JPS62124346A - Thrust generating device of v-belt stepless speed change gear - Google Patents

Abstract

PURPOSE:To prevent abrasion of the inside diameter portion of a diaphragm spring and to prevent a lowering of thrust generated by a torque cam device by rolling and supporting the inside diameter portion of the diaphragm spring for urging a movable sheave to a fixed sheave on a cam roller of the torque cam device through a retainer. CONSTITUTION:A diaphragm spring 7 for urging a movable sheave 4 to a fixed sheave 3 is fitted in a boss 31 provided in the base of the movable sheave 4, and a ring-shaped retainer 38 is interposed in a contact portion of the diaphragm ring and the boss 31. In this arrangement, the inside diameter portion of the diaphragm spring 7 is kept from sliding along the boss 31 to prevent abrasion of the inside diameter portion, so that thrust generated by a torque cam device can be prevented from being lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to (1) a thrust generating device for a belt-type continuously variable transmission, and particularly to a mechanical thrust generating device.

Conventional technology and its problems In the past, as a thrust generating device for a belt-type continuously variable transmission, as described in Japanese Patent Application Laid-open No. 58-142060, a belt transmission torque was used behind the movable sheave of the driven pulley. It is known that the sheave is equipped with a torque cam device that generates a thrust corresponding to the amount of thrust and a coil spring that biases the movable sheave toward the fixed sheave. However, when a coil spring is used as described above, the balance is poor with respect to the direction of rotation, and the spring load changes linearly with the IQ amount, so the spring of the coil spring decreases as the movable sheave moves. The disadvantage is that the load 1 also varies greatly.

Conventionally, it is known to use a diaphragm spring instead of a coil spring to solve the above drawbacks. Since the die 4/flam spring is disc-shaped, it is well balanced in the rotational direction, and the spring load does not change linearly with respect to one breath, and the spring load changes in the middle stroke range. It has the characteristic of having a region with a small amount.

However, when a diaphragm spring is used, the outer diameter part of the diaphragm spring is supported on the back of the movable sheave, and the inner diameter part is supported on a spring bearing member fixed to the shaft. As the torque cam device rotates relative to the other as the torque cam device operates, the inner diameter portion of the diaphragm spring and the spring bearing member move, causing the inner diameter portion of the diaphragm spring to wear out, and the torque cam device is generated due to the above-mentioned sliding resistance. The disadvantage is that the thrust is no longer proportional to the transmitted torque.

Purpose of the Invention The present invention has been made in view of these conventional problems.
The object is to provide a thrust generating device for a V-held continuously variable transmission that prevents wear of the inner diameter portion of a diaphragm spring and does not impair the performance of the torque cam device.

Structure of the Invention In order to achieve the above object, the present invention has a fixed sheave that rotates integrally with the shaft and a movable sheave that is movable in the axial and rotational directions with respect to the shaft. In the belt-type continuously variable transmission, a torque cam device that generates a thrust according to the input torque and a diaphragm spring that applies a predetermined spring load are installed behind the movable sheave, and the torque cam device is movable. a cam surface formed behind the sheave; and a stepped cam roller rotatably supported in a direction perpendicular to the above-mentioned axis, the inner diameter side small diameter portion of the cam roller being in contact with 1) the recording force surface; The large diameter portion on the outer diameter side supports the inner diameter portion of the diaphragm spring via an annular retainer.

In other words, by rolling and supporting the inner diameter part of the diaphragm spring with the cam roller of the torque cam device via a retainer, when the movable sheave is twisted as the torque cam device operates, the inner diameter part of the diaphragm spring does not wear out and the frictional resistance is reduced. is also reduced.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an example of a V-held continuously variable transmission according to the present invention, which is composed of a driving pulley 1, a driven-side boo U 10, and a V-held 20 wound between both pulleys. ing.

The drive pulley 1 has a fixed sheave 3 fixed to the drive shaft 2.
and a movable sheave 4 that is movable in the axial and rotational directions relative to the drive shaft 2, and a groove 5 is formed in which an expandable and contractible V-belt is hung, and a 1W force generator is configured behind the movable sheave 4. A torque cam device 6 and a diaphragm spring 7 are provided.

The driven pulley 10 has a fixed sheave 12 fixed to the driven shaft 11 and a movable sheave 13 that is movable in the axial direction with respect to the driven shaft 11.
Belt winding t4) A groove 14 is formed, and the movable sheave 1
3 J,? A hydraulic chamber 15 for controlling the pulley ratio is formed at the rear. By introducing control hydraulic pressure from a hydraulic control device (not shown) to this hydraulic chamber 15, the movable sheave 3 can be moved in the axial direction, and the pulley ratio between the driving side and the driven side can be changed steplessly.

Here, the specific structure of the driving pulley 1 will be explained with reference to FIGS. 2 and 3.

The fixed sheave 3 is formed into a conical shape, and a boss 30 fixed to the back surface thereof is spline-coupled to the drive shaft 2. On the back of the movable sheave 4, which has a symmetrical shape to the fixed sheave 3, there is a UA
A boss 31 that is movable in the axial and rotational directions with respect to the drive shaft is fixed, and two semicircular arc-shaped cam surfaces 32 are formed at the left end of the boss 31. This cam surface 3
2 is inclined so as to gradually protrude toward the counterclockwise direction in FIG. A terminal member 33 is spline-engaged with the left end of the drive shaft 2, and is fixed with a locking nut 34 to prevent removal. On the outer periphery of the terminal member 33, two cam rollers 36 are rotatably supported at symmetrical positions by roller bins 35 inserted perpendicularly to the drive shaft 2, and the roller bins 35 are attached to the terminal member 33 by press-fit bins 37. Extraction has been stopped. The cam roller 36 has a stepped shape, and its inner small diameter portion 36a is connected to the cam surface 36.
The cam roller 36 and the cam surface 32 constitute a torque cam device 6. In this torque cam device 6, as the input torque of the drive shaft 2 increases, the cam roller 36 rides on the cam surface 32, thereby giving the usable sheave 4 a thrust corresponding to the input torque.

The outer diameter part of the diaphragm spring 7 is the movable sheave 4
The inner diameter portion of the diaphragm spring 7 is supported by an annular retainer 38. The retainer 38 is slidably supported on the outer periphery of the boss 31, and the outer large diameter portion 36b of the cam roller 36 is pressed against the outer surface of the retainer 38 so as to be freely movable. The diaphragm spring 7 keeps the movable sheave 4 fixed at all times.
The spring load adjusts the thrust so that a predetermined contact pressure is maintained between the belt 20 and the pulley even when the V-belt continuously variable transmission is stopped.

In the 111 force generating device configured as described above, the drive shaft 2 and the movable sheave 4 rotate relative to each other as the torque cam device 6 operates, and the inner diameter side small diameter portion 36a of the cam roller 36
transfer from above. At this time, since the retainer 38 is disposed on the outer diameter side of the cam surface 32, the circumferential speed of the retainer 38 is greater than that of the cam surface 32. However, since the retainer 38 is in contact with the large outer diameter portion 36b of the cam roller 36, which has a high circumferential speed, no slipping occurs between the retainer 38 and the large outer diameter portion 36b, resulting in smooth transfer. . Therefore, the inner diameter portion of the retainer 38 or the diaphragm spring 7 does not wear out, and since there is almost no sliding resistance, there is no loss of thrust generated by the torque cam device 6 (tn).

In particular, the distances from the axis of the drive shaft 2 to the center of the inner diameter side small diameter part 36a and the center of the outer diameter side large diameter part 36b of the cam roller 36 are respectively R and R', Letting the radius and the radius of the outer large diameter portion 36b be r and r', respectively, if the relationship is set as R'/R=r'/r, the cam roller 36 and the cam surface 32, and the cam roller 36 and the retainer 38 Since the cam rollers 36, the cam surface 32, and the retainer 38 are in complete rolling contact with each other, the sliding friction between the cam roller 36, the cam surface 32, and the retainer 38 can be eliminated most effectively.

In addition, in the binary embodiment, an example was shown in which the driving pulley 1 was provided with the thrust generating device of the present invention and the driven pulley lO was provided with a hydraulic chamber for controlling the pulley ratio, but on the contrary, The driving pulley l may be provided with a hydraulic chamber for controlling the bobbin ratio, and the driven pulley l may be provided with a thrust generating device, and in place of the hydraulic chamber, a centrifugal actuating device that generates a thrust proportional to the square of the rotational speed may be used. etc. may be provided.

Effects of the Invention As is clear from the explanation in Section 2, according to the present invention, the inner diameter (small diameter part of the stepped cam roller) is brought into rolling contact with the cam surface, and the diaphragm spring is brought into contact with the cam surface at the large diameter part on the outer diameter side of the cam roller. Since the inner diameter portion is rotatably supported via the retainer, it is possible to eliminate wear of the diaphragm spring and loss of force generated by the torque cam device.

[Brief explanation of drawings]

Fig. 1 is a skeleton diagram showing the schematic structure of the belt-type continuously variable transmission according to the present invention, Fig. 2 is a cross-sectional view showing the specific structure of the drive-side pulley, and Fig. 3 is - ■It is a line sectional view. DESCRIPTION OF SYMBOLS 1... Drive side pulley, 2... Drive shaft, 3... Fixed sheave, 4... Movable sheave, 6... Torque cam device, 7... Diaphragm spring, 32... Cam surface, 35...Roller bin, 36...Cam roller, 36
a... Small diameter part on the inner diameter side, 36b... Large diameter part on the outer diameter side, 3
8...Retainer.

Claims (1)

[Claims] (1) V that can be expanded and contracted by a fixed sheave that rotates integrally with the shaft and a movable sheave that moves in the axial and rotational directions with respect to the shaft.
In a V-belt type continuously variable transmission formed with a belt winding groove, a torque cam device that generates a thrust according to input torque and a diaphragm spring that applies a predetermined spring load are provided behind the movable sheave, The torque cam device includes a cam surface formed behind a movable sheave, and a stepped cam roller that is rotatably supported in a direction perpendicular to the above-mentioned axis, and a small diameter portion on the inner diameter side of the cam roller contacts the above-mentioned cam surface. A thrust generating device for a V-belt continuously variable transmission, characterized in that the large diameter portion on the outer diameter side supports the inner diameter portion of the diaphragm spring via an annular retainer.