrust roller bearing 21a, it can flow smoothly. Further, even when the end surfaces 32a and 32b of the roller 31 are in contact with the wall surfaces 19a and 19b of the pocket 14 of the cage 11, the contact area can be reduced. Therefore, the torque of the thrust roller bearing 21a can be further reduced.

  Moreover, you may decide to provide a full crowning on the rolling surface 33 about the roller 31 with which the thrust roller bearing 21a is equipped. Full crowning refers to crowning provided on the entire rolling surface 33 so that the diameter of the central portion of the roller 31 in the axial direction is maximized. By doing so, the contact area between the roller 31 and the outer ring 22a or the inner ring 22b can be reduced, and slippage due to a difference in peripheral speed between the outer diameter side and the inner diameter side can be reduced. Moreover, lubricating oil can be smoothly poured. Therefore, the torque of the thrust roller bearing 21a can be further reduced.

  In the above embodiment, the second gap 30b is made wider than the first gap 30a by adjusting the radial lengths of the outer ring disc part 23a and the inner ring disc part 23b. However, the present invention is not limited to this, and the lengths of the outer ring flange portion 25a and the inner ring flange portion 25b in the rotation axis direction may be adjusted.

  FIG. 10 is a sectional view showing a part of the thrust roller bearing in this case, and corresponds to FIG. Referring to FIG. 10, the thrust roller bearing 21 c includes an outer ring 22 c, an inner ring 22 d, a plurality of rollers 31, and a cage 11. The outer ring 22c includes an outer ring disc portion 23c having an outer ring raceway surface 24c on the surface thereof, and an outer ring flange portion 25c extending in the rotation axis direction from an outer diameter side end portion of the outer ring disc portion 23c. The inner ring 22d includes an inner ring disc portion 23d having an inner ring raceway surface 24d on the surface thereof, and an inner ring flange portion 25d extending in the rotation axis direction from the inner diameter side end portion of the inner ring disc portion 23d. A first gap 30c is formed between the inner ring collar part 25d and the outer ring disk part 23c, and a second gap 30d is formed between the outer ring collar part 25c and the inner ring disk part 23d. The basic configuration of the thrust roller bearing 21c is the same as that of the thrust roller bearing 21a shown in FIG.

Here, the length in the rotation axis direction of the outer ring flange portion 25c involved in the formation of the second gap 30d is made shorter than the length in the rotation axis direction of the inner ring flange portion 25d involved in the formation of the first gap 30c. . In this way, the second gap 30d is made wider than the first gap 30c. Specifically, the cross-section shown in FIG. 10, i.e., in the cross section including the rotation axis 20c which is parallel to the rotational axis 20c of the outer ring 22c, and the rotation axis direction of the length of the outer ring flange portion 25c and L _7, the inner ring flange When the rotation axis direction of the length of the section 25d to _{L 8,} the _{L 7} is shorter than _{L 8.} In this manner, the length L ₆ of the second gap 30d, longer than the length L ₅ of the first gap 30c.

  Thus, the second gap 30d can be made wider than the first gap 30c also by adjusting the lengths of the outer ring flange portion 25c and the inner ring flange portion 25d in the rotation axis direction. Therefore, the retention of the lubricating oil can be reduced more reliably.

  In the above embodiment, the outer ring and the inner ring each include a disc part and a flange part. However, the present invention is not limited thereto, and for example, a thrust roller bearing including an outer ring or an inner ring that does not include a flange part. Applied. Further, the present invention is also applied to a thrust roller bearing including a cage whose cross section is bent into an M shape, a W shape, or the like, or a cage having a flat radial end surface. Furthermore, the present invention is also applied to a thrust roller bearing configured to supply the lubricating oil from the outer diameter side and discharge the lubricating oil from the inner diameter side.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The thrust roller bearing according to the present invention is effectively used for an automatic transmission of an automobile.

It is sectional drawing which shows a part of thrust roller bearing which concerns on one Embodiment of this invention. It is the figure which looked at the outer ring | wheel with which the thrust roller bearing which concerns on one Embodiment of this invention is equipped from the plate | board thickness direction. It is sectional drawing at the time of cut | disconnecting the outer ring | wheel shown in FIG. 2 in the III-III cross section in FIG. It is the figure which looked at the retainer with which the thrust roller bearing which concerns on one Embodiment of this invention is equipped from the plate | board thickness direction. It is a side view of the holder | retainer shown in FIG. It is the enlarged view which looked at the pocket part of the holder | retainer shown in FIG. 4 from the plate | board thickness direction. It is sectional drawing at the time of cut | disconnecting the holder | retainer shown in FIG. 4 in the VII-VII cross section in FIG. It is sectional drawing at the time of cut | disconnecting the pocket part of the holder | retainer shown in FIG. 6 in the VIII-VIII cross section in FIG. It is sectional drawing at the time of cut | disconnecting the pocket part of the holder | retainer shown in FIG. 6 in the IX-IX cross section in FIG. It is sectional drawing which shows a part of thrust roller bearing which concerns on other embodiment of this invention. It is sectional drawing which shows a part of conventional thrust roller bearing.

Explanation of symbols

  11 Cage, 12, 28 Through-hole, 13a, 13b Annular part, 14 Pocket, 15 Column part, 16a First roller stopper, 16b Second roller stopper, 17a First roller guide part, 17b Second Roller guide part, 18a, 18b convex shape part, 19a, 19b wall surface, 20a, 20b, 20c rotation axis, 21a, 21c thrust roller bearing, 22a, 22c outer ring, 22b, 22d inner ring, 23a, 23c outer ring disk part, 23b, 23d Inner ring disc part, 24a, 24c Outer ring raceway surface, 24b, 24d Inner ring raceway surface, 25a, 25c Outer ring collar part, 25b, 25d Inner ring collar part, 26a, 26b surface, 27a Staking part, 30a, 30c One gap, 30b, 30d Second gap, 31 rollers, 32a, 32b end face, 33 rolling surface.

Claims (5)

A pair of race rings,
A plurality of rollers disposed between the pair of raceways;
A thrust roller bearing comprising an annular cage for holding the roller,
Between the pair of raceways, a first gap to which the lubricating oil is supplied and a second gap from which the lubricating oil is discharged are formed,
The thrust roller bearing, wherein the second gap is wider than the first gap. Each of the race rings includes a disc portion having a raceway surface on its surface and extending in the radial direction, and a flange portion extending in the rotation axis direction from a radial end portion of the disc portion,
The disc portion included in one of the race rings and the flange portion included in the other race ring form the first gap,
2. The thrust roller bearing according to claim 1, wherein the flange portion included in one of the race rings and the disk portion included in the other race ring form the second gap. The radial length of the other disk part involved in the formation of the second gap is shorter than the radial length of the one disk part involved in the formation of the first gap. Item 3. A thrust roller bearing according to Item 2. The length in the rotation axis direction of one of the flange portions involved in the formation of the second gap is shorter than the length in the rotation axis direction of the other flange portion involved in the formation of the first gap. Item 4. The thrust roller bearing according to Item 2 or 3. The thrust roller bearing according to any one of claims 1 to 4, wherein the first gap is located on an inner diameter side, and the second gap is located on an outer diameter side.

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