JP2002005254A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a troidal type continuously variable transmission capable of preventing durability of a roller and a track face from being deteriorated and preventing torque transmission from becoming unstable. SOLUTION: A pair of input disks 4 having a recessed track face 4a are integrally and rotatably connected to an input shaft 3 and furthermore a pair of an output disk 6b having a recessed track face 6c respectively opposing to the track face 4a of each disk 4 are relatively and rotatably connected to the input shaft 3 by intermediating a plurality of the rollers 7 transmitting the torque. In addition, a recessed spherical portion 4c is provided on a center portion on back side of the track face 4a and it is slidably supported by a spherical seat 5 attached to the input shaft 3 so that the track face 4a of the input disk 4 can align relative to the opposed track face 6c of the output disk 6b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal type continuously variable transmission used for a continuously variable transmission of an automobile, for example.

[0002]

2. Description of the Related Art FIG. 4 is a schematic sectional view showing a main part of a conventional toroidal type continuously variable transmission. In FIG. 4, a variator 10 of a conventional toroidal-type continuously variable transmission includes an input shaft 13 which is connected to an output shaft 12 of an engine which is a power source of a vehicle and is driven to rotate. The heat-hardened input disks 15 are supported near both ends thereof. These input disks 15 are allowed to move slightly in the axial direction by splines S,
The input shaft 13 is integrally rotatably mounted. The movement of the input disk 15 is thus permitted because
This is because a required terminal load is applied to the variator 10 by, for example, urging the right input disk 15 in the figure toward the left input disk 15 by a hydraulic cylinder 17 connected to a hydraulic power source 16. A concave curved track surface 15b is formed on one side surface of the input disk 15.

An output section 18 of the variator 10 is rotatably supported at the center of the input shaft 13 in the axial direction. The output section 18 includes an output member 19 and the output member 1.
9 and a pair of output disks 20 supported on the respective end surfaces so as to be integrally rotatable.
A concave curved track surface 20b is formed on one side of the input disk 15 facing the track surface 15b. Further, a sprocket gear 19a meshing with the power transmission chain 23 is formed on the outer periphery of the output member 19. Further, between the raceway surface 15b of the input disk 15 and the raceway surface 20b of the output disk 20 facing each other,
Three disk-shaped rollers 21 that are in rolling contact with the respective raceway surfaces 15b, 20b are arranged at equal intervals around the circumference. Each roller 21 is rotatably supported by a carriage 22, and the relative position with respect to each track surface can be adjusted by the carriage 22.

As described above, the variator 10 is configured as a so-called double cavity type in which the input disk 15, the output disk 20, and the roller 21 are provided as one set and provided as a pair. On the other hand, torque is transmitted through the six rollers 21. Further, by adjusting the positions of the six rollers 21 by the carriage 22 (see the two-dot chain line in FIG. 4), the rotation speed (speed change ratio) of the output disk 20 can be increased or decreased.

[0005]

By the way, in the toroidal type continuously variable transmission, in order to surely transmit the torque between the input disk 15 and the output disk 20, each roller 21 is connected to the input disk 15. It is necessary to contact the raceway surface 15b and the raceway surface 20b of the output disk 20 uniformly with a high contact pressure. However, in the related art, the mounting accuracy of the input disk 15 to the input shaft 13 depends on the fitting accuracy of the spline hole of the input disk 15 and the spline shaft of the input shaft 13 constituting the spline S. Therefore, due to the machining accuracy of the spline hole, heat treatment distortion, or the like, the entire raceway surface 15b is inclined with respect to the axis of the input shaft 13, and the bending of the input shaft 13 generated during power transmission causes the input disk 15 The change in the relative position with respect to the output disk 20 causes a misalignment between the center of curvature of the raceway surface 15b of the input disk 15 and the center of curvature of the raceway surface 20b of the output disk 20, and the contact pressure of the specific roller 21 Becomes extremely high, and the durability of the roller 21 and the raceway surface 15b decreases,
There has been a problem that the contact pressure of the specific roller 21 decreases and torque transmission becomes unstable.

In view of the above-described conventional problems, the present invention provides a toroidal stepless motor which can prevent the durability of rollers and raceways from deteriorating, and prevent torque transmission from becoming unstable. It is an object to provide a transmission.

[0007]

SUMMARY OF THE INVENTION A toroidal-type continuously variable transmission according to the present invention comprises a pair of input disks having a concavely curved track surface, and a concavely curved track surface opposed to the track surface of each input disk. A pair of output disks, and a plurality of rollers arranged in a toroidal gap formed between the respective track surfaces of the input disk and the output disk, and transmitting torque between the two disks while rolling on both track surfaces. A toroidal-type continuously variable transmission including an input shaft inserted through a central portion of each input disk and an output disk, and each input disk is integrally rotatably connected via a spline;
Each of the input disks is provided so as to be tiltable with respect to the axis of the input shaft, and a concave spherical portion is formed at a center portion on the back side of the track surface, and the spherical portion is formed on the track surface of the input disk. Are slidably received by a spherical seat fixed to the input shaft so as to be capable of centering with respect to the orbital surface of the output disk opposed to the output disk (claim 1).

In the toroidal-type continuously variable transmission configured as described above, since the raceway surface of each input disk can be aligned with the raceway surface of the opposed output disk, the assembling accuracy of the input disk and the input shaft can be adjusted. Irrespective of the change in the relative position between the input disk and the output disk due to the bending of the disk, it is possible to prevent the occurrence of misalignment between the centers of curvature of the respective raceway surfaces. The contact pressure can be kept constant.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a toroidal type continuously variable transmission according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a main part of a toroidal type continuously variable transmission according to an embodiment of the present invention.
FIG. 2 is an enlarged sectional view of a main part of the input disk shown in FIG.
In FIG. 1, a variator 1 of the toroidal type continuously variable transmission according to the present embodiment includes an input shaft 3 which is connected to an output shaft 2 of an engine (not shown) which is a power source of a vehicle and is driven to rotate.
Are provided, and input disks 4 are respectively supported near both ends thereof. Further, an output portion 6 including an output member 6a and an output disk 6b supported integrally and rotatably on an end face of the output member 6a is rotatably supported at a central portion of the input shaft 3 in the axial direction. . A concave curved track surface 4a is formed on one side surface of each of the input disks 4, and a concave curved track surface 6c is formed on one side surface of each of the output disks 6b opposed to the track surface 4a. Have been.

The inner circumference of the input disk 4 is shown in FIGS.
As shown in FIG. 5, a spline hole 4b is formed. The spline hole 4b is provided with a plurality of grooves at predetermined intervals along the circumferential direction. The input disk 4 has the spline hole 4b fitted to the spline shaft 3a of the input shaft 3. 3 is connected so as to be integrally rotatable. The spline hole 4b of each input disk 4 is
3 is connected to the spline shaft 3a with a gap in the radial direction so as to be tiltable with respect to the axis of FIG.
(See also (a)). Each input disk 4 is formed with a concave spherical portion 4c at the center on the back side of the track surface 4a. The spherical portion 4c is formed by cutting out the side surface on the rear surface side of the input disk 4 so as to be concentric with the input shaft 3 with the input shaft 3 as a center. It is slidably received by a spherical seat 5 to be described later so that it can be aligned with the raceway surface 6c of 6b.

In the spline hole 4b, as shown in FIG. 3 (a), both sides in the axial direction of the input shaft 3 are formed in a tapered shape, and the tooth tips 4 projecting toward the spline shaft 3a are formed.
The length of b1 in the axial direction is shorter than that of the tooth base. By forming in such a tapered shape, compared to a non-tapered shape,
The range in which the input disk 4 can be tilted with respect to the axis of the input shaft 3 can be increased, and the range in which the raceway surface 4a can be aligned can be increased. The shape of the spline hole 4b is not limited to the above-mentioned tapered shape, and any shape may be used as long as at least the tooth tip 4b1 is cut off at both ends in the axial direction of the input shaft 3. Specifically, like the spline hole 4d shown in FIG. 3 (b), the above both sides may be cut out and the tooth tip 4d1 may be formed only at the center. Further, an arc-shaped tooth tip 4e1 may be formed as in a spline hole 4e shown in FIG. In this case, as shown in FIG.
1 is in line contact with the spline shaft 3a, so that the input disk 4 can tilt over a wide range with respect to the axis of the input shaft 3 without providing a large radial gap.

A spherical seat 5 for swingably supporting the input disk 4 is provided on the back side of the track surface 4a of each input disk 4. Further, the spherical seat 5 is provided with a spline hole 5a fitted to the spline shaft 3a, whereby the spherical seat 5 is connected to the input shaft 3 so as to be integrally rotatable. Furthermore, this spherical seat 5
The input shaft 4 is formed so as to conform to the spherical surface portion 4c of the input disk 4. The input shaft 4 is in close contact with the spherical surface portion 4c, and is prevented from moving away from the input disk 4 by the locking ring 51. Fixed. In addition, between the spherical seat 5 and the spherical portion 4c, resin coating is applied to at least one of the spherical seat 5 and the spherical portion 4c. Also,
Instead of applying such a resin coating, a solid lubricant may be filled between the spherical seat 5 and the spherical portion 4c.

A chain 6d is provided on the outer periphery of the output member 6a.
A sprocket gear 6e is formed so as to mesh with the output shaft, and power is transmitted to an output shaft (not shown) via the chain 6d. The output disk 6b is incorporated in the output member 6a in a state where fine movement in the axial direction is allowed, and a back-up plate 6h is provided on the back surface thereof with a gap 6g. The gap 6g is sealed by a casing 6f and a seal (not shown). By supplying pressure oil from a hydraulic power source 9a to the gap 6g, the output disc 6b is urged in the direction of the opposing input disc 4 to a predetermined position. Terminal load is applied.

The track surface 4 of the input disk 4 facing each other
a and a track surface 6c of the output disk 6b are formed as toroidal gaps. In this toroidal gap, three disk-shaped rollers 7 that are in rolling contact with the respective track surfaces 4a and 6c are provided. They are arranged equally around the circumference. Each roller 7 is rotatably supported by a carriage 8, and each track surface 4 a,
6c can be adjusted.

In the variator 1, torque is transmitted from the input disk 4 to the output disk 6b via the six rollers 7. Further, by adjusting the positions of the six rollers 7 by the carriage 8 (see the two-dot chain line in FIG. 1), the rotation speed (speed ratio) of the output disk 6b can be increased or decreased. In the variator 1, the input disk 4 is provided so as to be tiltable with respect to the axis of the input shaft 3, and the spherical portion 4 c of the input disk 4 is provided with the orbit of the output disk 6 b facing the orbital surface 4 a of the input disk 4. Since it is supported by the spherical seat 5 fixed to the input shaft 3 so that it can be aligned with the surface 6c, misalignment occurs between the center of curvature of the raceway surface 4a and the center of curvature of the raceway surface 6c. Can be prevented. For this reason, the contact pressure between each of the raceway surfaces 4a, 6c and each of the rollers 7 can be equalized, the durability of the raceway surfaces 4a, 6c and the roller 7 can be ensured, and the torque transmission can be stably performed. Can be performed.

More specifically, even if the input disk 4 is inclined with respect to the axis of the input shaft 3 due to, for example, the processing accuracy of the spline hole or heat treatment distortion, the input disk 4
Receives the pressing force from the roller 7 interposed between the raceway surface 6c and the spherical portion 4c slides on the spherical seat 5, and tilts in a direction to correct the tilt of the input shaft 3 with respect to the axis. ,
The track surface 4a is centered with respect to the opposed track surface 6c. As a result, it is possible to prevent the misalignment between the centers of curvature of the raceway surfaces 4b and 6c. Further, even when the relative position between the input disk 4 and the output disk 6b changes due to, for example, the bending of the input shaft 3 generated during power transmission, the track surface 4a faces the track surface 6c where the track surface 4a faces, as in the above case. In contrast, the alignment is performed, and the occurrence of misalignment can be prevented.

[0017]

As described above, according to the toroidal type continuously variable transmission of the present invention, the orbital surface of the input disk can be centered with respect to the orbital surface of the output disk which is opposed to the input disk. Irrespective of the change of the relative position between the input disk and the output disk due to the accuracy and the deflection of the input shaft, the misalignment occurs between the center of curvature of the track surface of the input disk and the center of curvature of the track surface of the output disk. And the contact pressure between the roller and the input and output disks can be kept constant. For this reason, in the toroidal-type continuously variable transmission of the present invention, it is possible to prevent the durability of the rollers and the raceway from being reduced, and to prevent the torque transmission from becoming unstable.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a main part of a toroidal type continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of an input disk.

3A is an enlarged view showing a spline hole of the input disk surrounded by a two-dot chain line in FIG. 2, FIG. 3B is an enlarged view showing another embodiment of the spline hole, and FIG. () Is an enlarged view showing still another embodiment of the spline hole.

FIG. 4 is a schematic sectional view showing a main part of a conventional toroidal-type continuously variable transmission.

[Explanation of symbols]

 Reference Signs List 1 variator 3 input shaft 3a spline shaft 4 input disk 4a raceway surface 4b spline hole 4b1 tooth tip 4c spherical part 4d spline hole 4d1 tooth tip 4e spline hole 4e1 tooth tip 6b output disk 6c track surface 7 roller

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuhiko Hasuda 3-5-8 Minamisenba, Chuo-ku, Osaka-shi F-term in Koyo Seiko Co., Ltd. 3J051 AA03 AA08 BA03 BB01 BD02 BE09 CB06 EA08 EB01 EC02 FA02

Claims (1)

[Claims] 1. A pair of input disks having a concavely curved orbital surface, a pair of output disks having a concavely curved orbital surface facing each of the input disk orbital surfaces, and an input disk and an output disk, respectively. A plurality of rollers arranged in a toroidal gap formed between the raceway surfaces and transmitting torque between the two disks while rolling on both raceway surfaces, and through the center of each input disk and output disk, An input disk wherein the input disk is integrally rotatably connected via a spline and an input shaft, wherein each of the input disks is provided so as to be tiltable with respect to the axis of the input shaft. A concave spherical portion is formed at the center on the back side of the raceway surface so that the spherical portion can align the raceway surface of the input disk with the raceway surface of the output disk that faces the same. A toroidal-type continuously variable transmission, which is slidably received by a spherical seat fixed to an input shaft.