JP2021148186A - Thrust roller bearing - Google Patents

Abstract

To provide a thrust roller bearing that improves initial lubrication performance and long-term lubrication performance.SOLUTION: A thrust roller bearing 10 comprises a plurality of rollers 11, and a retainer 12 constituted by fitting two retainer members 14 and 15 to each other in an axial direction, and comprising a pocket part 13 rollably retaining the plurality of rollers 11 in a circumferential direction. In a space S formed by fitting the two retaining member 14 and 15, an initial lubrication lubricant L1 for performing initial lubrication is housed in advance, and a long-term lubrication lubricant L2 for performing long-term lubrication is housed in advance, or supplied from the outside.SELECTED DRAWING: Figure 1

Description

The present invention relates to a thrust roller bearing, for example, a thrust roller bearing used for a rotation support portion of an automobile transmission, a torque converter, or the like.

As the thrust roller bearing, a plurality of needle-shaped rollers and two substantially parallel annular cage members made of punched metal plates are provided, and each of the two cage members is a plurality of members in the circumferential direction. It is known that each needle-shaped roller is held in a state where it is prevented from coming out to both sides in the axial direction of the cage by the corresponding pocket portion of the two cage members. (See, for example, Patent Document 1). Such a thrust roller bearing constitutes a so-called cage and roller, and each needle-shaped roller is rotatably arranged between two races arranged so as to face each other in the axial direction, and acts between the two races. We support thrust load (load in the axial direction).

In the thrust roller bearing of Patent Document 1, a solid lubricant is housed in a space formed by fitting two cage members to lubricate each needle-shaped roller.

JP-A-2008-190598

In the thrust roller bearing described in Patent Document 1, a lubricant-containing polymer is mentioned as a solid lubricant, and the lubricating action can be maintained for a long period of time by the lubricating oil contained therein. However, the solid lubricant alone does not provide sufficient lubrication at the initial stage of operation (initial lubrication), and there is room for improvement in improving the initial lubrication performance.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a thrust roller bearing in which both initial lubrication performance and long-term lubrication performance are improved.

The above object of the present invention is achieved by the following configuration.
(1) With multiple times
A cage formed by fitting two cage members in the axial direction to each other and forming a plurality of pockets for holding the plurality of rollers so as to be rollable in the circumferential direction.
Thrust roller bearing with
In the space formed by fitting the two cage members, an initial lubrication lubricant for initial lubrication is stored in advance, and a long-term lubrication lubricant for long-term lubrication is performed. Thrust roller bearings that are pre-stored or externally supplied.
(2) The long-term lubricating lubricant is a solid lubricant, and each pocket portion has a plurality of vacant spaces in phase and is formed in an annular shape.
The initial lubricating lubricant is grease, and is sealed between the long-term lubricating lubricant and the cage in the space on the inner diameter side of the roller on the inner diameter side of the roller (1). ) Described in the thrust roller bearing.
(3) One of the cage members is provided with a step portion that protrudes in the axial direction toward the other of the cage members on the inner diameter side with respect to the pocket portion.
A through hole extending in the radial direction toward the inner diameter side end surface of the roller is formed in the step portion.
In the space formed by fitting the two cage members, a solid lubricant formed in an annular shape having a space in phase with the pocket portion is provided.
The long-term lubricating lubricant is a portion of the solid lubricant located in a groove formed between the step portion and the inner peripheral side flange portion of one of the cage members.
The thrust roller bearing according to (1), wherein the initial lubricating lubricant is a portion of the solid lubricant that is located in a portion other than the groove portion.
(4) The initial lubricating lubricant is a pre-sealed grease.
The thrust roller bearing according to (1), wherein the long-term lubricating lubricant is grease supplied from the outside to the space.
(5) Of the space, a gap is formed in the inner diameter side space on the inner diameter side of the roller by denting the two cage members so as to approach each other.
The thrust roller bearing according to (1), wherein the grease which is the initial lubricating lubricant and the solid lubricant which is the long-term lubricating lubricant are housed on the inner diameter side of the gap.

In the thrust roller bearing of the present invention, both the initial lubrication performance and the long-term lubrication performance are improved by providing the initial lubrication lubricant and the long-term lubrication lubricant in the space formed by fitting the two cage members. However, it is possible to have good lubrication stability from the initial stage to a long period of time.

It is a figure which shows the 1st Embodiment of the thrust roller bearing of this invention, (a) is the sectional view along the radial direction, (b) is the sectional view along the line I-I of (a). It is an exploded cross-sectional view of the thrust roller bearing of FIG. It is sectional drawing which shows the 1st modification of the thrust roller bearing of 1st Embodiment. It is sectional drawing which shows the 2nd modification of the thrust roller bearing of 1st Embodiment. It is sectional drawing which shows the 2nd Embodiment of the thrust roller bearing of this invention. (A) is an enlarged view of FIG. 5, and (b) is a cross-sectional view taken along the VI-VI line of (a). FIG. 5 is an exploded cross-sectional view of the thrust roller bearing of FIG. It is a perspective view which shows the 3rd Embodiment of the thrust roller bearing of this invention. It is sectional drawing of the thrust roller bearing of FIG. It is a figure which shows the 4th Embodiment of the thrust roller bearing of this invention, (a) is the sectional view along the radial direction, (b) is the sectional view along the XX line of (a).

Hereinafter, each embodiment of the thrust roller bearing according to the present invention will be described in detail with reference to the drawings.

(First Embodiment)
As shown in FIGS. 1 to 3, the thrust roller bearing 10 of the first embodiment has a plurality of rollers 11 arranged radially with their axes oriented in the radial direction, and the plurality of rollers 11. A cage 12 having a plurality of pocket portions 13 that are rotatably held in the circumferential direction is provided.

The cage 12 is configured by fitting two cage members 14 and 15 made of an annular metal plate or the like in the axial direction to each other. One cage member 14 is bent axially from the annular portion 14a, the inner peripheral side flange portion 14b that bends in the axial direction from the inner peripheral side of the annular portion 14a, and the outer peripheral side of the annular portion 14a. It has an outer peripheral side flange portion 14c. The other cage member 15 is fitted to the inner peripheral surface of the annular portion 15a and the inner peripheral side flange portion 14b of the cage member 14 by bending in the axial direction from the inner peripheral side of the annular portion 15a. It has an inner peripheral side flange portion 15b and an outer peripheral side flange portion 15c that bends in the axial direction from the outer peripheral side of the annular portion 15a and is fitted to the outer peripheral surface of the outer peripheral side flange portion 14c of the cage member 14.

Further, the annular portion 14a of the cage member 14 and the annular portion 15a of the cage member 15 hold each roller 11 so as to be rollable with its axis (rotating axis of the roller 11) oriented in the radial direction. A plurality of pocket portions 13 are formed at equal intervals in the circumferential direction.

Then, in the first embodiment, the initial lubricating lubricant L1 and the long-term lubricating lubricant L2 are housed in the space S formed by fitting the two cage members 14 and 15. .. Here, the space S formed by fitting the two cage members 14 and 15 is the annular portion 14a, the inner peripheral side flange portion 14b, and the outer circumference of the cage member 14 in the fitted state. It is a space surrounded by the side flange portion 14c, the annular portion 15a of the cage member 15, the inner peripheral side flange portion 15b, and the outer peripheral side flange portion 15c. For convenience, the annular space on the inner diameter side of the roller 11 is referred to as "inner diameter side space S1", and the annular space on the outer diameter side of the roller 11 is referred to as "outer diameter side space S2".

The long-term lubricant L2 is a solid lubricant 20, and as shown in FIG. 2, is an annular member having a plurality of voids 22 in phase with each pocket portion 13 of the cage 12. In the solid lubricant 20, the cage 12 is provided so that the inner peripheral surface 22a of the vacant space 22 is in contact with the outer diameter side end surface 11a, the inner diameter side end surface 11b, and the rolling surface 11c of the roller 11 (see FIG. 1B). It is housed in the space S of. Further, the initial lubricating lubricant L1 is grease G, and in the inner diameter side space S1, the long-term lubricating lubricant L2 and the cage 12 (specifically, the inner peripheral side flange portion 14b of the cage member 14) It is enclosed between.

When assembling the thrust roller bearing 10, as shown in FIG. 2, the pocket portion 13 of one of the cage members 14 and the space 22 of the solid lubricant 20 are aligned with each other, and the cage member 14 is solid-lubricated. The agent 20 is arranged, and the rollers 11 are arranged at the positions of the pocket portion 13 of the cage member 14 and the empty space 22 of the solid lubricant 20. Further, in the inner diameter side space S1, the grease G is sealed in the space between the inner peripheral side flange portion 14b of the cage member 14 and the solid lubricant 20. Then, the pocket portion 13 of the other cage member 15, the pocket portion 13 of the one cage member 14, and the vacant space 22 of the solid lubricant 20 are aligned with each other, and the inner peripheral side flange of the other cage member 15 is aligned. The portion 15b is fitted to the inner peripheral side flange portion 14b of one of the cage members 14, and the outer peripheral side flange portion 15c is fitted to the outer peripheral side flange portion 15c. In this state, the thrust roller bearing 10 is formed by crimping the end portion of the inner peripheral side flange portion 15b with respect to the inner peripheral side flange portion 14b.

Examples of the solid lubricant 20 include molybdenum disulfide, carbon black, graphite, boron nitride, silane nitride, melamine cyanurate, a fluoropolymer, a lubricant-containing polymer, and the like. For the lubricant-containing polymer, for example, a raw material prepared by mixing a synthetic resin selected from the group of polyolefin resins with a lubricant in the form of a single oil or a mixed oil is heated at a temperature equal to or higher than the melting point of the synthetic resin. It is plasticized and then cooled to solidify.

The polyolefin-based resin is a group having basically the same chemical structure, such as polyethylene, polypropylene, polybutylene, and polymethylpentene. As the lubricant, any one of paraffin-based hydrocarbon oils such as polyα-olefin oil, naphthenic hydrocarbon oils, mineral oils, ether oils such as dialkylphenyl ether oils, and ester oils such as phthalates is used alone. Or mixed. Various additives such as antioxidants, rust preventives, anti-wear agents, antifoaming agents, and extreme pressure agents may be added to the lubricating oil in advance.

As the grease G as the initial lubricating lubricant L1, there are no restrictions on the base oil and the thickener, and generally used greases can be used. Specifically, mineral oil, synthetic oil, animal and vegetable oil, etc. can be used as the base oil, and there is no limitation as long as the above base oil can be held in a gel form as the thickener. Metal soaps such as aluminum soaps, sodium soaps, calcium complex soaps, aluminum complex soaps, lithium complex soaps, aromatic ureas, aliphatic ureas, alicyclic ureas, triureas, tetraureas and other urea compounds, sodium terephthalates, PTFE and other fluorines. Resin, organic bentnite, silica gel and the like can be used. Further, there is no limitation on the blending amount, and it is sufficient that the grease properties can be maintained. In addition, there are no restrictions on additives.

In the thrust roller bearing 10 configured in this way, the grease G is pushed toward the outer diameter side by centrifugal force as the bearing rotates, and the pocket portion 13 is formed through the gap between the solid lubricant 20 and the cage members 14 and 15. Furthermore, it flows out to the roller 11.

Further, the solid lubricant 20 comes into contact with the rollers 11 as the bearing rotates and is rubbed into powder, and gradually transfers to the rollers 11 to exhibit a lubricating action, but the contact state with the rollers 11 is unstable. At the initial stage of operation of the bearing, the transfer amount is not sufficient. Grease G contributes to lubrication during that period. Then, after the contact state between the roller 11 and the solid lubricant 20 stabilizes while the operation is continued, even if the grease G is depleted, the solid lubricant 20 contributes to lubrication thereafter. Therefore, lubrication is good from the initial stage of operation, and this good lubrication continues for a long period of time.

The volume ratio of the initial lubricating lubricant L1 and the long-term lubricating lubricant L2 can be arbitrarily set.

Various changes can be made in the first embodiment. For example, in the thrust roller bearing 10a shown in FIG. 3, a recess 21 is formed in the axial center portion of the inner diameter side end surface in contact with the grease G of the solid lubricant 20. As described above, centrifugal force acts on the grease G and flows out from the gap between the solid lubricant 20 and the cage members 14 and 15, but the grease G is stored inside the recess 21 of the solid lubricant 20. There is. The grease G stored in the recess 21 gradually flows out of the recess 21 when the thrust roller bearing 1a stops rotating, so that the grease flows out at once from the gap between the solid lubricant 20 and the cage members 14 and 15. The amount of G can be reduced, and the initial lubrication by the grease G can be lengthened.

Further, in the thrust roller bearing 10b shown in FIG. 4, a through hole 23 reaching the inner peripheral surface 22a of the vacant space 22 may be formed at the axial center portion of the end surface of the solid lubricant 20 in contact with the grease G. The grease G is supplied to the inner diameter side end surface 11b of the roller 11 through the through hole 23 in addition to the gap between the solid lubricant 20 and the cage members 14 and 15 by centrifugal force, so that the initial lubrication is performed better. Will be.

(Second Embodiment)
Next, a second embodiment of the thrust roller bearing of the present invention will be described with reference to FIGS. 5 to 7. In the second and third to fourth embodiments, the same components as those in the first embodiment are designated by the same reference numerals or equivalent reference numerals, and the description thereof will be omitted.

In the thrust roller bearing 10c of the second embodiment, the annular portion 14a of the cage member 14 projects axially toward the other cage member 15 along the pocket-side end surface 14d of the annular portion 14a. The step portion 14e is formed on the inner diameter side with respect to the pocket portion 13. The step portion 14e is separated from the other cage member 15 so that the solid lubricant 30 described later is arranged between the step portion 14e and the other cage member 15. Further, through holes 14f extending in the radial direction toward the inner diameter side end surface 11b of the roller 11 are formed in the step portion 14e at equal intervals in the circumferential direction.

Further, in the space S formed by fitting the two cage members 14 and 15, a solid lubricant 30 formed in an annular shape having a space 22 in phase with the pocket portion 13 is provided. Is provided. That is, the solid lubricant 30 is formed by cutting out a portion corresponding to the step portion 14e so as not to interfere with the step portion 14e of the cage member 14.

In this solid lubricant 30, the lubricating oil impregnated in the resin gradually exudes due to centrifugal force, but in the groove portion 14g formed between the step portion 14e and the inner peripheral side flange portion 14b of the cage member 14. The lubricating oil of the solid lubricant 30 located is restricted in radial movement by the step portion 14e. On the other hand, the lubricating oil impregnated with the solid lubricant 30 other than the groove portion 14 g is not restricted in its radial movement. Therefore, the lubricating oil exuded from the solid lubricant 30 due to the rotation of the bearing moves to the outer diameter side with a time lag.

Therefore, as shown in FIG. 6B, the long-term lubricating lubricant L2 is a solid lubricant located in the groove portion 14g formed between the step portion 14e and the inner peripheral side flange portion 14b of the cage member 14. It becomes 30 lubricating oils. The lubricating oil contained in this portion is restricted from moving outward in the radial direction by the step portion 14e. However, the movement-restricted lubricating oil passes through the through hole 14f and is gradually supplied to the roller 11.

Further, the initial lubricating lubricant L1 is a lubricating oil for the solid lubricant 30 located in a region other than the groove portion 14g, and is a portion above the axial end surface of the step portion 14e in FIG. 6B. In this initial lubricating lubricant L1, the lubricating oil seeps out from the initial state of using the bearing, and the lubricating oil is supplied through the contact portion with the solid lubricant 30 and 11. Further, since the solid lubricant 30 existing between the adjacent pocket portions 13 (pillar portion) also comes into direct contact with the rollers 11, it becomes the initial lubricating lubricant L1.

Therefore, in the present embodiment, long-term lubrication lubrication is a portion of the solid lubricant 30 located in the groove portion 14g formed between the step portion 14e and the inner peripheral side flange portion 14b of one of the cage members 14. Since the agent L2 and the initial lubricating lubricant L1 which is a portion of the solid lubricant 30 other than the groove portion 14g are provided, a time difference is provided at the time when the lubricating oil impregnated in the resin arrives at the roller 11. As a result, lubrication over a long period of time is realized from the initial stage.
Lubricating oil may be held in advance in the through hole 14f for initial lubrication.

When assembling the thrust roller bearing 10c, as shown in FIG. 7, the phase of the pocket portion 13 of the cage member 14 and the void 22 of the solid lubricant 30 are matched, and the thrust roller bearing 10c interferes with the step portion 14e of the cage member 14. The solid lubricant 30 is placed on the cage member 14 so as not to prevent it. Then, the rollers 11 are arranged in each vacant space 22. Further, by matching the phases of the pocket portion 13 of the cage member 15 and the pocket portion 13 of the cage member 14, the inner peripheral side flange portion 15b and the outer peripheral side flange portion 15c of the cage member 15 are placed inside the cage member 14. It is fitted to the peripheral side flange portion 14b and the outer peripheral side flange portion 14c, respectively. In this state, the thrust roller bearing 10c is formed by crimping the end portion of the inner peripheral side flange portion 15b with respect to the inner peripheral side flange portion 14b.

(Third Embodiment)
Next, a third embodiment of the thrust roller bearing of the present invention will be described with reference to FIGS. 8 and 9.

In the thrust roller bearing 10d of the third embodiment, in the annular portion 15a of the cage member 15, a plurality of through holes 15f communicating with the inner diameter side space S1 are formed at equal intervals in the circumferential direction. Further, in the space S formed by the cage members 14 and 15, grease G is pre-sealed as the initial lubricating lubricant L1.

As the bearing rotates, the grease G as the initial lubricating lubricant L1 moves to the outer diameter side due to centrifugal force and is consumed, but the same type of grease G as the long-term lubricating lubricant L2 is consumed through the through hole 15f. It is newly supplied from the outside of the bearing and can maintain a constant lubrication performance for a long period of time.

(Fourth Embodiment)
Next, a fourth embodiment of the thrust roller bearing of the present invention will be described with reference to FIG.

In the thrust roller bearing 10e of the fourth embodiment, a gap recessed so that the annular portion 14a of the cage member 14 and the annular portion 15a of the cage member 15 approach each other in the substantially central portion in the radial direction of the inner diameter side space S1. The portion 16 is formed in the entire circumferential direction. Grease G as the initial lubricating lubricant L1 and the solid lubricant 20a as the long-term lubricating lubricant L2 are housed in the inner diameter side space S1 on the inner diameter side of the gap 16. The solid lubricant 20a is formed in a ring shape having a circular cross section. The grease G may be pre-sealed in the remaining space S, that is, the remaining portion of the inner diameter side space S1 or the outer diameter side space S2.

Then, due to the centrifugal force due to the rotation of the bearing, the fluidized grease first flows out to the rollers 11 through the gap 16 to lubricate the rollers 11 (initial lubrication). Then, after a while, the solid lubricant 20a rubs against the annular portions 14a and 15a of the two cage members 14 and 15 to form powder, which is transferred to the rollers 11 through the gaps 16 to move the rollers 11 to the rollers 11. Lubricate (long-term lubrication).

The present invention is not limited to the above-described embodiment, and can be appropriately modified or improved.

10 Thrust roller bearing 11 Roll 12 Cage 13 Pockets 14, 15 Cage members 14a, 15a Rings 14b, 15b Inner peripheral flanges 14c, 15c Outer peripheral flanges 14f, 15f Through holes 16 Gap 20, 20a Solid Lubricant 30 Solid Lubricant G Grease L1 Initial Lubrication Lubricant L2 Long-term Lubrication Lubricant

Claims (5)

With multiple times
A cage formed by fitting two cage members in the axial direction to each other and forming a plurality of pockets for holding the plurality of rollers so as to be rollable in the circumferential direction.
Thrust roller bearing with
In the space formed by fitting the two cage members, an initial lubrication lubricant for initial lubrication is stored in advance, and a long-term lubrication lubricant for long-term lubrication is performed. Thrust roller bearings that are pre-stored or externally supplied. The long-term lubricating lubricant is a solid lubricant, and is formed in an annular shape with a phase-matched void in the pocket portion.
The claim that the initial lubricating lubricant is grease, and is sealed between the long-term lubricating lubricant and the cage in the inner diameter side space on the inner diameter side of the roller. The thrust roller bearing according to 1. One of the cage members is provided with a step portion that protrudes in the axial direction toward the other of the cage members on the inner diameter side with respect to the pocket portion.
A through hole extending in the radial direction toward the inner diameter side end surface of the roller is formed in the step portion.
In the space formed by fitting the two cage members, a solid lubricant formed in an annular shape having a space in phase with the pocket portion is provided.
The long-term lubricating lubricant is a portion of the solid lubricant located in a groove formed between the step portion and the inner peripheral side flange portion of the one cage member.
The initial lubricating lubricant is a portion of the solid lubricant that is located outside the groove.
The thrust roller bearing according to claim 1. The initial lubricating lubricant is a pre-sealed grease.
The thrust roller bearing according to claim 1, wherein the long-term lubricating lubricant is grease supplied from the outside to the space. A gap is formed in the space on the inner diameter side of the space on the inner diameter side of the roller by denting the two cage members so as to approach each other.
The thrust roller bearing according to claim 1, wherein the grease which is the initial lubricating lubricant and the solid lubricant which is the long-term lubricating lubricant are housed on the inner diameter side of the gap.

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