JP2021081038A - Thrust roller bearing - Google Patents

Abstract

To provide a thrust roller bearing having improved wear resistance.SOLUTION: A thrust roller bearing 1 comprises: a plurality of radially arranged rollers 2; and a pair of annular bearing washers 3, 4 having raceway surfaces 3a, 4a on which the plurality of rollers 2 roll, the washers 3, 4 being disposed in such a manner that the raceway surfaces 3a, 4a are opposite to each other. Each of the rollers 2 is composed of high carbon chromium bearing steel, and has a surface roughness expressed as Rvk of 0.01-0.10, and expressed as Rk of 0.01-0.08. At least one of the bearing washers 3, 4 is composed of carbon steel, each of the raceway surfaces 3a, 4a has a surface compressive residual stress of -1400 MPa to -1000 MPa and Vickers hardness of 850-900.SELECTED DRAWING: Figure 1

Description

The present invention relates to thrust roller bearings.

Thrust roller bearings are known to include a plurality of rollers arranged radially and a pair of annular track discs having a raceway surface on which the plurality of rollers roll (see, for example, Patent Document 1). Thrust roller bearings are inserted between a non-rotating member and a rotating member, for example, in a vehicle transmission, and are used to smooth the rotation of the rotating member while receiving a thrust force in the direction of the central axis of the bearing.

Japanese Unexamined Patent Publication No. 2003-239891

In thrust roller bearings, wear tends to increase in a poorly lubricated environment where the amount of oil in the lubricating oil is small. In recent years, the amount of lubricating oil supplied to vehicle transmissions and the like has been decreasing, and thrust roller bearings having high wear resistance that can suppress wear even in a poor lubrication environment are desired.

Therefore, an object of the present invention is to provide a thrust roller bearing having improved wear resistance.

The present invention has a plurality of rollers arranged radially and a raceway surface on which the plurality of rollers roll, and an annular shape arranged so that the raceway surfaces face each other, for the purpose of solving the above problems. The roller is made of high carbon chrome bearing steel and has a surface roughness of 0.01 or more and 0.10 or less in Rvk and 0.01 or more and 0.08 in Rk. At least one of the racetracks is made of carbon steel, the surface compressive residual stress of the raceway surface is -1400 MPa or more and -1000 MPa or less, and the Vickers hardness of the surface of the raceway surface is 850 or more and 900 or less. Provide a thrust roller bearing.

According to the present invention, wear resistance can be improved.

It is sectional drawing which shows the cross section including the bearing central axis of the thrust roller bearing which concerns on one Embodiment of this invention. It is a figure explaining the movement of the lubricating oil in a poor lubrication environment. It is a figure explaining Rvk and Rk which are parameters representing surface roughness. (A) is a diagram for explaining a temperature measurement position in a test for evaluating wear resistance, and (b) is a diagram for explaining a wear start time. It is a figure which shows various parameters of a roller in an Example, a conventional example, and a comparative example of this invention, (a) is Rvk, (b) is Rk, (c) is hardness, (d) is surface residual stress. It is a figure which shows. It is a figure which shows various parameters of the raceway plane in an Example, a conventional example, and a comparative example of this invention, (a) is Rvk, (b) is Rk, (c) is hardness, (d) is surface residual stress. It is a figure which shows. It is a figure which shows the wear start time in an Example, a conventional example, and a comparative example of this invention.

[Embodiment]
Embodiments of the present invention will be described with reference to FIGS. 1 to 7. It should be noted that the embodiments described below are shown as suitable specific examples for carrying out the present invention, and there are some parts that specifically exemplify various technically preferable technical matters. , The technical scope of the present invention is not limited to this specific aspect.

FIG. 1 is a cross-sectional view showing a cross section including a bearing central axis of the thrust roller bearing according to the present embodiment. In the thrust roller bearing 1, a plurality of rollers 2 arranged radially, an annular first track board 3 having a first raceway surface 3a on which the plurality of rollers 2 roll, and a plurality of rollers 2 roll. It is provided with an annular second track board 4 having a second track surface 4a. The first and second racetracks 3 and 4 are arranged so that the first and second raceway surfaces 3a and 4a face each other in the axial direction of the bearing central axis O. In this thrust roller bearing, the first racetrack 3 and the second racetrack 4 rotate relative to each other around the bearing center axis O.

The thrust roller bearing 1 is inserted between a rotating member and a non-rotating member in, for example, a vehicle transmission or an industrial machine, and the rotating member rotates while receiving an axial thrust force due to the rolling of the plurality of rollers 2. To facilitate.

The plurality of rollers 2 are rotatably held by the annular cage 5 shown by the broken line in FIG. 1, and rotate as the first track board 3 and the second track board 4 rotate relative to each other. While being held by the cage 5, it revolves around the bearing central axis O. The first track board 3 has an annular and flat plate-shaped track portion 31 perpendicular to the axial direction and one side in the axial direction from the radial inner end of the track portion 31 (right side in FIG. 1, second). A short cylindrical brim 32 extending to the track board 4 side) is integrally provided. The surface on one side of the track portion 31 in the axial direction is the first track surface 3a. The second track board 4 has an annular and flat plate-shaped track portion 41 perpendicular to the axial direction. The surface of the track portion 41 on the other side in the axial direction (left side in FIG. 1, side of the first track board 3) is the second track surface 4a. In the present embodiment, the first track board 3 is provided on the rotating member, and the second track board 4 is provided on the non-rotating member.

The shapes of the first and second track boards 3 and 4 are not limited to those shown in the figure. For example, the brim 32 in the first track board 3 may be omitted, or the second track board 4 has a short cylindrical brim extending from the radial outer end of the track portion 41 to the other side in the axial direction. May have.

As the roller 2, it is preferable to use one made of high carbon chrome bearing steel having high wear resistance. In the present embodiment, the roller 2 is used in which the high carbon chrome bearing steel is subjected to a special heat treatment to further improve the surface hardness. More specifically, the roller 2 contains 0.1 mass% or more and 0.6 mass% or less of carbon and 1.1 mass% or more and 1.6 mass% or less of nitrogen in a range of 0.1 mm from the surface. In the present embodiment, the surface compressive residual stress of the roller 2 is set to -1200 MPa or more and less than -900 MPa, and the Vickers hardness of the surface of the roller 2 is set to 700 or more and 850 or less. It is conceivable to further improve the surface hardness of the roller 2 by applying shot peening to the roller 2, but as described later, applying shot peening to the roller 2 lowers the wear resistance of the thrust roller bearing 1. It has been confirmed that the roller 2 is shot peened, which is not preferable. As the first and second track discs 3 and 4, those made of carbon steel, which is relatively hard and has high wear resistance, were used.

As shown in FIG. 2, in a poorly lubricated environment in which the amount of lubricating oil 6 is small, the lubricating oil 6 moves between the first and second raceway surfaces 3a and 4a via the rollers 2. For example, the lubricating oil 6 supplied to the first raceway surface 3a moves to the surface of the roller 2 due to the rotation of the roller 2, and is further supplied from the surface of the roller 2 to the second raceway surface 4a.

At this time, if the surface of the roller 2 is rough, the lubricating oil 6 is held too much on the surface of the roller 2, and it becomes difficult for the lubricating oil 6 to be supplied to the raceway surfaces 3a and 4a. Therefore, it is desirable to make the surface of the roller 2 as smooth as possible so that the roller 2 does not hold the lubricating oil 6 too much. Further, it is desired to harden the raceway surfaces 3a and 4a so that the raceway surfaces 3a and 4a are not worn even when the lubricating oil 6 is low. Therefore, in the present embodiment, the wear resistance is improved by smoothing the surface of the rollers 2 and increasing the hardness of the surfaces of the raceway surfaces 3a and 4a by applying shot peening to the raceway discs 3 and 4. I let you.

Specifically, in the present embodiment, the surface roughness of the roller 2 is 0.01 or more and 0.10 or less in Rvk and 0.01 or more and 0.08 or less in Rk. Further, in the present embodiment, by applying shot peening to the raceway plates 3 and 4, the surface compressive residual stress of the raceway surfaces 3a and 4a is set to -1400 MPa or more and −1000 MPa or less, and the Vickers hardness of the surface of the raceway surfaces 3a and 4a is set. The value was 850 or more and 900 or less. It is desirable that the surface residual stress and hardness of both the raceway surfaces 3a and 4a of the first and second track discs 3 and 4 are within the above numerical ranges as in the present embodiment, but the first Also, by setting the surface residual stress and hardness of at least one of the raceway surfaces 3a and 4a of the second racetracks 3 and 4 within the above numerical ranges, the effect of improving the wear resistance can be obtained as compared with the conventional case. In particular, in the first racetrack 3 that rotates with the rotation of the rotating member, the lubricating oil 6 is likely to scatter due to centrifugal force and poor lubrication is likely to occur. Therefore, at least the first raceway surface in the first racetrack 3 It can be said that it is desirable that the surface residual stress and hardness of 3a are within the above numerical ranges.

Further, in order to suppress the scattering of the lubricating oil 6 due to the centrifugal force, the surface roughness of the first raceway surface 3a on the first raceway board 3 is made relatively rough, and the lubricating oil 6 is applied to the first raceway surface 3a. It is more desirable to make it easier to hold. However, if the surface roughness of the first raceway surface 3a is made too rough, it becomes difficult for the lubricating oil 6 to move to the rollers 2 and the second raceway surface 4a, which may reduce the wear resistance. Therefore, it is desirable that the surface roughness of the first raceway surface 3a is adjusted to an appropriate roughness so that the lubricating oil 6 can be appropriately retained. In the present embodiment, the surface roughness of the first raceway surface 3a is 0.05 or more and 0.22 or less in Rvk and 0.05 or more and 0.15 or less in Rk. In the present embodiment, the surface roughness of both the first and second orbital surfaces 3a and 4a is 0.05 or more and 0.22 or less in Rvk and 0.05 or more and 0.15 in Rk. It was as follows. The surface roughness of the rollers 2 and the raceway surfaces 3a and 4a can be appropriately adjusted depending on the polishing conditions in the polishing process such as barrel polishing. Further, the surface compressive residual stress of the raceway surfaces 3a and 4a and the Vickers hardness of the surface can be appropriately adjusted according to the shot peening conditions.

Here, Rvk and Rk representing the surface roughness are lubricity evaluation parameters (load curve parameters) of the plateau structure surface. As shown in FIG. 3, the region between the height positions where the equivalent straight line 72, which is the gentlest inclination of the central portion in the load curve 71 of the surface unevenness, intersects the load length ratios of 0% and 100% is the core portion 73. To do. The height (difference between the upper and lower levels) of the core portion 73 is Rk. Rvk represents the depth of the protruding valley portion 74.

(Evaluation of wear resistance)
The thrust roller bearing 1 according to the present embodiment was prototyped and used as an example, and the wear resistance was evaluated.
The thrust roller bearing 1 according to the embodiment was manufactured as follows. The bar of JISSUJ2 was cut and used as the work of the example. The atmosphere was set to a carbon potential of 1.2 to 1.6 and an ammonia concentration of 0.1 to 0.5 vol%, and the work was carburized and nitrided by holding the work of the example at a temperature of 820 to 870 ° C. for 1 hour. , Immersed in oil at 80 ° C., rapidly cooled and quenched. After quenching, tempering was performed at 200 ° C. for 1 hour, then polishing and barrel polishing were performed for 2 hours to obtain the value 2 in the example. In the range of 0.1 mm from the surface of the roller 2 of the example, carbon is 1.1 mass% to 1.6 mass%, and nitrogen is 0.1 mass% to 0.1 0.6 mass%. The steel plate of SAE1075 was punched in an annular shape and forged to produce a work of the first track board of the example and a work of the second track board of the example. Hold the first track board work of Example and the second track board work of Example at a temperature of 760 to 830 ° C. for 0.5 hours, immerse in oil at 80 ° C., quench and quench. did. After quenching, it was tempered at 200 ° C. for 1 hour, followed by shot peening, polishing, and barrel polishing for 5 hours to obtain the first track board 3 of the example and the second track board 4 of the example. .. The conditions for shot peening are as follows.
-Shot particle size: 100 μm or less-Shot grain material: Iron-Shot pressure: 0.5 MPa
The steel plate of SPCD was punched out so as to remove the annular and pocket portion, and used as the cage 5. A thrust roller bearing 1 is manufactured by combining the roller 2 of the embodiment, the first track board 3 of the embodiment, the second track board 4 of the embodiment, and the cage 5, and this is used as the thrust roller bearing 1 of the embodiment. And said.

As shown in FIG. 4A, the first and second track discs 3 and 4 are attached to the jig 80, the axial load is 9 kN, the rotation speed is 2000 rpm, and the lubricating oil 6 is applied to the first track surface 3a. The test was carried out by dropping 0.05 g of. In the test, the temperature of the region shown by A in FIG. 4A, that is, the back surface of the jig 80 holding the second track board 4, was measured, and the test was terminated when the temperature rose to 80 degrees.

FIG. 4B shows the time change of the temperature measured in the above test. As shown in FIG. 4 (b), the time change of this temperature includes a first region in which the temperature gradually rises after the start of the test, a second region in which the temperature becomes substantially constant and stable, and wear occurs and the temperature rises. It can be divided into a third area to be used. The start time of this third region is defined as the wear start time. In the present embodiment, the wear resistance was evaluated based on this wear start time. The number of tests was three.

Further, for comparison with the embodiment, a roller 2 made of a hardened and tempered material of high carbon chrome bearing steel is used, and the surface roughness of the roller 2 and the raceway surfaces 3a and 4a is not adjusted or shot peening is not performed. A thrust roller bearing was prepared and the wear resistance was evaluated in the same manner as in the examples.

The thrust rolling bearing 1 according to the conventional example was manufactured as follows. The bar of JISSUJ2 was cut and used as the work of the conventional example. The work of the conventional example was held at a temperature of 820 to 850 ° C. for 0.5 hours, and then immersed in oil at 80 ° C. for rapid cooling and quenching. After quenching, tempering was performed at 200 ° C. for 1 hour, polishing was performed, and barrel polishing was performed for 1 hour to obtain the value of 2 in the conventional example. The steel plate of SAE1075 was punched in an annular shape and forged to produce a work of the first track board of the conventional example and a work of the second track board of the conventional example. The work of the first track board of the conventional example and the work of the second track board of the conventional example are held at a temperature of 760 to 830 ° C. for 0.5 hours, immersed in oil at 80 ° C., rapidly cooled and quenched. did. After quenching, it was tempered at 200 ° C. for 1 hour, then polished and barrel-polished for 1 hour to obtain a first track board 3 of the conventional example and a second track board 4 of the conventional example. The steel plate of SPCD was punched out so as to remove the annular and pocket portion, and used as the cage 5. A thrust roller bearing 1 is manufactured by combining a conventional roller 2, a conventional first track board 3, a conventional second track board 4, and a cage 5, and this is used as a conventional thrust roller bearing 1. And said.

Further, in Comparative Example 1 in which the same rollers as in the examples were used as the rollers 2 and only the surface roughness of the raceway surfaces 3a and 4a was adjusted and shot peening was not performed, and high carbon chrome bearings in which the rollers 2 were shot peened. The thrust roller bearings of Comparative Example 2 were prepared using steel as the track discs 3 and 4 using the same ones as those of the examples, and the wear resistance was evaluated in the same manner as in the examples.

The thrust rolling bearing 1 according to Comparative Example 1 was manufactured as follows. The bar of JISSUJ2 was cut and used as the work of Comparative Example 1. Carburizing and nitriding was performed by holding the work of Comparative Example 1 for 1 hour at a temperature of 820 to 870 ° C. in an atmosphere having a carbon potential of 1.2 to 1.6 and an ammonia concentration of 0.1 to 0.5 vol%. After that, it was immersed in oil at 80 ° C., rapidly cooled and quenched. After quenching, tempering was performed at 200 ° C. for 1 hour, then polishing and barrel polishing were performed for 2 hours to obtain the value of Comparative Example 1. In the range of 0.1 mm from the surface of the roller 2 of Comparative Example 1, carbon is 1.1 mass% to 1.6 mass%, and nitrogen is 0.1 to 0.6 mass%. The steel plate of SAE1075 was punched in an annular shape and forged to produce a work of the first track board of Comparative Example 1 and a work of the second track board of Comparative Example 1. The work of the first track board of Comparative Example 1 and the work of the second track board of Comparative Example 1 were held at a temperature of 760 to 830 ° C. for 0.5 hours, and immersed in oil at 80 ° C. for quenching. And hardened. After quenching, it was tempered at 200 ° C. for 1 hour, then polished and barrel-polished for 5 hours to obtain a first track board 3 of Comparative Example 1 and a second track board 4 of Comparative Example 1. The steel plate of SPCD was punched out so as to remove the annular and pocket portion, and used as the cage 5. A thrust roller bearing 1 is manufactured by combining the roller 2 of Comparative Example 1, the first track board 3 of Comparative Example 1, the second track board 4 of Comparative Example 1, and the cage 5, and this is used in Comparative Example 1. The thrust roller bearing 1 was used.

The thrust roller bearing 1 according to Comparative Example 2 was manufactured as follows. The bar of JISSUJ2 was cut and used as the work of Comparative Example 2. Carburizing and nitriding was performed by holding the work of Comparative Example 2 for 1 hour at a temperature of 820 to 870 ° C. in an atmosphere having a carbon potential of 1.2 to 1.6 and an ammonia concentration of 0.1 to 0.5 vol%. Then, it was immersed in oil at 80 ° C., rapidly cooled and quenched. After quenching, tempering was performed at 200 ° C. for 1 hour, then shot peening was performed, polishing was performed, and barrel polishing was performed for 2 hours to obtain 2 in Comparative Example 2. In the range of 0.1 mm from the surface of the roller 2 of Comparative Example 2, carbon is 1.1 mass% to 1.6 mass%, and nitrogen is 0.1 to 0.6 mass%. The conditions for shot peening are as follows.
-Shot particle size: 100 μm or less-Shot grain material: Iron-Shot pressure: 0.5 MPa
The steel plate of SAE1075 was punched in an annular shape and forged to produce a work of the first track board of Comparative Example 2 and a work of the second track board of Comparative Example 2. The work of the first track board of Comparative Example 2 and the work of the second track board of Comparative Example 2 were held at a temperature of 760 to 830 ° C. for 0.5 hours, and immersed in oil at 80 ° C. for quenching. And hardened. After quenching, it is tempered at 200 ° C. for 1 hour, then shot peened, polished, and barrel-polished for 5 hours. And said. The conditions for shot peening are as follows.
-Shot particle size: 100 μm or less-Shot grain material: Iron-Shot pressure: 0.5 MPa
The steel plate of SPCD was punched out so as to remove the annular and pocket portion, and used as the cage 5. A thrust roller bearing 1 is manufactured by combining the roller 2 of Comparative Example 2, the first track board 3 of Comparative Example 2, the second track board 4 of Comparative Example 2, and the cage 5, and this is used in Comparative Example 2. The thrust roller bearing 1 was used.

As shown in Table 1, Comparative Example 1 is the same as the Example except that the track discs 3 and 4 are not shot peened, and Comparative Example 2 is the same as the Example except that the roller 2 is shot peened. It is the same.

The Rvk of the roller 2 surface in Examples, Conventional Examples, and Comparative Examples 1 and 2 is shown in FIG. 5 (a), the Rk is shown in FIG. 5 (b), and the Vickers hardness of the roller 2 surface is shown in FIG. 5 (c). The surface residual stress of the roller 2 is shown in FIG. 5 (d), respectively. Further, Rvk on the surfaces of the racetracks 3a and 4a of the track discs 3 and 4 in Examples, Conventional Examples, and Comparative Examples 1 and 2 is shown in FIG. 6A, Rk is shown in FIG. 6B, and the raceway surfaces 3a, The Vickers hardness of 4a is shown in FIG. 6 (c), and the surface residual stresses of the raceway surfaces 3a and 4a are shown in FIG. 6 (d), respectively.

As shown in FIG. 5A, the Rvk on the surface of the roller 2 is larger than 0.1 in the conventional example, whereas it is 0.01 in the examples and comparative examples 1 and 2 in which the surface roughness is improved. It is 0.10 or less. Further, as shown in FIG. 5B, the Rk on the surface of the roller 2 is larger than 0.1 in the conventional example, whereas it is 0 in the examples and the comparative examples 1 and 2 in which the surface roughness is improved. It is 0.01 or more and 0.08 or less. As described above, in the examples (and Comparative Examples 1 and 2) according to the present invention, both Rvk and Rk of the surface of the roller 2 are smaller and the surface roughness is smaller than that of the conventional example.

Further, as shown in FIG. 5 (c), the Vickers hardness of the surface of the roller 2 is larger than 850 in Comparative Example 1 in which shot peening is applied, whereas shot peening is not applied. In Examples (and Comparative Example 2), it is 700 or more and 850 or less. Further, as shown in FIG. 5D, the surface compressive residual stress of the roller 2 is −900 MPa in the conventional example, which is smaller than -1200 in Comparative Example 1, whereas in Example (and Comparative Example). In 2), it is -1200 MPa or more and less than -900 MPa. That is, the example (and Comparative Example 2) according to the present invention has a surface compressive residual stress intermediate between the conventional example and the comparative example 2.

Further, as shown in FIG. 6A, the Rvk of the surfaces of the raceway surfaces 3a and 4a is larger than 0.22 in the conventional example, whereas the surface roughness is improved in Examples and Comparative Example 1. , 2 is 0.05 or more and 0.22 or less. Further, as shown in FIG. 6B, the Rk on the surfaces of the raceway surfaces 3a and 4a is 0.2 or more in the conventional example, whereas it is 0.05 or more and 0.15 or less in the embodiment. is there. As described above, in the examples (and Comparative Examples 1 and 2) according to the present invention, both Rvk and Rk of the surfaces of the raceway surfaces 3a and 4a are smaller and the surface roughness is smaller than in the conventional examples.

Further, as shown in FIG. 6C, the Vickers hardness of the surfaces of the raceway surfaces 3a and 4a is less than 850 in the conventional example and the comparative example in which shot peening is not performed, whereas shot peening is performed. In Examples and Comparative Example 2, it is 850 or more and 900 or less. Further, as shown in FIG. 6D, the surface compressive residual stresses of the raceway surfaces 3a and 4a are −600 MPa or less in the conventional example and Comparative Example 1 in which shot peening is not applied, whereas in Examples. In (and Comparative Example 2), it is -1400 MPa or more and -1000 MPa or less. That is, in the examples (and Comparative Examples 2) according to the present invention, the surfaces of the raceway surfaces 3a and 4a are harder and the absolute value of the surface compressive residual stress is larger than that of the conventional example and the comparative example 1.

FIG. 7 shows the measurement results of the wear start time of Examples, Conventional Examples, and Comparative Examples 1 and 2. The measurement result of FIG. 7 represents the average value of three tests. As shown in FIG. 7, in Comparative Example 1, although the wear start time is slightly longer than that in the conventional example by improving the surface roughness of the roller 2, the hardness of the raceway surfaces 3a and 4a is insufficient. It is considered that the wear is increasing. In Comparative Example 2, it is considered that by applying shot peening to the rollers 2, the raceway surfaces 3a and 4a were relatively easily worn, and a sufficient wear start time could not be obtained. On the other hand, in the example according to the present invention, the wear start time is 5 times or more as compared with the conventional example, and it can be seen that the wear resistance in a poor lubrication environment is significantly improved.

(Actions and effects of embodiments)
As described above, in the thrust roller bearing 1 according to the present embodiment, the roller 2 is made of high carbon chrome bearing steel, and the surface roughness thereof is 0.01 or more and 0.10 or less in Rvk and Rk. At least one of the bearing plates 3 and 4 is made of carbon steel, and the surface compressive residual stress of the bearing surfaces 3a and 4a is -1400 MPa or more and -1000 MPa or less, and the bearing surface 3a The Vickers hardness of the surface of 4a is 850 or more and 900 or less.

By reducing the surface roughness of the roller 2, the lubrication oil 6 easily circulates between the first and second raceway surfaces 3a and 4a due to the rotation of the roller 2, and the wear resistance is improved even in a poor lubrication environment. be able to. Further, by increasing the hardness of the surfaces of the raceway surfaces 3a and 4a by shot peening, it is possible to suppress wear even when the amount of lubricating oil 6 is very small and further improve wear resistance.

(Additional note)
Although the present invention has been described above based on the embodiments, these embodiments do not limit the invention according to the claims. It should also be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

In addition, the present invention can be appropriately modified and implemented without departing from the spirit of the present invention. For example, in the above embodiment, the case where the rollers 2 are arranged in one row in the circumferential direction has been described, but the arrangement of the rollers 2 is not limited to this, and for example, the rollers 2 may be arranged in two or more rows. ..

1 ... Thrust roller bearing 2 ... Roller 3 ... First track board 3a ... First track surface 31 ... Track section 32 ... Brim 4 ... Second track board 4a ... Second track surface 41 ... Track section 5 ... Holding Vessel 6 ... Lubricating oil 71 ... Load curve 72 ... Equivalent straight line 73 ... Core part 74 ... Protruding valley part 80 ... Jig O ... Bearing central axis

Claims (5)

With multiple rollers arranged in a radial pattern
It has a raceway surface on which the plurality of rollers roll, and includes a pair of annular racetracks arranged so that the raceway surfaces face each other.
At the time mentioned above
Made of high carbon chrome bearing steel
The surface roughness is 0.01 or more and 0.10 or less in Rvk, and 0.01 or more and 0.08 or less in Rk.
At least one of the track boards
Made of carbon steel
The surface compressive residual stress of the raceway surface is -1400 MPa or more and -1000 MPa or less.
The Vickers hardness of the surface of the raceway surface is 850 or more and 900 or less.
Thrust roller bearing. The pair of track discs are a first track disc provided on a rotating member and rotating with the rotation of the rotating member, and a second track disc provided on the non-rotating member and not rotating with the rotation of the rotating member. And have
The first track board
Made of carbon steel
The surface compressive residual stress of the raceway surface is -1400 MPa or more and -1000 MPa or less.
The Vickers hardness of the surface of the raceway surface is 850 or more and 900 or less.
The thrust roller bearing according to claim 1. The first track board is
The surface roughness of the raceway surface is 0.05 or more and 0.22 or less in Rvk and 0.05 or more and 0.15 or less in Rk.
The thrust roller bearing according to claim 2. Both of the pair of track boards
Made of carbon steel
The surface compressive residual stress is -1400 MPa or more and -1000 MPa or less.
The Vickers hardness of the surface is 850 or more and 900 or less.
The thrust roller bearing according to any one of claims 1 to 3. At the time mentioned above
Within 0.1 mm from the surface, carbon is contained in an amount of 0.1 mass% or more and 0.6 mass% or less, and nitrogen is contained in a range of 1.1 mass% or more and 1.6 mass% or less.
The surface compressive residual stress is -1200 MPa or more and less than -900 MPa.
The thrust roller bearing according to any one of claims 1 to 4.

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