JP2598886Y2 - Toroidal type continuously variable transmission - Google Patents

Description

[Detailed description of the invention]

[0001]

The toroidal type continuously variable transmission according to the present invention can be used as a transmission for an automobile.

[0002]

2. Description of the Related Art The use of a toroidal type continuously variable transmission as schematically shown in FIG. 3 has been studied as a transmission for an automobile. This toroidal-type continuously variable transmission supports an input side disk 2 concentrically with an input shaft 1 and an output side disk at an end of an output shaft 3 as disclosed in, for example, Japanese Utility Model Application Laid-Open No. 62-71465. 4 is fixed. The inner surface of a casing containing the toroidal-type continuously variable transmission, or a support bracket provided in the casing, swings around pivots 16, 16 which are twisted with respect to the input shaft 1 and the output shaft 3. A moving trunnion 5, 5 is provided.

Each of the trunnions 5, 5 is made of a metal material having sufficient rigidity, and the pivots 16, 16 are provided on the outer surfaces of both ends. Power rollers 7 are rotatably supported around displacement shafts 6 provided at the center of each trunnion 5, respectively. The power rollers 7, 7 are sandwiched between the input side and output side disks 2, 4.

The input side and output side disks 2 and 4 have, on one side in the axial direction, surfaces opposed to each other, each having a circular cross section whose center is a point on the center line of the pivots 16 and 16. A concave surface 2a and an output-side concave surface 4a are formed. Then, the outer peripheral surfaces 7a, 7a of the power rollers 7, 7, which are formed as spherical convex surfaces, are connected to the input-side concave surface 2a and the output-side concave surface 4a.
a.

[0005] A loading device 8 of a loading cam type is provided between the input shaft 1 and the input disk 2, and the input disk 2 is elastically directed toward the output disk 4 by the pressing device 8. Is pressed. This pressurizing device 8
It comprises a cam plate 9 that rotates with the input shaft 1 and a plurality (for example, four) of rollers 11, 11 held by a holder 10. On one side surface (the right side surface in FIG. 3) of the cam plate 9, a cam surface 12 which is an uneven surface extending in the circumferential direction is formed, and the outside surface of the input side disk 2 (the left side surface in FIG. 3). Also, a similar cam surface 13 is formed. The plurality of rollers 11, 11 are rotatable about an axis in a radial direction with respect to the center of the input shaft 1.

When the cam plate 9 rotates with the rotation of the input shaft 1, a plurality of rollers 11, 11
Is pressed against the cam surface 13 on the outer surface of the input disk 2. As a result, the input side disk 2 is pressed by the plurality of power rollers 7, 7 and at the same time, based on the engagement between the pair of cam surfaces 12, 13 and the plurality of rollers 11, 11, The input side disk 2 rotates. And
The rotation of the input disk 2 is transmitted to the output disk 4 via the plurality of power rollers 7, 7, and the output shaft 3 fixed to the output disk 4 rotates.

[0007] Outer rings 14, 14 are provided at the base ends of the displacement shafts 6, 6, and annular retainers 15, 15 are provided between the outer rings 14, 14 and the power rollers 7, 7. In addition, a plurality of balls 21 ( see FIG. 2 described later) are rotatably held, and the power rollers 7, 7 for the outer races 14, 14 are held.
Is freely rotatable. Although not shown, a plurality of rolling elements (usually needles) are also provided between the outer peripheral surfaces of the displacement shafts 6 and 6 and the inner peripheral surfaces of the power rollers 7 and The rotation of the power rollers 7, 7 with respect to 6, 6 is free.

When changing the rotation speed between the input shaft 1 and the output shaft 3 and first reducing the speed between the input shaft 1 and the output shaft 3, as shown in FIG. , 16 around the trunnions 5, 5 so that the outer peripheral surfaces 7a, 7a of the power rollers 7, 7 are shifted toward the center of the input-side concave surface 2a and the outer-peripheral portion of the output-side concave surface 4a. Each of the displacement shafts 6, 6 is inclined so as to abut each other. Conversely, when increasing the speed, the trunnions 5, 5 are swung as shown in FIG. 4B, and the outer peripheral surfaces 7a, 7a of the power rollers 7, 7 are moved to the outer peripheral surface of the input side concave surface 2a. Each of the displacement shafts 6, 6 is tilted so as to abut against the deviated portion and the deviated portion on the center of the output side concave surface 4a. Each displacement axis 6,
If the inclination angle of 6 is set between those in FIGS. 3A and 3B, an intermediate speed ratio between the input shaft 1 and the output shaft 3 can be obtained.

Outer peripheral surfaces 7a, 7 of the power rollers 7, 7
a is a spherical convex surface that can freely contact the concave surfaces 2a and 4a. In order to form the spherical convex surface using a processing machine such as a polishing machine, the power rollers 7, 7 must be shoe-type. Must be held in the holder. Conventionally,
The outer peripheral surface 7a of the power roller 7 has a spherical surface portion 17 and a cylindrical surface portion 18 as shown in FIG. The center of the spherical portion 17 is located on the center line of the pivot 16,
The center of the cylindrical surface portion 18 is made coincident with the center of the displacement shaft 6. When processing the spherical portion 17, a processing operation is performed with the cylindrical surface portion 18 held in a holder portion of a processing machine.

[0010]

The toroidal-type continuously variable transmission according to the present invention has low durability by reducing the risk that the corners of the power rollers 7, 7 hit the input side concave surface 2a or the output side concave surface 4a. It is intended to improve.

As in the conventional structure shown in FIG. 2, when a spherical surface 17 and a cylindrical surface 18 continuous from the end of the spherical surface 17 are formed on the outer peripheral surface 7a of the power roller 7, If the sizes are the same, it is inevitable that the length l of the generatrix of the spherical portion 17 becomes shorter than when the cylindrical surface portion 18 is not provided.

On the other hand, the spherical portion 17 and the input side concave surface 2a
When the toroidal type continuously variable transmission is used, the output side concave surface 4a comes into contact with an elliptical portion (contact ellipse) whose major axis is in the generatrix direction of each surface. In a normal use state, the major axis of the contact ellipse is small, and the contact ellipse is accommodated in the spherical portion 17 . On the other hand , if the torque transmitted by the toroidal-type continuously variable transmission becomes excessive for some reason, the spherical portion 17, the input side concave surface 2a and the output side
The contact portion with the concave surface 4a reaches the edge of the spherical portion 17
I do. In other words, the part that should become the contact ellipse (before
The spherical portion 17 facing the concave surfaces 2a, 4a has a sufficient length.
Will be present at the contact if it is assumed to be
It is conceivable that one end portion in the long diameter direction protrudes from the spherical portion 17.

When the portion that should become the contact ellipse protrudes from the spherical portion 17, the spherical portion 17 and the cylindrical surface portion 1
The edge 19 existing at the boundary with the contact surface 8 contacts the input side concave surface 2a and the output side concave surface 4a. In this way,
When the sharp edge 19 contacts each concave surface 2a, 4a, an excessive stress is applied to a part of each concave surface 2a, 4a, and
a, 4a may be peeled off.

The toroidal type continuously variable transmission according to the present invention has been devised in view of the above-described circumstances.

[0015]

The toroidal type continuously variable transmission according to the present invention has an input shaft and an input side having an arc-shaped cross section on one side in the axial direction, similarly to the above-mentioned conventional toroidal type continuously variable transmission. A concave surface, an input disk rotating with the rotation of the input shaft, and an axially-sided output-side concave surface having an arc-shaped cross section, with the output-side concave surface and the input-side concave surface facing each other. And an output disk supported concentrically with the input shaft so as to rotate freely with respect to the input shaft, a plurality of trunnions swinging about a pivot axis which is twisted with respect to the input shaft, and each trunnion. A displacement shaft supporting and fixing a base end thereof, an outer ring provided around the base end of each displacement shaft, an annular power roller rotatably supported at a tip end of each of the displacement shafts, Rollably installed between the power roller and each outer ring And a plurality of balls that are the respective power rollers, for machining the spherical portion and the spherical portion in contact with the input-side concave surface and the output side concave surface, the spherical portion
The cylindrical surface concentric with the central axis of the
A track having an arcuate cross section for contacting the ball is provided on one side thereof.

In particular, in the toroidal type continuously variable transmission of the present invention, the outer diameter of the cylindrical surface is smaller than the diameter of the inscribed circle of the plurality of balls , and the cylindrical surface is it is characterized in that present on the inner diameter side portion than the track in some aspects.

[0017]

With the toroidal-type continuously variable transmission of the present invention configured as described above, the operation itself when freely changing the gear ratio between the input shaft and the output shaft is the same as the conventional toroidal-type continuously variable transmission described above. This is the same as in the case of the transmission.

In particular, in the case of the toroidal type continuously variable transmission according to the present invention, it is possible to polish the spherical portion by an industrial method while ensuring a sufficient length of the generatrix of the spherical portion of the power roller. Therefore, on the outer peripheral surface of the power roller, the portion deviating from the spherical surface does not come into contact with the input side concave surface and the output side concave surface, and excessive stress is applied to each concave surface, and each concave surface is damaged. You will not receive it. Also, spherical part
Of the power roller end
, The maximum outer diameter of the inner ring can be increased. this
As a result, the pitch diameter (PCD) of the ball can be increased
So it is necessary to increase the diameter of the ball or increase the number of balls
It is possible to increase the load capacity of thrust ball bearings,
Even larger power rollers transmit more torque
I can do it.

[0019]

FIG. 1 shows an embodiment of the present invention. The toroidal-type continuously variable transmission according to the present invention is characterized by the shape of the power roller, and the basic configuration is the same as the conventional structure shown in FIG.

A ring-shaped outer ring 14 provided around the base end of the displacement shaft 6 (FIG. 3) facing each other in the assembled state.
Orbit 20a with one side (lower surface in FIG. 1), wherein the in one side surface of the power roller 7 rotatably supported annular to the distal end of the displacement shaft 6 (the upper surface in FIG. 1), an arc-shaped cross section, respectively ,
20b. And both tracks 20a, 20b
A plurality of balls 21, 21 are provided to be able to roll freely between them, and constitute a thrust ball bearing for supporting a thrust load applied to the power roller 7. Each of the balls 21 and 21 is rotatably held by a holder 22 made of synthetic resin.

The outer peripheral surface 7a of the power roller 7 has an input side concave surface 2a of the input side disk 2 and an output side disk 4
And a central axis of the spherical portion 23 for processing the spherical portion 23 that contacts the output side concave surface 4a (FIG. 3).
And a concentric cylindrical surface portion 24.

In the toroidal-type continuously variable transmission according to the present invention, the outer diameter D of the cylindrical surface portion 24 is equal to the plurality of balls 21,
21 is smaller than the diameter R of the inscribed circle (D <R). The cylindrical surface portion 24 is connected to the power roller 7.
In the inner peripheral portion of one side surface, present on the inner diameter side portion than the trajectory 20b.

As such a cylindrical surface portion 24 is formed on one side surface of the power roller 7, the retainer 22
The thinner part 25 is formed on the inner peripheral part of the holder to prevent the retainer 22 from interfering with the cylindrical surface part.

In the case of the toroidal type continuously variable transmission of the present invention having the above-described configuration, the spherical portion 23 of the power roller 7 is secured by a sufficient length L in the spherical portion 23 by an industrial method. Can be polished.

That is, when processing the spherical portion 23 using a processing machine such as a grinder, the processing operation is performed while the cylindrical surface portion 24 is held in a shoe type holder. In the case of the power roller 7 incorporated in the toroidal type continuously variable transmission according to the present invention, the cylindrical surface portion 24 is provided inside the balls 21, 21. Cylindrical surface 18 continuous from the large diameter end
Is provided, the generatrix length L of the spherical portion 23 can be increased.

For this reason, even when the transmission torque increases and the contact ellipse between the spherical portion 23 and the input-side concave surface 2a and the output-side concave surface 4a increases, the outer peripheral surface of the power roller 7 retains the spherical portion. The portion deviating from 23 does not contact the input side concave surface 2a and the output side concave surface 4a.
As a result, excessive stress is applied to the concave surfaces 2a, 4a, so that the concave surfaces 2a, 4a are not damaged. In addition, the cylindrical surface portion 24 for holding at the time of processing is formed by the balls 21, 2
1 and the power roller 7 and thrust
The thickness dimension of the portion combined with the ball bearing does not increase.

Also, by eliminating the cylindrical surface portion 18 shown in FIG. 2, the length of the generatrix of the spherical portion 23 can be increased from 1 to L, so that the maximum outer diameter of the inner race formed by the end surface of the power roller 7 is d. It can be increased to d _L from _S. As a result,
Since the pitch circle diameter (PCD) of the balls 21, 21 can also be increased, the diameter of the balls 21, 21 must be increased, or
The number of 1, 21 can be increased, and the load capacity of the thrust ball bearing can be increased. Therefore, according to the present invention, a larger torque can be transmitted even with the power roller 7 having the same size.

[0028]

[Effect of the Invention] Since the toroidal type continuously variable transmission of the present invention is configured and operates as described above, a toroidal type continuously variable transmission which is small in size, has excellent durability , and can transmit a large torque is industrially manufactured. It is possible to make it by a proper method.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a power roller and a thrust bearing incorporated in the toroidal type continuously variable transmission according to the present invention;

FIG. 2 is a cross-sectional view showing a power roller incorporated in a conventional toroidal-type continuously variable transmission together with a thrust bearing.

FIG. 3 is a side view showing the basic structure of the toroidal-type continuously variable transmission in a state of maximum deceleration and a state of maximum acceleration.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 input side disk 2a input side concave surface 3 output shaft 4 output side disk 4a output side concave surface 5 trunnion 6 displacement shaft 7 power roller 7a outer peripheral surface 8 pressurizing device 9 cam plate 10 retainer 11 roller 12 cam surface 13 cam Surface 14 Outer ring 15 Cage 16 Axis 17 Spherical part 18 Cylindrical part 19 Edge 20a Track 20b Track 21 Ball 22 Cage 23 Spherical part 24 Cylindrical part 25 Thin part

Claims (1)

(57) [Scope of request for utility model registration] 1. An input shaft, an input side concave surface having an arc-shaped cross section on one side in an axial direction, an input disk rotating with the rotation of the input shaft, and an axial side having an arc-shaped cross section on one side. An output-side disk supported concentrically with the input shaft, with the output-side concave surface facing the input-side concave surface with the output-side concave surface facing the input-side concave surface,
A plurality of trunnions swinging about a pivot at a position twisted with respect to the input shaft, a displacement shaft having a base end supported and fixed to each trunnion, and an outer ring provided around the base end of each displacement shaft An annular power roller rotatably supported at the tip end of each of the displacement shafts, and a plurality of balls rotatably provided between each power roller and each of the outer rings,
The power rollers are for processing the spherical portion and the spherical portion in contact with the input-side concave surface and the output side concave surface, the
In a toroidal-type continuously variable transmission having a cylindrical surface concentric with the center axis of a spherical portion on its outer peripheral surface and an arc-shaped cross-section orbit on one side thereof for contacting the plurality of balls ,
The outer diameter of the cylindrical surface, the smaller than the diameter of the inscribed circle of the plurality of balls, and, the cylindrical surface portion, characterized in that present on the inner diameter side portion than the track part of the one side Toroidal type continuously variable transmission.