JP2008240751A - Thrust roller bearing and retainer for 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 in torque. <P>SOLUTION: This retainer 11 for a thrust roller bearing is a retainer 11 for an annular thrust roller bearing including a plurality of pockets 14 holding rollers. An outer circumference surface 18a and an inner circumference surface 18b of the retainer 11 include a plurality of projection parts 29a, 29b provided spaced apart in a circumference direction. <P>COPYRIGHT: (C)2009,JPO&amp;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. 7, thrust roller bearing 101 is disposed between a pair of race rings 102a, 102b and race rings 102a, 102b, and a plurality of needle rollers that roll on raceway surfaces of race rings 102a, 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. 7 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, the outer peripheral surface or the inner peripheral surface of the cage includes a plurality of protrusions provided in the circumferential direction at intervals.

  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 cage and the raceway are in contact with each other in the radial direction, the outer circumferential surface or the inner circumference surface of the cage includes a plurality of projections provided in the circumferential direction at intervals. Will come into contact. If it does so, the contact area of a bearing ring and a holder | retainer can be made small, and reduction in torque can be achieved. Therefore, the cage of such a thrust roller bearing can reduce the risk of breakage and can reduce the torque.

  Preferably, the projecting portions are provided substantially equally in the circumferential direction. By carrying out like this, the load loaded on a cage | basket from a track ring in radial direction can be received equally to the circumferential direction. Therefore, the risk of breakage of the cage can be further reduced.

  More preferably, the retainer includes a pair of annular portions having different diameters, and a plurality of pillar portions that extend in the radial direction so as to connect the pair of annular portions and form a pocket. It is provided at the position to be arranged. The position where the column portion is provided in the circumferential direction has high radial strength. Therefore, by providing the projecting portion at such a position, it is possible to make contact with the raceway at a portion having a high radial strength in the cage, and to reduce the risk of breakage.

  More preferably, the protrusion includes a substantially arc shape in a cross section cut along a plane parallel to the rotation axis of the cage and including the rotation axis. By carrying out like this, when a protrusion part and a bearing ring contact, it can be made point contact. Therefore, since the contact area can be reduced, 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 in the radial direction between the race and the cage can be reduced, the torque can be 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. Even when the cage and the raceway are in contact with each other in the radial direction, the outer circumferential surface or the inner circumference surface of the cage includes a plurality of projections provided in the circumferential direction at intervals. Will come into contact. If it does so, the contact area of a bearing ring and a holder | retainer can be made small, and reduction in torque 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 in the radial direction between the race and the cage can be reduced, the torque can be reduced.

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

  With reference to FIGS. 1-5, 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. 1 and 2, 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. 4 and 5). 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, the outer peripheral surface 18a and the inner peripheral surface 18b of the retainer 11 include a plurality of protrusions 29a and 29b provided at intervals in the circumferential direction. The protrusions 29a and 29b are provided approximately equally in the circumferential direction. Here, the protruding portions 29a and 29b are provided at positions where the column portions 15 are disposed.

  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. 6 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 cross-sectional view of the cage 11 shown in FIG. 1 cut along a VI-VI cross section in FIG. Part. 1 to 6, the thrust roller bearing 21 includes a pair of race rings 22a and 22b, a plurality of rollers 23 that roll on raceway surfaces 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. Further, the protrusions 29 a and 29 b include a substantially arc shape in the cross section shown in FIG. 6, that is, the cross section cut along a plane parallel to the rotation axis 20 of the cage 11 and including the rotation axis 20.

  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 races 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 of the arrow B in FIG.

  However, since the cage 11 is not bent in the 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, when the cage 11 and the races 22a and 22b contact each other in the radial direction, the projection 11a included in the outer circumferential surface 18a of the cage 11 and provided in a plurality in the circumferential direction at intervals, and the inner circumference A plurality of protrusions 29b included in the surface 18b and provided in the circumferential direction at intervals are in contact with the race rings 22a and 22b. Specifically, the surfaces 26a and 26b of the flanges 25a and 25b of the races 22a and 22b are in contact with the protrusions 29a and 29b. If it does so, the contact area of the bearing rings 22a and 22b and the holder | retainer 11 can be made small. Therefore, the thrust roller bearing 21 can reduce the friction generated in the contact state and reduce the torque.

  In this case, it is possible to reduce the contact area on the outer peripheral surface 18a and the inner peripheral surface 18b of the cage 11 to reduce the torque.

  In addition, since the protrusions 29a and 29b are provided at substantially equal intervals in the circumferential direction, the load applied to the cage 11 from the race rings 22a and 22b in the radial direction can be equally received in the circumferential direction. . Therefore, the risk of breakage can be further reduced.

  Here, the radial strength is high at the position where the column portion 15 is provided in the circumferential direction. In this case, since the column portion 15 is provided at a position where the column portion 15 is disposed, the cage 11 can be brought into contact with the raceway rings 22a and 22b at a portion having a high radial strength, and further, The risk of breakage can be reduced.

  Furthermore, since the protrusions 29a and 29b have a substantially arc shape in the cross section shown in FIG. 6, the race rings 22a and 22b and the protrusions 29a and 29b are in point contact. Therefore, the contact area can be reduced, and 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 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 peripheral surface 18a and the inner peripheral surface 18b of the cage 11 include the protruding portions 29a and 29b protruding in the radial direction. It is good also as a structure containing the protrusion parts 29a and 29b which protrude in a radial direction about either one among the internal peripheral surfaces 18b.

  In the above description, the projecting portions 29a and 29b have a substantially arc shape in the above-described cross-sectional shape, but are not limited thereto, and may have other cross-sectional shapes such as an R-surface shape. Furthermore, the cross-sectional shape comprised from a some curve may be sufficient. By carrying out like this, protrusion part 29a, 29b can be made into a more suitable shape.

  In the above-described embodiment, the protrusions 29a and 29b are provided at positions where the column portions 15 are arranged in the circumferential direction, but other positions may be used. Furthermore, although the protrusion parts 29a and 29b were provided in substantially equal distribution, it is not restricted to this but is provided in the various positions of the outer peripheral surface 18a or the inner peripheral surface 18b.

  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 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. 1 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. 3 in the IV-IV cross section in FIG. It is sectional drawing at the time of cut | disconnecting the pocket part of the holder | retainer shown in FIG. 3 in the VV 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 outer peripheral surface, 18b inner peripheral surface, 19a, 19b wall surface, 20 rotation axis, 21 thrust roller bearing, 22a, 22b raceway ring, 23 roller, 24a, 24b raceway surface, 25a, 25b collar part, 26a, 26b Surface, 27a, 27b End surface, 28 Rolling surface, 29a, 29b Protruding part.

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,
The retainer of a thrust roller bearing, wherein the outer peripheral surface or the inner peripheral surface of the retainer includes a plurality of protrusions provided in the circumferential direction at intervals. The retainer of a thrust roller bearing according to claim 1, wherein the protrusions are provided substantially equally in the circumferential direction. The retainer includes a pair of annular portions having different diameters, and a plurality of pillar portions that connect the pair of annular portions and extend in the radial direction so as to form the pockets,
The cage of the thrust roller bearing according to claim 1 or 2, wherein the protruding portion is provided at a position where the pillar portion is disposed. The holding of the thrust roller bearing according to any one of claims 1 to 3, wherein the protrusion includes a substantially arc shape in a cross section cut along a plane parallel to the rotation axis of the cage and including the rotation axis. vessel. A thrust roller bearing comprising the thrust roller bearing retainer according to claim 1 and a plurality of rollers.

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