JP2008240749A - Retainer for thrust roller bearing and thrust roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer for a thrust roller bearing, reduced in risk of breakage and also reduced torque. <P>SOLUTION: An annular retainer 11 for a thrust roller bearing is provided with pockets 14 for receiving rollers, and is not bent in the plate thickness direction. In a cross section of the retainer 11 cut by a plane parallel to the rotation axis 20 and including the rotation axis 20, the radial outer and inner side end surfaces of the retainer 11 have convex parts 18a, 18b projecting in the radial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cage for a thrust roller bearing and a thrust roller bearing, and more particularly to a cage for an annular thrust roller bearing and a thrust roller bearing provided with such a cage.

  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.

  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. A sectional view of a part of a conventional thrust roller bearing is shown in FIG. Referring to FIG. 8, a thrust roller bearing 101 is disposed between a pair of race rings 102a and 102b and race rings 102a and 102b, and a plurality of needle rollers that roll on raceway surfaces of the race rings 102a and 102b. 103 and a retainer 104 that holds a plurality of needle rollers 103. The cage 104 is bent a plurality of times in the direction of the rotation axis of the cage 104 so that the cross section thereof has a W shape. A collar portion 105a extending in the axial direction is provided at the outer diameter side end portion of the raceway ring 102a. A flange 105b extending in the axial direction is also provided at the inner diameter side end of the race 102b.

  Techniques relating to thrust roller bearings having the same configuration as described above are disclosed in Japanese Unexamined Patent Application Publication No. 2006-170369 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2006-170370 (Patent Document 2). According to Patent Literature 1 and Patent Literature 2, 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 3), the cage provided in the thrust roller bearing is a combination of a pair of elements that are formed in an annular shape with a U-shaped cross section in the middle. Configured. Also in Patent Document 3, the contact area in the radial direction between the bearing ring and the cage is reduced to reduce friction and reduce torque.
JP 2006-170369 A JP 2006-170370 A JP 2006-118562 A

  Referring to FIG. 8 again, during the operation of the thrust roller bearing 101, the race rings 102a and 102b rotate together with the cage 104. However, due to a dimensional error or the like, the rotation axis of the race rings 102a and 102b In some cases, the rotational axis 104 may deviate. Moreover, when the thrust roller bearing 101 is used for a transmission etc., it arrange | positions vertically. In such a case, the cage 104 is sandwiched between the bearing rings 102a and 102b in the radial direction, specifically, between the flanges 105a and 105b of each of the bearing rings 102a and 102b. A load is applied in the radial direction. Therefore, the cage 104 is required to have strength against a radial load.

  Here, according to Patent Document 1 and Patent Document 2, the cage has a shape in which a thin plate-like member is bent a plurality of times so as to have a W-shaped cross section. Since the cage having such a shape has a low radial strength, the cage may be damaged or deformed in the above case.

  Also in Patent Document 3, since the cage is composed of elements on two thin plates bent in the axial direction, the cage may be separated and damaged by a load applied from the radial direction. There is.

  An object of the present invention is to provide a retainer for a thrust roller bearing that can reduce the risk of breakage and reduce torque.

  Another object of the present invention is to provide a thrust roller bearing capable of reducing the risk of breakage and reducing torque.

  A cage for a thrust roller bearing according to the present invention is a cage for an annular thrust roller bearing that has a plurality of pockets for accommodating rollers and is not bent in the plate thickness direction. Here, in a cross section cut by a plane parallel to the rotation axis of the cage and including the rotation axis, at least one end face in the radial direction of the cage includes a convex portion protruding in the radial direction.

  Since the cage of such a thrust roller bearing is not bent in the plate thickness direction, the radial strength is high. If it does so, even if it is a case where it is equipped with a thrust roller bearing and a load is loaded to a radial direction from a bearing ring in the driving | running state, the failure | damage or deformation | transformation of a cage | basket can be reduced. Even when the bearing ring and the cage are in contact with each other in the radial direction, the radial end surface of the cage includes a convex portion projecting in the radial direction in the above-described cross section. The contact area can be reduced. If it does so, the friction which generate | occur | produces in a contact state can be made small, and torque reduction can be achieved. Therefore, the cage of such a thrust roller bearing can reduce the risk of breakage and can reduce the torque.

  Preferably, both end surfaces in the radial direction of the cage include convex portions. By carrying out like this, a contact area can be made small in the outer diameter side end surface and inner diameter side end surface of a holder | retainer. Therefore, the torque can be further reduced.

  More preferably, the convex portion includes a substantially arc shape. By doing so, the raceway and the cage come into line contact, and the contact area can be further reduced. Therefore, the torque can be further reduced.

  In another aspect of the present invention, a thrust roller bearing includes any one of the above-described thrust roller bearing cages and a plurality of rollers.

  Such a thrust roller bearing includes a cage for a thrust roller bearing having a high radial strength, and thus can reduce the risk of breakage. Further, since the contact area between the race ring and the cage in the radial direction can be reduced, the torque can be reduced.

  Preferably, the end surface of the roller includes a convex curved surface protruding in the axial direction of the roller. By doing so, the contact area can be reduced when the end face of the roller comes into contact with the wall surface of the cage pocket in the operating state of the thrust roller bearing. Therefore, the torque of the thrust roller bearing can be further reduced.

  Since the cage of such a thrust roller bearing is not bent in the plate thickness direction, the radial strength is high. If it does so, even if it is a case where it is equipped with a thrust roller bearing and a load is loaded to a radial direction from a bearing ring in the driving | running state, the failure | damage or deformation | transformation of a cage | basket can be reduced. In addition, even when the raceway and the cage are in contact with each other in the radial direction, the radial end surface of the cage includes a convex portion protruding in the radial direction in the above-described cross section. The contact area can be reduced. If it does so, the friction which generate | occur | produces in a contact state can be made small, and torque reduction can be achieved. Therefore, the cage of such a thrust roller bearing can reduce the risk of breakage and can reduce the torque.

  Moreover, since such a thrust roller bearing is provided with a cage for a thrust roller bearing having a high radial strength, the risk of breakage can be reduced. Further, since the contact area between the race ring and the cage in the radial direction can be reduced, the torque can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a view of a cage of a thrust roller bearing according to one embodiment of the present invention as viewed from the thickness direction. FIG. 3 is a side view of the cage shown in FIG. FIG. 4 is an enlarged view of a pocket portion indicated by IV in FIG. 2 in the cage shown in FIG. FIG. 1 is a cross-sectional view of the cage shown in FIG. 2 taken along the line II in FIG. FIG. 5 is a cross-sectional view when the pocket portion of the cage shown in FIG. 4 is cut along the VV cross section in FIG. 4. 6 is a cross-sectional view when the pocket portion of the cage shown in FIG. 4 is cut along the VI-VI cross section in FIG.

  With reference to FIGS. 1-6, the structure of the holder | retainer of the thrust roller bearing which concerns on one Embodiment of this invention is demonstrated. As shown in FIGS. 2 and 3, 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.

  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. Specifically, the first roller stopper 16a and the first roller guide portion 17a are the central portions in the radial direction of the cage 11 among the side wall surfaces of the column portions 15 located on both sides of the pocket 14 in the circumferential direction. Is provided. The second roller stopper 16 b and the second roller guide 17 b are provided at both ends of the cage 11 in the radial direction on the side wall surface of the column 15. The first and second roller stoppers 16 a and 16 b have a shape protruding from the side wall surface of the column part 15 toward the pocket 14. 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 first roller guide portion 17a is provided on the side wall surface of the column portion 15 so as to be continuous with the first roller stopper portion 16a in the plate thickness direction. Similarly, the second roller guide portion 17b is provided on the side wall surface of the column portion 15 so as to be continuous with the second roller stopper portion 16b in the plate thickness direction. 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. 5 and 6). 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.

  Here, in the cross section shown in FIG. 1, that is, the cross section cut in a plane parallel to the rotation axis 20 of the cage 11 and including the rotation axis 20, the outer diameter side end surface and the inner diameter side end surface of the cage 11 have a diameter of Convex-shaped portions 18a and 18b protruding in the direction are included. 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 above-described cage 11 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. 7 is a cross-sectional view showing a part of a thrust roller bearing according to an embodiment of the present invention, which corresponds to FIG. 1 to 7, a thrust roller bearing 21 includes a pair of race rings 22a and 22b, a plurality of rollers 23 that roll on race surface 24a and 24b of the pair of race rings 22a and 22b, and a plurality of rollers. And a cage 11 that holds the rollers 23. The thrust roller bearing 21 supports a thrust load applied in the plate thickness direction of the cage 11.

  The race 22a disposed on the outer diameter side is provided with a flange portion 25a extending in the direction opposite to the direction of the arrow A from the outer diameter side end. Further, the bearing ring 22b disposed on the inner diameter side is provided with a flange portion 25b extending in the direction of arrow A from the inner diameter side end. The cage 11 in which the rollers 23 are accommodated in the pockets 14 is disposed between the pair of race rings 22a and 22b. In this case, the flange portion 25a of the race ring 22a is positioned on the radially outer side of the cage 11, and the flange portion 25b of the track ring 22b is positioned on the radially inner side.

  Here, the operating state of the thrust roller bearing 21 will be described. During the operation of the thrust roller bearing 21, the roller 23 rolls, and the race rings 22a and 22b and the cage 11 rotate. In this case, the rotation axes (not shown) of the races 22a and 22b and the rotation axis 20 of the cage 11 are configured to be the same in design dimensions. However, the rotation axis of the bearing rings 22a and 22b and the rotation axis 20 of the cage 11 may deviate due to a dimensional error of the races 22a and 22b and the cage 11. Moreover, when the thrust roller bearing 21 is used for a transmission etc., it arrange | positions vertically. Then, the race rings 22a and 22b and the cage 11 come into contact in the radial direction. Specifically, among the races 22a and 22b, the inner surface 26a of the flange 25a and the outer surface 26b of the flange 25b are in contact with the cage 11. In such a case, the cage 11 is loaded in the radial direction from the track rings 22a and 22b, that is, in the direction indicated by the arrow B in FIG.

  However, since the cage 11 having the above-described configuration is not bent in the plate thickness direction, the strength in the radial direction is high. If it does so, even if it is a case where a load is loaded to the radial direction from the track rings 22a and 22b in the driving | running state, the fear of the failure | damage and deformation | transformation of the holder | retainer 11 can be reduced. Further, even when the race rings 22a and 22b and the cage 11 are in contact with each other in the radial direction, the outer diameter side and the inner diameter side end surfaces of the cage 11 are provided with substantially arc-shaped convex portions 18a and 18b projecting in the radial direction. Therefore, the contact area between the race rings 22a and 22b and the cage 11 can be reduced. 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, the torque can be reduced by reducing the contact area on the outer diameter side end face and the inner diameter side end face of the cage 11.

  Moreover, since the convex-shaped parts 18a and 18b are substantially circular arc shape, when the track rings 22a and 22b and the holder | retainer 11 contact in radial direction, they will carry out line contact. Therefore, since the contact area can be further reduced, the torque can be further reduced.

  In addition, since such a thrust roller bearing 21 includes the cage 11 having a high radial strength, the risk of breakage can be reduced. Further, since the contact area between the race rings 22a and 22b and the cage 11 in the radial direction can be reduced, the torque can be reduced.

  Here, the roller 23 provided in the thrust roller bearing 21 may have a configuration including a convex curved surface projecting in the axial direction of the roller 23 on the end surface. Specifically, for example, the end surfaces 27 a and 27 b of the roller 23 are round surfaces protruding in the axial direction of the roller 23. By doing so, even when the end surfaces 27a and 27b of the roller 23 are in contact with the wall surfaces 19a and 19b of the pocket 14 of the cage 11 in the operating state of the thrust roller bearing 21, the contact area can be reduced. Therefore, the torque of the thrust roller bearing 21 can be further reduced.

  Moreover, you may decide to provide a full crowning on the rolling surface 28 about the roller 23 with which the thrust roller bearing 21 is equipped. Full crowning refers to crowning provided on the entire rolling surface 28 so that the diameter of the central portion of the roller 23 in the axial direction is maximized. By doing so, the contact area between the roller 23 and the races 22a and 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. Therefore, the torque of the thrust roller bearing 21 can be further reduced.

  In the above-described embodiment, the outer diameter side and inner diameter side end faces of the cage 11 include the convex portions 18a and 18b protruding in the radial direction. It is good also as a structure containing the convex-shaped part which protrudes in a radial direction about either one among inner diameter side end surfaces. Further, the entire outer diameter side and inner diameter side end surfaces protrude in the radial direction. However, the present invention is not limited to this, and a protruding portion protruding in the radial direction is provided on a part of the outer diameter side and inner diameter side end surfaces. You may decide.

  Moreover, in the above, although the convex-shaped part was substantially circular arc shape in above-mentioned cross-sectional shape, it is not restricted to this, Other cross-sectional shapes, such as R surface shape, may be sufficient. Furthermore, the cross-sectional shape comprised from a some curve may be sufficient. By carrying out like this, a convex-shaped part can be made into a more suitable shape.

  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 cage for a thrust roller bearing and the thrust roller bearing according to the present invention are effectively used for an automatic transmission of an automobile.

It is sectional drawing which shows a part of cage | basket of the thrust roller bearing which concerns on one Embodiment of this invention. It is the figure which looked at the retainer of the thrust roller bearing which concerns on one Embodiment of this invention 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. 2 from the plate | board thickness direction. It is sectional drawing at the time of cut | disconnecting the pocket part of the holder | retainer shown in FIG. 4 in the VV cross section in FIG. It is sectional drawing at the time of cut | disconnecting the pocket part of the holder | retainer shown in FIG. 4 in the VI-VI cross section in FIG. It is sectional drawing which shows a part of thrust roller bearing provided with the holder | retainer shown in FIG. It is sectional drawing which shows a part of conventional thrust roller bearing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Cage, 12 Through-hole, 13a, 13b Annular part, 14 Pocket, 15 Pillar part, 16a 1st roller stopper part, 16b 2nd roller stopper part, 17a 1st roller guide part, 17b 2nd roller Guide part, 18a, 18b Convex-shaped part, 19a, 19b Wall surface, 20 Rotating axis, 21 Thrust roller bearing, 22a, 22b Race ring, 23 Roller, 24a, 24b Raceway surface, 25a, 25b Ridge part, 26a, 26b face, 27a, 27b End face, 28 Rolling surface.

Claims (5)

A cage for an annular thrust roller bearing having a plurality of pockets for accommodating rollers and not bent in the plate thickness direction,
In a cross section cut in a plane parallel to the rotation axis of the cage and including the rotation axis,
A cage for a thrust roller bearing, wherein an end face on at least one side in the radial direction of the cage includes a convex portion protruding in the radial direction. The cage for a thrust roller bearing according to claim 1, wherein both end surfaces of the cage in the radial direction include the convex portion. The cage of a thrust roller bearing according to claim 1 or 2, wherein the convex portion includes a substantially arc shape. A thrust roller bearing comprising the thrust roller bearing retainer according to any one of claims 1 to 3 and a plurality of rollers. The thrust roller bearing according to claim 4, wherein the end surface of the roller includes a convex curved surface protruding in the axial direction of the roller.

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