Thrust needle roller bearing

Abstract

This technology provides a way to increase the rated load with a simple configuration. [Solution] The thrust needle roller bearing 1 comprises a plurality of needle rollers 2 and an annular cage 4 having a plurality of pockets 6 for holding the plurality of needle rollers 2 along the circumferential direction. The cage 4 has a pair of annular members 10a, 12a. Each of the plurality of pockets 6 holds at least two of the plurality of needle rollers 2 in an aligned state. The pair of annular members 10a, 12a each have a plurality of holding holes 14, 16 having inner walls 14a, 16a that constitute the plurality of pockets 6. The inner walls 14a, 16a each have a pair of radial surfaces 20a, 20b that face both end faces 2b of the two needle rollers 2. The pair of radial surfaces 20a, 20b have a pair of guide protrusions 24, 28 that project toward the pocket 6 side and are interposed between the circumferential surfaces of the two needle rollers 2, holding the two needle rollers 2 so that they do not come into contact with each other.

Description

Technical Field

[0001] The present disclosure relates to a thrust needle roller bearing.

Background Art

[0002] Patent Document 1 discloses a thrust needle roller bearing.

Prior Art Documents

Patent Documents

[0003] <00000,16>

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a thrust needle roller bearing, an increase in the rated load may be attempted for the purpose of improving the lifespan and reducing the size. As a method of increasing the rated load of a thrust needle roller bearing, increasing the number of needle rollers can be considered.

[0005] However, in the conventional thrust needle roller bearing, when attempting to increase the number of needle rollers, it is necessary to form the column portion located between the needle rollers extremely thin, which may reduce the strength of the cage that holds the needle rollers. Moreover, forming the column portion extremely thin is considered to be a bottleneck in manufacturing, and it has not been easy to increase the rated load.

Means for Solving the Problems

[0006] A thrust needle roller bearing according to an embodiment of the present disclosure comprises a plurality of needle rollers and an annular cage having a plurality of pockets for holding the plurality of needle rollers along the circumferential direction. The cage has a pair of annular members arranged opposite to each other on both axial sides so as to sandwich the plurality of needle rollers. Each of the plurality of pockets holds at least two of the plurality of needle rollers side by side. Each of the pair of annular members has a plurality of holding holes having inner walls that constitute the plurality of pockets. Each of the inner walls of the plurality of holding holes has a pair of radial surfaces that face both end faces of the two needle rollers. The pair of radial surfaces have a pair of guide protrusions that project toward the pocket side and are interposed between the circumferential surfaces of the two needle rollers, holding the two needle rollers so that they do not come into contact with each other. [Effects of the Invention]

[0007] According to this disclosure, the rated load can be increased with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a partial plan view showing an example of a thrust needle roller bearing according to the first embodiment. [Figure 2] Figure 2 is a cross-sectional view taken along the line II-II in Figure 1. [Figure 3] Figure 3 is an enlarged view of the main part shown in Figure 1. [Figure 4] Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 3. [Figure 5A] Figure 5A is a plan view of the main part of a thrust needle roller bearing according to the second embodiment. [Figure 5B] Figure 5B is a cross-sectional view taken along the line VV in Figure 5A. [Figure 6] Figure 6 is a cross-sectional view of the main part of a thrust needle roller bearing according to the third embodiment. [Modes for carrying out the invention]

[0009] First, the details of the embodiment will be listed and explained. [Summary of the Embodiment]

[0010] (1) A thrust needle roller bearing according to an embodiment of the present disclosure comprises a plurality of needle rollers and an annular cage having a plurality of pockets for holding the plurality of needle rollers along the circumferential direction. The cage has a pair of annular members that are positioned opposite each other on both axial sides so as to sandwich the plurality of needle rollers. Each of the plurality of pockets holds at least two of the plurality of needle rollers side by side. Each of the pair of annular members has a plurality of holding holes having inner walls that constitute the plurality of pockets. Each of the inner walls of the plurality of holding holes has a pair of radial surfaces that face both end faces of the two needle rollers. The pair of radial surfaces have a pair of guide protrusions that project toward the pocket side and are interposed between the circumferential surfaces of the two needle rollers, holding the two needle rollers so that they do not come into contact with each other. According to the above configuration, by providing a pair of guide protrusions in the holding holes of each of the pair of annular members, the distance between the two needle-shaped rollers lined up in the pocket can be narrowed to a non-contact range without providing extremely thin columnar parts or the like. In other words, with the above configuration, the simple guide projection allows the spacing between two needle-shaped rollers arranged in the pocket to be narrowed, and the number of needle-shaped rollers held by the retainer can be increased. Thus, according to this disclosure, the number of needle rollers can be increased by a simple configuration of guide protrusions, and the rated load of the thrust needle roller bearing can be increased.

[0011] (2) In the thrust needle roller bearing described in (1) above, at least one of the pair of guide projections may have a pair of sliding contact portions that slide against the two circumferential surfaces of the two needle rollers.

[0012] (3) In addition, in the thrust needle roller bearing described in (2) above, if the circumferential surface has a racing surface provided between the two end faces, the pair of sliding contact portions may slide against the two racing surfaces of the two needle rollers. In this case, the guide projection can more reliably hold the two needle rollers by slidingly contacting the two rolling surfaces.

[0013] (4) In the thrust needle roller bearing of (2) above, when the circumferential surface has a rolling surface provided between the both end faces and a chamfer portion connecting the both end faces and the rolling surface, the pair of sliding contact portions may be in sliding contact with the two chamfer portions of the two needle rollers. In this case, if the guide projection is configured not to contact the rolling surface, the guide projection does not affect the rolling surface.

[0014] (5) In the thrust needle roller bearing of (2) above, when the one guide projection has a pair of opposing surfaces facing the two circumferential surfaces of the two needle rollers, the pair of opposing surfaces may include the pair of sliding contact portions. In this case, since the pair of opposing surfaces are in sliding contact with the circumferential surfaces of the two needle rollers, an increase in surface pressure between the guide projection and the needle rollers is suppressed, and the frictional force can be alleviated.

[0015] (6) In the thrust needle roller bearing of (5) above, each of the pair of annular members has an inner surface facing each other and an outer surface on the opposite side of the inner surface, and when the contour shape of a cross section orthogonal to the protruding direction of the one guide projection has a pair of inclined lines inclined to taper from the outer surface side toward the inner surface side, the pair of inclined lines may include the contour lines of the pair of opposing surfaces. In this case, by making the contour shape of the guide projection a tapered shape, the opposing surfaces can be easily provided.

[0016] [Details of Embodiment] Hereinafter, preferred embodiments will be described with reference to the drawings. [Regarding the First Embodiment] FIG. 1 is a partial plan view showing an example of a thrust needle roller bearing according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1. In FIGS. 1 and 2, the thrust needle roller bearing 1 includes a plurality of needle rollers 2 and an annular cage 4. The thrust needle roller bearing 1 may have a pair of races. The pair of races has raceways on which the plurality of needle rollers 2 roll, and are members that are arranged to face each other so as to sandwich the cage 4 holding the plurality of needle rollers 2. In this specification, the pair of races is shown omitted. In the following description, the direction parallel to the central axis C of the thrust needle roller bearing 1 is referred to as the axial direction, the direction orthogonal to the central axis C is referred to as the radial direction, and the direction along a circle centered on the central axis C is referred to as the circumferential direction. Also, among the radial directions, the direction toward the central axis C is referred to as the inner radial direction, and the opposite direction is referred to as the outer radial direction.

[0017] The plurality of needle rollers 2 have a needle shape or an elongated cylindrical shape. The plurality of needle rollers 2 are held by the cage 4. The cage 4 has a plurality of pockets 6. The plurality of pockets 6 are provided at equal intervals along the circumferential direction. The plurality of pockets 6 accommodate the needle rollers 2. The plurality of pockets 6 hold the needle rollers 2 so as to be freely rotatable. Each of the plurality of pockets 6 holds a roller set 2s. The roller set 2s includes two of the plurality of needle rollers 2. The pocket 6 has a rectangular hole shape. The center line c1 passing through the circumferential center of the pocket 6 passes through the central axis C. The pocket 6 holds the two needle rollers 2 such that the axes of the two needle rollers 2 are parallel to each other along the center line c1. The pocket 6 holds the two needle rollers 2 in a state of being arranged along a direction orthogonal to the center line c1.

[0018] As shown in FIG. 2, the cage 4 has a first annular body 10 and a second annular body 12. The first annular body 10 and the second annular body 12 are combined and fixed so as to sandwich the plurality of needle rollers 2 from both axial sides.

[0019] The first annular body 10 includes a first annular member 10a, a first outer bent portion 10b, and a first inner bent portion 10c. The first annular member 10a is a plate-shaped member formed in an annular shape. The first outer bent portion 10b is a cylindrical member extending from the outer peripheral edge of the first annular member 10a toward the second annular body 12. The first inner bent portion 10c is a cylindrical member extending from the inner peripheral edge of the first annular member 10a toward the second annular body 12.

[0020] The second annular body 12 includes a second annular member 12a, a second outer bent portion 12b, and a second inner bent portion 12c. The second annular member 12a is a plate-shaped member formed in an annular shape. The second outer bent portion 12b is a cylindrical member extending from the outer peripheral edge of the second annular member 12a toward the first annular body 10. The second inner bent portion 12c is a cylindrical member extending from the inner peripheral edge of the second annular member 12a toward the first annular body 10.

[0021] The first outer bent portion 10b and the second outer bent portion 12b are in contact with and fitted together. The first inner bent portion 10c and the second inner bent portion 12c are in contact with and fitted together. A crimping portion 10b1 is provided at the tip of the first outer bent portion 10b. A crimping portion 10c1 is also provided at the tip of the first inner bent portion 10c. The first annular body 10 and the second annular body 12 are fixed together by these crimping portions 10b1 and 10c1.

[0022] Furthermore, the tip 12b1 of the second outer bent portion 12b and the tip 12c1 of the second inner bent portion 12c abut against the first annular member 10a. As a result, the first annular member 10a and the second annular member 12a are positioned opposite each other with a predetermined distance between them. In other words, the pair of annular members, the first annular member 10a and the second annular member 12a, are arranged opposite each other from both axial sides so as to sandwich a plurality of needle-shaped rollers 2.

[0023] The first annular member 10a has a plurality of first retaining holes 14. The plurality of first retaining holes 14 are rectangular in shape. The second annular member 12a has a plurality of second retaining holes 16. The plurality of second retaining holes 16 also have a rectangular shape. The plurality of first retaining holes 14 and the plurality of second retaining holes 16 are aligned in the axial direction. The first retaining holes 14 and the second retaining holes 16 that are aligned in the axial direction have inner walls 14a and inner wall 16a that constitute the pocket 6. Roller sets 2s are arranged inside the first retaining holes 14 and inside the second retaining holes 16.

[0024] The roller set 2s is positioned inside the first retaining hole 14 and inside the multiple second retaining holes 16, and is held by the first annular member 10a and the second annular member 12a so as to be sandwiched from both sides in the axial direction.

[0025] Figure 3 is an enlarged view of the main part in Figure 1. Figure 3 shows a magnified view of the first retaining hole 14. As shown in Figures 3 and 2, the inner wall 14a of the first retaining hole 14 has a pair of radial surfaces 20. The pair of radial surfaces 20 includes a first radial surface 20a located radially outward of the two needle rollers 2 and a second radial surface 20b located radially inward of the two needle rollers 2.

[0026] The first radial surface 20a faces one end face 2b of the two needle rollers 2 with a predetermined clearance between them. The end face 2b faces radially outward. The first radial surface 20a has a first flat portion 22 and a first guide projection 24. The first flat portion 22 is parallel to the direction perpendicular to the radial centerline c1 of the pocket 6 and the first retaining hole 14. The first guide projection 24 protrudes toward the pocket 6 along the direction perpendicular to the first flat portion 22. The first guide projection 24 is located in the center of the first flat portion 22 along the centerline c1.

[0027] The second radial surface 20b faces the other end face 2b of the two needle rollers 2 with a predetermined clearance. The other end face 2b faces in the radial direction. The second radial surface 20b has a second planar portion 26 and a second guide projection 28. The second planar portion 26 is parallel to the direction perpendicular to the center line c1. The second guide projection 28 protrudes toward the pocket 6 along the direction perpendicular to the second planar portion 26. The second guide projection 28 is located in the center of the second planar portion 26 along the center line c1.

[0028] Thus, the pair of radial surfaces 20 of the first retaining hole 14 have a pair of guide protrusions, namely a first guide projection 24 and a second guide projection 28.

[0029] Furthermore, as shown in Figure 2, the inner wall 16a of the second retaining hole 16 has a pair of radial surfaces 30. The pair of radial surfaces 30 includes a third radial surface 30a located radially outward of the two needle rollers 2 and a fourth radial surface 30b located radially inward of the two needle rollers 2.

[0030] The third radial surface 30a faces one end face 2b of the two needle rollers 2 with a predetermined clearance between them. The third radial surface 30a has a third planar portion 32 and a third guide projection 34. The third planar portion 32 is parallel to the direction perpendicular to the center line c1. The third guide projection 34 protrudes toward the pocket 6 along the direction perpendicular to the third planar portion 32. The third guide projection 34 is located in the center of the third planar portion 32.

[0031] The fourth radial surface 30b faces the other end face 2b of the two needle rollers 2 with a predetermined clearance between them. The fourth radial surface 30b has a fourth planar portion 36 and a fourth guide projection 38. The fourth planar portion 36 is parallel to the direction perpendicular to the center line c1. The fourth guide projection 38 protrudes toward the pocket 6 side along a direction perpendicular to the fourth planar portion 36. The fourth guide projection 38 is located in the center of the fourth planar portion 36.

[0032] Thus, the pair of radial surfaces 30 of the second retaining hole 16 have a pair of guide protrusions, namely a third guide protrusion 34 and a fourth guide protrusion 38.

[0033] Here, the first retaining hole 14 of the first annular member 10a and the second retaining hole 16 of the second annular member 12a have similar configurations. Also, the pair of radial surfaces 20 of the first retaining hole 14 have similar configurations to each other. Therefore, the first guide projection 24, the second guide projection 28, the third guide projection 34, and the fourth guide projection 38 have similar configurations to each other. Therefore, in the following explanation, we will describe the first guide projection 24 on the first radial surface 20a of the first retaining hole 14, and omit the explanation of the other guide projections.

[0034] As shown in Figures 2 and 3, the first guide projection 24 protrudes toward the pocket 6 and is interposed between the circumferential surfaces 2a of the two needle-shaped rollers 2. The circumferential surface 2a includes a rolling surface 2a1 and a chamfered portion 2a2. The rolling surface 2a1 is a cylindrical surface provided between the end faces 2b on both sides. The chamfered portion 2a2 is an annular curved surface connecting the end faces 2b and the edge of the rolling surface 2a1. The tip of the first guide projection 24 extends to the rolling surface 2a1.

[0035] Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 3. As shown in Figure 4, the first guide projection 24 has a rectangular parallelepiped shape. The axial thickness of the first guide projection 24 is the same as the thickness of the first annular member 10a. The first guide projection 24 has a tip surface 24a, a pair of side surfaces 24b, an inner surface 24c, and a pair of inner corners 24d. The pair of side surfaces 24b are surfaces that connect the edge of the tip surface 24a to the first flat surface 22. The inner surface 24c is a surface that faces the second annular member 12a. The pair of inner corners 24d are corners formed by the pair of side surfaces 24b and the inner surface 24c. The pair of inner corners 24d extend along the circumferential surface of the needle roller 2.

[0036] A portion of the pair of inner corners 24d is in sliding contact with the two rolling surfaces 2a1 of the two needle-shaped rollers 2. Furthermore, a portion of the pair of inner corners 34d of the third guide projection 34 also slides against the two rolling surfaces 2a1 of the two needle-shaped rollers 2, similar to the pair of inner corners 24d. Furthermore, the second guide projection 28 and the fourth guide projection 38 also slide against the two rolling surfaces 2a1 of the two needle-shaped rollers 2, similar to the first guide projection 24 and the third guide projection 34 (not shown). At this time, the two needle-shaped rollers 2 included in the roller set 2s are held at a slight distance apart by these guide protrusions 24, 28, 34, and 38.

[0037] In this manner, the pair of guide protrusions 24 and 28 provided in the first retaining hole 14, and the pair of guide protrusions 34 and 38 provided in the second retaining hole 16, protrude toward the pocket 6 side and are interposed between the circumferential surfaces 2a of the two needle rollers 2, thereby holding the two needle rollers 2 so that they do not come into contact with each other.

[0038] According to the above configuration, by providing a pair of guide protrusions (guide protrusions 24, 28, 34, 38) in the holding holes (first holding hole 14 and second holding hole 16) of each of the pair of annular members (first annular member 10a and second annular member 12a), the distance between the two needle-shaped rollers 2 lined up in the pocket 6 can be narrowed to a non-contact range without providing extremely thin columnar parts or the like. In other words, with the above configuration, the simple configuration of guide protrusions 24, 28, 34, and 38 makes it possible to narrow the distance between the two needle-shaped rollers 2 lined up in the pocket 6, and to increase the number of needle-shaped rollers 2 held by the retainer 4. Thus, according to this disclosure, the number of needle rollers 2 can be increased by the simple configuration of guide protrusions 24, 28, 34, and 38, and the rated load of the thrust needle roller bearing 1 can be increased.

[0039] Furthermore, in this embodiment, a portion of the pair of inner corners 24d of the first guide projection 24 constitutes a sliding contact portion that slides against the two rolling surfaces 2a1 of the two needle-shaped rollers 2. The same applies to the other guide projections 28, 34, and 38, where a portion of the pair of inner corners 24d of the first guide projection 24 constitutes a sliding contact portion. In this case, each guide projection slides against 24, 28, 34, 38, and the two rolling surfaces 2a1, thereby more securely holding the two needle-shaped rollers 2.

[0040] [Regarding the second embodiment] Figure 5A is a plan view of the main part of the thrust needle roller bearing 1 according to the second embodiment. Figure 5B is a cross-sectional view taken along the line VV in Figure 5A. This embodiment differs from the first embodiment in that the guide projections 24, 28, 34, and 38 of the thrust needle roller bearing 1 slide against the chamfered portion 2a2 of the needle roller 2. Although only the first guide projection 24 will be described here, the other guide projections 28, 34, and 38 have a similar configuration.

[0041] As shown in Figure 5A, the tip of the first guide projection 24 is located at the chamfered portion 2a2. Therefore, the first guide projection 24 does not reach the rolling surface 2a1. Therefore, as shown in Figure 5B, in this embodiment, the pair of tip portions 24d1 of the first guide projection 24 are in sliding contact with the chamfered portion 2a2. Also, the first guide projection 24 does not come into contact with the rolling surface 2a1. The pair of tip portions 24d1 are edge portions where the pair of inner corner portions 24d connect to the tip surface 24a.

[0042] The pair of tip portions 24d1 slide against the chamfered portion 2a2, and the portions of each guide projection 28, 34, and 38 corresponding to the tip portions 24d1 slide against the chamfered portion 2a2, so that the two needle-shaped rollers 2 are held with a small gap between them.

[0043] In this embodiment, the guide protrusions 24, 28, 34, and 38 hold the needle-shaped rollers 2 by sliding against the chamfered portion 2a2 without contacting the rolling surface 2a1. Therefore, the guide protrusions 24, 28, 34, and 38 do not affect the rolling surface 2a1.

[0044] [Regarding the third embodiment] Figure 6 is a cross-sectional view of the main part of the thrust needle roller bearing 1 according to the third embodiment. Figure 6 shows a cross-section of the first guide projection 24. The cross-section in Figure 6 is parallel to the plane perpendicular to the protruding direction of the first guide projection 24. This embodiment differs from the first embodiment in that each guide projection 24, 28, 34, 38 of the thrust needle roller bearing 1 has a pair of opposing surfaces 40. Here, we will only describe the first guide projection 24, but the other guide projections 28, 34, and 38 have a similar configuration.

[0045] As shown in Figure 6, the pair of opposing surfaces 40 are provided so as to be chamfer the space between the pair of side surfaces 24b and the inner surface 24c. Therefore, the pair of opposing surfaces 40 are inclined with respect to the side surfaces 24b and the inner surface 24c, respectively. The pair of opposing surfaces 40 face the two rolling surfaces 2a1 of the two needle rollers 2. Furthermore, a portion of each of the pair of opposing surfaces 40 slides against the rolling surface 2a1. In other words, the pair of opposing surfaces 40 includes a pair of sliding contact portions that slide against the two rolling surfaces 2a1 of the two needle rollers 2.

[0046] As a portion of the pair of opposing surfaces 40 slides against the rolling surface 2a1, and the portions of each guide projection 28, 34, and 38 corresponding to the opposing surfaces 40 slide against the chamfered portion 2a2, the two needle-shaped rollers 2 are held with a small gap between them.

[0047] In this embodiment, the opposing surfaces of each guide projection 24, 28, 34, 38 slide against the rolling surface 2a1 of the needle roller 2, thereby suppressing the increase in surface pressure between each guide projection 24, 28, 34, 38 and the needle roller 2, and mitigating frictional force.

[0048] Furthermore, as shown in Figure 6, the contour shape of the first guide projection 24 includes the contour lines L of a pair of opposing surfaces 40. The pair of contour lines L are inclined to taper from the outer surface 10a1 side to the inner surface 10a2 side of the first annular member 10a. Due to this pair of contour lines L, the contour shape of the first guide projection 24 has a tapered shape that narrows from the outer surface 10a1 side to the inner surface 10a2 side. Thus, by having a tapered contour shape for the guide projection, a pair of opposing surfaces can be easily provided.

[0049] 〔others〕 It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. For example, in each of the above embodiments, the roller set 2s held in the pocket 6 is shown to include two needle-shaped rollers 2, but the roller set 2s may include a larger number of needle-shaped rollers 2.

[0050] Furthermore, in the above embodiment, the example given was that the two needle-shaped rollers 2 included in the roller set 2s are held in the pocket 6 such that the axes of the two needle-shaped rollers 2 are parallel to each other along the center line c1. However, the circumferential width of the first guide projection 24 and the circumferential width of the third guide projection 34 may be made wider than the circumferential width of the second guide projection 28 and the circumferential width of the fourth guide projection 38, so that the two needle-shaped rollers 2 included in the roller set 2s are held in the pocket 6 such that the axes of the two needle-shaped rollers 2 are aligned radially. In this case, the shape of the pocket 6 is also changed according to the arrangement of the two needle-shaped rollers 2.

[0051] The scope of the present invention is indicated by the claims, not in the sense described above, and is intended to include the meaning and scope of equivalents of the claims, and all modifications within that scope. [Explanation of Symbols]

[0052] 1 bearing 2a Circumferential surface 2a1 Rolling surface 2a2 Chamfered section 2b End face 2s set 4 Cage 6 pockets 10 First Ring Body 10a First annular member 10a1 External surface 10a2 inner surface 10b First outer bend 10b1 part 10c First inner bend 10c1 part 12. Second Ring Body 12a Second annular member 12b Second outer bend 12b1 Tip 12c Second inner bend 12c1 tip 14 1st holding hole 14a Internal wall 16 2nd holding hole 16a Inner wall 20 Radial surface 20a First radial surface 20b Second radial plane 22 1st plane part 24 First guide projection 24a Tip surface 24b side 24c inner 24d Interior corner 24d1 Tip 26 2nd plane part 28 Second guide projection 30 Radial surface 30a 3rd radial plane 30b 4th radial plane 32 3rd plane part 34 Third guide projection 34d Interior corner 35 balls 36 4th plane part 38. Fourth guide projection 40 Opposing surfaces

Claims

1. A thrust needle roller bearing comprising a plurality of needle rollers and an annular cage having a plurality of pockets for holding the plurality of needle rollers arranged along the circumferential direction, The retainer has a pair of annular members that are positioned opposite each other on both axial sides so as to sandwich the plurality of needle rollers, Each of the aforementioned multiple pockets holds at least two of the multiple needle-shaped rollers in an aligned state, Each of the pair of annular members has a plurality of retaining holes having inner walls that constitute the plurality of pockets, The inner walls of the plurality of retaining holes each have a pair of radial surfaces facing both end faces of the two needle-shaped rollers. The pair of radial surfaces protrude toward the pocket and are interposed between the circumferential surfaces of the two needle rollers, and have a pair of guide protrusions that hold the two needle rollers so that they do not come into contact with each other. Thrust needle roller bearing.

2. At least one of the pair of guide protrusions has a pair of sliding contact portions that slide against the two circumferential surfaces of the two needle-shaped rollers. The thrust needle roller bearing according to claim 1.

3. The circumferential surface has a rolling surface provided between the two end faces, The pair of sliding contact portions slide against the two rolling surfaces of the two needle rollers. The thrust needle roller bearing according to claim 2.

4. The aforementioned circumferential surface is A turning surface provided between the two end faces, It has a chamfered portion connecting the two end faces and the rolling surface, The pair of sliding contact portions slide against the two chamfered portions of the two needle-shaped rollers. The thrust needle roller bearing according to claim 2.

5. The aforementioned guide projection has a pair of opposing surfaces that face the two circumferential surfaces of the two needle-shaped rollers, The pair of opposing surfaces include the pair of sliding contact portions. The thrust needle roller bearing according to claim 2.

6. Each of the pair of annular members has an inner surface facing each other and an outer surface opposite to the inner surface, The contour shape of the cross-section perpendicular to the protruding direction of one of the guide protrusions has a pair of inclined lines that taper from the outer surface side toward the inner surface side, The pair of inclined lines include the contour lines of the pair of opposing surfaces. The thrust needle roller bearing according to claim 5.

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