JP2003166612A - Toroidal continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toroidal continuously variable transmission that can suppress wear by waviness of a belleville spring contact surface resulting from deformation of a disk loaded at a plurality of power roller contact points per rotation. <P>SOLUTION: An urging mechanism 6 for pre-loading power rollers 10 and 11 comprises a cylindrical collar 61 arranged in a peripheral position on a torque transmission shaft 2 and brought into contact at one end face with the torque transmission shaft 2, an L-sectioned spacer 62 arranged in a peripheral position on the collar 61 and brought into contact at one end face with a back surface of the second input disk 4 to limit the axial travel of the second input disk 4, a belleville spring 63 arranged in a peripheral position on the spacer 62 and brought into contact at one end with an L-shaped inner corner, and a loading nut 64 coupled to an end of the torque transmission shaft 2 while holding an axial position limited by the collar 61 to press the other end of the belleville spring 63. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a toroidal type continuously variable transmission applied as a vehicle transmission.

[0002]

2. Description of the Related Art Conventionally, as a toroidal type continuously variable transmission, for example, one described in Japanese Patent Laid-Open No. 2000-74167 is known.

In this conventional source, a collar, a spacer and a disc spring are used as an urging means for applying a preload to the power roller via the input disc for the purpose of preventing the disc spring from coming into close contact with each other when the torque is input. A configuration with a loading nut is described.

That is, as shown in FIG. 6, in a double-cavity toroidal type continuously variable transmission, a disc spring is arranged on the rear surface of a rear input disk, and the disc spring is tightened by a loading nut. In addition, a spacer and a collar are provided inside the disc spring to prevent the loading nut from loosening by the collar, and the initial load of the disc spring is set by the length of the collar. Further, the spacer regulates the stroke of the disc spring.

The initial load of the disc spring is set by the length dimension of the collar (P in FIG. 6 of JP 2000-74167 A), that is, the length from the contact surface with the spline groove to the contact surface with the loading nut. Since it is determined by the length, a plurality of collars having different lengths are prepared at the time of assembly, a collar that can obtain an appropriate initial load is selected, and this is fastened and fixed by a loading nut.

[0006]

However, in the conventional toroidal type continuously variable transmission, since the back surface of the input disk and the disc spring are always in contact with each other, wear occurs on this contact surface. There is a problem.

The contact surface wear of the disc spring is not caused by the rotation of the input disk, but is generated by the undulating deformation of the back surface of the input disk. That is, the input disc is deformed by the load (loading force) applied from two contact points of the power roller per one rotation. This deformation is caused by the pair of powers of the inner diameter hole of the input disc as shown in FIG. The deformation is an elliptical shape having the roller direction as the major axis, and the back surface of the input disk that comes into contact with the disc spring is undulated due to the elliptical deformation of the inner diameter hole of the input disk.

An object of the present invention is toroidal type continuously variable transmission capable of suppressing wear due to waviness of a disc spring contact surface due to deformation of a disk to which a load is applied from a plurality of power roller contact points per one rotation. To provide.

[0009]

In order to achieve the above object, the present invention comprises a pressing force generating means for pinching the power roller according to the transmission torque, and an urging means for applying a preload to the power roller. In the toroidal type continuously variable transmission, the urging means is disposed coaxially with the input / output disk, and an elastic member is interposed between the back surface of one disk and the fastening member fastened to the end of the shaft. An intervening member having one end surface in contact with the disk back surface and the other end surface in contact with the elastic member was disposed between the disk back surface and the elastic member.

[0010]

According to the present invention, an interposing member having one end surface in contact with the disk back surface and the other end surface in contact with the elastic member is arranged between the disk back surface of the biasing means and the elastic member. The elastic member and the back surface of the disk do not come into direct contact with each other due to the intervening member, and suppress the abrasion due to the waviness of the disc spring contact surface due to the deformation of the disk to which a load is applied from a plurality of power roller contact points per one rotation. be able to.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment for realizing a toroidal type continuously variable transmission of the present invention will be described based on a first embodiment corresponding to claims 1 to 3.

(First Embodiment) First, the configuration will be described. FIG. 1 is a schematic diagram showing a speed change mechanism of a toroidal type continuously variable transmission according to a first embodiment, in which a rotational driving force from an engine is input to an input shaft 1 via a torque converter and a forward / reverse switching mechanism (not shown). It

A torque transmission shaft 2 is arranged coaxially with the input shaft 1, and a first input disc 3 and a second input disc 4 are splined at both ends of the torque transmission shaft 2 so as to be movable in the axial direction. Are connected.

The rear surface of the first input disk 3 and the input shaft 1
A loading cam mechanism 5 (pressing force generating means) that generates an axial thrust force in accordance with the input torque is interposed between and.

A biasing mechanism 6 (biasing means) for applying a preload (initial load) to both input disks 3 and 4 is interposed between the back surface of the second input disk 4 and the torque transmission shaft 2. ing. The urging mechanism 6 is arranged coaxially with both the input disks 3 and 4 and an output disk 8 described later.

An output disk 8 mounted on the torque transmission shaft 2 is arranged at an intermediate position between the two input disks 3 and 4. The output disc 8 is formed by integrally combining the back faces of two output discs with each other, and an output gear 9 is formed on the outer peripheral portion of the output disc 8.

Output disk 8 of the first input disk 3
The side facing surface and the output disk 8 of the second input disk 4
The side facing surface and both input disks 3 of the output disk 8
4, the toroidal grooves 3a,
4a, 8a, 8b are formed.

Between the toroidal grooves 3a and 8a,
Two left and right first power rollers 10, 10 are sandwiched so that power can be transferred by an oil film shearing force. Similarly,
Two left and right second power rollers 11 and 11 are sandwiched between the toroidal grooves 4a and 8b so that power can be transferred by an oil film shearing force.

The first input disk 3, the output disk 8 and the first power rollers 10, 10 constitute a first toroidal transmission section 12, and the second input disk 4, the output disk 8 and the second power rollers 11, 11 are provided. The second toroidal transmission unit 13 is configured by the above. That is, it is a double-cavity toroidal-type continuously variable transmission including two sets of toroidal transmissions 12 and 13.

In the above speed change mechanism, each power roller 1
0, 10, 11, and 11 are respectively tilted by an operation described later so that a tilt angle corresponding to the gear ratio is obtained, and the input rotations of both input disks 3 and 4 are continuously and continuously changed. To the output disk 8.

FIG. 2 is a schematic diagram showing a shift control system of the toroidal type continuously variable transmission according to the first embodiment.
0 and 10 are supported at one end of the trunnions 14 and 14 and are rotatable around the power roller rotating shafts 15 and 15. At the other end of the trunnions 14, 14,
Servo pistons 16, 16 as hydraulic actuators for tilting the power rollers 10, 10 by moving the trunnions 14, 14 in the axial direction are provided. The second
Similarly, the power rollers 11, 11 are also supported at one end of the trunnion, and are provided with servo pistons as hydraulic actuators that move the trunnion in the axial direction to tilt the power rollers 11, 11. The four trunnions are connected by synchronizing wires (not shown) so that they move in synchronization.

As a hydraulic control system for controlling the operation of the servo pistons 16 and 16, a high side oil passage 17 connected to the high side oil chambers 16b and 16b defined by the pistons 16a and 16a and a low side oil chamber 16c. , 16c for connecting the low side oil passage 18 and the high side oil passage 17 to the port 1
A shift control valve 19 having a port 19b connecting the oil passage 9a to the oil passage 9a is provided.

The line pressure port 19 of the shift control valve 19
Line pressure is supplied to c from an oil pressure source having an oil pump and a relief valve (not shown).

Shift spool 19d of the shift control valve 19
Is coupled with a lever 20 and a recess cam 21 which detect the axial direction and the tilting direction of the trunnions 14, 14 and feeds back to the shift control valve 19, and is driven by a step motor 22 so as to be displaced in the axial direction.

A CVT control unit 23 is provided as an electronic control system for driving and controlling the step motor 22, and the CVT control unit 23 has a throttle opening sensor 24, an engine rotation sensor 25, an input disk rotation sensor 26, and an output. Shaft rotation sensor (vehicle speed sensor) 27, inhibitor switch 28, oil temperature sensor 2
Input information from 9 etc. is taken in.

FIG. 3 is a sectional view showing the urging mechanism 6 used in the toroidal type continuously variable transmission of the first embodiment.

The urging mechanism 6 is arranged at the outer peripheral position of the torque transmission shaft 2 and has one end surface having a step portion 2a of the torque transmission shaft 2.
And a cylindrical collar 61 which is in contact with the outer peripheral surface of the collar 61, one end surface of which is in contact with the back surface of the second input disk 4 and which has an L-shaped cross section for restricting the axial movement amount of the second input disk 4. 62 (intervening member) and the spacer 62
And a disc spring 63 (elastic member), one end of which is in contact with the L-shaped inner corner, is fastened to the end of the torque transmission shaft 2 while maintaining the axial position regulated by the collar 61. A loading nut 64 (fastening member) that presses the other end of the disc spring 63.

The spacer 62 having an L-shaped cross section is provided.
Is constituted by an axial direction cylindrical portion 62a and a radial direction flange portion 62b extending from the end of the axial direction cylindrical portion 62a in the outer radial direction, and the radial direction flange portion 62b is provided at the back position of the second input disk 4. A spacer groove 4b having a groove inner diameter substantially matching the outer diameter and a groove depth substantially matching the thickness of the radial flange portion 62b was formed.

Next, the operation will be described.

[Gear Ratio Control Operation] In the toroidal type continuously variable transmission, the gear ratio is changed by displacing the trunnions 14, 14 in the tilt axis direction (vertical direction in FIG. 2) and tilting the power rollers 10, 10. change.

That is, the CVT control unit 23
When the speed change spool 19d is displaced by rotating the step motor 22 according to a drive command for obtaining the target speed change ratio from, the hydraulic oil is introduced into one servo piston chamber of the servo pistons 16 and 16, and the other servo piston chamber from the other servo piston chamber. The hydraulic oil is discharged, and the trunnions 14 and 14 are displaced in the tilt axis direction.

As a result, the power roller rotating shafts 15, 1
5 is offset with respect to the disk rotation center position. This offset causes the power rollers 10, 10 to tilt due to the side slip force generated at the contact portion between the power rollers 10, 10 and the input / output disks 3, 8.

This tilting movement and offset are transmitted via the precess cam 21 and the lever 20 to the speed change spool 19d.
Is transmitted to the trunnion 14, 1 at a time when it comes to a predetermined tilt angle at a position equilibrium with the step motor 22.
The displacement given to 4 is returned to the original disk rotation center position,
This is done by stopping the tilting operation of the power rollers 10, 10. The gear ratio is determined by the tilt angle of the power rollers 10, 10. Note that the power roller 11, 11 also exhibits a similar gear ratio control action.

[Deterioration of Disc Spring due to Adhesion and Suppression of Wear] For example, in the conventional toroidal type continuously variable transmission as described in Japanese Patent Publication No. 6-72655,
When the stroke of the Belleville spring used as an elastic member for giving a preload is large and the input torque is large, the Belleville springs arranged in series are operated in close contact with each other. There was a problem that abrasion was accelerated.

On the other hand, in the case of the first embodiment, since the spacer 62 for restricting the axial movement amount of the second input disk 4 is provided, the axial movement amount of the second input disk 4 to the right in FIG. The axial clearance between the spacer 62 and the loading nut 64 is regulated to the amount until it is crushed, and the disc springs 63 due to the two pieces do not come into close contact with each other. It is possible to reduce deterioration and wear due to the stroke.

[Inhibition of Disc Spring Wear by Disc Waviness] In the above gear ratio control, the axial load applied to the second input disc 4 from two contact points with the power rollers 10, 10 per revolution. As a result, the second input disk 4 is deformed by the deformation of the second input disk 4 as shown in FIG.
It becomes an elliptical deformation whose major axis is the direction connecting 0 and 10, and the back surface of the second input disc 4 is undulatingly deformed by this elliptical deformation of the inner diameter hole of the second input disc 4.

Therefore, when the input disc and the disc spring are in direct contact with each other as in the conventional case, the undulation of the back face of the input disc causes the disc spring contact surface to reciprocate relative to each other in the circumferential direction, and the disc spring contact surface is abraded. , The amount of wear increases with the passage of time.

On the other hand, in the case of the first embodiment, the second input disk 4 and the disc spring 63 are not brought into direct contact with each other, and the spacer 62 having an L-shaped cross section is interposed between the both 4, 63. Therefore, most of the undulations on the back surface of the second input disk 4 are absorbed by the spacer 62, and even if the back surface of the second input disk 4 is undulated, the contact position between the spacer 62 and the disc spring 63 is small. There is no relative displacement, and wear of the disc-side contact portion of the disc spring 63 is suppressed.

Further, in the first embodiment, when a large input torque is applied, in particular, the power roller 1
When the tilt angle of 0, 10 is the angle of the high gear ratio (see FIG. 1), as shown in FIG. 4, the spacer 62 having an L-shaped cross section causes the lower portion of the second input disc 4 to rotate about the rotation axis. Since a wide range from the power roller to the second input disk 4 is supported, when the load F is applied to the second input disk 4 from the power roller, the high support force of the spacer 62 causes the second input disk 4
The tilt deformation in the right direction of FIG. 4 can be suppressed to be small. As a result, it is possible to suppress the acceleration of wear of the disc spring 63 due to the tilt deformation of the second input disk 4.

By the way, in the prior art disclosed in Japanese Patent Laid-Open No. 2000-74167, as shown in FIG. 5, the cylindrical spacer only supports the lower part of the input disk, so that the power roller can be connected to the input disk. When a load F is applied to the input disk, the input disk is tilted and deformed to the right in FIG. 5 due to the insufficient supporting force of the spacer, and the tilted deformation of the input disk accelerates the wear of the disc spring.

Next, the effect will be described.

(1) Between the back surface of the second input disk 4 of the urging mechanism 6 and the disc spring 63, one end surface is the second input disk 4
Since the spacer 62 having an L-shaped cross section which is in contact with the back surface of the disk and the other end surface of which is in contact with the disk spring 63 is arranged, the disk spring 63 and the back surface of the second input disk 4 do not come into direct contact with each other by the spacer 62, and 2 It is possible to suppress the abrasion due to the waviness of the disc spring contact surface due to the deformation of the second input disk 4 to which the load is applied from the contact point of the power roller.

(2) The urging mechanism 6 is arranged at the outer peripheral position of the torque transmission shaft 2, and has a cylindrical collar 61 whose one end surface is in contact with the torque transmission shaft 2 and an outer peripheral position of the collar 61. An end surface is in contact with the back surface of the second input disk 4, and a spacer 62 having an L-shaped cross section that restricts the amount of axial movement of the second input disk 4 and an outer peripheral position of the spacer 62,
A disc spring 63, one end of which contacts the L-shaped inner corner, and a loading nut, which is fastened to the end of the torque transmission shaft 2 while maintaining the axial position regulated by the collar 61, and presses the other end of the disc spring 63. In addition to the effect of the above (1), the spacer 62 exerts a function of restricting the axial movement amount of the second input disk 4 and the second input disk 4 is kept in contact with the disc spring 63. It is possible to reduce the deterioration and wear due to the axial stroke of the.

(3) The spacer 62 having an L-shaped cross section is constituted by the axial cylindrical portion 62a and the radial flange portion 62b extending from the end of the axial cylindrical portion 62a in the outer radial direction. Since the spacer groove 4b having the groove inner diameter that substantially matches the outer diameter of the radial flange portion 62b and the groove depth that substantially matches the thickness of the radial flange portion 62b is formed at the back surface position,
Due to the high supporting force of the radial flange portion 62b, the inclination deformation of the second input disk 4 can be suppressed. As a result,
The wear of the disc spring 63 due to the tilt deformation of the second input disk 4 can be suppressed, and the axial dimension can be shortened while using the spacer 62 having an L-shaped cross section. That is, the radial flange portion 62b of the spacer 62
Is attached in a state of being housed in the spacer groove 4b.
It can be suppressed to the same level as the conventional technique described in Japanese Patent No. 167.

(Other Embodiments) The toroidal type continuously variable transmission of the present invention has been described above based on the first embodiment. However, the specific configuration is not limited to this first embodiment. Modifications and additions to the design are permissible as long as they do not depart from the gist of the invention according to each of the claims.

For example, in the first embodiment, an example of application to a double-cavity toroidal type continuously variable transmission having two sets of toroidal transmission parts is shown. However, in a toroidal type continuously variable transmission having one set of toroidal transmission parts. It can also be applied to biasing means.

In the first embodiment, an example of the spacer having the intervening function and the function of restricting the axial movement amount of the second input disk is shown as the interposing member, but the axial movement amount of the second input disk is An intervening member may be provided separately from the spacer having the function of restricting. Moreover, the cross-sectional shape of the intervening member is not limited to the L-shape.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a speed change mechanism of a toroidal type continuously variable transmission according to a first embodiment.

FIG. 2 is a schematic diagram showing a shift control system of the toroidal continuously variable transmission according to the first embodiment.

FIG. 3 is a sectional view showing an urging mechanism adopted in the toroidal type continuously variable transmission according to the first embodiment.

FIG. 4 is a cross section L which is a component of the biasing mechanism of the first embodiment.
It is a figure explaining the inclination deformation prevention effect of the 2nd input disk by a letter-shaped spacer.

FIG. 5 is a diagram for explaining the tilting and deforming action of the input disc by the cylindrical spacer of the prior art.

FIG. 6 is a sectional view showing an urging mechanism adopted in a conventional toroidal type continuously variable transmission.

FIG. 7 is an explanatory view of the undulation deformation of the input disc which is a cause of wear of the disc spring.

[Explanation of symbols]

1 input axis 2 Torque transmission shaft 3 first input disc 4 Second input disc 4b Spacer groove 5 Loading mechanism (pressing force generating means) 6 Biasing mechanism (biasing means) 61 colors 62 Spacer (Intervening member) 62a Axial cylinder part 62b radial flange 63 Disc spring (elastic member) 64 Loading nut (fastening member) 8 output discs 9 Output gear 10 First power roller 11 Second power roller 12 1st toroidal transmission 13 2nd toroidal transmission 14 trunnion

Claims (3)

[Claims] 1. An input disk and an output disk which are coaxially arranged, a plurality of power rollers which are squeezed between opposing surfaces of these input and output disks so that power can be transmitted, and the power rollers are squeezed in accordance with transmission torque. In a toroidal type continuously variable transmission including a pressing force generating means and a biasing means for applying a preload to the power roller, the biasing means is arranged coaxially with the input / output disk, and An elastic member is interposed between the disk back surface and a fastening member fastened to the end of the shaft, and one end surface is in contact with the disk back surface and the other end surface is an elastic member between the disk back surface and the elastic member. A toroidal-type continuously variable transmission characterized in that an intervening member that contacts is arranged. 2. The toroidal-type continuously variable transmission according to claim 1, wherein the first input disk and the second input disk are arranged at both ends, and the output disk is arranged in the central portion, thereby providing an input / output disk. A double-cavity toroidal-type continuously variable transmission including two sets of toroidal speed-change parts by power rollers, wherein the pressing force generating means is a loading cam mechanism arranged at a rear position of the first input disk, The means is a biasing mechanism that is disposed coaxially with the input / output disk at the rear surface of the second input disk, is arranged at the outer peripheral position of the torque transmission shaft, and has a cylindrical collar whose one end surface is in contact with the torque transmission shaft. And a spacer having an L-shaped cross section, which is arranged at an outer peripheral position of the collar, one end surface of which is in contact with the back surface of the disk, and which restricts an axial movement amount of the second input disk, and an outer surface of the spacer. A disc spring arranged at a circumferential position and having one end in contact with an L-shaped inner corner is fastened to the end of the torque transmission shaft while maintaining the axial position regulated by the collar, and presses the other end of the disc spring. A toroidal-type continuously variable transmission having a loading nut. 3. The toroidal type continuously variable transmission according to claim 2, wherein the spacer having an L-shaped cross-section is provided with an axial cylindrical portion and a radial flange portion that extends outward from an end of the axial cylindrical portion. And a spacer groove having a groove depth substantially equal to the outer diameter of the radial flange and a groove depth substantially equal to the thickness of the radial flange. A toroidal type continuously variable transmission characterized by.