JPS6213814A - Thrust bearing device - Google Patents

Abstract

PURPOSE:To retain sufficient load capacity from low-speed rotation to high- speed rotation by disposing a rolling bearing and a slide bearing side by side in the radial direction. CONSTITUTION:A thrust bearing 55 comprises a roller bearing 70 and an inclined slide bearing 71. Both bearings 70, 71 have annular plates 72, 73 respectively fixed to a support member of a ball screw mechanism 50 and a rotary member such as a shaft 3 or the like, and further a collar-like retaining ring 75 having the outer line bent is fixed to the support plate 72. A roller 76 forming a roller bearing and annular race 77 are arranged side by side on the inside diameter side and on the outside diameter side, respectively between the ring 75 and the movable plate 73. Further, a wedge-shaped inclined surface 77a confronting with the ring 75 and expanding in the direction of rotation is formed on the race 77.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application The present invention relates to a thrust bearing device, particularly to a thrust bearing device suitable for use in a belt-type continuously variable transmission.

(b) Conventional technology In general, belt-type continuously variable transmissions installed in automobiles are equipped with a primary pulley and a secondary pulley, each consisting of a movable sheave and a fixed sheave, and an endless belt wrapped around both pulleys. There is. A large axial force acts on both of these pulleys so as to clamp the belt with a predetermined clamping force, and in order to correspond to the wide speed range of the automobile, the speed is frequently controlled at a large gear ratio. .

In addition, conventionally, in order to support the above-mentioned large axial force, rollers or restrust bearings made of rollers or balls are interposed between the movable sheave and the speed change operation means and between the speed change operation means and the thrust and support members. are doing.

←→ Problems to be Solved by the Invention By the way, in this type of continuously variable transmission, the gears are frequently changed in response to stopping, acceleration, and deceleration of the automobile, and a large axial force corresponding to the transmitted torque is applied. Therefore, the above-mentioned thrust bearing, at rotational speed from zero to maximum speed,
It is necessary to carry a large axial force, but with roller thrust bearings, there is no problem at low rotation speeds, but as the rotation speed increases, the load capacity decreases, causing problems in durability (Figure 3). (see , 1).

On the other hand, as a thrust bearing, there is a sliding bearing that forms an oil film based on relative rotation and supports thrust force with the oil film. However, when using such sliding bearings, at high speed rotations, sufficient oil film pressure can be generated and a large load capacity can be carried, but at low rotation speeds, especially when starting rotation from zero, the oil film formation is not sufficient and the metal Direct contact between the two causes problems with durability, etc.

Therefore, an object of the present invention is to provide a thrust bearing device that has sufficient load capacity in a large rotational speed range from zero to maximum speed so that it can be used in the Bell 1 continuously variable transmission. It is something.

(b) Means for Solving the Problem The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIG. 1, the thrust bearing 55 is
It is characterized in that a rolling bearing 70 and a sliding bearing 71 are arranged side by side in the radial direction.

(E) Effect Based on the above-described configuration, during low-speed rotation, the oil film formed by the sliding bearing 71 is not sufficient, and the thrust force is exclusively carried by the rolling bearing 70. Furthermore, during high-speed rotation, a sufficient oil film is formed on the sliding bearing 71, and the sliding bearing 71 mainly carries thrust force.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the belt-type continuously variable transmission 1 according to this embodiment has a primary shirt l linked to the engine side.
-2 and a secondary shaft 3 interlocked with the wheel side, the primary shaft 2 is equipped with a primary pulley 5, the secondary shaft 3 is equipped with a secondary pulley 6, and both of these pulleys 5
, 6, an endless belt B is wound around them. and,
The primary pulley 5 consists of a movable sheave 7 and a fixed sheave 9 that move relative to each other in the axial direction, and the boss portion 7 of the movable sheave 7
a is rotatably and slidably fitted to the shaft 2, and the boss portion 9a of the fixed sheave 9 is connected to the ball spline 1.
0, and are slidably fitted together. Further, a pressure regulating cam mechanism 11 is interposed between the back surface of the flange portion 9b of the fixed sheave 9 and the stepped expanded diameter portion 2a of the shaft 2. The pressure regulating cam mechanism 11 consists of a movable race 12, a fixed race 13, and a plurality of tapered rollers 15. The movable race 12 is spline-coupled to the fixed sheave 9, and a bookmark is pressed against the back surface of the flange portion 9b via a disc spring 14. , and a fixed race 13 is fixed to the expanded diameter portion 2a and rotatably supported by a housing (not shown) via a bearing 16. Furthermore, the opposing end surfaces of both races 12.13 are formed with undulations in a wave-like manner, and the tapered rollers 15 are sandwiched between the end surfaces. Generate Fp.

Further, a stepped collar 19 constituting a thrust support member is fixed and supported by a nut 17 at the distal end of the shaft 2, and the collar 19 and thus the shaft distal end are supported by a bearing 20. and,
A ball screw mechanism 21 constituting a speed change operation means is interposed between the collar 19 and the back surface of the flange portion 7b of the movable sheave 7. The ball screw mechanism 21 has a female threaded portion 22, a male threaded portion 23, a large number of balls 25, and two gears 26 and 27 having different numbers of teeth.

One gear 26 with a large number of teeth is integrally fixed to the female screw part 22, and the boss part 27a of the other gear 27 with a small number of teeth is fitted into the shirt).2 through a needle. At the same time, its outer periphery is slidably connected to the male threaded portion 23 via a ball spline 29. Furthermore, one end surface of the male threaded portion 23 is in contact with the back surface of the flange portion 7b via a thrust bearing 30, and the other end surface of the gear 27 is in contact with the end surface of the collar 19 via a thrust bearing 31. Also, both gears 26.27
A thrust bearing 32 is interposed between the opposing side surfaces of.

On the other hand, the secondary pulley 6 also consists of two sheaves 33°35, and the boss portion 33a of the movable sheave 33 is rotatably and slidably fitted to the shaft 3, and the boss portion 35a of the fixed sheave 35 is connected to a ball spline. They are slidably fitted together via 36. Similarly to the primary pulley 5, a fixed race 39, a movable race 40, a tapered roller 41, and a disc spring are connected between the back surface of the flange portion 35b of the fixed sheave 35 and the collar 37 fixed to the tip of the shaft 3 with a nut 38. A pressure regulating cam mechanism 43 consisting of 42 is interposed. Similarly, between the back surface of the flannelé portion 33b of the movable sheave 33 and the stepped expanded diameter portion 3a of the shaft 3, a female screw portion 45, a male screw portion 46, a ball, and a large diameter gear 47 are provided.
, a ball screw mechanism 50 consisting of a small diameter gear 49 and a ball spline 48 is interposed. Note that bearings 51, 52 and 53, 55, and 56 that support the shaft 3 are thrust bearings that receive the axial force Fs from the sheave 33. And the primary and secondary shaft 2,
A countershaft 57 is disposed between the countershafts 3 and 3, and both ends of the countershaft 57 are rotatably supported by bearings 59 and 60. Further, a large diameter gear 61 and a small diameter gear 62 are spline connected to one end portion of the shaft 57, and these gears 61 and 62 mesh with the small diameter gear 27 and the large diameter gear 26 of the primary side ball screw mechanism 21, respectively. There is. Further, a large diameter gear 63 and a small diameter gear 65 are spline connected to the other end of the shaft 57, and these gears 63 and 65 mesh with the small diameter gear 49 and the large diameter gear 47 of the secondary ball screw mechanism 50, respectively. ing. Furthermore, a worm wheel 6 is attached to the shaft 57.
6 is spline-coupled, and the wheel 66 has a worm gear 67 that is linked to a speed change operation means such as a motor.
are meshing.

And each thrust) bearing 30, 31, 32 (
(primary side) and 53, 55, 56 (secondary side) each have a large axial force Fp to pinch the belt.
, Fs are acting, but in addition, the thrust bearing 30.31 between the ball screw mechanism 21.50, which is stationary outside the speed change operating means, and the normally rotating movable sheave 7.33 and shafts 2, 3. , 53, and 55, a large relative rotation is acting between them. Therefore, the thrust bearing according to the present invention is used for the bearings 30° 31.53, 55. Note that all these bearings have the same configuration, so based on Fig. 1, the bearing 55
Only this will be explained, and other explanations will be omitted.

The thrust bearing 55 consists of a roller (or needle) bearing 70 and an inclined piece type sliding bearing 71, as shown in FIG. 1(a).

Both bearings 70 and 71 each have a ball screw mechanism 50.
It has annular plates 1-72 and 73 fixed to a supporting member and a rotating member such as the shaft 3, and furthermore, the supporting plate 72 has a brim-shaped retaining ring 75 whose outer line is bent. Fixed. Between the ring 75 and the movable plate 73, a roller 76 forming a rolling bearing is arranged on the inner diameter side, and an annular race 77 forming a sliding bearing on the outer diameter side. , and the race 77 is formed with a wedge-shaped inclined surface 77g facing the ring 75 and extending in the rotational direction (see arrow). Note that (the one shown in C1 has inclined pieces 77a formed on both the left and right sides to enable forward and reverse rotation. Furthermore, an oil passage 79 is bored in the shaft 3, and the oil passage 79 is in communication with the bearing 55 via an oil hole 80.As shown in FIG. Similarly, an oil passage 79 is bored in the bearing 30, and the oil passage 79 also communicates with the thrust bearings 30, 31 and other parts requiring lubrication.

Since the present embodiment has the above-described configuration, the rotation of the primary shaft 2 based on the engine output is transmitted from its expanded diameter portion 2a to the fixed race 13 of the pressure regulating cam mechanism 11, and further transmitted to the fixed race 13 of the pressure regulating cam mechanism 11. 12 to the sheave 9 of the primary pulley 5. At this time, the transmission torque between the fixed race 13 and the movable race 12 of the pressure regulating cam mechanism 11, that is, the axial force Fp corresponding to the input torque acting on the shaft 2 is transmitted to the sheave 9 through the disc spring 14.
On the other hand, the ball screw mechanism 21 of the other sheave 7 is fixed in its longitudinal direction in accordance with a predetermined gear ratio, and therefore an equivalent force is applied to the back surface of the sheave 7 via the thrust bearing 30. A reaction force Fp acts on the primary pulley 5, which causes the primary pulley 5 to exert a clamping force F corresponding to the input torque.
Clamp belt B at p. The torque of the pulley 5 that rotates integrally through the ball spline 10 is transmitted to the secondary pulley 6 through the belt B, and further transmitted to the secondary shaft 3 through the pressure regulating cam mechanism 43. At this time, based on the pressure regulating cam mechanism 43, the secondary shirt! An axial force Fs corresponding to the output torque transmitted to the ball screw mechanism 5 acts on the sheave 35 via the disc spring 42, and the ball screw mechanism 5 is also fixed on the back surface of the other sheave 33.
A reaction force Fs acts from 0, so that the secondary pulley 6 also clamps the belt B with a clamping force Fs corresponding to the output torque. However, in the torque transmission state described above, the generated axial force Fpt F B of the pressure regulating cam m structure 11, 43
Therefore, both disc springs 14 and 42 are in close contact with the movable race 12 and the sheave 9, and the movable race 40 and the sheave 33, respectively.

In the constant torque ratio state, the axial force Fp acting on the movable sheave 7 of the primary pulley 5 is transmitted to the ball screw mechanism 21 via the thrust bearing 30, further transmitted to the gear 27 via the thrust bearing 32, and then The thrust bearing 32 interposed between both gears 26 and 27 cannot rotate equally because both gears 26 and 27 are stationary. do not have. Therefore,
Thrust bearings 30 and 31 interposed between the movable sheave 7 and the male threaded portion 23 and between the collar 19 and the gear 27 bear a large relative rotation corresponding to the rotation of the pulley 5.

Similarly, on the secondary side, both gears 47,490
The bearing 56 between the movable sheave 33 and the male threaded portion 46 does not rotate equally, and the bearing 56 between the movable sheave 33 and the male threaded portion 46 and the shaft expanded diameter portion 3
A thrust bearing 53.55 between the gear 49 and the gear 49 carries a large axial force Fs and relative rotation. In these bearings 30, 31, 53, and 55, during low-speed rotation such as when starting rotation from a stopped state, the oil film pressure due to the inclined surface 77a is not sufficient, and the rolling bearing 70 located on the inner diameter side is used to generate thrust. However, since the load capacity of the rolling bearing 70 is large during low speed rotation, a large axial force FpyFS is applied to the sliding bearing 71.
Be able to support it comfortably without acting on it. Also,
During high-speed rotation tζ, the lubricating oil supplied from the oil passage 79 is applied to the movable sheave 7.33 and the shaft (collar) 19.3.
The inclined surface 77a of the race 77, which rotates together with the ring 75, acts in a wedge-like manner to form a sufficient oil film to separate the annular race 77 from the ring 75.
Axial force Fp at.

It carries Fs. As a result, these thrust bearings 30, 31, 53, and 55 have sufficient load capacity in all rotational speed ranges from zero to maximum rotational speed, as shown in Figure 3(c). Supports large axial forces Fp and Fs.

To change the speed of the V-belt continuously variable transmission 1, the rotation of the motor linked to the worm gear 67 is controlled based on various driving signals such as vehicle speed, throttle opening, and engine speed. For example, when the worm gear 67 is rotated clockwise, that is, in the upshift direction, the worm wheel 6
6 rotates clockwise when viewed from the right side of the drawing (the same applies hereafter), and connects each gear 61, 62, 6 via a counter shaft 57.
3 and 65 also rotate in the same direction. Then, the gears 26 and 27 of the primary ball screw mechanism 21 rotate counterclockwise, but the rotation speed of the small diameter gear 27 becomes larger than the rotation speed of the large diameter gear 26 based on the difference in the number of teeth. This results in
A male screw portion 23 rotates together with the gear 27 via a ball spline 29, and a female screw portion 2 rotates together with the gear 26.
2, the right-handed ball screw extends to the right, moves the movable sheave via the strut bearing 31 so that the distance between it and the fixed sheave 9 becomes smaller, and the bell I-B Change the effective diameter of the Similarly, based on the counterclockwise relative rotation of the gear 49° 47 of the secondary ball screw mechanism 50 by the gears 63 and 65, the male threaded portion 46 that rotates together with the gear 49 becomes the female threaded portion that rotates together with the gear 47. The rotation becomes larger compared to the rotation of 45, and the ball screw consisting of a right-handed screw shrinks to the right.
The movable sheave 33 is moved so as to increase the distance from the fixed sheave 35, and the effective diameter of the belt B is changed to become smaller. In addition, at this time, ball screw machine 11J21.50
Although the male threaded portion 23.46 and female threaded portion 22.45 of Even if it is not used, the meshing relationship can be maintained reliably at all times. Furthermore, when the worm gear 67 is rotated counterclockwise, that is, in the downshift direction, it rotates in the opposite direction to the upshift described above, causing the primary ball screw mechanism 21 to contract leftward and the secondary ball screw mechanism 50 to the left. After being extended, both booleans 1J5 and 1J6 move the belt B in the direction of deceleration.

At this time, both the primary and secondary ball screw mechanisms 21.50 have their female threaded portions 22.45 and male threaded portions 23.
．． 46 rotates relative to each other, but the rotational speed is small compared to the rotational speed of pulleys 5 and 6, and no large rotational load is applied to the thrust bearings 32.56.

In addition, ball screw machines start from $21.50, with movable sheave 7.
Axial forces Fp and Fs act on the thrust bearings 30 and 31, which consist of a rolling bearing 70 and a sliding bearing 71, as described above.
5.

In addition, in the above embodiment, the rolling bearing 70 is provided on the inner diameter side.
Although the sliding bearing 71 is installed on the outer diameter side, it goes without saying that this arrangement may be reversed. Further, although the race 77 having an annular shape having an inclined surface 77a is used as the sliding bearing 71, a race 77 made of a pivot type thrust piece or one having an even load distribution structure may also be used.

Further, in the above embodiment, the thrust bearing is applied to a V-belt type continuously variable transmission, but it is not limited to this, but may be applied to other devices with a wide rotational speed range and a large supported axial force. Of course.

(g) As described in detail, according to the present invention, a thrust bearing on which a large axial force acts over a wide rotational speed range is arranged in parallel with a rolling bearing 70 and a sliding bearing 71 in the radial direction. Therefore, in the low speed rotation range, the rolling bearing 70 carries the load exclusively, and in the high rotation speed range, the sliding bearing 71 carries the load, so that sufficient load capacity is maintained in any rotation speed range, Furthermore, since the rolling bearing 70 is always sufficiently lubricated, durability can be greatly improved.

In particular, if the thrust bearings 30, 31, 53° 55 are installed in the parts of the belt transmission 1 where large axial force and relative rotational speed act, the durability and transmission load capacity of the transmission 1 will be greatly improved. Be able to do it.

Furthermore, by arranging the rolling bearing 70 on the inner diameter side and the sliding bearing 71 on the outer diameter side, the rolling bearing 70, which mainly functions during low speed rotation, can be used in the portion of the inner diameter side where the relative speed is small. In addition, the sliding bearing 71, which mainly functions during high-speed rotation, can be used in the portion of the outer diameter side where the relative speed is large, resulting in an advantageous configuration both during low-speed rotation and high-speed rotation.

9 Furthermore, if an inclined piece type sliding bearing equipped with a race 77 made of an annular member having an inclined surface 77a is used as the sliding bearing 71, the rolling bearing 70 carries the load up to a predetermined rotational speed, and the sliding bearing Since no axial force is applied, there is no problem even if the race 77 is tilted due to insufficient oil film during low speed rotation.
In addition, during intermediate speed rotation, both the rolling and sliding bearings work together to prevent excessive axial force from acting locally, and furthermore, the extremely simple structure consisting of one race It can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, in which (a) is a sectional view taken in the radial direction, and (b) is a view expanded in the circumferential direction. Further, FIG. 2 is a sectional view showing a V-belt type continuously variable transmission to which the present invention is applied, and FIG. 3 is a diagram showing the load capacity of each bearing at each rotation speed. 1. Belt type continuously variable transmission, 2. Primary shaft, 3. Secondary shaft. 3a, 19
・Slus 1 - Support member (collar, expanded diameter part),
5-Primary pulley, 6...Secondary pulley, 7,33...Movable sheave, 9.35...
・Fixed sheave, 11, 43・Pressure regulating cam mechanism,
21.50・Speed change operation means (ball screw mechanism),
30, 31, 53, 55... Thrust bearing
, 70. Rolling bearing, 71.. Sliding bearing, 75.. Retaining ring, 77..
Race, 77a...Slope, 79...Oil channel
.

Claims (4)

[Claims] (1) A thrust bearing used in a device that has a wide rotational speed range and is subjected to a large axial force, and the thrust bearing is composed of a rolling bearing and a sliding bearing arranged in parallel in the radial direction. Thrust bearing device. (2) The thrust bearing device according to claim 1, wherein the device is a V-belt type continuously variable transmission, and the thrust bearing is interposed between the speed change operation means and the movable sheave and the thrust support member. . (3) The thrust bearing device according to claim 1, wherein the thrust bearing has a rolling bearing on its inner diameter side and a sliding bearing on its outer diameter side. (4) The thrust bearing device according to claim 1, wherein the sliding bearing is an inclined piece type sliding bearing having an inclined surface and a race made of an annular member.