JPH11280861A - Toroidal continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuously variable transmission in which an output disc is supported to an output gear in a wide axial range so as to restrain inclination of the output disc, and which can stably control gear ratio. SOLUTION: An output gear which is fitted on a main shaft 3 of a toroidal continuously variable transmission at a substantially center position so as to be relatively rotatable, has a hollow shaft part 30 which is extended along the main shaft 3 over the substantially overall length of a fitting hole 33 in an output disc 5. The hollow shaft part 30 is fitted by a faucet fitting part 31 faucet-fitted on the gear body 21 side of the output gear 22, and a spline fitting part 32 on the input disc 4 side facing the output disc 5. The output disc 5 is fitted to the output gear 21 in an axially wide range so that the inclination thereof is restrained, and accordingly, the positional relationship to a power roller 6 is not changed, thereby making it possible to stably control gear ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to a power transmission section of a vehicle or the like, and is a toroidal in which the rotation of an input shaft is steplessly changed via a tiltable power roller and output to an output shaft. The present invention relates to a continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, as a toroidal type continuously variable transmission,
A set or a plurality of toroidal transmission units including an input disk driven by the input shaft, an output disk disposed opposite to the input disk and connected to the output shaft, and a power roller frictionally contacting both disks are provided on the same shaft. 2. Description of the Related Art Toroidal-type continuously variable transmissions arranged in sets are known. In this toroidal-type continuously variable transmission, by changing the tilt angle of the power roller, the rotation of the input disk can be transmitted to the output disk at a continuously variable speed.

As such a toroidal-type continuously variable transmission, for example, as shown in FIGS. 2 and 3, a so-called double-cavity toroidal-type continuously variable transmission in which two sets of toroidal transmission portions are arranged on the same shaft. There is something called a machine. FIG. 2 is a schematic view of a double-cavity toroidal continuously variable transmission, and FIG. 3 is a cross-sectional view showing details of one toroidal transmission section of the double-cavity toroidal continuously variable transmission shown in FIG.

In the double-cavity toroidal type continuously variable transmission shown in FIG. 2, two sets of toroidal transmission portions 1 and 2 are arranged on a main shaft 3. The toroidal transmission unit 1 is provided with an input disk 4, an output disk 5 arranged opposite to the input disk 4, and a friction member disposed between the input disk 4 and the output disk 5 and having a toroidal curved surface on both disks 4, 5. And a power roller 6 to be engaged. Similar to the toroidal transmission unit 1, the toroidal transmission unit 2 includes an input disk 7, an output disk 8 disposed opposite to the input disk 7, and an input disk 7 disposed between the input disk 7 and the output disk 8. And a power roller 9 frictionally engaged with the toroidal curved surfaces 7 and 8. Each of the toroidal transmission units 1 and 2 is provided with two power rollers 6 and 9, respectively. Each of the power rollers 6 and 9 is rotatable about its own rotation axis 10, and the tilt axis 1 is orthogonal to the rotation axis 10.
1 (perpendicular to the plane of the paper).

[0005] The input shaft 13 is arranged on the same axis as the main shaft 3 so that the power from the engine is supplied to the torque converter 1.
2 is input to the input shaft 13. In the toroidal transmission units 1 and 2, the input disks 4 and 7 can be displaced in the axial direction of the main shaft 3 via the ball spline 17 and can rotate integrally with the main shaft 3. A loading cam 14 having a cam roller 15 is provided at the tip of the input shaft 13. By the action of the cam, the toroidal transmission unit 1 connects the input disk 4 to the power roller 6 according to the magnitude of the input torque. A pressing thrust force is generated. As shown in FIG. 3, a thrust bearing 16 is interposed between the main shaft 3 and the loading cam 14, so that the main shaft 3 can rotate relative to the loading cam 14, but is integrally formed in the axial direction. It is connected to. When the thrust force is generated, the main shaft 3 is pulled toward the input shaft 13 due to the reaction, and the input disk 7 is pressed against the power roller 9 in the toroidal transmission portion 2. Therefore, the thrust force sandwiches the power rollers 6, 9 between the input disks 4, 7 and the output disks 5, 8, and provides a frictional engagement force according to the magnitude of the transmission torque. A part of the rotational force from the loading cam 14 is transmitted to the input disk 4 of the toroidal transmission unit 1 via the cam roller 15, and the rotation of the input disk 4 is transmitted to the output disk 5 via the rotation of the power roller 6. . On the other hand, the remainder of the rotational force from the loading cam 14 is transmitted to the input disk 7 of the toroidal transmission unit 2 via the ball spline 17 and the main shaft 3, and
The rotation of the input disk 7 is transmitted to the output disk 8 via the rotation of the power roller 9.

In the toroidal transmission units 1, 2, the power rollers 6, 9 are tilted around the tilt shaft 11, so that the rotation of the input disks 4, 7 is controlled by the output disks 5, 8 in accordance with the tilt angle θ. The speed is continuously changed and transmitted. The power rollers 6, 9 are rotatably and swingably supported with respect to a trunnion (not shown), and can cope with the axial displacement of the main shaft 3 caused by the thrust force.

At the neutral position where the rotation axis 10 of the power rollers 6, 9 intersects with the axis of the main shaft 3, the tilt angle θ of the power rollers 6, 9 maintains the state at that time, and the gear ratio is Holds the value of When the trunnion is moved in the axial direction of the tilting shaft 11 during torque transmission, the power rollers 6, 9 are accordingly displaced in the tilting axis direction, and the power rollers 6, 9 and the input disks 4, 7 and the output disk are moved. The contact position with 5, 8 is displaced from the contact position in the neutral position. As a result, the power rollers 6 and 9 receive the tilting force from both disks, and tilt around the tilt shaft 11 in a direction and a speed corresponding to the moving direction and the moving amount of the tilt shaft 11. . When such tilting occurs, the radius drawn by the frictional contact points between the input disks 4 and 7 with the power rollers 6 and 9 and the radius drawn by the frictional contact points between the output disks 5 and 8 with the power rollers 6 and 9 are calculated. , The stepless speed change is performed. In the tilt control of the power rollers 6, 9, the displacement of the trunnion in the tilt axis direction is controlled by a controller (not shown) by operating an actuator (not shown) so as to achieve the target gear ratio.

The output disks 5 and 8 respectively have a hollow shaft portion 40 extending integrally from both sides of the gear body 22 of the output gear 21 so as to transmit torque from the power rollers 6 and 9 and rotate together with each other. Spline fit. The spline fitting portion 42 is formed by meshing a spline formed on the outer periphery of the hollow shaft portion 40 with a spline formed on the inner periphery of the fitting hole 43 of the output disk 5.
The output gear 21 is rotatably supported by the casing 19 via an angular bearing 23 having an inner ring 24a and an outer ring 24b. The output gear 21 is provided rotatably with respect to the main shaft 3. Hereinafter, the output disk 5,
The support of the output disk 8 will be described with respect to the output disk 5 of the toroidal transmission unit 1, but the same applies to the output disk 8.

Roller bearing 46 for rotatably supporting main shaft 3
Is disposed on the inner peripheral portion of the output disk 5 on the side of the front end portion 45 facing the input disk 4. The roller bearing 46 is a bearing that allows a slight axial movement of the main shaft 3. Also,
The position of the output disk 5 in the thrust direction is determined by abutting the back surface 18 on the side of the output gear 21 with the abutting portion 29 via the spacer 28. The spacer 28 is in contact with the inner ring 24 a of the bearing 23. The radial position of the output disk 5 is determined by fitting the output disk 5 to the outer peripheral surface of the hollow shaft portion 40 of the output gear 21 at the inner peripheral portion near the rear surface 18 by the spigot fitting portion 41. The output disk 5 receives a thrust force as indicated by an arrow A and a radial force as indicated by an arrow B from the power roller 6. The thrust force indicated by the arrow A is supported from the bearing 23 to the casing 19 via the spacer 28, and the radial force indicated by the arrow B is supported from the bearing 23 to the casing 19 via the hollow fitting portion 41 via the hollow shaft portion 40. Is done.

[0010] The torque transmitted to the output disks 5 and 8 is extracted from the chain transmission device 20, that is, the output gear 21, through the chain 26 and the sprocket 25, and to the counter shaft 27 (Fig. 2) as an output shaft. A disc spring 49 is interposed between the loading cam 14 and the input disk 4 to press the input disks 4, 7 against the power rollers 6, 9 even when no input torque is applied. The main shaft 3 is formed with an oil passage 47 formed so as to extend in the axial direction, and an oil passage 48 penetrating in a radial direction from the oil passage 47 to supply lubricating oil to each contact portion and the rotating portion. I have.

Regarding the support of the output disk, see
There is a toroidal type continuously variable transmission disclosed in JP-A-92655, JP-A-5-39830, or JP-A-8-61453. In these toroidal-type continuously variable transmissions, the input shaft is rotatably supported with a slight axial movement with respect to the transmission cover, and a pair of output discs are rollers with respect to the outer periphery of the input shaft. It is rotatably supported via a bearing, and is serration-fitted to a boss portion of an output gear disposed so as to be rotatable relative to the input shaft between the two output disks. The output gear is rotatably supported on the transmission cover via a ball bearing with respect to the casing. Japanese Patent Application Laid-Open No. 6-147282 discloses that a pair of input disks or output disks arranged with their back surfaces facing each other is fitted with a cylindrical portion extending between the two disks so that both disks can be connected to one disk. There has been disclosed a toroidal-type continuously variable transmission which has a rigid structure and prevents both disks from falling down.

The conventional toroidal type continuously variable transmission as described above has the following problems. That is,
In the toroidal type continuously variable transmission, when the contact points between the power rollers 6, 9 and the input disks 4, 7 and the output disks 5, 8 change, the gear ratio changes. Looking at the support of the output disk 5, in the thrust direction, the abutment 2
There is no particular restraint other than the abutment at 9, and it is only restricted in the radial direction by the spigot fitting portion. The diameter of the abutting portion 29 on the back surface 18 of the output disk 5 is substantially equal to the diameter D of the spigot fitting portion 41, and is much smaller than the outer diameter of the output disk 5 in terms of layout. The spigot fitting portion 41 between the output disk 5 and the output gear 21 exists near the abutting portion 29, and the fitting length L is also shorter than the diameter D of the fitting portion. Further, the fitting of the spigot fitting portion 41 and the spline fitting portion 42 is a gap fitting from the viewpoint of the workability of assembly, and the spline fitting portion 42 fits with a larger gap than the spigot fitting portion 41. It has become.

Therefore, for example, when a force is exerted to tilt the output disks 5 and 8 from the power rollers 6 and 9, the output disks 5 and 8 are connected to the output gear 5 at the abutting portion 29 and the spigot portion 30 which are close to each other. The effect of preventing an inclination with respect to 21 is poor. A bearing 46 disposed between the main shaft 3 and the output disks 5 and 8 is provided.
Is located substantially at the center of the long main shaft 3 to rotatably support the main shaft 3, and it is difficult to expect that the radial position of the output disk 5 is positioned with high accuracy. Since the spline fitting portion 42 is farther from the abutting portion 29 than the spigot fitting portion 41 and the gap in the spline fitting portion 42 is larger than the gap in the spigot portion 41, the output disks 5 and 8 tend to be inclined. is there. Due to such a support structure of the output disks 5, 8, the geometrical arrangement of the output disks 5, 8 and the power rollers 6, 9 changes to change the speed ratio, and the originally intended speed ratio cannot be obtained. And a stable gear ratio cannot be obtained. Also, due to repeated contact between the back surfaces of the output disks 5 and 8 and the spacer 28,
There is also a problem that fretting wear occurs in the abutting portion and that the support rigidity of the main shaft and the mounting accuracy are easily reduced because the main shaft is supported by the output gear via the output disk.

[0014]

Therefore, in the toroidal type continuously variable transmission, the output disk is inclined when an external force is applied to the output disk by widening the support range of the output disk with respect to the output gear. Therefore, there is a problem to be solved in that the output disc is easily prevented from tilting with respect to the output gear.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem, and by widening an axial fitting range of an output disk to an output gear, the output disk can be mounted to the output gear. An object of the present invention is to provide a toroidal-type continuously variable transmission that can prevent inclination and prevent the toroidal-type continuously variable transmission from shifting unintentionally and can stably maintain a predetermined gear ratio.

According to the present invention, there is provided a first input disk to which the torque of an input shaft is transmitted via a loading cam.
A main shaft fixed to one end of the input disk so as to be integrally fixed in the rotation direction and movable in the axial direction, a second input disk fixed to the other end of the main shaft, and opposed to both input disks. A first and a second output disk disposed so as to be relatively rotatable with respect to the main shaft, and the input disk disposed between the input disk and the output disk and according to a tilt angle with respect to the two disks; A power roller for continuously changing the rotation of the output disk and transmitting the output disk to the output disk; an output gear connected to the both output disks;
And an output shaft operatively connected to the output gear, wherein the output gear extends along the main shaft from the gear body disposed between the output disks, and a fitting hole for each of the output disks. And the hollow shaft portion extends over substantially the entire length of the fitting hole of the output disk.

In the toroidal-type continuously variable transmission, the main shaft is supported on the inner peripheral surface of the hollow shaft portion via a bearing so as to be relatively rotatable.

In the toroidal-type continuously variable transmission, the fitting portion in which the output disk and the hollow shaft portion are fitted is a spigot fitting portion located on the gear body side of the output gear and the input shaft. And a spline fitting portion located on the disk side.

Further, in the toroidal type continuously variable transmission, each of the output disks is abutted against the gear body of the output gear via a spacer.

Since the toroidal type continuously variable transmission according to the present invention is configured as described above, it operates as follows. That is, since the hollow shaft portion provided along the main shaft from the gear body and fitted into the fitting hole of each output disk extends over substantially the entire length of the fitting hole of each output disk, the output disk is Over almost the entire axial area of the fitting hole,
It is supported by the hollow shaft. For example, when the output disk is inclined due to the pressing force from the power roller, the hollow shaft generates a reaction force opposing the inclination of the output disk over a wide range, so that the inclination of each output disk is greatly suppressed. Is done. The amount by which the power roller disposed between the input disk and the output disk is operated with respect to the power roller to continuously change the rotation of the input disk and transmit the rotation to the output disk is the tilt angle with respect to both disks. It is. By suppressing the tilt of the output disk, the arrangement relationship between the power roller and the output disk does not change, and as a result, the tilt angle does not change to an unintended angle. Therefore, the speed ratio of the toroidal-type continuously variable transmission is accurately controlled according to the tilt angle, and a stable speed ratio is maintained when a constant speed ratio is obtained.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment 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 diagram showing a main part of an embodiment of a toroidal type continuously variable transmission according to the present invention. In the toroidal type continuously variable transmission shown in FIG. 1, the main shaft, the output disk, and the related structure of the output gear are shown, and other structures not shown are the conventional toroidal type continuously variable transmission shown in FIGS. The structure shown in FIG.
And the same reference numerals as those used in FIG.

In the embodiment of the toroidal type continuously variable transmission according to the present invention shown in FIG. 1, only the toroidal transmission unit 1 is shown, but as shown in FIG. It is provided with. However, since the two toroidal transmission units 1 and 2 are symmetrically arranged, only the toroidal transmission unit 1 will be described below. The hollow shaft portion 30 extending along the main shaft 3 from the gear main body 22 of the output gear 21 which is fitted to the main shaft 3 so as to be rotatable relative to the main shaft 3 extends over substantially the entire axial range of the fitting hole 33 of the output disk 5. Extending across. Therefore, the output disk 5 is supported by the hollow shaft portion 30 extending in the axial direction of the main shaft 3.

A fitting portion between the output disk 5 and the hollow shaft portion 30 of the output gear 21 includes a spigot fitting portion 31 on the gear body 22 side of the output gear 21 and a spline on the input disk 4 side facing the output disk 5. And a fitting portion 32. The spigot fitting portion 31 is formed by fitting a spigot fitting surface 34 on the hollow shaft portion 30 side with a spigot fitting surface 35 on the fitting hole 33 side of the output disk 5 and is relatively precise. Are fitted by a small gap. The spline fitting portion 32 is formed by meshing a spline 36 formed on the outer periphery of the hollow shaft portion 30 with a spline 37 formed on the inner periphery of the fitting hole 33 of the output disk 5.
The torque can be transmitted between the output disk 5 and the output gear 21. The hollow shaft portion 30 extends over substantially the entire length of the fitting hole 33 of the output disk 5, and the hollow shaft portion 30
A rolling surface 38 for a roller bearing 39 is formed on the inner peripheral surface at the distal end of the roller. The main shaft 3 is rotatably supported by the output gear 21 via a roller bearing 39. The hollow shaft 3
0 is the part of the inner ring 24 of the bearing 23
a is a bearing fitting portion 30a to be fitted.

As described above, the output disk 5 is supported by the output gear 21 over a wide range in the axial direction of the fitting hole 33. That is, the hollow shaft portion 30 extends to the vicinity of the opening of the fitting hole 33 on the input disk 4 side, and the hollow fitting portion 3
The output disk 5 is supported even at a position away from the output disk 5. When the output disk 5 is inclined with the spigot fitting portion 31 as a fulcrum, the spline fitting portion 32 far from the spigot fitting portion 31 immediately opposes the inclination of the output disk 5. Therefore, when an external force such as a pressing force from the power roller 6 acts on the output disk 5, the inclination of the output disk 5 with respect to the output gear 21 is significantly smaller than the inclination of the output disk in the conventional toroidal type continuously variable transmission. That is, the positional relationship between the output disk 5 and the power roller 6 does not change. As a result, the gear ratio can be controlled in accordance with the tilt angle θ of the power roller 6, and if a constant gear ratio is to be maintained, the gear ratio can be stably maintained without fluctuating. .

Since the inclination of the output disk 5 with respect to the output gear 21 can be prevented, the output disk 5
Back surface 18 which is a side surface on the side of output gear 21 and spacer 28
Will always adhere. Therefore, it is possible to prevent the occurrence of fretting wear caused by the back surface 18 of the output disk 5 being repeatedly brought into contact with and separated from the spacer 28 as seen in a conventional toroidal type continuously variable transmission. Further, since the main shaft 3 is supported by the casing 19 from the bearing 39 via the hollow shaft portion 30 and the bearing 23, the main shaft 3 is connected to the bearing 4 like a conventional toroidal type continuously variable transmission.
6 is supported on the output disk 5 via the output gear 6 and further supported on the casing 19 by the bearing 23 via the output gear 21. The number of components to be used can be reduced, and the support rigidity of the main shaft 3 with respect to the casing 19 and the assembling accuracy can be improved.

[0026]

As described above, in the toroidal type continuously variable transmission according to the present invention, the axial fitting area of the output disk with respect to the output gear is widened, so that the inclination of the output disk with respect to the output gear is greatly reduced. Is suppressed. Therefore, the positional relationship between the output disk and the power roller does not fluctuate due to the inclination of the output disk, so that the toroidal type continuously variable transmission does not shift to an unintended speed ratio, and the tilt angle of the power roller is reduced. It is possible to control the gear ratio accurately according to the speed, and if the gear ratio is kept constant,
A stable gear ratio can be maintained. Further, there is no problem such as fretting wear between the output disk and the spacer. Furthermore, since the main shaft is supported by the casing, the number of components interposed between the main shaft and the casing can be reduced, and the rigidity of supporting the main shaft and the assembly accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a toroidal type continuously variable transmission according to the present invention.

FIG. 2 is a diagram illustrating an example of a conventional toroidal-type continuously variable transmission.

FIG. 3 is an enlarged sectional view showing a part of a conventional toroidal type continuously variable transmission.

[Explanation of symbols]

 1, 2 Toroidal transmission unit 3 Main shaft 4, 7 Input disk 5, 8 Output disk 6, 9 Power roller 11 Tilting shaft 13 Input shaft 14 Loading cam 19 Casing 21 Output gear 22 Gear body 28 Spacer 29 Butt end 30 Hollow shaft Part 31 spigot fitting part 32 spline fitting part 33 fitting hole 34, 35 spigot fitting surface 36, 37 spline 39 bearing

Claims (4)

[Claims] A first input disk to which torque of an input shaft is transmitted via a loading cam, and one end of the first input disk which is integrally fixed in a rotational direction and is movable in an axial direction. A second input disk fixed to the other end of the main shaft, first and second output disks disposed opposite to the two input disks and rotatable relative to the main shaft; A power roller disposed between an input disk and the output disk and for continuously changing the rotation of the input disk and transmitting the rotation to the output disk according to a tilt angle with respect to the two disks;
An output gear connected to the output disks; and an output shaft operatively connected to the output gear, wherein the output gear is arranged along the main shaft from a gear body disposed between the output disks and the gear body. And a hollow shaft portion that fits into the fitting hole of each of the output disks, and the hollow shaft portion extends over substantially the entire length of the fitting hole of the output disk. Continuously variable transmission. 2. The toroidal-type continuously variable transmission according to claim 1, wherein the main shaft is rotatably supported on an inner peripheral surface of the hollow shaft portion via a bearing. 3. A fitting part in which the output disk and the hollow shaft part are fitted includes a spigot fitting part located on the gear body side of the output gear and a spline fitting part located on the input disk side. The toroidal-type continuously variable transmission according to claim 1, wherein the transmission comprises: 4. The toroidal stepless motor according to claim 1, wherein each of said output disks is abutted against said gear body of said output gear via a spacer. transmission.