JP2001295904A - Disk pushing device for toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic loading type disk pushing device for toroidal type continuously variable transmission provided with a seal material having high durability. SOLUTION: A hydraulic loading type disk pushing device 45 is provided with an input disk 11 provided in an input shaft 40 and a cylinder member 47. A piston part 46 is provided 9 on the back surface side of the input disk 11. The piston part 46 is inserted into the cylinder member 47 and forms an oil pressure chamber 55. The piston part 46 and the cylinder member 47 are integrally rotated with the input shaft 40. A seal material 60 for sealing the oil pressure chamber 55 is provided between the piston part 46 and the cylinder member 47. A connecting means 61 formed of a key 62 and a key way 63 is provided between the piston part 46 and the cylinder member 47. A gap of the rotation between the piston part 46 and the cylinder member 47 due to a torque fluctuation of the input shaft 40 is prevented by engaging the key 62 with the key way 63.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a hydraulic loading type disc pressing device used in a toroidal type continuously variable transmission.

[0002]

2. Description of the Related Art A toroidal type continuously variable transmission transmits power through rotation of a power roller sandwiched between an input disk and an output disk. Therefore, it is necessary to apply a large pressing force to the contact portion between each disk and the power roller. As a means for giving a pressing force, a mechanical loading type and a hydraulic loading type are known.

[0003] The optimum pressing force between each disk and the power roller changes according to various conditions such as the speed ratio and the temperature of the lubricating oil according to the operating conditions that change every moment. In this regard, the hydraulic loading type is preferable as a disk pressing device of a toroidal type continuously variable transmission because the pressing force can be controlled according to various conditions. Usually, the hydraulic loading type disc pressing device is arranged on the rear side of the input disc.

As an example of a hydraulic loading type pressing device, USP. No. 5,338,268,
It is known to use the back of an input disk as part of a piston. A cylinder member accommodating the piston portion is fixed to an input shaft of the toroidal type continuously variable transmission. The input disk having the piston portion and the input shaft are connected to each other via a ball spline.
Therefore, the input disk rotates integrally with the input shaft and is movable in the axial direction of the input shaft.

[0005] A seal member is provided between the cylinder member and the piston for sealing the hydraulic chamber. This sealing material is in contact with the inner surface of the cylinder member only by the elastic force of the sealing material.

[0006]

As described above, the cylinder member and the piston portion are individually connected to the input shaft, but the cylinder member and the piston portion are not directly connected. Therefore, when a sudden torque change occurs on the input shaft, the cylinder member and the piston portion generate a slight rotational deviation around the input shaft. When the rotational displacement is repeated, the seal material may be worn or damaged due to rubbing or excessive bending of the seal material, and oil in the hydraulic chamber may leak. If an oil leak occurs, the efficiency of the hydraulic pump decreases, and a sufficient disc pressing force cannot be obtained.

Particularly, in a half toroidal type continuously variable transmission, the input shaft and the input disk are often connected to each other via a ball spline. Rotational deviation between the cylinder member and the input disk easily occurs, and an excessive load is easily applied to the seal material. As a result of repeated rubbing of the seal material, wear and breakage of the seal material occur.

In a half toroidal type continuously variable transmission, two power rollers are often provided between an input disk and an output disk. In this case, the input disk is pressed at two points by the power rollers. Since the input disk bends due to this force, a slight rotational displacement around the input shaft occurs between the cylinder member and the piston portion due to torque fluctuation or the like. The rotation may cause wear of the seal material.

Accordingly, an object of the present invention is to improve the durability of a seal member provided between a cylinder member and a piston portion in a hydraulic loading type disc pressing device of a toroidal type continuously variable transmission.

[0010]

In order to achieve the above object, the present invention relates to a hydraulic loading type disc pressing apparatus having a cylinder member and a piston portion which are attached to an input shaft and rotate integrally with the input shaft. A seal member for sealing a hydraulic chamber is provided between the member and the piston portion, and a coupling means for suppressing a rotation difference between the cylinder member and the piston portion is provided. .

According to the present invention, it is preferable that when the input shaft fluctuates in rotational speed or torque, the piston and the cylinder member constituting the hydraulic loading type disc pressing device are displaced around the rotary shaft. This prevents wear and damage of the sealing material. The coupling means allows the cylinder member and the piston portion to relatively move in the axial direction of the input shaft, for example, a combination of a keyway and a key along the axial direction of the input shaft,
A combination of a groove and a ball is employed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a double-cavity half-toroidal continuously variable transmission 1. The toroidal-type continuously variable transmission 1 has an input disk 11 and an output disk 1 which form a first cavity 10.
2 and an input disk 21 and an output disk 22 constituting the second cavity 20.

Each of the cavities 10 and 20 is provided with, for example, two power rollers 30. First
The outer peripheral surface of the power roller 30 in the cavity 10 is in contact with the traction surfaces of the input / output disks 11 and 12.
The outer peripheral surface of the power roller 30 in the second cavity 20 is
It is in contact with the traction surfaces of the input / output disks 21 and 22. These power rollers 30 are rotatably supported by trunnions 32 by power roller bearings 31, respectively. Each of the trunnions 32 is swingable about a trunnion shaft 33.

The input disk 11 of the first cavity 10
Is an input shaft 40 of the continuously variable transmission 1 as shown in FIG.
Are supported in a rotational direction by a ball spline 41 and are movably supported in the direction of the axis P of the input shaft 40. The ball spline 41 includes the ball 41a and the groove 4
1b. On a part (back side) of the input disk 11, a piston part 46 forming a part of a hydraulic loading type disk pressing device 45 is formed.

The piston part 46 includes a cylinder member 47.
And can be moved in the direction of the axis P of the input shaft 40. The cylinder member 47 is fitted to the input shaft 40 at the spline portion 50, and the cylinder member 47 rotates integrally with the input shaft 40. The cylinder member 47 is urged in the direction of the axis P of the input shaft 40 by a spring 52 provided between the cylinder member 47 and the flange portion 51 of the input shaft 40.

The inner surface of the cylinder member 47 and the piston 46
A hydraulic chamber 55 is formed by the inner surface of the cylinder. Oil of a desired pressure is supplied to the hydraulic chamber 55 from a hydraulic source (not shown) through an oil passage 56 formed in the input shaft 40.
The piston portion 46, that is, the input disk 11, moves in the direction of the axis P with respect to the cylinder member 47 according to the hydraulic pressure. The cylinder member 47 is connected to a drive shaft 58 via an engagement portion 57. The drive shaft 58 is driven to rotate by a torque generated by an engine (not shown).

A seal member 60 is provided on the outer periphery of the piston 46. The seal member 60 is constituted by an elastic body such as an O-ring and an annular seal provided on the outer peripheral side thereof, and seals the hydraulic chamber 55 by making liquid-tight contact with the inner peripheral surface of the cylinder member 47.

Input disk 11 having piston portion 46
A key 62 and a key groove 63 functioning as coupling means 61 according to the present invention are provided between the outer peripheral portion of the cylinder member 47 and the cylinder member 47. In the case of this embodiment, the input disk 11
The key 62 is attached to the cylinder member 47, and the key groove 63 is formed in the cylinder member 47. However, the positional relationship between the key 62 and the key groove 63 may be reversed. Since the key 62 and the key groove 63 mesh with each other, the relative rotation of the piston portion 46 and the cylinder member 47 around the axis P is prevented. The key 62 can slide in the direction of the axis P with respect to the key groove 63.

As shown in FIG. 1, the input disk 21 of the second cavity 20 is
0, and the movement in the axis P direction is restricted by the nut 71. On the other hand, the output disks 12, 22
Are rotatably supported on the input shaft 40 by bearings 75, respectively. These output disks 12, 2
Reference numerals 2 are connected to each other via an output gear 76, and are movable in the direction of the axis P with respect to the input shaft 40.

Next, the operation of the toroidal type continuously variable transmission 1 having the above configuration will be described. The torque of the drive shaft 58 rotated by the engine is transmitted to the cylinder member 47 via the engagement portion 57. Since the cylinder member 47 is fitted to the input shaft 40 at the spline portion 50, the cylinder member 47 rotates integrally with the input shaft 40. On the other hand, since the input disk 11 is connected to the input shaft 40 via the ball 41a of the ball spline 41, the input disk 11 also rotates integrally with the input shaft 40.

When the pressurized oil is supplied to the hydraulic chamber 55, the input disk 11 of the first cavity 10 is pressed toward the output disk 12, and the output disk 22 of the second cavity 20 is pressed. Input disk 21
Pressed toward. Therefore, the input disks 11, 21
Is transmitted to the output disks 12 and 22 via the power roller 30.

Here, the input disk 11 is a power roller 3
0 to receive the reaction force from the output disk 12,
When rotation fluctuation or torque fluctuation occurs in the drive shaft 58, the torsion of the input shaft 40 or the ball 41a of the ball spline 41
Due to the play (gap) between the cylinder member 47 and the outer peripheral portion of the input disk 11, a rotational displacement about the axis P tends to occur.

However, in this embodiment, the input disk 1
Since the key 62 and the key groove 63 mesh with each other at the outer peripheral portion of the input disk 1, the input disk 11 and the cylinder member 47 are connected to each other.
1 and the cylinder member 47 are prevented from rotating. The input disk 11 is allowed to move in the direction of the axis P with respect to the cylinder member 47.

The coupling means 61 formed by the key 62 and the key groove 63 prevents the seal member 60 from slipping, thereby preventing the seal member 60 from being worn or damaged. Therefore, a decrease in pump efficiency due to oil leakage of the seal member 60 is prevented, and a reduction in disc pressing force can be prevented, thereby improving the durability of the toroidal type continuously variable transmission 1. Further, since the coupling means 61 is provided, the deformation of the piston portion 46 is reduced.
Also becomes smaller. For this reason, deformation of the sealing material 60 is suppressed, which also leads to improvement in durability of the sealing material 60.

The shapes of the key 62 and the key groove 63 are not limited to the above embodiment. For example, a key having a cylindrical shape or a rectangular parallelepiped shape may be adopted. Good. The number of the keys 62 and the key grooves 63 may be one, or a plurality of the keys 62 and the key grooves 63 may be provided in the circumferential direction of the disk 11.

Next, according to a second embodiment of the present invention, a hydraulic loading type disc pressing device 45A shown in FIG.
This will be described with reference to FIG. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and a part of the description is omitted. The disc pressing device 45A according to the second embodiment includes a ball 80 and a groove 81 in which a part of the ball 80 is fitted as a coupling means 61A for preventing a rotational displacement between the piston portion 46 and the cylinder member 47. Has been adopted. The groove 81 is the axis P of the input shaft 40.
Along the direction.

The ball type coupling means 61A allows the input disk 11 to move in the direction of the axis P with respect to the cylinder member 47. However, relative rotation between the cylinder member 47 and the input disk 11 is prevented. This coupling means 6
1A, the disc pressing device 45 of the first embodiment is used.
Similarly to the case described above, wear and excessive deformation of the sealing material 60 are suppressed. Moreover, according to the ball-type coupling means 61A, the action of the ball 80 allows the piston portion 46 to move more smoothly in the direction of the axis P with respect to the cylinder member 47 in accordance with the fluctuation of the hydraulic pressure supplied to the hydraulic chamber 55. it can. In this case, it is possible to reduce the load of the hydraulic system that supplies the hydraulic pressure to the hydraulic chamber 55 and maintain the life of the hydraulic chamber 55 in order to maintain the optimum disc pressing force.

Next, a third embodiment of the present invention will be described with reference to a hydraulic loading type disc pressing device 45B shown in FIGS. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and a part of the description is omitted. The disc pressing device 45B according to the third embodiment includes a coupling means 6 for preventing a rotational displacement between the piston portion 46 and the cylinder member 47.
As 1B, the protrusion 85 is formed integrally with the outer peripheral portion of the input disk 11. As shown in FIG. 5, a plurality of protrusions 85 are formed in the circumferential direction of the input disk 11. A hole 87 for passing the input shaft 40 is formed in the center of the input disk 11.

These projections 85 are inserted into grooves 86 formed in the cylinder member 47. The protrusion 85 is fitted in the groove 86 so that the piston portion 46 can move in the direction of the axis P with respect to the cylinder member 47. By doing so, abrasion and deformation of the seal member 60 can be suppressed as in the case of the disc pressing device 45 of the first embodiment.

Next, regarding a fourth embodiment of the present invention,
Hydraulic loading type disc pressing device 45 shown in FIG.
This will be described with reference to C. The disc pressing device 45C of the fourth embodiment is a so-called double piston type. That is, the intermediate movable member 90 is provided between the input disk 11 and the cylinder member 47. The intermediate movable member 90 is connected to the first end wall 9 located on the cylinder member 47 side.
1 and a second end wall 92 located on the input disk 11 side.

A first hydraulic chamber 93 is formed between the cylinder member 47 and the first end wall 91, and a second hydraulic chamber is formed between the second end wall 92 and the piston portion 46 of the input disk 11. 9
4 are formed. These oil chambers 93 and 94 communicate with a hydraulic source (not shown) through an oil passage 56 formed in the input shaft 40, and a desired hydraulic pressure is supplied from the hydraulic source.
The intermediate movable member 90 and the input disk 11 move in the direction of the axis P of the input shaft 40 according to the hydraulic pressure. By cooperating the two hydraulic chambers 93, 94 in this way, it is possible to reduce the size of the hydraulic pump for applying hydraulic pressure to the hydraulic chambers 93, 94.

The seal member 10 is provided on the outer periphery of the intermediate movable member 90.
0 is provided. The first hydraulic chamber 93 is sealed by the sealing member 100 being in contact with the inner peripheral surface of the cylinder member 47 in a liquid-tight manner. A seal member 101 is also provided on the outer peripheral portion of the piston portion 46 and the outer peripheral portion of the end wall 92 of the input disk 11. The second hydraulic chamber 94 is sealed by the sealing member 101 being in liquid-tight contact with the inner peripheral surface of the cylinder portion 102 of the intermediate movable member 90.

Between the cylinder member 47 and the intermediate movable member 90, there are provided a key 111 and a groove 112 which function as the coupling means 110 according to the present invention. The key 111 is slidable with respect to the groove 112 in the direction of the axis P. In this embodiment, the key 111 is attached to the intermediate movable member 90 and the groove 112 is formed in the cylinder member 47.
The positional relationship between and the groove 112 may be opposite to each other. Since the key 111 and the groove 112 mesh with each other, a rotational displacement of the cylinder member 47 and the intermediate movable member 90 about the axis P is prevented.

The coupling means 120 according to the present invention is provided between the piston portion 46 of the input disk 11 and the intermediate movable member 90.
A key 121 and a groove 122 functioning as a key are provided. The key 121 is slidable with respect to the groove 122 in the direction of the axis P. In this embodiment, the input disk 11 has a key 1
21, the groove 122 is formed in the intermediate movable member 90. However, the positional relationship between the key 121 and the groove 122 may be reversed. Since the key 121 and the groove 122 mesh with each other, a rotational displacement of the piston portion 46 of the input disk 11 and the intermediate movable member 90 about the axis P is prevented.

As in this embodiment, two hydraulic chambers 93,
Also in the disc pressing device 45C provided with the 94, the disc pressing devices 45, 45 of the first to third embodiments are also used.
Similarly to A and 45B, the rotational displacement between the piston portion 46 and the cylinder member 47 due to torque fluctuation of the drive shaft 58 or the like can be restrained by the coupling means 110 and 120.
Therefore, wear of the seal members 100 and 101 can be reduced, and the durability of the disc pressing device 45C is improved.

Note that the keys 111 and 1 in the present embodiment
The shape of 21 may be, for example, a cylinder or a rectangular parallelepiped, and is not limited to the embodiment. Also, keys 111,
The locations where 121 and grooves 112 and 122 are provided are 1
It may be provided at each location or at multiple locations in the circumferential direction of the disk 11. Further, the ball type coupling means 61A as described in the second embodiment (FIG. 3) is
It may be used instead of 121 and grooves 112 and 122.

[0037]

According to the present invention, the hydraulic chamber is sealed by providing a coupling means for preventing rotation of the cylinder member and the piston constituting the hydraulic loading type disc pressing device, for preventing rotation of the both. The wear of the sealing material can be suppressed, the durability of the disc pressing device can be improved, and the efficiency of the toroidal type continuously variable transmission can be prevented from lowering. In particular, when the present invention is applied to a toroidal-type continuously variable transmission used for an automobile transmission, the durability of the transmission can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a toroidal-type continuously variable transmission showing a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a part of the toroidal type continuously variable transmission shown in FIG. 1;

FIG. 3 is a sectional view of a part of a toroidal-type continuously variable transmission according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a part of a toroidal-type continuously variable transmission according to a third embodiment of the present invention.

FIG. 5 is a front view of an input disk of the toroidal-type continuously variable transmission shown in FIG. 4;

FIG. 6 is a sectional view of a part of a toroidal-type continuously variable transmission according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Toroidal type continuously variable transmission 11 ... Input disk 12 ... Output disk 40 ... Input shaft 45, 45A, 45B, 45C ... Disk pressing device 46 ... Piston part 47 ... Cylinder member 55 ... Hydraulic chamber 60 ... Sealing material 61, 61A , 61B ... connecting means 93, 94 ... hydraulic chamber 100, 101 ... sealing material 110, 120 ... connecting means

Claims (1)

[Claims] 1. A hydraulic loading type disc pressing device having a cylinder member and a piston portion attached to an input shaft and rotating integrally with the input shaft, for sealing a hydraulic chamber between the cylinder member and the piston portion. A disc pressing device for a toroidal-type continuously variable transmission, comprising: a sealing member; and coupling means for suppressing a rotation difference between the cylinder member and the piston portion.