JP4631709B2 - Thrust roller bearing - Google Patents

Description

  The present invention relates to a thrust roller bearing (including a thrust needle bearing), and more particularly to a thrust roller bearing excellent in durability.

A thrust roller bearing is mounted on a rotating part of an automobile transmission or the like, for example, and supports a thrust load (axial load) acting on a rotating shaft. And a plurality of rollers disposed between the pair of races, and a cage for radially disposing the rollers. When the pair of races rotate relatively, the rollers revolve while rotating.
On the other hand, when there is no relative rotation in each race, that is, when the pair of races rotate in synchronization with each other, the rollers revolve in synchronization with the pair of races without rotating.
At this time, since the roller supports the thrust force while being in contact with the same position of the pair of races, the oil film of the support portion is interrupted by a minute vibration (for example, a direction perpendicular to the axial direction), and metal contact occurs. There are things to do. Such a phenomenon may also occur when a minute vibration is applied to the bearing while the bearing is stopped without rotating. Such metal contact is a cause of so-called fretting wear, and reduces the durability of the thrust roller bearing.
Therefore, in order to prevent such metal contact, an invention is disclosed in which the rollers do not continue to contact the same position of the race when the pair of races rotate synchronously or when minute vibrations are applied with the rotation stopped. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-339322 (page 3-4, FIG. 1)

  However, in the invention disclosed in Patent Document 1, the pair of races can be moved in the radial direction by gravity, and the amount of movement of each pair is different, so that the rollers on one vertical upper surface are positioned closer to the outer periphery of the race. On the other hand, the roller on one side of the vertical lower portion is in contact with a position closer to the inner periphery of the race. The race and the cage tend to rotate little by little due to circumferential frictional force (becomes somewhat uneven) acting on the contact portion due to vibration or the like.

  For this reason, when the pair of races rotate relative to each other (rotate without synchronization), the pair of races continue to be displaced in the direction in which they are once deviated, respectively, or each of them deviates without There is a problem that the rotation and revolution of the rollers may not be smooth. In addition, since it is necessary to provide means for regulating the amount of movement of each of the pair of races for each of the pair of races, there is a problem that the manufacturing cost increases. Further, when the race is used in a substantially horizontal state, there is a problem that a desired effect cannot be obtained because there is no difference in the amount of movement of the race.

  The present invention has been made to solve such a problem. Even when a pair of races rotate synchronously or when a minute vibration is applied in a rotation stopped state, the roller rotates and revolves by vibration. The specific surface of the roller is not kept in contact with the same position of the race, and when the pair of races rotate relative to each other, smooth rotation and revolution of the roller are ensured, and the structure is simple. An object of the present invention is to provide a thrust roller bearing that is inexpensive to manufacture and has no restrictions on the installation posture.

(1) A thrust roller bearing of the present invention includes a pair of annular races, a plurality of rollers arranged between the pair of races, and a cage that arranges the plurality of rollers in a radial direction. Thrust roller bearing
A plurality of swells inclined by a predetermined angle with respect to the radial direction are formed on a surface of the pair of races on which the rollers of the races come into contact.
(2) In addition, one or both of the number of the plurality of rollers or the number of swells of the plurality of undulations is an odd number.

Therefore, the thrust roller bearing of the present invention has the following effects.
(I) Since the rollers slantly contact the swells formed on the rails, the rollers rotate in the circumferential direction (rotation and revolution) when the race vibrates in the radial direction. It does not keep touching the position. Therefore, the oil film is prevented from being interrupted and the durability is improved.
(Ii) Also, since one or both of the number of rollers and the number of undulations are odd numbers, when the race vibrates in the radial direction, the rotational forces acting on the respective rollers do not cancel each other. Rotate (rotate and revolve) more reliably in the circumferential direction.

FIG. 1 is a schematic view showing a thrust roller bearing according to an embodiment of the present invention, in which (a) is a sectional view in side view and (b) is a sectional view of a vertical surface of a rotating shaft.
In FIG. 1A, a thrust roller bearing 100 includes a pair of annular races 1 and 4, a plurality of rollers 3 arranged between the races 1 and 4, and a holder that arranges the rollers 3 in a radial direction. (Not shown). The race 1 is installed on one rotating member 200, and the race 1 is installed on the other rotating member 300, respectively, to ensure smooth relative rotation between the rotating member 200 and the rotating member 300. In the figure, the alternate long and short dash line 9 indicates the rotation axis of the relative rotation. A plurality of undulations 2 are formed on the surface with which the rollers 3 of one race 1 abut.
In FIG. 1 (b), the undulation 2 is a smooth mountain-like (for example, substantially sinusoidal) protrusion, and is inclined by a predetermined angle with respect to the radial direction. At this time, the height “H” of the undulation 2 absorbs a manufacturing error (for example, 10 microns or less) of the roller 3 and exhibits the “swell effect” described later. Alternatively, it is set to about 0.1 to 0.2 mm.

FIGS. 2-4 is a top view which shows typically the Example of the race 1 of the thrust roller bearing shown in FIG.
In FIG. 2A, the race 1a of the thrust roller bearing is provided with 15 rollers 3a (indicated by a solid line in the radial direction in the figure) and equally divided in the circumferential direction. Three “swells 2a” are formed (indicated by hatching in the figure). At this time, the undulation 2a is inclined by a predetermined angle (α) with respect to the radial direction. Further, since the number (15) of the rollers 3a is an integral multiple (5 times) of the number (3) of the undulations 2a, the three undulations 2a have the same form as the rollers 3a (the same in the radial direction). Abut (at distance). Furthermore, since the number of the undulations 2a is an odd number, the pair of undulations 2a is not formed at a position (opposed position) that is 180 ° apart in the circumferential direction.
Hereinafter, a race in which the number of swells is “j” and the number of arranged rollers is “k” is referred to as “jk type” for convenience. That is, the race 1a shown in FIG. 2A is a “3-15 type”.

  FIG. 2B shows a “4-15 type” race 1b. At this time, the undulation 2b is inclined by a predetermined angle with respect to the radial direction. Further, since the number of the rollers 3b is not an integral multiple of the number of the swells 2b, the four swells 2b are in contact with the rollers 3b in different forms (at different distances in the radial direction). Furthermore, since the number of the undulations 2b is an even number, a pair of undulations 2a are formed at positions 180 ° apart (opposing positions) in the circumferential direction, but the number of rollers 3b is an odd number. The form of contact with the undulations 2b and 3b at positions 180 ° apart (opposing positions) in the circumferential direction is different.

  FIG. 2C shows a “5-15 type” race 1c. At this time, the undulation 2c is inclined by a predetermined angle with respect to the radial direction. Further, since the number of the rollers 3c is an integral multiple of the number of the swells 2c, the five swells 2c are in contact with the rollers 3c in the same form (at different distances in the radial direction). Furthermore, since the number of the undulations 2c is an odd number, the pair of undulations 2c is not formed at a position (opposite position) that is 180 ° apart in the circumferential direction.

  FIGS. 3D and 3F show a “3-16 type” race 1d and a “5-16 type” race 1f. At this time, the undulations 2d and 4f are inclined by a predetermined angle with respect to the radial direction. The number of rollers 3d and 3f is an even number (16, 16), whereas the number of undulations 2d and 4f is an odd number (3 and 5). 3f is in contact with each other in different forms.

  FIG. 3E shows a “4-16 type” race 1e. At this time, the undulation 2e is inclined by a predetermined angle with respect to the radial direction. Further, since the number (16) of the rollers 3e is an integral multiple (4 times) of the number (4) of the waviness 2e, the waviness 2e is in the same form as the rollers 3e (at the same distance in the radial direction). It is in contact. Furthermore, since the number of the undulations 2e is an even number, a pair of undulations 2e are formed at positions (opposite positions) separated by 180 ° in the circumferential direction. That is, the same state is obtained at intervals of 90 ° in the circumferential direction.

  FIG. 4 (g) shows a "16-8 type" race 1g. At this time, the undulation 2g is inclined by a predetermined angle with respect to the radial direction. Further, since the number (8) of the rollers 3g and the number (16) of the waviness 2g are both an even number and an integral multiple of each other, a position 180 ° apart in the circumferential direction (opposite position) , A pair of undulations 2g are formed, and the pair of undulations 2g at the opposing positions are in contact with each other in the same form as the rollers 3g.

4 (h) and 4 (i) show a "18-12 type" race 1h and a "15-12 type" race 1i. At this time, the undulations 2h and 2i are inclined by a predetermined angle with respect to the radial direction. Although the number of rollers 3h, 3i is an even number (12, 12), the number of rollers 3h, 3i (12, 12) and the number of swells 2h, 2i (18, 15) are integral multiples of each other. Since the relationship is not established, the undulations 2h and 2i are in contact with the rollers 3h and 3i in different forms.
In addition, the above shows a part of Example, This invention is not limited to this, The number of the wave | undulation 2 and the number of the rollers 3 may be any.

FIG. 5 is a schematic diagram for explaining the rotation of the rollers in the thrust roller bearing according to the embodiment of the present invention, wherein (a) is a partial perspective view for capturing (b) and (c); ) Is a plan view showing a state in which one race is moved upward (+ Y direction), and (c) is a plan view showing a state in which one race is moved downward (−Y direction).
5 (a) and 5 (b), the thrust roller bearing 100 has a plurality of rollers 3 arranged in the radial direction, and a radial direction is provided on a surface where the rollers 3 of the race 1 abut (roll). Is provided with a mountain-shaped ridge 3 (shown by diagonal lines in the figure and referred to as “swell” as described above). In addition, description of the holder | retainer which arrange | positions the roller 3 in the circumferential direction at predetermined intervals is abbreviate | omitted.

When one race 1 moves upward in the figure (in the + Y direction, indicated by a white arrow), the roller 3 is precisely “in position A” on the lower surface in the figure by elastic deformation. It contacts the swell 2 in a predetermined range around the position “A”.
At this time, the “moving force F” in the moving direction of the race 1 acts on the rollers 3. In other words, the roller 3 is subjected to the axial force “thrust force T in the axial direction” toward the outer peripheral side and the clockwise “rotational force R around the axial center” when viewed toward the outer periphery. However, since the rollers 3 are aligned in a radial direction by a cage (not shown), even if the inner peripheral side (range close to the rotary shaft 9) moves by a predetermined distance, the outer peripheral side (range far from the rotary shaft 9) It is necessary to move more than the inner circumference side. That is, the roller 3 “mainly rolls” on the undulation 2 on the inner peripheral side, but “mainly slides” on the undulation 2 on the outer peripheral side.
Then, the retainer (not shown) receives a force (represented by an arrow) that revolves counterclockwise in the drawing due to the force of the roller 3 to move.

In FIG. 5C, when one race 1 moves downward in the figure (-Y direction, indicated by a white arrow), the roller 3 moves to “position B” on the lower surface in the figure. In the above, the swell 2 comes into contact with the undulation 2 in a predetermined range around the “position B” by elastic deformation.
At this time, the “moving force F” in the moving direction of the race 1 acts on the roller 3 in the same manner as described above, and the direction of the force is opposite to that described above, so "Thrust force T" and counterclockwise "rotational force R about the shaft center" act when viewed toward the outer periphery. However, since the rollers 3 are aligned in a radial direction by a cage (not shown), even if the outer peripheral side (range far from the rotary shaft 9) moves by a predetermined distance, the inner peripheral side (range close to the rotary shaft 9) The amount of movement is less than the outer peripheral side. For this reason, the roller 3 “mainly rolls” on the undulation 2 on the outer peripheral side, but “mainly slides” on the undulation 2 on the inner peripheral side.

FIG. 6 is a schematic diagram illustrating roller revolution in the thrust roller bearing according to the embodiment of the present invention. FIG. 6 uses “3-16 type” as an example for convenience of explanation, but the revolutions of the rollers are the same for other types.
In FIG. 6, the three swells 2 are referred to as “swells U1, U2, U3” for convenience, and the 16 rollers 2 are referred to as “rollers K1, K2,... K16” for convenience. That is, the undulation U1 is in contact with the roller K1, the undulation U2 is in contact with the roller K7, and the undulation U3 is in contact with the roller K12. First, the revolution of the roller when one race 1 moves upward in the figure (+ Y direction, indicated by a white arrow) will be described.

Since the rotational force R1 acts on the roller K1 at the “position A1”, the retainer (not shown) applies a moment M1 (counterclockwise) proportional to a value obtained by multiplying the distance between the rotational shaft 9 and the position A1 by the rotational force R1. ) Will act. Similarly, since the rotational force R2 acts on the roller K7 at the “position A2”, the retainer (not shown) is operated by a moment M2 (proportional to a value obtained by multiplying the distance between the rotational shaft 9 and the position A2 by the rotational force R2 Counterclockwise). Similarly, since the rotational force R3 acts on the roller K12 at the “position A3”, a retainer (not shown) is provided with a moment M3 (proportional to a value obtained by multiplying the distance between the rotational shaft 9 and the position A3 by the rotational force R3. (Clockwise) will act.
Accordingly, the cage (not shown) is subjected to a revolution (temporarily referred to as “moment A”) by the sum of the moment M1 (counterclockwise), the moment M2 (counterclockwise), and the moment M3 (clockwise). Will do.

Next, when one race 1 moves downward (−Y direction) in the figure, a force in the opposite direction (to be exact, the direction slightly fluctuates) acts. At this time, the contact position between the roller K1 and the undulation U1 is moved to the outer peripheral side from the “position A1” by the thrust force T1 due to the upward movement (+ Y direction) described above. The moment is different from the moment M1. Similarly, the contact position between the roller K7 and the undulation U2 moves to the outer peripheral side from the “position A2”, while the contact position between the roller K12 and the undulation U3 is closer to the inner peripheral side than the “position A3”. Has moved.

  Accordingly, the respective moments at the positions A1, A2, and A3 after the movement are different from the moments M1, M2, and M3. Therefore, the sum of these moments (referred to as “moment B”) is The absolute value of the moment A is not equal in the opposite direction. That is, since the moment A and the moment B are not canceled out, a moment in a fixed direction acts repeatedly on a cage (not shown) and revolves. Therefore, at the same time, roller 3 also revolves. At this time, the moment is generated in the thrust bearing 100 regardless of its posture (regardless of whether the race 1 is horizontal or vertical).

As described above, the thrust bearing 100 causes the roller 3 to rotate and revolve by vibration even when the pair of races 1 and 4 rotate synchronously or when minute vibration is applied in a rotation stopped state, and the specific surface of the roller 3 The races 1 and 4 are not kept in contact with the same position. On the other hand, when the pair of races 1 and 4 rotate relative to each other, the roller 3 smoothly rotates and revolves. Furthermore, since the thrust bearing 100 has a simple structure, it can be manufactured at low cost.
Normally, the vibrations received by the thrust bearing 100 are not necessarily repeated with the same amplitude. From this point, the moment A and the moment B are not canceled out.

The above is an example of the “3-16 type”, but the same applies to the other types, and the moments of the respective sizes and directions act at the contact positions with the respective swells 2 and 3, and this is applied. A rotational force in a certain direction acts on the cage by the moment obtained by summing the moments.
When the number of swells 2 and 3 is both an even number and one is an integral multiple of the other, moments at positions 180 degrees apart (opposite positions) in the circumferential direction can cancel each other. Therefore, it is desirable that the number of the swell 2 and the number of 3 are both odd numbers.

  Since this invention is the above structure, it can be utilized widely as various thrust roller bearings and thrust needle bearings.

The schematic diagram which shows the thrust roller bearing which concerns on embodiment of this invention. The top view which shows typically the Example of the race 1 of the thrust roller bearing shown in FIG. The top view which shows typically the Example of the race 1 of the thrust roller bearing shown in FIG. The top view which shows typically the Example of the race 1 of the thrust roller bearing shown in FIG. The schematic diagram explaining the rotation of the roller in the thrust roller bearing shown in FIG. The schematic diagram explaining the revolution of the roller in the thrust roller bearing shown in FIG.

Explanation of symbols

1 Race 2 Swell 3 Roll 4 Race
9 Rotating shaft 100 Thrust bearing 200 Rotating member 300 Rotating member

Claims (2)

A thrust roller bearing comprising a pair of annular races, a plurality of rollers arranged between the pair of races, and a cage for arranging the plurality of rollers in a radial direction,
A thrust roller bearing, wherein a plurality of swells inclined at a predetermined angle with respect to a radial direction are formed on a surface of the pair of races on which the rollers abut against each other. 2. The thrust roller bearing according to claim 1, wherein one or both of the number of the plurality of rollers and the number of swells of the plurality of undulations are odd numbers.

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