JP2940375B2 - Friction wheel type continuously variable transmission - Google Patents

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 is disclosed in Japanese Utility Model Laid-Open No. 62-100334. The friction wheel type continuously variable transmission shown here has an input disk,
An output disk and a friction roller for transmitting a rotational force between the two disks are provided. The input disk is supported on the input shaft so as to be rotatable about the input shaft and movable in the axial direction. A thrust cam device is disposed on the back side of the input disk. The thrust cam device includes a cam flange, a rear surface of the input disk, and a cam roller that is disposed therebetween and generates a force that presses the input disk toward the output disk when they rotate relatively. I have. The inner diameter of the cam flange is connected to the input shaft by a spline. A disc spring that constantly presses the cam flange toward the input disk is disposed on the side of the cam flange. Further, the cam flange is restricted from moving in the axial direction by a stopper which is fitted to the input shaft so as not to be movable in the axial direction.

[0003]

However, in the above-described conventional friction wheel type continuously variable transmission, when the input shaft and the cam flange are slid, friction is applied to the spline portion by the sprung tooth surface normal force due to the rotational torque. Occur. For this reason,
The necessary pressing force is supplemented by increasing the pressing force by a disc spring in advance in order to prevent sliding failure due to friction. As a result, although the above-mentioned sliding defect is improved, since a large pressing force by the disc spring is constantly applied to the input shaft and the cam flange, the thickness of the cam flange is increased in order to secure durability. Is required, which causes an increase in weight. In addition, when driven with the same torque, the larger the spline shaft radius, the smaller the tooth surface normal force and the lower the friction. Therefore, in order to solve the above problem, if the spline shaft diameter is increased, In order to process the spline, it is necessary to increase the diameter of the entire input shaft similarly, which causes a problem of increasing the weight. Although it is conceivable to increase the diameter of only the portion of the input shaft where the spline is to be machined, there is a problem that the input disk inserted from the spline side to the input shaft cannot be assembled.

[0004]

According to a first aspect of the present invention, a cam flange is connected to an input flange which rotates integrally with an input shaft, the cam flange being relatively movable in the axial direction but not being relatively rotatable. The above problem is solved by forming the inner diameter side of the input flange on the stopper of the cam flange. That is, the friction wheel type continuously variable transmission according to the present invention includes an input disk (18) provided rotatably about the input shaft (14) and movable in the axial direction, and the input disk (18) concentrically with the input disk (18). An output disk (20) mounted face-to-face and rotatable and restrained from moving away from the input disk (18); and a toroidal groove formed by the disks (18, 20). A friction roller arranged to be in frictional contact with both disks (18, 20), and a thrust corresponding to the input torque, which is provided on the back side opposite to the friction roller contact surface of the input disk (18) A thrust cam device (44) generated on the disk (18);
The thrust cam device (44) includes a rear surface of the input disk (18), a cam flange (46), and a cam roller (48) provided on the facing cam surface.
Wherein the input shaft (14) comprises:
The input flange (7
0) is connected, and the input flange (70) can move relative to the input flange (70) in the axial direction, but cannot rotate relative to the input flange (70). It is connected via a claw (46a) provided on the back side opposite to the surface, and between the input flange (70) and the cam flange (46),
A spring (74) for constantly pressing the cam flange (46) in the direction of the input disk (18) is provided, and the cam flange (46) is provided on the inner diameter side of the input flange (70).
A stopper (70a) capable of restricting the movement of the shaft in the axial direction is formed. The present invention according to claim 2 is characterized in that the input flange is arranged at the same axial position as the cam flange. The numbers in parentheses indicate the corresponding members in the embodiments described later.

[0005]

According to the first and second aspects of the invention, when the input torque is input to the input shaft, the input torque is transmitted to the cam flange via the input flange which rotates integrally with the input shaft. When the input torque increases, the cam flange moves relatively while sliding against the input disk in the opposite direction to the input disk while pressing and contracting the cam against the elastic force of the spring. After compressing the spring, the cam flange abuts against the stopper on the input flange and is restrained from further movement.

[0006]

FIG. 1 shows a first embodiment of the present invention. Input shaft 14 to which rotation of a torque converter (not shown) is transmitted
Is connected to a friction wheel type continuously variable transmission mechanism 16. The friction wheel type continuously variable transmission mechanism 16 has an input disk 18, an output disk 20, and a friction roller (not shown) for transmitting a rotational force between the two. The contact surfaces of the input disk 18 and the output disk 20 with the friction roller are toroidal surfaces. By changing the contact state of the friction roller with the input disk 18 and the output disk 20, the rotation speed ratio between the input disk 18 and the output disk 20 can be continuously changed. The input shaft 14 is connected to the casing 3 via an input side bearing 30 and a needle bearing 32.
4 rotatably supported. An output disk 20 is rotatably supported on the input shaft 14 via a bearing 38. The output disk 20 is provided with an output shaft 27 integrally formed with an output gear 26 so as to rotate integrally. The output shaft 27 is an output side bearing 40
Through the casing 34. An input disk 18 is provided on the input shaft 14 via a bearing 42 so as to be rotatable and movable in the axial direction.

A thrust cam device 44 is provided on the rear side of the input disk 18, that is, on the side opposite to the side facing the output disk 20. The thrust cam device 44 includes a cam flange 46, a rear side of the input disk 18, and a cam roller 48. The cam rollers 4 are attached to the cam surfaces of the cam flange 46 and the input disk 18 facing each other.
8 are provided. The cam roller 48 is the input disk 1
It is shaped so as to generate a force for pressing the input disk 18 toward the output disk 20 when the cam 8 and the cam flange 46 rotate relative to each other. An input flange 70 is disposed between the inner diameter of the cam flange 46 and the outer diameter of the input shaft 14. Input flange 70 and input shaft 14
And are connected by a spline. The input flange 70 is disposed so as to be axially movable relative to the inner diameter of the cam flange 46 via the friction reducing bush 72. The friction reducing bush 72 is made of Teflon or metal. The input flange 70 is formed in a stepped shape, and its tip extends vertically in the radial direction, and is engaged with a claw portion 46 a projecting in the axial direction from the cam flange 46 so as to be relatively movable in the axial direction. I have. Side of cam flange 46 and input flange 70
Vertical portion 70 radially extending from the connection portion with the input shaft 14
A disc spring (spring) 74 is provided between the cam flange 46 and the cam flange 46 to apply a force toward the input disk 18 to the cam flange 46. The vertical portion 70a of the input flange 70 functions as a stopper that restricts the movement of the cam flange 46 in the axial direction. A loading nut 76 is screwed into the input shaft 14 so as to contact a vertical portion 70a of the input flange 70. Loading nut 7
Numeral 6 tightens the whole friction wheel type continuously variable transmission mechanism 16 and fixes the input flange 70 to the input shaft 14. Oil holes 50 and 52 are formed in a portion of the input flange 70 bent radially from a portion connected to the input shaft 14 and a portion of the cam flange 46 facing the input flange 70, respectively. Lubricating oil is supplied from the inside of the input shaft 14 through the oil holes 50 and 52 to a portion where the cam roller 48 between the cam flange 46 and the input disk 18 is arranged. Input flange 70
, An input torque is input from a forward / reverse switching mechanism (not shown).

Next, the operation of the first embodiment will be described. When an input torque from a forward / reverse switching mechanism (not shown) is input to the input flange 70, the pawl portion 4 provided on the rear side opposite to the cam surface of the cam flange 46.
It is transmitted to the cam flange 46 via 6a. When the input torque increases, the cam flange 46 moves in the direction of the loading nut 76 while compressing and contracting the disc spring 74 against the elastic force of the disc spring 74. The pawl portion 46a moves relative to the input flange 70 in the axial direction because it moves together with the cam flange 46. Since the vertical force of the pawl portion 46a at this time is inversely proportional to the effective diameter of the portion where the pawl portion 46a is provided, the friction that prevents the movement of the cam flange 46 in proportion to this vertical force has a large effective diameter. It becomes smaller. The effective diameter here is the impulse during torque transmission.
The set flange 70 and the claw portion 46a of the cam flange 46;
It shows the center diameter of the meshing portion. Disc spring 74
After pressing the cam flange 46, the cam flange 46 abuts on the inner diameter side of the vertical portion 70a of the input flange 70 via the disc spring 74, and further movement is restricted. At this time, the pressing force from the cam flange 46 is applied to the inner diameter side of the vertical portion 70a of the input flange 70,
No bending force is applied to the input flange 70. Therefore, the input flange 70 can be formed thin. Also, the cam flange 46 and the input flange 7
Since 0 is arranged at the same axial position, that is, in a double structure, the axial dimension can be reduced.

FIG. 2 shows a second embodiment. The disc spring 74 is removed, the axial dimension of the inner diameter portion of the cam flange 80 is increased, and a vertical portion 80b extending radially from the inner diameter portion of the cam flange 80 and a vertical portion 70a of the input flange 70 are formed.
And the friction reducing bush 8 provided between the cam flange 80 and the input flange 70 by the increased axial dimension of the inner diameter portion of the cam flange 80.
4 and the cam flange 80 is positioned between the vertical portion 80b of the cam flange 80 and the lower portion of the input flange 70 connecting the pawl portion 80a of the input flange 70 in the direction of the input disk 18. The structure is the same as that of the first embodiment except that a coil spring 82 that constantly presses the coil spring 82 is provided.

Next, the operation of the second embodiment will be described.
The input torque transmitted to the cam flange 80 increases,
The cam flange 80 moves in the direction of the loading nut 76 against the elastic force of the coil spring 82,
0 is the vertical portion 80b of the input flange 70.
It is the same as the first embodiment except that it directly contacts the inner diameter side of Oa. When the coil spring 82 is used, the spring constant can be set smaller than when the disc spring 74 is used, so that the change in the load when the cam flange 80 moves in the axial direction is reduced. The pressing force can be generated accurately. Further, when the coil spring 82 is used, the thickness dimension of the vertical portion 80b of the cam flange 80 can be increased by a thickness corresponding to the thickness of the disc spring 74 as compared with the case where the disc spring 74 is used. The flange 80 can withstand a large input torque.

[0011]

As described above, according to the first aspect of the present invention, since the input torque is transmitted to the cam flange via the input flange, the cam flange is provided on the rear side of the input flange. It moves relative to the input shaft in the axial direction via the hook. In this case, since the pawl portion can be provided at a relatively large diameter position, the sliding friction when the pawl portion slides can be reduced to a small value. Therefore, it is not necessary to increase the pressing force of the spring to compensate for the sliding failure due to friction. This eliminates the need to increase the thickness of the member on which the spring force acts, and can suppress an increase in weight. Further, since the stopper is formed on the inner diameter side of the input flange, no bending force is applied to the input flange, so that the input flange can be formed thin. Therefore, the axial dimension of the friction wheel type continuously variable transmission can be reduced.
According to the second aspect of the present invention, since the cam flange and the input flange are arranged at the same axial position, that is, a double structure, the axial dimension of the friction wheel type continuously variable transmission is further reduced. can do.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 14 input shaft 18 input disk 20 output disk 44 thrust cam device 46 cam flange 46a pawl portion 48 cam roller 70 input flange 70a vertical portion (stopper) 74 disc spring (spring)

Claims (2)

(57) [Claims] An input disk (18) provided rotatably about an input shaft (14) and movable in an axial direction.
An output disk (20) provided concentrically with the input disk (18) so as to face the input disk (18), and being rotatable and restrained from moving in a direction away from the input disk (18); A friction roller arranged in frictional contact with the two discs (18, 20) in a toroidal groove formed by the input disc (20); and a rear side opposite to the friction roller contact surface of the input disc (18). And a thrust cam device (4) for generating a thrust corresponding to the input torque on the input disk (18).
The thrust cam device (44) includes a rear surface of the input disk (18), a cam flange (46), and a cam roller (48) provided on the facing cam surface. In the friction wheel type continuously variable transmission, an input flange (70) is connected to the input shaft (14) so as to rotate integrally therewith, and the input flange (70) is connected to the input flange (70). The cam flange (46) has a pawl (46a) provided on the back side opposite to the cam surface of the cam flange (46). And the input flange (70) and the cam flange (4).
A spring (74) for constantly pressing the cam flange (46) in the direction of the input disk (18) is provided between the input flange (46) and the cam flange (46) on the inner diameter side of the input flange (70). Stopper (7) that can regulate the axial movement of
0a) is formed. A continuously variable transmission of a friction wheel type. 2. The continuously variable transmission according to claim 1, wherein the input flange is disposed at the same axial position as the cam flange.