JPH06280959A - Continuously variable transmission with friction wheel - Google Patents

Abstract

PURPOSE:To prevent an input and an output disc from being damaged by the corner of a friction roller even if a load is applied at shifting of the gear. CONSTITUTION:A continuously variable transmission concerned includes an input 10 and an output disc 12, a pair of friction rollers 14, 16 installed in a troidal groove formed by the two discs 10, 12 in such a way as in frictional contact with them, and roller supporting members 22, 24 which support the friction rollers 14, 16 rotatably through eccentric shafts 18, 20, are rotatable round rotary shaft perpendicular to the axes of the discs 10, 12, and are movable in the axial direction of the rotary shaft. The dimensions are so selected that the intersecting point A at which the normals from the points of the friction rollers 14, 16 contacting the discs 10, 12, lies nearer their axes of rotation than their center of curvature B according to the design.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction wheel type continuously variable transmission.

[0002]

2. Description of the Related Art A conventional friction wheel type continuously variable transmission has an input disk, an output disk, and a toroidal groove formed by both disks, as disclosed in, for example, Japanese Patent Laid-Open No. 4-29659. A friction roller disposed so as to make frictional contact with the friction roller, which is rotatably supported via an eccentric shaft, and is rotatable about a rotation shaft portion orthogonal to the axes of both discs, and the shaft of the rotation shaft portion. A roller support member that is movable in the direction. The point at which the normal line from the point of contact of both discs of the friction roller intersects, the tilt center of the roller support member, and the center of curvature of both discs are at the same point. As a result, even if the roller support member is tilted due to gear shift, the contact point between the friction roller and both disks does not deviate from the toroidal curved surface. Therefore, under no load, it is possible to shift gears without moving the input disc and the output disc in the axial direction and without swinging the friction roller.

[0003]

However, in the conventional friction wheel type continuously variable transmission described above, when a load is applied and the two disks, the roller supporting member, etc. are elastically deformed, the contact points of the friction rollers of both disks are designed. Move from the contact point of
The apparent friction roller opening angle increases. As a result, there is a problem that the corners of the friction roller (that is, the rear end portion of the curved surface of the friction roller) enter into the contact ellipse between the friction roller and both discs and scratch both discs. This problem can be solved by improving the rigidity of both disks, the roller support member, and the like to reduce the elastic deformation amount of the component, but in this case, there is a problem that the weight increases. The present invention aims to solve such problems.

[0004]

According to the present invention, the point at which the normal from the point of contact of the friction roller with both discs intersects, rather than the designed center of curvature of both discs. The above problem is solved by arranging so as to be located on the side close to. That is, the friction wheel type continuously variable transmission of the present invention is arranged so as to make frictional contact with the input disc (10), the output disc (12), and a toroidal groove formed by both discs. A pair of friction rollers (14, 16) and a friction roller (1
4, 16) are rotatably supported via eccentric shafts (18, 20), respectively, and are rotatable about a rotation shaft portion orthogonal to the shaft centers of both disks and movable in the axial direction of the rotation shaft portion. Of the friction roller (14, 16) intersects with the normal line from the point of contact with both discs of the friction roller (14, 16) (A in the first embodiment, second embodiment). Then, the dimensional relationship is set so that C) is located closer to the rotation center axis of both discs than the designed curvature center of both discs (B in the first embodiment, D in the second embodiment). It is characterized by Further, as in the second embodiment described later, the designed curvature center (D) of both disks and the roller support members (22, 2) when no load is applied.
It can be assumed that the axis center (F) of the rotating shaft portion of 4) is aligned. The numbers in parentheses above are reference numerals of corresponding members in the embodiments described later.

[0005]

The friction roller is arranged so that the intersection of the normals from the points of contact with both disks is closer to the center of rotation of both disks than the designed center of curvature of both disks. Has been done. When a load is applied during gear shifting, the point where the normal line from the point of contact with both discs of the friction roller intersects in the direction away from the rotation center axis of both discs.
That is, it moves in a direction coinciding with the center of curvature of both disks. Therefore, when the load is applied, it is almost the same as the conventional no-load condition.The corners of the friction roller do not enter the contact ellipse between the friction roller and both discs. It does not hurt them.

[0006]

1 shows a friction wheel type continuously variable transmission according to the present invention.
The input shaft 26, the input disc 10 connected to the input shaft 26 via the ball spline 100 so as to be axially movable and rotationally drivable, the output disc 12, the input disc 10, and the output disc 12 And a pair of friction rollers 14 and 16 for transmitting the rotational force therebetween.
Friction roller 1 for input disk 10 and output disk 12
The contact surface with 4 and 16 is a toroid surface. Friction roller 1 for input disk 10 and output disk 12
By changing the contact state of 4 and 16, the rotation speed ratio between the input disk 10 and the output disk 12 can be continuously changed. The pair of friction rollers 14 and 16 are
It is rotatably supported by a pair of roller support members 22 and 24 via eccentric shafts 18 and 20, respectively. The pair of roller support members 22 and 24 are rotatably and vertically movable by link plates (not shown) on the upper and lower rotary shafts (not shown). The roller support members 22 and 24 are shown in FIG.
As shown in FIG. 6, the axes E of the rotary shafts of the conventional shafts are arranged closer to each other as compared with the conventional one. This allows
The point A where the normals from the points of contact of the friction rollers 14 and 16 to both discs 10 and 12 intersect is the both discs 10.
And 12 are closer to the rotation center axis side of both disks 10 and 12 than the designed curvature center B. By arranging the roller support members 22 and 24 as described above, the input disk 10 is pushed and moved in the axial direction, so that the point A is laterally displaced as shown in FIG. The cam flange 30 is connected to a forward-reverse switching mechanism and a torque converter, which are not shown, via a claw portion 30a formed on the cam flange 30, whereby the rotational force of the engine is input. A thrust cam device 28 is arranged on the back side of the input disk 10. The thrust cam device 28 is
It is composed of a cam flange 30, the back side of the input disk 10, and a cam roller 32. Cam flange 30
A cam roller 32 is provided on the cam surfaces of the input disk 10 facing each other. The cam roller 32 is shaped so as to generate a force that presses the input disk 10 toward the output disk 12 when the input disk 10 and the cam flange 30 rotate relative to each other. A disc spring 34 is provided between the input disk 10 and the cam flange 30. The disc spring 34 is provided in parallel with the thrust cam device 28 so that the input disc 1
0 is pressed to the output disk 12 side. Output disk 12
Is rotatably supported on the input shaft 26 via a needle bearing 101. A drive gear 36 is provided so as to rotate integrally with the output disk 12. Although not shown, a coned disc spring provided with a biasing force and a deformation allowance is provided between the input shaft 26 and the rear surface of another input disc that is symmetrical to the input disc 10 via the drive gear 36. Is provided. This disc spring has an input disc 10
Is pressed to the output disk 12 side.

Next, the operation of this embodiment will be described.
When a torque is input to the cam flange 30, the thrust cam device 28 generates a thrust corresponding to the input torque, and drives the input disk 10 to rotate. As the input disk 10 rotates, the input shaft 26 coupled to the input disk 10 via the ball spline 100 rotates. Due to the thrust, the friction rollers 14 and 16 are sandwiched between the input disk 10 and the output disk 12 and rotate without slipping, so that the input disk 1
Power is transmitted from 0 to the output disk 12. When gear shifting is performed with no load, the input disk 10 moves axially in the direction of the cam flange 30 and the friction roller 14 moves.
And 16 swing. However, when a load is applied and both disks 10 and 12 are elastically deformed, both disks 1
The positional relationship between 0 and 12 and the friction rollers 14 and 16 is that the friction rollers 14 and 16 are both disks 10 and 12.
The point A at which the normal from the point of contact with the point A intersects with the designed center of curvature B of both disks 10 and 12 (see FIGS. 2 and 4). That is, the state is the same as the state in which the conventional friction wheel type continuously variable transmission is not elastically deformed, and the corner portions of the friction rollers 14 and 16 do not damage both disks. In this case, the roller support member 22
It is considered that the point E actually moves in the direction corresponding to the points A and B due to the elastic deformation of points 24 and 24. In this embodiment, since the cam flange 30 and the input disk 10 are not displaced relative to each other when the gear is changed under no load,
The input disk 10 moves left and right in the axial direction integrally with the input shaft 26 in correspondence with the speed change direction. However, by flexurally deforming the above-mentioned disc spring (not shown), the input disk 1
A movement amount of 0 can be absorbed.

Next, a second embodiment will be described. Figure 5
As shown in FIG. 2, the input shaft 66, the input disc 50 coupled to the input shaft 66 via the ball spline 200 so as to be axially movable and rotationally drivable, the output disc 52, and the input disc 50. And output disc 52
A pair of friction rollers 54 and 5 for transmitting the rotational force between
6 and 6. The contact surfaces of the input disk 50 and the output disk 52 with the friction rollers 54 and 56 are toroidal surfaces. By changing the contact state of the friction rollers 54 and 56 with respect to the input disk 50 and the output disk 52, the rotational speed ratio between the input disk 50 and the output disk 52 can be continuously changed. The pair of friction rollers 54 and 56 are rotatably supported by the pair of roller support members 62 and 64 via eccentric shafts 58 and 60, respectively. The pair of roller support members 62 and 64 are rotatably supported in the upper and lower rotary shaft portions (not shown) by a link plate (not shown) and movable in the vertical direction. Roller support member 6
The friction rollers 54 and 56 are arranged close to each other, while the axes F of the rotary shaft portions 2 and 64 are the same as those of the conventional one. That is, the point C where the normals from the points of contact of the friction rollers 54 and 56 with both disks 50 and 52 intersect is closer to the rotation center axis of both disks 50 and 52 than the center of curvature D of both disks 50 and 52. So as to support the back surfaces of the friction rollers 54 and 56.
The receiving surfaces of 2 and 64 are arranged close to each other (see FIG. 7). The cam flange 70 is connected to a forward-reverse switching mechanism (not shown) and a torque converter (not shown) via a claw portion 70a formed on the cam flange 70, whereby the rotational force of the engine is input. A thrust cam device 68 is arranged on the back side of the input disk 50. Thrust cam device 6
Reference numeral 8 is composed of a cam flange 70, a back side of the input disc 50, and a cam roller 72. Cam rollers 72 are provided on the cam surfaces of the cam flange 70 and the input disk 50 facing each other. The cam roller 72 is
The shape is such that when the input disk 50 and the cam flange 70 rotate relative to each other, a force that presses the input disk 50 toward the output disk 52 is generated. Input disk 50
The disc spring 74 is provided between the cam flange 70 and the cam flange 70. The disc spring 74 presses the input disk 50 toward the output disk 52 in parallel with the thrust cam device 28. The output disk 52 is rotatably supported on the input shaft 66 via the needle bearing 201. Output disc 52
A drive gear 76 is provided so as to rotate integrally therewith. Although illustration is omitted, as in the first embodiment, a biasing force is applied between the input shaft 50 and the rear surface of another input disk that is symmetrical to the input disk 50 via the drive gear 76, and A disc spring with a deformation allowance is provided. This disc spring has an input disk 50 and an output disk 5
Press to the 2 side.

Next, the operation of the second embodiment will be described. When a torque is input to the cam flange 70, the thrust cam device 68 generates a thrust corresponding to the input torque, and drives the input disk 50 to rotate. As the input disk 50 rotates, the input shaft 66 connected to the input disk 50 via the ball spline 200 rotates. The thrust forces the friction rollers 54 and 56 into the input disk 50 and the output disk 52.
It is sandwiched between and and rotates without slipping, and power is transmitted from the input disk 50 to the output disk 52. When gear shifting is performed under no load, the input disc 50 moves axially toward the cam flange 70. However, point D and point F
Therefore, the friction rollers 54 and 56 do not swing. When a load is applied and both disks 50 and 52 are elastically deformed, both disks 50 and 52 are deformed.
And the friction rollers 54 and 56 are located at a point C where a normal line from the point where the friction rollers 54 and 56 contact the disks 50 and 52 intersect with each other, and both the disks 50 and 52.
And the center of curvature D of are matched (see FIGS. 6 and 8). That is, the state is the same as that of the conventional friction wheel type continuously variable transmission which is not deformed, and the corner portions of the friction rollers 54 and 56 do not damage both disks. In the present embodiment as well, similar to the first embodiment, when gear shifting is performed under no load, the input disk 50 integrally moves with the input shaft 66 in the axial direction corresponding to the gear shifting direction. The amount of movement of the input disk 50 can be absorbed by flexibly deforming a disc spring (not shown).

[0010]

As described above, according to the present invention, in the friction roller, the point at which the normal line from the point of contact with both the disks intersects rather than the designed center of curvature of both disks. It is arranged so as to be located near the center axis of rotation of the disk. As a result, when a load is applied during gear shifting, the point where the normal line from the point where the friction roller contacts the discs intersects moves in a direction that coincides with the center of curvature of both discs. For this reason, the corners of the friction roller do not enter the contact ellipse between the friction roller and both discs, so that they do not come into contact with both discs and damage them.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment (when no load is applied) of the present invention.

FIG. 2 is a diagram showing a state during load shifting according to the first embodiment.

FIG. 3 is an enlarged view of the vicinity of the center of curvature of both discs in FIG.

FIG. 4 is an enlarged view of the vicinity of the center of curvature of both discs in FIG.

FIG. 5 is a diagram showing a second embodiment (when no load is applied).

FIG. 6 is a diagram showing a state during load shifting according to a second embodiment.

FIG. 7 is an enlarged view near the center of curvature of both discs in FIG.

FIG. 8 is an enlarged view of the vicinity of the center of curvature of both discs in FIG.

[Explanation of symbols]

 10 Input Disc 12 Output Disc 14, 16 Friction Roller 18, 20 Eccentric Shaft 22, 24 Roller Support Member

Claims (2)

[Claims] 1. An input disc (10), an output disc (12), and a pair of friction rollers (14, 14) arranged in frictional contact with both discs within a toroidal groove formed by the discs. 16) and the friction rollers (14, 16) to the eccentric shafts (18, 2), respectively.
0), and a roller support member (22, which is rotatable about a rotary shaft portion orthogonal to the shaft centers of both disks and is movable in the axial direction of the rotary shaft portion).
24) and a friction wheel type continuously variable transmission having: The point (A) where the normal line from the point of contact of both disks of the friction rollers (14, 16) intersects is the designed curvature center of both disks. A friction wheel type continuously variable transmission characterized in that the dimensional relationship is set so as to be located closer to the center of rotation of both discs than in (B). 2. The center of curvature (D) in the design of both discs under no load and the axis (F) of the rotary shaft portion of the roller support member (22, 24) coincide with each other. Friction car type continuously variable transmission.