JPH10159926A - Toroidal type continuous variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction in the torque transmission capacity, although some power roller are displaced cue to the dimensional tolerance. SOLUTION: An input disc 82a connected to a torque transmission shaft 70, an output disc connected to an output shaft, plural power rollers held by these input- and output discs, and an energizing means for pressing the power rollers through the input and output discs and a ball spine 86 which is interposed between the torque transmission shaft 70 and the input disc 82a to connect the torque transmission shaft 70 in the direction of rotation are provided and the ball spline 86 permits the input to be displaced in its axial direction and permits the input disc 82a to be inclined to the torque transmission shaft 70.

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 disk support structure of a toroidal type continuously variable transmission used in a vehicle or the like.

[0002]

2. Description of the Related Art As a toroidal type continuously variable transmission used for a vehicle or the like, one disclosed in Japanese Patent Application Laid-Open No. 2-261950 is known.

[0003] As shown in FIG. 5, this is provided with first and second toroidal transmission portions 82 and 84 comprising two sets of input / output disks arranged coaxially, and a double cavity for increasing transmission torque. 2. Description of the Related Art A continuously variable transmission 1 of the type is conventionally known.

In FIG. 5, a continuously variable transmission 1 is connected to an engine via a torque converter T / C and a forward / reverse switching device 96, while an output shaft 94 is connected to a drive shaft.

[0005] The first toroidal transmission portion 82 of the continuously variable transmission 1 has an input disk 82a and an output disk 82b.
A pair of power rollers 82c and 82d are sandwiched between the opposite surfaces of the input disk 84a and the output disk 84b, and the second toroidal transmission portion 84 similarly sandwiches a pair of power rollers 84c and 84d between the opposite surfaces of the input disk 84a and the output disk 84b. I have.

The input disk 82a of the first toroidal transmission 82 and the input disk 84 of the second toroidal transmission 84
a is coupled in the rotational direction via a torque transmission shaft 70, and the output disk 82 b of the first toroidal transmission unit 82 and the output disk 84 b of the second toroidal transmission unit 84 have their back surfaces connected via an output gear 90. In addition to being coupled, the output gear 90 supports the torque transmission shaft 70 coaxially and relatively rotatably.

The power rollers 82c and 82d of the first toroidal transmission portion 82 and the power rollers 84c and 84d of the second toroidal transmission portion 84 are driven synchronously by a shift control means (not shown), and are driven by tilting motion. The gear ratio can be continuously changed by changing the contact radius with the output disk.

The driving force is transmitted by the oil film shearing stress between the input / output disk and the power roller. Therefore, the input disks 82a and 84a are connected to the torque transmission shaft 70 via the ball splines 86 and 88. The loading cam device 10 (biasing means) for generating an axial thrust is disposed on the back surface of the input disk 82a of the first toroidal transmission portion 82 while being displaceably supported in the axial direction. On the back surface of the input disk 84a of the two-toroidal transmission unit 84, a disc spring 98 for applying a preload is provided.

Here, the support structure of the input disk 82a on the first toroidal transmission portion 82 side will be described. The loading cam device 10 disposed on the back of the input disk 82a is connected to the output side of the forward / reverse switching device 96. The drive plate 97 is coaxially connected to the torque transmission shaft 70 via the thrust bearing 72, and the cam roller 44 is interposed between the drive plate 97 and the input disk 82a.

The drive plate 97 and the input disk 82
a, the cam roller 44 moves the input disk 8
2a to the output disk 82b side (the right side in FIG. 6),
As a result, the input disk 84a of the second toroidal transmission portion 84 connected via the torque transmission shaft 70 is also pressed toward the output disk 84b, and the input / output disks 82a, 82a.
b and power roller 82 clamped between 84a and 84b
c, 82d and 84c, 84d can be pressed to transmit torque. In this way, in order to generate and transmit axial thrust, between the input disks 82a, 84a and the torque transmission shaft 70, Ball splines 86, 88 are interposed to couple in the rotational direction while permitting relative displacement in the axial direction.

The ball spline 86 is formed as shown in FIG.
An axial groove 8 formed on the inner periphery of the input disk 82a
6a and a groove 86 formed on the outer periphery of the torque transmission shaft 70
b 'and a plurality of balls 86a interposed between the grooves 86a and 86b'.

The grooves 86a and 86b 'are formed in parallel with the axial direction of the torque transmitting shaft 70, and the depth and width of these grooves are set to constant values. Therefore, while the input disks 82a and 84a are coupled in the rotation direction, they can be relatively displaced in the axial direction, and can prevent the inclination with respect to the axis and accurately hold and press the power roller between the output disks 82b and 84b. can do. The ball spline 88 interposed between the input disk 84a of the second toroidal transmission portion 84 and the torque transmission shaft 70 has a similar configuration (not shown).

[0013]

However, in the above-mentioned conventional toroidal-type continuously variable transmission, the positions of the power rollers 82c, 82d and 84c, 84d may deviate from predetermined positions due to dimensional tolerances and the like. However, the input discs 82a and 84a that press the power roller are connected around the shaft with the torque transmission shaft 70 as the input shaft via the ball splines 86 and 88, while being supported so as to be relatively displaceable in the axial direction. When the position of the power roller is shifted as described above, the gap between the input disks 82a and 84a and the torque transmission shaft 70 and the elastic deformation of each part may cause the power roller to be inclined. The input discs 82a and 84a are inclined to absorb the displacement of the power roller.

In a state where the input disks 82a and 84a are inclined due to such elastic deformation or the like, a force for returning to the side opposite to the inclined direction is generated, and the pressing force of the pair of power rollers becomes non-uniform. There is a problem that the torque transmission capacity of the continuously variable transmission 1 is reduced to a smaller pressing force.

The present invention has been made in view of the above problems, and provides a toroidal-type continuously variable transmission capable of preventing a reduction in torque transmission capacity irrespective of a displacement caused by a dimensional tolerance of a power roller. The purpose is to do.

[0016]

According to a first aspect of the present invention, there is provided an input disk connected to an input shaft, an output disk connected to an output shaft, and a toroidal shape formed on a facing surface of the input / output disk. A plurality of power rollers sandwiched in the groove, biasing means for pressing the power roller via the input / output disk, and a power roller interposed between the input shaft and the input disk to rotate the input shaft and the input disk; In the toroidal-type continuously variable transmission, the support means allows the input disk to be inclined with respect to the input shaft while the input means is coupled in the direction.

In a second aspect based on the first aspect, the support means includes a first groove formed on one of the input shaft and the input disk and parallel to the axis of the input shaft; The groove width at the central portion in the axial direction formed on the other side of the disk and facing the first groove portion is narrow, and the depth at the central portion in the axial direction is also formed to be shallow, and the groove width and the depth toward both ends are reduced. It is composed of an increasing second groove and a plurality of balls interposed between the first and second grooves.

[0018]

Accordingly, the first aspect of the present invention is that the input disk is attached to the input shaft when the position of the power roller sandwiched and pressed between the input disk and the output disk is deviated from a predetermined position due to dimensional tolerance or the like. Since it is inclined with respect to the pair of power rollers, it can contact equally with the pair of power rollers. At this time, since there is no elastic deformation as in the conventional example, no reaction force against the inclination is generated, and the pressing force against the pair of power rollers is generated. Can be maintained evenly, and the torque transmission capacity of the continuously variable transmission can be prevented from lowering while absorbing the positional deviation due to dimensional tolerances, and the performance of the toroidal type continuously variable transmission can be improved. Becomes possible.

According to a second aspect of the present invention, the support means for the input disk includes a second groove portion whose groove width and depth increase from the center of the axial length to both ends, and which are provided on one of the input shaft and the input disk. While the other has a first parallel to the input axis.
Since the groove is formed and the ball is formed by a ball spline having a ball interposed between the first and second grooves, the input disk is inclined around the center of the entire length of the groove, and the pair of power rollers has a dimensional tolerance. Even if there is a displacement due to, for example, contact can be made equally, and at this time, since there is no elastic deformation as in the conventional example, no reaction force against inclination is generated, and the pressing force against the pair of power rollers is reduced. It is possible to hold them evenly.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 3 show an example in which the present invention is applied to the double-cavity type toroidal type continuously variable transmission 1 shown in FIG.
2 and 84, only the ball spline 86 interposed between the input disk 82a of the first toroidal transmission portion 82 and the torque transmission shaft 70 is shown, and the groove portion 86b 'of the conventional example is shown.
Is replaced with a groove 86b. The other configuration is the same as that of the conventional example shown in FIG. 5, and the same components are denoted by the same reference numerals and duplicate description is omitted.

A ball spline 86 is provided between the input disk 82a and the torque transmitting shaft 70 as an input shaft, the ball spline 86 being connected in the rotating direction and allowing relative displacement in the axial direction.

The ball spline 86 has a groove 86c (first groove) formed on the inner periphery of the input disk 82a.
And a groove 86b formed on the outer periphery of the torque transmission shaft 70.
(A second groove) and a plurality of balls 86a that engage with both grooves 86c and 86b.

In the groove 86c formed on the inner periphery of the input disk 82a, a groove 86c is formed in parallel with the axis of the torque transmission shaft 70 as in the conventional example, and the depth and width of the groove 86c are constant. Is set.

On the other hand, the groove 86b formed on the outer periphery of the torque transmission shaft 70 is formed as a recess having a predetermined length L in a range facing the groove 86c on the input disk 82a side.
The groove width W and the depth D are variable from the center of the entire length L toward the both ends 86e.

First, in the cross section along the center line C in the width direction, the depth D of the groove 86b is Dc, which is the shallowest at the center of the full length L, as shown in FIGS. With a curve R whose depth gradually increases toward both ends 86e, the maximum depth De is obtained at a predetermined position between the end and the center. Then, the depth decreases from the position of the depth De toward the end 86e, and the depth D becomes 0 at both ends 86e. The depth Dc at the center is set to the minimum value at which the ball 86a can roll, and the maximum depth De is such that the input disk 82a can be inclined by a predetermined amount in the ZY plane in the drawing. Is set to an appropriate value.

As shown in FIGS. 2 and 3, the groove width W is the narrowest Wc at the center of the entire length L, and a curve R2 whose width gradually increases from the center toward both ends 86e. Accordingly, the maximum width We is obtained at a predetermined position between the end 96e and the center.

Then, from the position of the maximum width We toward the end 86e, the width W gradually decreases, and the both ends 86e.
In e, the width W = 0. The width Wc of the central portion is set to the minimum value at which the ball 86a can roll, and the maximum width We is a value at which the input disk 82a can tilt by a predetermined amount in the XY plane in the drawing. Is set to

Although not shown, the ball spline 88 between the input disk 84a of the second toroidal transmission portion 84 and the torque transmission shaft 70 is formed in the same manner as described above.
The input disk 84a can be inclined with respect to the torque transmission shaft 70.

The operation is described below, with the above configuration.

The groove 86b on the side of the torque transmitting shaft 70 constituting the ball spline 86 is formed such that the bottom is raised at the center by a curve R.
Since the peripheral edge of the groove b is formed by the curve R2 such that the groove width W increases from the center toward the end 86e, a gap is generated between the ball 86a on the end 86e and the groove 86b, and the input disk 82a is X about the center of the entire length L of the groove 86e.
-It becomes possible to incline in the Y plane and the ZY plane, respectively.

Therefore, the power rollers 82c held and pressed by the input disk 82a and the output disk 82b,
When the position of 82d is deviated from a predetermined position due to dimensional tolerance or the like, the input disk 82a is inclined in the XY plane and the ZY plane about the center of the entire length L of the groove 86b, respectively, as shown in FIG. As shown, a pair of power rollers 82
c and 82d, and at this time, since there is no elastic deformation as in the conventional example described above, no reaction force against inclination is generated, and a pair of power rollers 82c and 82d
Of the continuously variable transmission 1 can be prevented while reducing the displacement caused by dimensional tolerances, and the performance of the toroidal type continuously variable transmission can be prevented. Can be improved.

When machining the groove 86b,
A cutter or the like corresponding to the cross-sectional shape of the groove 86b can be easily processed by changing the cutting depth in a direction perpendicular to the axis so that the central portion becomes shallower in accordance with the feed in the axial direction.

In the above embodiment, the groove 86b
To the torque transmitting shaft 70, and the groove 86c to the input disk 82.
a, but conversely, the groove 86 c is formed in the torque transmitting shaft 70.
Alternatively, a groove 86b may be formed in the input disk 82a.

[Brief description of the drawings]

FIG. 1 is an essential part cross-sectional view showing an embodiment of the present invention and showing a support structure of an input disk.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along the line BB of FIG. 1;

FIG. 4 is an explanatory diagram showing an operation, and is a conceptual diagram of a first toroidal transmission unit.

FIG. 5 shows a conventional example, and is a schematic configuration diagram of a toroidal-type continuously variable transmission.

FIG. 6 is a sectional view of a main part showing a support structure of the input disk.

[Explanation of symbols]

 Reference Signs List 1 continuously variable transmission 10 loading cam device 44 cam roller 70 torque transmission shaft 82 first toroidal transmission portion 82a input disk 82b output disk 82c, 82d power roller 84 second toroidal transmission portion 84a input disk 84b output disk 84c, 84d power roller 86 , 88 Ball spline 86a, 88a Ball 86b, 86c Groove 97 Drive plate

Claims (2)

[Claims] 1. An input disk connected to an input shaft, an output disk connected to an output shaft, and a plurality of power rollers sandwiched by toroidal grooves formed respectively on opposing surfaces of the input and output disks. A biasing means for pressing a power roller through the input / output disk, and a biasing means interposed between the input shaft and the input disk to couple the input shaft and the input disk in the rotational direction, A toroidal-type continuously variable transmission, comprising: a support means for allowing directional displacement; wherein the support means allows an input disk to be inclined with respect to an input shaft. A first groove formed on one of the input shaft and the input disk and parallel to an axis of the input shaft; and a first groove formed on the other of the input shaft and the input disk. A second groove portion having a narrow groove width at the opposed central portion in the axial direction, a small depth at the central portion in the axial direction, and a groove width and a depth increasing toward both end portions; The toroidal-type continuously variable transmission according to claim 1, comprising a plurality of balls interposed between the second grooves.