WO2018123397A1 - Thrust roller bearing and raceway rings for thrust roller bearing - Google Patents

Abstract

Raceway rings (10, 20) for a thrust roller bearing are provided with raceway surfaces (11, 21) on which a plurality of first rollers (30) roll. The raceway surfaces (11, 21) have first full crownings (12, 22) in contact with the first rollers (30). In a radial cross-section of the raceway rings (10, 20) for a thrust roller bearing, the shape of first surfaces (12s, 22s) of the first full crownings (12, 22) is a first single circular arc. As a result, heat generated when the first rollers (30) roll on the raceway rings (10, 20) for a thrust roller bearing can be reduced.

Description

Thrust roller bearing and thrust ring for thrust roller bearing

The present invention relates to a thrust roller bearing and a bearing ring for a thrust roller bearing.

2. Description of the Related Art Thrust roller bearings are known that are installed in rotating parts of electrical components such as automobile transmissions, torque converters, and compressors for automobile air conditioners (see Patent Document 1). A thrust roller bearing is used to support a thrust load applied to the rotating portion. The thrust roller bearing described in Patent Document 1 includes a bearing ring disposed in the rotation axis direction, a plurality of rollers that roll on the raceway surface of the bearing ring, and a cage that holds the plurality of rollers.

JP 2003-83333 A

However, in the thrust roller bearing disclosed in Patent Document 1, the roller slides with respect to the raceway due to the difference between the peripheral speed of the roller rolling surface and the raceway surface of the raceway. Heat is generated by the rollers sliding against the race. This heat causes surface origin separation on the raceway surface of the thrust roller bearing raceway on which the roller rolls.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a thrust roller bearing and a thrust roller configured so as to reduce heat generated by the roller sliding with respect to the raceway. It is to provide a bearing ring for a bearing.

The thrust roller bearing of the present invention includes a first thrust roller bearing raceway, a second thrust roller bearing raceway, a first thrust roller bearing raceway, and a second thrust roller bearing raceway. And a plurality of first rollers disposed along a circumferential direction of the first thrust roller bearing raceway and the second thrust roller bearing raceway. Each of the first thrust roller bearing raceway and the second thrust roller bearing raceway includes a raceway surface on which the first roller rolls. At least one of the raceway surface of the first thrust roller bearing raceway and the raceway surface of the second thrust roller bearing raceway has a first full crowning portion that contacts the first roller. The shape of the first surface of the first full crowning portion in the radial cross section of the thrust roller bearing is a first single arc.

The thrust roller bearing race ring of the present invention includes a raceway surface on which a plurality of first rollers roll. The raceway surface has a first full crowning portion that contacts the first roller. The shape of the first surface of the first full crowning portion in the radial cross section of the thrust roller bearing race is a first single arc.

The thrust roller bearing of the present invention generates heat generated when the first roller slides with respect to the thrust roller bearing raceway (first thrust roller bearing raceway, second thrust roller bearing raceway). Can be reduced.

The thrust roller bearing raceway of the present invention is generated when the first roller slides with respect to the thrust roller bearing raceway (first thrust roller bearing raceway, second thrust roller bearing raceway). Heat to be reduced.

It is a schematic perspective view of the thrust roller bearing of Embodiment 1 and the first and second thrust roller bearing raceways. FIG. 3 is a schematic cross-sectional view of a first thrust roller bearing raceway according to the first embodiment. FIG. 4 is a schematic cross-sectional view of a second thrust roller bearing raceway according to the first embodiment. 3 is a schematic enlarged cross-sectional view of a first roller according to Embodiment 1. FIG. It is a general | schematic partial expanded sectional view of the thrust roller bearing of Embodiment 1, and the 1st and 2nd thrust roller bearing raceway. It is a general | schematic partial expanded sectional view of the thrust roller bearing of Embodiment 1, and the 1st and 2nd thrust roller bearing raceway. It is a figure which shows the graph showing the relationship between the rotational speed of the thrust roller bearing of an Example and the comparative example 1, and a temperature rise rate. It is a figure which shows the graph showing the relationship between the position on the 1st rolling surface of the 1st roller in the thrust roller bearing of an Example, and the emitted-heat amount per unit length in the said position. In the thrust roller bearing of the embodiment, the position between the first rolling surface of the first roller and the first rolling surface of the first roller and the raceway surface of the first thrust roller bearing raceway. It is a figure which shows the graph showing the relationship with a contact surface pressure. It is a figure which shows the graph showing the relationship between the position on the 1st rolling surface of the 1st roller in the thrust roller bearing of the comparative example 1, and the emitted-heat amount per unit length in the said position. In the thrust roller bearing of Comparative Example 1, between the position on the first rolling surface of the first roller and the first rolling surface of the first roller and the raceway surface of the first thrust roller bearing raceway. It is a figure which shows the graph showing the relationship with the contact surface pressure. It is a figure which shows the graph showing the relationship between the curvature radius of the 1st full crowning part, center contact surface pressure, and edge contact surface pressure of the thrust roller bearing of Embodiment 1. It is a general | schematic partial expanded sectional view of the thrust roller bearing of Embodiment 2, and the 1st and 2nd thrust roller bearing raceway. FIG. 6 is a schematic partial enlarged cross-sectional view of a thrust roller bearing and first and second thrust roller bearing raceways of a modification of the second embodiment. FIG. 4 is a schematic partial enlarged cross-sectional view of a thrust roller bearing and first and second thrust roller bearing raceways of Embodiment 3. 6 is a schematic enlarged cross-sectional view of a first roller of a third embodiment. FIG. FIG. 10 is a schematic enlarged cross-sectional view of a second roller of the third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
1 to 6, thrust roller bearing 1 and thrust roller bearing raceway according to the first embodiment (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20). Will be explained. The thrust roller bearing 1 mainly includes a first thrust roller bearing race ring 10, a second thrust roller bearing race ring 20, and a plurality of first rollers 30. The thrust roller bearing 1 may further include a cage 40 that holds the first roller 30. The first thrust roller bearing race ring 10 rotates with respect to the second thrust roller bearing race ring 20 about the rotation shaft 8 via the first roller 30. In the present specification, the inner side is defined as the side closer to the rotation axis 8, and the outer side is defined as the side far from the rotation axis 8. In the present specification, the radial direction is defined as a direction orthogonal to the rotation axis 8.

The first thrust roller bearing ring 10 is an annular plate member. The first thrust roller bearing raceway ring 10 has a raceway surface 11 on which the first roller 30 rolls and a first main surface 15 opposite to the raceway surface 11.

The raceway surface 11 of the first thrust roller bearing raceway ring 10 includes the first surface 12s of the first full crowning portion 12 of the first thrust roller bearing raceway ring 10. The raceway surface 11 of the first thrust roller bearing race 10 may further include a first outer flat portion 13 and a first inner flat portion 14. A first outer flat portion 13 may be provided outside the first full crowning portion 12. A first inner flat portion 14 may be provided on the inner side with respect to the first full crowning portion 12.

The first main surface 15 may be flat. The flat first main surface 15 enables the first thrust roller bearing race 10 to be attached to a housing (not shown) without gaps. Therefore, when a thrust load is applied to the thrust roller bearing 1, the thrust roller bearing 1 can appropriately receive the thrust load.

The second thrust roller bearing race 20 is an annular plate member. The second thrust roller bearing raceway ring 20 has a raceway surface 21 on which the first roller 30 rolls and a second main surface 25 opposite to the raceway surface 21.

The raceway surface 21 of the second thrust roller bearing race 20 includes a first surface 22 s of the first full crowning portion 22 of the second thrust roller bearing race 20. The raceway surface 21 of the second thrust roller bearing race 20 may further include a second outer flat portion 23 and a second inner flat portion 24. A second outer flat portion 23 may be provided outside the first full crowning portion 22. A second inner flat portion 24 may be provided inside the first full crowning portion 22.

The second main surface 25 may be flat. The flat second main surface 25 enables the second thrust roller bearing race 20 to be attached to the housing (not shown) without gaps. Therefore, when a thrust load is applied to the thrust roller bearing 1, the thrust roller bearing 1 can appropriately receive the thrust load.

In the present embodiment, the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the raceway surface 21 of the second thrust roller bearing raceway ring 20 each have a first full crowning portion 22. Yes. At least one of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the raceway surface 21 of the second thrust roller bearing raceway ring 20 has the first full crowning portion 22 in contact with the first roller 30. You may have. A first full crowning portion is provided only on one of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the raceway surface 21 of the second thrust roller bearing raceway ring 20, and the first thrust roller The first full crowning portion may not be provided on the other of the raceway surface 11 of the bearing raceway 10 and the raceway surface 21 of the second thrust roller bearing raceway 20. In the present specification, the crowning portion means a bulge formed on the raceway surfaces 11 and 21. In the present specification, the full crowning portion is the entire rolling surface (first rolling surface 31) of the roller (first roller 30) except for the chamfered portion (chamfered portion 32) of the roller (first roller 30). It means the crowning part opposite to.

The first full crowning portion 12 of the first thrust roller bearing race 10 extends annularly in the circumferential direction of the first thrust roller bearing race 10. The first full crowning portion 12 of the first thrust roller bearing raceway ring 10 is provided at the center of the raceway surface 11 of the first thrust roller bearing raceway ring 10 in the radial direction of the thrust roller bearing 1. Also good. The first full crowning portion 12 of the first thrust roller bearing race 10 is directed from the first outer flat portion 13 and the first inner flat portion 14 toward the first rolling surface 31 of the first roller 30. May swell. The first full crowning portion 12 of the first thrust roller bearing race 10 may be formed so as to be smoothly connected to the first outer flat portion 13 and the second inner flat portion 24.

The first full crowning portion 22 of the second thrust roller bearing raceway ring 20 extends annularly in the circumferential direction of the second thrust roller bearing raceway ring 20. The first full crowning portion 22 of the second thrust roller bearing race 20 is provided at the center of the raceway surface 21 of the second thrust roller bearing race 20 in the radial direction of the thrust roller bearing 1. Also good. The first full crowning portion 22 of the second thrust roller bearing race 20 is directed from the second outer flat portion 23 and the second inner flat portion 24 toward the first rolling surface 31 of the first roller 30. May swell. The first full crowning portion 22 of the second thrust roller bearing race 20 may be formed so as to be smoothly connected to the first outer flat portion 13 and the second inner flat portion 24.

5 and 6, the radial cross section of the thrust roller bearing 1 (the radial cross section of the first thrust roller bearing raceway ring 10, the radial cross section of the second thrust roller bearing raceway ring 20). The shape of the first surfaces 12s and 22s of the first full crowning portions 12 and 22 in the cross section) is a first single arc. The first full crowning portion 12 of the first thrust roller bearing race 10 has a shape of a part of a circle having a single radius of curvature r ₁ around the point O ₁ . The first full crowning portion 22 of the second thrust roller bearing race 20 has a shape of a part of a circle having a single radius of curvature r ₂ around the point O ₂ .

In the present embodiment, the radius of curvature r ₂ of the first full crowning portion 22 of the second thrust roller bearing raceway ring 20 is equal to that of the first full crowning portion 12 of the first thrust roller bearing raceway ring 10. It is equal to the curvature radius r ₁ . The radius of curvature r ₂ of the first full crowning portion 22 of the second thrust roller bearing race 20 is different from the radius of curvature r ₁ of the first full crown 12 of the first thrust roller bearing race 10. May be.

Referring to FIG. 6, the center 31c of the first rolling surface 31 of the first roller 30 in the direction in which the first roller rotating shaft 30r of the first roller 30 extends (the radial direction of the thrust roller bearing 1) is The center 12c of the first full crowning portion 12 of the first thrust roller bearing race 10 in the radial direction of the thrust roller bearing 1 may be contacted. The center 31c of the first rolling surface 31 of the first roller 30 in the direction in which the first roller rotating shaft 30r of the first roller 30 extends (the radial direction of the thrust roller bearing 1) is the diameter of the thrust roller bearing 1. You may contact the center 22c of the first full crowning portion 22 of the second thrust roller bearing race 20 in the direction.

An example of a manufacturing method of the first thrust roller bearing raceway ring 10 including the first full crowning portion 12 and the second thrust roller bearing raceway ring 20 including the first full crowning portion 22 includes the following steps. You may prepare. An annular plate member having a substantially constant thickness is prepared. The first full crowning portions 12 and 22 are formed by cutting the annular plate member so that the first full crowning portions 12 and 22 remain.

Another example of the manufacturing method of the first thrust roller bearing raceway ring 10 including the first full crowning portion 12 and the second thrust roller bearing raceway ring 20 including the first full crowning portion 22 is as follows. A process may be provided. An annular plate member having a substantially constant thickness is prepared. The first full crowning portions 12 and 22 are formed by building up a part of the annular plate member.

The first roller 30 includes a first thrust roller bearing raceway 10 and a second thrust roller bearing between the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20. The track ring 20 is disposed along the circumferential direction. The first roller 30 may be a cylindrical roller or a needle roller. The first rollers 30 are in contact with the raceway surfaces 11 and 21 of the first thrust roller bearing raceway ring 10 and the second thrust roller bearing raceway ring 20, respectively, in particular, the first full crowning portions 12 and 22. A first rolling surface 31 is provided. The first roller 30 does not have a crowning portion. Therefore, the cost of the thrust roller bearing 1 can be reduced.

Referring to FIG. 4, the first roller 30 rotates around a first roller rotation shaft 30 r along the radial direction of the thrust roller bearing 1, and the thrust roller bearing raceway ring (for the first thrust roller bearing). Rolls on the raceway surfaces 11 and 21 of the raceway ring 10 and the second thrust roller bearing raceway ring 20). The first roller 30 has a first roller length L ₁ . The first roller length L ₁ are defined in the first roller rotating shaft 30r, the distance between the first outer end face 33 of the first roller 30 and the first inner end face 34 of the first roller 30 . The first outer end 36 of the first rolling surface 31 of the first roller 30 is the end of the first rolling surface 31 on the first outer end surface 33 side. The first inner end 37 of the first rolling surface 31 of the first roller 30 is the end of the first rolling surface 31 on the first inner end surface 34 side. The first roller 30 is between the first outer end surface 33 of the first roller 30 and the first rolling surface 31 and between the first outer end surface 33 of the first roller 30 and the first rolling surface 31. Further, the chamfered portion 32 may be included.

The retainer 40 has a plurality of pockets 45 arranged at intervals in the circumferential direction. The first rollers 30 are accommodated in the pockets 45, respectively. The cage 40 holds the first roller 30 so that the first rollers 30 do not contact each other.

The operation state of the thrust roller bearing 1 of the present embodiment will be described. In the operating state of the thrust roller bearing 1, the first roller 30 accommodated in the pocket 45 of the cage 40 is a thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing). Rolling on the raceway surfaces 11 and 21 of the bearing ring 20). Specifically, the first roller 30 is provided on the first full crowning portion 12 provided on the first thrust roller bearing raceway ring 10 and on the second thrust roller bearing raceway ring 20. Roll on the first full crowning portion 22. The first thrust roller bearing race ring 10 rotates with respect to the second thrust roller bearing race ring 20 about the rotation shaft 8 via the first roller 30.

Examples of the present embodiment will be described.
FIG. 7 shows the rotational speed of the first thrust roller bearing raceway 10 relative to the second thrust roller bearing raceway 20, the temperature rise rate of the thrust roller bearing 1 of this embodiment, and the thrust roller of Comparative Example 1. The relationship with the temperature rise rate of a bearing is shown. The rotational speed of the first thrust roller bearing race 10 relative to the second thrust roller bearing race 20 is the first thrust roller bearing race relative to the second thrust roller bearing race 20 per minute. It is defined as the number of rotations of the wheel 10.

In the thrust roller bearing 1 of the present embodiment, the first full crowning portion 12 of the first thrust roller bearing race 10 has a radius of curvature r ₁ of 520 mm, and the second thrust roller bearing raceway. The first full crowning portion 22 of the ring 20 has a radius of curvature r ₂ of 520 mm. In the thrust roller bearing of Comparative Example 1, the first full crowning portions 12 and 22 are omitted from the thrust roller bearing 1 of the present embodiment.

In the thrust roller bearing 1 of the present embodiment and the thrust roller bearing of Comparative Example 1, the first roller 30 has a first roller length of 5.4 mm along the first roller rotation shaft 30r of the first roller 30. Have A thrust load of 3 kN is applied to the thrust roller bearing 1 of this example and the thrust roller bearing of Comparative Example 1. In the thrust roller bearing 1 of this example and the thrust roller bearing of Comparative Example 1, a lubricating oil having a viscosity of ISO VG32 is used. The temperature rise rates of the thrust roller bearing 1 of the present embodiment and the thrust roller bearing of the comparative example 1 are the temperature rise rates of the first main surface 15 and the second main surface 25.

As shown in FIG. 7, the temperature rise rate of the thrust roller bearing 1 of the present embodiment and the temperature rise rate of the thrust roller bearing of the comparative example 1 are both the first with respect to the second thrust roller bearing race 20. This increases as the rotational speed of the thrust roller bearing raceway 10 increases. However, the thrust roller bearing 1 of the present embodiment has a lower temperature increase rate of the thrust roller bearing 1 than the thrust roller bearing of the first comparative example. As shown in Table 1, the amount of heat generated by the thrust roller bearing 1 of this example is smaller than the amount of heat generated by the thrust roller bearing of Comparative Example 1.

The reason why the thrust roller bearing 1 of this embodiment can reduce the amount of heat generated by the thrust roller bearing 1 and the temperature increase rate of the thrust roller bearing 1 can be reduced as compared with the thrust roller bearing of the comparative example 1. This will be described below.

FIG. 8 shows the position d on the first rolling surface 31 of the first roller 30 in the radial direction of the thrust roller bearing 1 and the calorific value h ₁ per unit length at the position d in this embodiment. Show the relationship. In this specification, the calorific value per unit length at the position d is normalized by the length at which the first rolling surface 31 and the raceway surfaces 11 and 21 are in line contact with each other. It is defined as the amount of heat generated between the surface 31 and the raceway surfaces 11 and 21. FIG. 9 shows the position d on the first rolling surface 31 of the first roller 30 in the radial direction of the thrust roller bearing 1 and the first rolling of the first roller 30 at the position d in this embodiment. It shows the relationship between the contact surface pressure P ₁ between the surface 31 and the raceway surfaces 11, 21. With reference to FIG. 6, the position of the center 31 c on the first rolling surface 31 of the first roller 30 in the radial direction of the thrust roller bearing 1 is defined as d = 0. The position d on the first rolling surface 31 of the first roller 30 located outside the center 31c of the first roller 30 is defined as a positive position (d> 0). The position d on the first rolling surface 31 of the first roller 30 located inside the center 31c of the first roller 30 is defined as a negative position (d <0).

At the center 31 c of the first roller 30, the first rolling surface 31 of the first roller 30 is a thrust roller bearing raceway (first thrust roller bearing raceway 10, second thrust roller bearing raceway). It is in line contact with the raceway surfaces 11 and 21 of the ring 20). At the center 31 c of the first roller 30, the peripheral speed of the raceway surface 11 of the first thrust roller bearing raceway 10 with respect to the raceway surface 21 of the second thrust roller bearing raceway 20 is the same as that of the first roller 30. It is equal to the peripheral speed of the first rolling surface 31. At the center 31 c of the first roller 30, the first rolling surface 31 of the first roller 30 does not slide with respect to the raceway surfaces 11 and 21. Therefore, at the center 31 c of the first roller 30, no heat is generated due to differential slip between the first rolling surface 31 of the first roller 30 and the raceway surfaces 11 and 21. The calorific value h ₁ per unit length at the center 31c of the first roller 30 is 0 [W / mm].

On the other hand, as the position d of the first roller 30 moves away from the center 31c of the first roller 30, the first rolling surface 31 of the first roller 30 increases with respect to the raceway surfaces 11 and 21. slide. Specifically, the peripheral speed of the first rolling surface 31 of the first roller 30 is constant regardless of the position d on the first rolling surface 31 of the first roller 30. On the other hand, the circumferential speed of the raceway surface 11 of the first thrust roller bearing raceway 10 relative to the raceway surface 21 of the second thrust roller bearing raceway 20 is changed from the rotary shaft 8 of the thrust roller bearing 1 to the thrust roller bearing. Increasing toward the outside of 1. As the position d of the first roller 30 moves away from the center 31 c of the first roller 30, the circumferential speed of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the first rolling surface of the first roller 30. The difference between the peripheral speed of 31 increases. Therefore, the differential slip between the first rolling surface 31 of the first roller 30 and the raceway surfaces 11 and 21 increases as the position d of the first roller 30 moves away from the center 31c of the first roller 30. Become. As the differential slip increases, the heat generated between the first rolling surface 31 of the first roller 30 and the raceway surfaces 11 and 21 increases. Hereinafter, this heat is defined as heat resulting from an increase in the peripheral speed difference.

As the contact surface pressure P ₁ between the first rolling surface 31 of the first roller 30 and the raceway surfaces 11 and 21 increases (decreases), this differential slip causes the first rolling of the first roller 30. Heat generated between the surface 31 and the raceway surfaces 11 and 21 increases (decreases). Hereinafter, this increased (decreased) heat is defined as heat due to contact surface pressure.

In this embodiment, the raceway surfaces 11, 21 of the thrust roller bearing raceway (first thrust roller bearing raceway 10, second thrust roller bearing raceway 20) are in contact with the first roller 30. The first full crowning portions 12 and 22 are provided. The first full in the radial section of the thrust roller bearing 1 (the radial section of the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20)). The shape of the first surfaces 12s and 22s of the crowning portions 12 and 22 is a first single arc. Since the shape of the first surfaces 12 s and 22 s of the first full crowning portions 12 and 22 is a first single arc, the position d of the first roller 30 moves away from the center 31 c of the first roller 30. The first surfaces 12 s and 22 s of the first full crowning portions 12 and 22 have a shape away from the first rolling surface 31 of the first roller 30. Therefore, as shown in FIG. 9, as the position d of the first roller 30 moves away from the center 31 c of the first roller 30, the first rolling surface 31 and the raceway surfaces 11, 21 of the first roller 30 The contact pressure P ₁ during the period decreases, and the heat caused by the contact pressure P ₁ decreases.

A thrust load is applied to the thrust roller bearing 1, and the first thrust roller bearing raceway ring 10, the second thrust roller bearing raceway ring 20 and the first roller 30 are elastically deformed. Therefore, in the region A shown in FIGS. 8 and 9, the first rolling surface 31 of the first roller 30 is a thrust roller bearing raceway (first thrust roller bearing raceway 10, second thrust roller). It is in line contact with the raceway surfaces 11 and 21 of the roller bearing raceway ring 20). In the region A, the influence of the increase in heat caused by the increase in the peripheral speed difference is larger than the influence of the decrease in heat caused by the decrease in the contact surface pressure. Therefore, in the region A, the position d of the first roller 30 moves away from the first roller 30 of the center 31c, the heating value h ₁ per unit length at the position d of the first roller 30 is increased.

Also in the region B shown in FIGS. 8 and 9, the first rolling surface 31 of the first roller 30 is in line contact with the raceway surfaces 11 and 21 as in the region A. However, since the shape of the first surfaces 12 s and 22 s of the first full crowning portions 12 and 22 is a first single arc, in the region B, the first of the first rollers 30 is further increased than the region A. The contact surface pressure P ₁ between the rolling surface 31 and the raceway surfaces 11 and 21 decreases. In the region B, the influence of the heat reduction due to the decrease in the contact surface pressure is larger than the influence of the heat increase due to the increase in the peripheral speed difference. Therefore, in the region B, the position d of the first roller 30 moves away from the first roller 30 of the center 31c, the heating value h ₁ per unit length at the position d of the first roller 30 is reduced.

The shape of the first surfaces 12s and 22s of the first full crowning portions 12 and 22 is a first single arc. The first surfaces 12 s and 22 s of the first full crowning portions 12 and 22 cause the first rolling of the first roller 30 as the position d of the first roller 30 moves away from the center 31 c of the first roller 30. It has a shape away from the surface 31. Therefore, in the region C shown in FIGS. 8 and 9, even if the first thrust roller bearing raceway ring 10, the second thrust roller bearing raceway ring 20 and the first roller 30 are elastically deformed, the first The first rolling surface 31 of the roller 30 is not in line contact with the raceway surfaces 11 and 21.

In the region C, the first rolling surface 31 of the first roller 30 and the raceway surface 11 of the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20). , 21 does not generate differential slip. In the region C, the first rolling surface 31 of the first roller 30 and the raceway surface 11 of the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20). , the contact surface pressure P ₁ between 21 becomes zero. In the region C, the heat generation amount h ₁ per unit length at the position d of the first roller 30 is zero. The first full crowning parts 12 and 22 of the present embodiment can prevent the occurrence of edge loading in Comparative Example 1 described later.

FIG. 10 shows the position d on the first rolling surface 31 of the first roller 30 in the radial direction of the thrust roller bearing 1 and the calorific value h ₂ per unit length at the position d in Comparative Example 1. Show the relationship. FIG. 11 shows a position d on the first rolling surface 31 of the first roller 30 in the radial direction of the thrust roller bearing 1 in Comparative Example 1, and a rolling surface of the first roller 30 at the position d. It shows the relationship between the contact surface pressure P ₂ between the raceway surface of the bearing ring for a thrust roller bearing.

In Comparative Example 1, the raceway surface of the thrust roller bearing raceway is flat and does not have the first full crowning portions 12 and 22. A thrust load is applied to the thrust roller bearing raceway, and the thrust roller bearing raceway and the first roller 30 are elastically deformed. Therefore, the first rolling surface 31 of the first roller 30 is in line contact with the raceway surface of the thrust roller bearing raceway.

As shown in FIG. 11, as the position d of the first roller 30 moves away from the center 31 c of the first roller 30, the first rolling surface 31 of the first roller 30 and the raceway of the thrust roller bearing raceway. The contact pressure P ₂ between the surfaces increases. In particular, in Comparative Example 1, the first rolling surface of the first roller 30 at the end of the first rolling surface 31 of the first roller 30 (the first outer end 36 and the first inner end 37). The contact surface pressure P ₂ between 31 and the raceway surface of the thrust roller bearing raceway abruptly increases. In Comparative Example 1, between the end portion (first outer end portion 36, first inner end portion 37) of the first rolling surface 31 of the first roller 30 and the raceway surface of the thrust roller bearing raceway, A large edge load occurs.

Therefore, in Comparative Example 1, as the position d of the first roller 30 moves away from the center 31c of the first roller 30, the heat due to the circumferential speed difference increases and the heat due to the contact surface pressure P ₂ also increases. To increase. As shown in FIG. 10, in Comparative Example 1, as the position d of the first roller 30 moves away from the center 31 c of the first roller 30, the first rolling surface 31 of the first roller 30 and the thrust roller bearing. The heat generated between the bearing ring and the raceway surface increases rapidly.

In this way, the thrust roller bearing 1 of the present embodiment has a first rolling surface 31 of the first roller 30 and a thrust roller bearing raceway (the first roller bearing 1) compared to the thrust roller bearing 1 of the first comparative example. Heat generated between the raceway surfaces 10 and 21 of the thrust roller bearing raceway ring 10 and the second thrust roller bearing raceway ring 20) can be reduced. Compared with the thrust roller bearing of Comparative Example 1, the thrust roller bearing 1 of the present embodiment can suppress the temperature rise of the thrust roller bearing 1.

As shown in Table 2, in the thrust roller bearing 1 of this example, the first rolling surface 31 of the first roller 30 has a thrust roller bearing raceway than the thrust roller bearings of Comparative Example 2 and Comparative Example 3. Heat generated by sliding with respect to the raceway surfaces 11 and 21 of the rings (first thrust roller bearing raceway ring 10 and second thrust roller bearing raceway ring 20) can be reduced.

In the thrust roller bearing of Comparative Example 2, the raceway surface of the thrust roller bearing raceway has logarithmic full crowning portions instead of the first full crowning portions 12 and 22 of the thrust roller bearing 1 of this embodiment. Yes. The shape of the surface of the logarithmic full crowning portion in the radial cross section of the thrust roller bearing (the radial cross section of the thrust roller bearing raceway) is a logarithmic curve. In the thrust roller bearing of Comparative Example 3, the raceway surface of the thrust roller bearing raceway has a partial crowning portion instead of the first full crowning portions 12 and 22 of the thrust roller bearing 1 of this embodiment. . The partial crowning portion means a crowning portion that faces only a part of the rolling surface (first rolling surface 31) of the roller (first roller 30).

The thrust load is applied to the thrust roller bearing 1, and the first thrust roller bearing raceway ring 10, the second thrust roller bearing raceway ring 20 and the first roller 30 are elastically deformed. The first rolling surface 31 of the first roller 30 is in line contact with the raceway surfaces 11 and 21. Since the shape of the first surfaces 12 s and 22 s of the first full crowning portions 12 and 22 is a first single circular arc, the first roller 30 is more suitable than the second comparative example and the third comparative example. The length of the first rolling surface 31 in line contact with the raceway surfaces 11 and 21 can be reduced. Therefore, in the thrust roller bearing 1 of the present embodiment, the first rolling surface 31 of the first roller 30 has a thrust roller bearing raceway ring (first thrust roller bearing raceway ring 10, second thrust roller bearing use). Heat generated by sliding with respect to the raceway surfaces 11 and 21 of the raceway ring 20) can be reduced.

FIG. 12 shows the relationship among the radii of curvature r ₁ and r _{2 of} the first full crowning portions 12 and 22, the center contact surface pressure, and the edge contact surface pressure in the present embodiment. The edge contact surface pressure is the first rolling surface 31 of the first roller 30 at the end (first outer end 36, first inner end 37) of the first rolling surface 31 of the first roller 30. And the contact surface pressure between the raceway surfaces 11 and 21 of the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) of the present embodiment. Is done. The center contact surface pressure is determined by the first rolling surface 31 of the first roller 30 and the thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway) at the center 31c of the first roller 30. 10, the contact surface pressure between the raceway surfaces 11 and 21 of the second thrust roller bearing raceway ring 20).

When the edge contact surface pressure increases, at the contact portion between the end portion (first outer end portion 36, first inner end portion 37) of the first rolling surface 31 of the first roller 30 and the raceway surfaces 11 and 21, The thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20) is damaged. In order to prevent such damage of the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20), the edge contact surface pressure is 2.6 GPa or less. It may be 2.49 GPa or less, 2.15 GPa or less, or 1.6 GPa or less. In order to prevent the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20) from being damaged, the first full crowning of the present embodiment is used. The curvature radii r ₁ and r ₂ of the portions 12 and 22 may be 2100 mm or less, 2000 nm or less, 1600 mm or less, or 1200 mm or less.

The raceway surfaces 11, 21 of the thrust roller bearing raceway (first thrust roller bearing raceway 10, second thrust roller bearing raceway 20) of the present embodiment are the first full crowning portion 12, 22. Therefore, as shown in FIGS. 9 and 11, the center contact surface pressure of the present embodiment _{(P 1 (d = 0)} ) , the center contact surface pressure _{(P 2 (d = 0)} ) of Comparative Example 1 Bigger than.

When the center contact surface pressure in the present embodiment increases, the center 31c of the first roller 30 and the thrust roller bearing raceway of the present embodiment (the first thrust roller bearing raceway 10, the second thrust roller). At the contact portions of the bearing race 20) with the raceways 11 and 21, the thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10 and second thrust roller bearing raceway). 20) will be damaged. In order to prevent the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) from being damaged, the center contact surface pressure of the present embodiment is 2.0 GPa or less, 1.8 GPa or less, 1.7 GPa or less, or 1.67 GPa or less. In order to prevent the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20) from being damaged, the first full crowning of the present embodiment is used. The curvature radii r ₁ and r ₂ of the portions 12 and 22 may be 250 mm or more, 445 mm or more, 600 mm or more, or 720 mm or more.

The effects of the thrust roller bearing 1 and the thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) will be described.

The thrust roller bearing 1 of the present embodiment includes a first thrust roller bearing raceway ring 10, a second thrust roller bearing raceway ring 20, a first thrust roller bearing raceway ring 10 and a second thrust roller. A plurality of first rollers 30 arranged along the circumferential direction of the first thrust roller bearing raceway ring 10 and the second thrust roller bearing raceway ring 20 between the roller bearing raceway ring 20. Prepare. The first thrust roller bearing raceway ring 10 and the second thrust roller bearing raceway ring 20 each include raceway surfaces 11 and 21 on which the first roller 30 rolls. At least one of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the raceway surface 21 of the second thrust roller bearing raceway ring 20 contacts the first roller 30 with the first full crowning portion 12. , 22. The shape of the first surfaces 12s and 22s of the first full crowning portions 12 and 22 in the radial cross section of the thrust roller bearing 1 is a first single arc.

The first full crowning portions 12 and 22 in which the shapes of the first surfaces 12s and 22s are first single circular arcs can reduce the heat caused by the difference in peripheral speed and the heat caused by the contact surface pressure. . In the thrust roller bearing 1 of the present embodiment, the first rolling surface 31 of the first roller 30 is a thrust roller bearing raceway (first thrust roller bearing raceway 10, second thrust roller bearing raceway). Heat generated by sliding with respect to the raceway surfaces 11 and 21 of the wheel 20) can be reduced. The thrust roller bearing 1 according to the present embodiment causes the raceway surface 11 of the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) due to this heat. , 21 can be prevented from occurring.

The first full crowning portions 12 and 22 in which the shapes of the first surfaces 12s and 22s are the first single arc are the end portions of the first roller 30 (the first outer end portion 36 and the first inner end portion). 37) and the raceway surfaces 11 and 21 of the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) are reduced. Can do. In the thrust roller bearing 1 according to the present embodiment, the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20) is damaged due to the edge load. It can be prevented from receiving.

In the thrust roller bearing 1 of the present embodiment, the first single arc has radii of curvature r ₁ and r ₂ of 250 mm or more and 2100 mm or less. Therefore, the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) can be prevented from being damaged.

The thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) has a raceway surface 11 on which a plurality of first rollers 30 roll. , 21 are provided. The raceway surfaces 11 and 21 have first full crowning portions 12 and 22 that contact the first rollers 30. First surfaces 12 s of the first full crowning portions 12, 22 in the radial cross section of the thrust roller bearing raceway (first thrust roller bearing raceway 10, second thrust roller bearing raceway 20). , 22s is a first single arc.

The first full crowning portions 12 and 22 in which the shapes of the first surfaces 12s and 22s are first single circular arcs can reduce the heat caused by the difference in peripheral speed and the heat caused by the contact surface pressure. . In the thrust roller bearing raceway (first thrust roller bearing raceway 10, second thrust roller bearing raceway 20) of the present embodiment, the first roller 30 is a thrust roller bearing raceway (first Heat generated by sliding with respect to the raceway surfaces 11 and 21 of the first thrust roller bearing raceway ring 10 and the second thrust roller bearing raceway ring 20) can be reduced. The thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) of the present embodiment is caused by this heat, and the thrust roller bearing raceway (first thrust roller bearing raceway 10). It is possible to prevent the surface starting point separation from occurring on the raceway surfaces 11 and 21 of the first thrust roller bearing raceway ring 10 and the second thrust roller bearing raceway ring 20).

The first full crowning portions 12 and 22 in which the shapes of the first surfaces 12s and 22s are the first single arc are the end portions of the first roller 30 (the first outer end portion 36 and the first inner end portion). 37) and the raceway surfaces 11 and 21 of the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) are reduced. Can do. The thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20) of the present embodiment is caused by this edge load. It is possible to prevent the first thrust roller bearing raceway ring 10 and the second thrust roller bearing raceway ring 20) from being damaged.

In the thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20), the first single arc has a curvature of 250 mm or more and 2100 mm or less. It has radii r ₁ and r ₂ . Therefore, the thrust roller bearing raceway (first thrust roller bearing raceway 10 and second thrust roller bearing raceway 20) can be prevented from being damaged.

(Embodiment 2)
With reference to FIG. 13, the thrust roller bearing 1a and the thrust roller bearing raceway (the first thrust roller bearing raceway 10a, the second thrust roller bearing raceway 20a) according to the second embodiment will be described. . The thrust roller bearing 1a and the thrust roller bearing raceway (the first thrust roller bearing raceway 10a and the second thrust roller bearing raceway 20a) of the present embodiment are the same as the thrust roller bearing 1 of the first embodiment. And the same configuration as the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20), but mainly differs in the following points.

In the thrust roller bearing 1a of the present embodiment, the first roller 30a is a tapered roller. The first roller 30 a that is a tapered roller has a diameter that gradually increases from the first inner end 37 toward the first outer end 36.

In the thrust roller bearing 1a of the present embodiment, the raceway surfaces 11a and 21a of the first thrust roller bearing raceway 10a have the first outer flat portion 13 and the first inner flat portion shown in FIGS. The part 14 is not included. The first thrust roller bearing race 10a includes a first outer flange 51 located outside the raceway surface 11a and a first inner flange 52 located inside the raceway surface 11a. Contains. The first outer flange 51 and the first inner flange 52 restrict the position of the first roller 30a in the radial direction of the thrust roller bearing 1a. At least one of the first outer flange 51 and the first inner flange 52 may be in contact with the first roller 30a to guide the first roller 30a.

In the thrust roller bearing 1a of the present embodiment, the raceway surfaces 11a and 21a of the second thrust roller bearing raceway 20a have the second outer flat portion 23 and the second inner flatness shown in FIGS. The part 24 is not included. The second thrust roller bearing race 20a includes a second outer flange 56 located outside the raceway surface 21a and a second inner flange 57 located inside the raceway surface 21a. Contains. The second outer flange 56 and the second inner flange 57 regulate the position of the first roller 30a in the radial direction of the thrust roller bearing 1a. At least one of the second outer flange 56 and the second inner flange 57 may be in contact with the first roller 30a to guide the first roller 30a.

Referring to FIG. 14, the thrust roller bearing 1 b and the thrust roller bearing raceway (first thrust roller bearing raceway 10 a, second thrust roller bearing raceway 20) according to a modification of the present embodiment. Will be explained. The thrust roller bearing 1b and the thrust roller bearing raceway (first thrust roller bearing raceway 10a, second thrust roller bearing raceway 20) of the modification of the present embodiment are the thrusts of the present embodiment. Although it has the same configuration as the roller bearing 1a and the thrust roller bearing raceway (first thrust roller bearing raceway 10a, second thrust roller bearing raceway 20a), it differs mainly in the following points.

The second thrust roller bearing race 20 of the modification of the present embodiment has the same configuration as the second thrust roller bearing race 20 of the first embodiment. The raceway surface 21 of the second thrust roller bearing race 20 of the modification of the present embodiment includes a second outer flat portion 23 and a second inner flat portion 24. The second thrust roller bearing race 20 of the modification of the present embodiment does not include the second outer flange 56 and the second inner flange 57 shown in FIG.

The cage 40b of the modification of the present embodiment includes an inclined portion 43 that is inclined so as to be separated from the raceway surface 21 of the second thrust roller bearing raceway ring 20 from the inside to the outside of the thrust roller bearing 1b. Yes. The pocket 45 that accommodates the first roller 30 a is disposed in the inclined portion 43.

In addition to the effects of the thrust roller bearing 1 of the first embodiment, the effects of the thrust roller bearings 1a and 1b of the present embodiment and its modifications are as follows.

The first roller 30 a that is a tapered roller has a diameter that gradually increases from the first inner end 37 toward the first outer end 36. As it goes from the first inner end 37 toward the first outer end 36, the peripheral speed of the first rolling surface 31 of the first roller 30a increases. The first roller 30a, which is a tapered roller, has a first rolling motion of the first roller 30a in the radial direction of the thrust roller bearings 1a, 1b (the direction in which the first roller rotating shaft of the first roller 30a extends). The difference between the circumferential speed of the surface 31 and the circumferential speed of the raceway surface 11a of the first thrust roller bearing raceway ring 10a can be reduced.

Therefore, the thrust roller bearings 1a and 1b of the present embodiment and its modifications are thrust roller bearing race rings (first thrust roller bearing race ring 10a, second thrust roller bearing race rings 20 and 20a). It is possible to reduce the slip of the first roller 30a with respect to the raceway surfaces 11a, 21 and 21a, and to reduce the heat generated by the slip. The thrust roller bearings 1a and 1b of the present embodiment cause the thrust roller bearing raceway (first thrust roller bearing raceway 10a, second thrust roller bearing raceway 20 and 20a) due to this heat. It is possible to prevent the surface starting point peeling from occurring on the track surfaces 11a, 21 and 21a.

(Embodiment 3)
Referring to FIGS. 15 to 17, thrust roller bearing 1c and thrust roller bearing raceway according to Embodiment 3 (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c). Will be explained. The thrust roller bearing 1c and the thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) of the present embodiment are the same as the thrust roller bearing 1 of the first embodiment. And the same configuration as the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20), but mainly differs in the following points.

As shown in FIG. 15, the thrust roller bearing 1c of the present embodiment includes double-row rollers (first roller 30c, second roller 60). Specifically, the thrust roller bearing 1c of the present embodiment includes a plurality of second rollers 60 between the first thrust roller bearing raceway ring 10c and the second thrust roller bearing raceway ring 20c. Further prepare. The second roller 60 is disposed along the circumferential direction of the first thrust roller bearing race 10c and the second thrust roller bearing race 20c. The second roller 60 is disposed on the inner side with respect to the first roller 30c. The second roller 60 rolls on the raceway surfaces 11c and 21c of the thrust roller bearing raceway (the first thrust roller bearing raceway 10c and the second thrust roller bearing raceway 20c).

In the present embodiment, the raceway surface 11c of the first thrust roller bearing raceway ring 10c has the second full crowning portion 16 that comes into contact with the second roller 60, and for the second thrust roller bearing. The raceway surface 21 c of the raceway 20 c has a second full crowning portion 26 that contacts the second roller 60. A second full crowning portion 16 in which at least one of the raceway surface 11c of the first thrust roller bearing raceway ring 10c and the raceway surface 21c of the second thrust roller bearing raceway ring 20c contacts the second roller 60, 26 may be included. The second full crowning portion 16 is located inside the first full crowning portion 12, and the second full crowning portion 26 is located inside the first full crowning portion 22.

The first thrust roller bearing raceway ring 10 c may have a first inner flat portion 14 on the outer side with respect to the second full crowning portion 16. The first thrust roller bearing raceway 10 c may have a third flat portion 17 inside the second full crowning portion 16. The second full crowning portion 16 may bulge from the first inner flat portion 14 and the third flat portion 17 toward the first rolling surface 31 of the first roller 30. The second full crowning portion 16 may be formed so as to be smoothly connected to the first inner flat portion 14 and the third flat portion 17.

The second thrust roller bearing raceway 20 c may have a second inner flat portion 24 on the outer side with respect to the second full crowning portion 26. The second thrust roller bearing race 20 c may have a fourth flat portion 27 inside the second full crowning portion 26. The second full crowning portion 26 may bulge from the second inner flat portion 24 and the fourth flat portion 27 toward the first rolling surface 31 of the first roller 30. The second full crowning portion 26 may be formed so as to be smoothly connected to the second inner flat portion 24 and the fourth flat portion 27.

The raceway surface 11 c includes a first surface 12 s of the first full crowning portion 12 and a second surface 16 s of the second full crowning portion 16. The raceway surface 11 c may further include a first outer flat portion 13 on the outer side with respect to the first full crowning portion 12. The raceway surface 21 c includes a first surface 22 s of the first full crowning portion 22 and a second surface 26 s of the second full crowning portion 26. The raceway surface 21 c may further include a second outer flat portion 23 on the outer side with respect to the first full crowning portion 22.

Second full crowning portion 16 in the radial cross section of thrust roller bearing 1c (the radial cross section of first thrust roller bearing raceway ring 10c, the radial cross section of second thrust roller bearing raceway ring 20c). 26, the second surfaces 16s and 26s have a second single arc shape. The radius of curvature of the second full crowning portions 16 and 26 may be equal to the radius of curvature of the first full crowning portions 12 and 22. The curvature radii of the second full crowning portions 16 and 26 may be different from the curvature radii of the first full crowning portions 12 and 22.

End portions (second outer end portion 66, second inner end portion 67) of second roller 60 and thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway) In order to prevent the thrust roller bearing raceway (the first thrust roller bearing raceway 10c and the second thrust roller bearing raceway 20c) from being damaged at the contact portions of the raceway 20c) with the raceway surfaces 11c and 21c. The radius of curvature of the second full crowning portions 16 and 26 of the present embodiment may be 2100 mm or less, 2000 nm or less, 1600 mm or less, or 1200 mm or less. Good. In order to prevent such damage to the thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c), the second of the present embodiment. The radius of curvature of the full crowning portions 16, 26 may be 250 mm or more, 445 mm or more, 600 mm or more, or 720 mm or more.

The first roller 30c of the present embodiment has the same configuration as the first roller 30 of the first embodiment, but differs in the following points. The first roller length L _1c of the first roller 30c of the present embodiment (see FIG. 16), the first roller length L ₁ of the first roller 30 of the first embodiment (see FIG. 4) Shorter than.

Referring to FIG. 17, the second roller 60 has a length L ₂ second rollers. Roller length L ₂ of the second, is defined in the second roller rotation axis 60r, as the distance between the second outer end face 63 of the second roller 60 and the second inner end face 64 of the second roller 60 . The second roller 60 rotates around the second roller rotation shaft 60r along the radial direction of the thrust roller bearing 1c, while the thrust roller bearing raceway (the first thrust roller bearing raceway 10c, the second Rolls on the raceway surfaces 11c and 21c of the thrust roller bearing raceway 20c). The second outer end portion 66 of the second rolling surface 61 of the second roller 60 is an end portion of the second rolling surface 61 on the second outer end surface 63 side. A second inner end 67 of the second rolling surface 61 of the second roller 60 is an end of the second rolling surface 61 on the second inner end surface 64 side. The second roller 60 is between the second outer end surface 63 and the second rolling surface 61 of the second roller 60 and between the second inner end surface 64 and the second rolling surface 61 of the second roller 60. Further, a chamfer 62 may be included.

The second roller 60 of the present embodiment has a configuration similar to that of the first roller 30 of the first embodiment, but differs in the following points. The second roller length L ₂ of the second roller 60 of the present embodiment (see FIG. 17) is the first roller length L ₁ of the first roller 30 of the first embodiment (see FIG. 4). Shorter than. The sum of the first roller length L _1c of the first roller 30c of the present embodiment and the second roller length L ₂ of the second roller 60 is the first roller length of the first embodiment. It may be shorter than L ₁ . The second roller 60 may have the same configuration as the first roller 30c.

The effects of the thrust roller bearing 1c and the thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) of the present embodiment are the same as the thrust roller of the first embodiment. In addition to the effects of the bearing 1 and the thrust roller bearing raceway (the first thrust roller bearing raceway 10 and the second thrust roller bearing raceway 20), the following advantages are achieved.

In the thrust roller bearing 1c of the present embodiment, the first thrust roller bearing raceway 10c and the second thrust roller bearing raceway 10c and the second thrust roller bearing raceway ring 20c and the second thrust roller bearing raceway ring 20c are provided. And a plurality of second rollers 60 arranged along the circumferential direction of the thrust roller bearing raceway 20c. The second roller 60 rolls on the raceway surface 11c of the first thrust roller bearing raceway ring 10c and the raceway surface 21c of the second thrust roller bearing raceway ring 20c. At least one of the raceway surface 11 c of the first thrust roller bearing raceway ring 10 c and the raceway surface 21 c of the second thrust roller bearing raceway ring 20 c is in contact with the second roller 60. , 26. The second full crowning portions 16 and 26 are located inside the first full crowning portions 12 and 22. The shape of the second surfaces 16s and 26s of the second full crowning portions 16 and 26 in the radial cross section of the thrust roller bearing 1c is a second single arc.

The thrust roller bearing 1c of the present embodiment includes a first roller 30c and a second roller 60 between a first thrust roller bearing raceway ring 10c and a second thrust roller bearing raceway ring 20c. Contains. The second roller 60 that contacts the second full crowning portions 16 and 26 is disposed on the inner side with respect to the first roller 30 c that contacts the first full crowning portions 12 and 22. The peripheral speed of the second rolling surface 61 of the second roller 60 can be lower than the peripheral speed of the second rolling surface 61 of the first roller 30c.

The second difference between the circumferential speed of the raceway surface 11c of the first thrust roller bearing raceway ring 10c and the circumferential speed of the first rolling surface 31 of the first roller 30c in the present embodiment is This is less than the first difference between the circumferential speed of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the circumferential speed of the first rolling surface 31 of the first roller 30 in the first mode. The third difference between the circumferential speed of the raceway surface 11c of the first thrust roller bearing raceway ring 10c and the circumferential speed of the second rolling surface 61 of the second roller 60 in the present embodiment is This is less than the first difference between the circumferential speed of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the circumferential speed of the first rolling surface 31 of the first roller 30 in the first mode.

Therefore, compared with the first rolling surface 31 of the first roller 30 of the first embodiment, the first rolling surface 31 of the first roller 30c and the second rolling of the second roller 60 of the present embodiment. The moving surface 61 slides less with respect to the raceway surfaces 11c and 21c. The thrust roller bearing 1c of the present embodiment is generated when the first rolling surface 31 of the first roller 30c and the second rolling surface 61 of the second roller 60 slide with respect to the raceway surfaces 11c and 21c. Heat can be reduced. The thrust roller bearing 1c according to the present embodiment causes the raceway surface 11c of the thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) due to this heat. , 21 c can be prevented from occurring.

The second full crowning portions 16 and 26 in which the shapes of the second surfaces 16s and 26s are the second single arc are the end portions of the second roller 60 (second outer end portion 66 and second inner end portion). 67) and the second rolling surface 61 of the second roller 60 and the raceway surface 11c of the thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c). , 21 c can be reduced. The second full crowning portions 16 and 26 in which the shapes of the second surfaces 16s and 26s are the second single arc are the end portions of the second roller 60 (second outer end portion 66 and second inner end portion). 67) and the thrust roller bearing raceway (the first thrust roller bearing raceway 10c and the second thrust roller bearing raceway 20c) are reduced in edge load. Can do. In the thrust roller bearing 1c of the present embodiment, the thrust roller bearing raceway (the first thrust roller bearing raceway 10c and the second thrust roller bearing raceway 20c) is damaged due to the edge load. It can be prevented from receiving.

In the thrust roller bearing 1c of the present embodiment, not only the first roller 30c but also the second roller 60 receives a thrust load. Therefore, the thrust roller bearing 1c of the present embodiment can withstand a larger thrust load.

In the thrust roller bearing 1c of the present embodiment, the second single circular arc may have a radius of curvature of 250 mm or more and 2100 mm or less. Therefore, the thrust roller bearing raceway (the first thrust roller bearing raceway 10c, the second thrust roller bearing raceway 20c) can be prevented from being damaged.

The thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) is a plurality of second rolling elements rolling on raceway surfaces 11c and 21c. Second full crowning portions 16 and 26 that contact the roller 60 are further provided. The second full crowning portions 16 and 26 are located inside the first full crowning portions 12 and 22. Second surface 16s of second full crowning portions 16, 26 in the radial cross section of the thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c). , 26s is a second single arc.

The thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) includes first full crowning portions 12 and 22, Second full crowning portions 16 and 26 located inside the full crowning portions 12 and 22 are included. The 2nd roller 60 which contacts the 2nd full crowning parts 16 and 26 may be arranged inside the 1st roller 30c. Therefore, the peripheral speed of the second rolling surface 61 of the second roller 60 can be lower than the peripheral speed of the first rolling surface 31 of the first roller 30a.

The second difference between the circumferential speed of the raceway surface 11c of the first thrust roller bearing raceway ring 10c and the circumferential speed of the first rolling surface 31 of the first roller 30c in the present embodiment is This is less than the first difference between the circumferential speed of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the circumferential speed of the first rolling surface 31 of the first roller 30 in the first mode. The third difference between the circumferential speed of the raceway surface 11c of the first thrust roller bearing raceway ring 10c and the circumferential speed of the second rolling surface 61 of the second roller 60 in the present embodiment is This is less than the first difference between the circumferential speed of the raceway surface 11 of the first thrust roller bearing raceway ring 10 and the circumferential speed of the first rolling surface 31 of the first roller 30 in the first mode.

Therefore, compared with the first rolling surface 31 of the first roller 30 of the first embodiment, the first rolling surface 31 of the first roller 30c and the second rolling of the second roller 60 of the present embodiment. The moving surface 61 slides less with respect to the raceway surfaces 11c and 21c. The thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) of the present embodiment includes the first rolling surface 31 and the first rolling surface 31 of the first roller 30c. The second rolling surface 61 of the second roller 60 is relative to the raceway surfaces 11c and 21c of the thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c). Heat generated by sliding can be reduced. The thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) of the present embodiment is caused by this heat, and the thrust roller bearing raceway (first thrust roller bearing raceway (first thrust roller bearing raceway 20c)). It is possible to prevent the surface starting point peeling from occurring on the raceway surfaces 11c and 21c of the first thrust roller bearing raceway ring 10c and the second thrust roller bearing raceway ring 20c).

The second full crowning portions 16 and 26 in which the shapes of the second surfaces 16s and 26s are the second single arc are the end portions of the second roller 60 (second outer end portion 66 and second inner end portion). 67), the contact surface pressure between the second rolling surface 61 of the second roller 60 and the raceway surfaces 11c and 21c can be reduced. The second full crowning portions 16 and 26 in which the shapes of the second surfaces 16s and 26s are the second single arc are the end portions of the second roller 60 (second outer end portion 66 and second inner end portion). 67) and the edge load generated between the track surfaces 11c and 21c can be reduced. The thrust roller bearing raceway (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c) of the present embodiment is caused by this edge load, and the thrust roller bearing raceway ( It is possible to prevent the first thrust roller bearing race 10c and the second thrust roller bearing race 20c) from being damaged.

In the thrust roller bearing raceway of the present embodiment (first thrust roller bearing raceway 10c, second thrust roller bearing raceway 20c), the second single arc has a curvature of 250 mm or more and 2100 mm or less. It may have a radius. Therefore, the thrust roller bearing raceway (the first thrust roller bearing raceway 10c, the second thrust roller bearing raceway 20c) can be prevented from being damaged.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. For example, at least one of the first outer collar part 51, the first inner collar part 52, the second outer collar part 56, and the second inner collar part 57 of the second embodiment and the modifications thereof is the embodiment. 1 and the thrust roller bearing 1c of the third embodiment may be provided. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1, 1a, 1b, 1c thrust roller bearing, 8 rotary shafts, 10, 10a, 10c first thrust roller bearing raceway, 11, 11a, 11c raceway surface, 12, 22 first full crowning portion, 12c, 22c center, 12s, 22s first surface, 13 first outer flat part, 14 first inner flat part, 15 first main surface, 16, 26 second full crowning part, 16s, 26s second Surface, 17 third flat portion, 20, 20a, 20c second thrust roller bearing raceway, 21, 21a, 21c raceway surface, 23 second outer flat portion, 24 second inner flat portion, 25th 2 main surface, 27, fourth flat portion, 30, 30a, 30c, first roller, 30r, first roller rotating shaft, 31, first rolling surface, 31c center, 32, 62 chamfered portion, 33 1 outer end surface, 34 first inner end surface, 36 first outer end portion, 37 first inner end portion, 40, 40b cage, 43 inclined portion, 45 pocket, 51 first outer collar portion, 52 first inner side Buttock, 56 second outer ridge, 57 second inner ridge, 60 second roller, 60r second roller rotating shaft, 61 second rolling surface, 63 second outer end surface, 64 second inner end surface 66 second outer end, 67 second inner end.

Claims (11)

1. A thrust roller bearing,
   A first thrust roller bearing raceway;
   A second thrust roller bearing raceway,
   Circumferential directions of the first thrust roller bearing raceway and the second thrust roller bearing raceway between the first thrust roller bearing raceway and the second thrust roller bearing raceway And a plurality of first rollers arranged along the
   Each of the first thrust roller bearing raceway and the second thrust roller bearing raceway includes a raceway surface on which the first roller rolls,
   At least one of the raceway surface of the first thrust roller bearing raceway and the raceway surface of the second thrust roller bearing raceway has a first full crowning portion in contact with the first roller. And a thrust roller bearing, wherein a shape of the first surface of the first full crowning portion in the radial cross section of the thrust roller bearing is a first single arc.
2. The thrust roller bearing according to claim 1, wherein the first single arc has a radius of curvature of 250 mm or more and 2100 mm or less.
3. The thrust roller bearing according to claim 1 or 2, wherein a center of a rolling surface of the first roller in an axial direction of the first roller is in contact with a center of the first full crowning portion in the radial direction. .
4. The thrust roller bearing according to any one of claims 1 to 3, wherein the first roller is a cylindrical roller or a needle roller.
5. The thrust roller bearing according to any one of claims 1 to 3, wherein the first roller is a tapered roller.
6. The circumference of the first thrust roller bearing raceway and the second thrust roller bearing raceway is between the first thrust roller bearing raceway and the second thrust roller bearing raceway. A plurality of second rollers arranged along the direction;
   The second roller rolls on the raceway surface of the first thrust roller bearing raceway and the raceway surface of the second thrust roller bearing raceway,
   At least one of the raceway surface of the first thrust roller bearing raceway and the raceway surface of the second thrust roller bearing raceway has a second full crowning portion in contact with the second roller. And the second full crowning portion is located on the inner side with respect to the first full crowning portion, and the shape of the second surface of the second full crowning portion in the radial cross section is second. The thrust roller bearing according to any one of claims 1 to 5, wherein the thrust roller bearing is a single arc.
7. The thrust roller bearing according to claim 6, wherein the second single arc has a radius of curvature of 250 mm or more and 2100 mm or less.
8. A bearing ring for a thrust roller bearing,
   A raceway surface on which a plurality of first rollers roll,
   The raceway surface has a first full crowning portion that contacts the first roller, and a shape of a first surface of the first full crowning portion in a radial cross section of the thrust roller bearing raceway ring. Is a first single circular arc, a bearing ring for a thrust roller bearing.
9. The thrust ring for a thrust roller bearing according to claim 8, wherein the first single arc has a radius of curvature of 250 mm or more and 2100 mm or less.
10. The raceway surface has a second full crowning portion that contacts a plurality of second rollers rolling on the raceway surface,
    The second full crowning portion is located on the inner side with respect to the first full crowning portion, and the shape of the second surface of the second full crowning portion in the radial cross section is a second single shape. The thrust ring for a thrust roller bearing according to claim 8 or 9, wherein the bearing ring is an arc.
11. The thrust ring for a thrust roller bearing according to claim 10, wherein the second single arc has a radius of curvature of not less than 250 mm and not more than 2100 mm.

Images