JP4188887B2 - Toroidal continuously variable transmission - Google Patents

Description

  The present invention relates to a toroidal-type continuously variable transmission, and more particularly to a servo piston that reciprocates a trunnion that supports a power roller so as to be rotatable and tiltable in the direction of a tilt axis.

  Conventional toroidal-type continuously variable transmissions have an input / output disk coaxially arranged opposite to each other, a power roller sandwiched between the input / output disks, and a tiltable attachment to the transmission case so that the power roller can rotate. And a trunnion to be supported. The speed change operation for obtaining the speed ratio according to the tilt angle of the power roller is performed by offsetting the power roller from the center of the disk, and by this offset, the power roller is caused by the side slip force generated at the contact portion between the power roller and the input disk. And the displacement applied to the trunnion when the predetermined tilt angle is reached is returned to the original rotation center position of the input / output disk, and the tilting operation of the power roller is stopped.

  In the toroidal type continuously variable transmission, torque transmission is performed by oil film shear between the input / output disk and the power roller. Therefore, the power roller is strongly pressed by the input / output disk, and the power roller receives a thrust force that is pushed radially outward from the input / output disk. To avoid the lateral displacement of the trunnion that supports the power roller due to this thrust force, the trunnion is constrained laterally by the upper link between the upper ends and laterally constrained by the lower link between the lower ends. .

  However, due to the thrust force, the trunnion itself is deformed with the position where it is connected to the upper link and the lower link as a fulcrum, and the servo piston is also tilted with respect to the power roller tilt axis along with the deformation. As a result, the tilted servo piston comes into contact with the servo piston body, and the servo piston insertion portion interferes with the inner peripheral surface of the servo piston insertion hole, thereby inhibiting the movement of the servo piston and reducing the controllability and control accuracy in shifting. There was a problem.

In order to solve this problem, in the prior art, the servo piston lower outer diameter is reduced, or the servo piston insertion hole inner diameter is increased so that the gap between the servo piston lower outer circumference and the servo piston insertion hole inner circumference is reduced. The clearance is enlarged, and even if the servo piston is inclined by the thrust force, the servo piston lower outer periphery and the servo piston insertion hole inner periphery are prevented from interfering with each other. Also, the same member as the servo piston is arranged on the inner periphery of the servo piston insertion hole, or the same member as the servo piston insertion hole is arranged on the outer periphery of the lower part of the servo piston, so that the same member slides inside the insertion hole. The peripheral surface is protected (for example, refer to Patent Document 1).
JP 2000-27961 A

  However, in the above prior art, even if the servo piston lower outer diameter is reduced, the clearance between the peripheral portion of the seal ring groove provided in the servo piston and the servo piston insertion hole for holding the seal ring is changed. Absent. Therefore, when the inclination of the servo piston increases, there is a problem that the peripheral portion of the seal ring groove interferes with the inner peripheral surface of the servo piston insertion hole.

  Also, when the clearance between the periphery of the seal ring groove and the servo piston insertion hole is increased, the pressure receiving area in the seal ring is increased, the surface pressure on the side surfaces of the seal ring and the seal ring groove is increased, and the amount of wear is increased. As a result, the sealing performance is deteriorated. In addition, when the servo piston is tilted, a bias occurs over the entire clearance between the servo piston and the servo piston insertion hole, and the surface pressure applied to the seal ring is biased, resulting in uneven wear of the seal ring and lowering the sealing performance. There is a risk.

  Furthermore, when the same member as the servo piston is arranged on the inner periphery of the servo piston insertion hole, or when the same member as the servo piston insertion hole is arranged on the outer periphery of the lower portion of the servo piston, the number of parts and man-hours are increased due to the provision of another member. There was a problem of inviting.

  The present invention has been made paying attention to the above-mentioned problems, and the object of the present invention is to ensure the sealing performance without increasing the number of parts and man-hours even when the servo piston is inclined, and the servo piston and the servo piston. The object is to provide a toroidal continuously variable transmission that avoids interference with the body.

  In order to achieve the above object, in the present invention, an input disk and an output disk that are opposed to each other on a rotating shaft, a power roller that can be tilted by being sandwiched between opposed surfaces of the input disk and the output disk, and the power A trunnion that supports a roller around a rotation axis of a power roller and that can reciprocate in the direction of the tilting axis of the power roller, and a servo piston that is coupled to the trunnion and reciprocates the trunnion in the direction of the tilting axis of the power roller And a servo piston body having a servo piston insertion hole through which the insertion portion of the servo piston is inserted, and forming a working pressure chamber for reciprocating the servo piston together with the insertion portion of the servo piston. In the transmission, center the hole of the servo piston insertion hole to the axis center of the servo piston. There was a placing eccentrically on the rotary shaft side.

  Therefore, even if the servo piston is inclined, it is possible to provide a toroidal continuously variable transmission that avoids interference between the servo piston and the servo piston body while ensuring sealing performance without increasing the number of parts and man-hours. .

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A best mode for realizing a toroidal continuously variable transmission and a manufacturing method thereof according to the present invention will be described below based on a first embodiment shown in the drawings.

[Overall configuration of toroidal-type continuously variable transmission]
Example 1 will be described with reference to FIGS. FIG. 1 is a skeleton diagram of the present toroidal continuously variable transmission. The toroidal continuously variable transmission 1 includes a torque converter 2, an input shaft 3, a torque transmission shaft 4, a forward / reverse switching mechanism 11, a loading cam device 21, and a toroidal transmission mechanism 30. In the drawing, the x-axis is parallel to the axial direction of the toroidal-type continuously variable transmission 1.

  A rotational driving force is input to the torque converter 2 from an engine (not shown) and transmitted to the input shaft 3. The rotational driving force transmitted to the input shaft 3 is transmitted to the toroidal transmission mechanism 30 via the forward / reverse switching mechanism 11, the loading cam device 21, and the torque transmission shaft 4.

  The forward / reverse switching mechanism 11 includes a planetary gear mechanism 12, a forward clutch 13, and a reverse brake 14. The planetary gear mechanism 12 includes a pinion carrier 16 that supports the double pinion 15 and a ring gear 17 and a sun gear 18 that mesh with the double pinion 15, and the input shaft 3 is coupled to the sun gear 18. A loading cam device 21 is connected to the pinion carrier 16.

  The loading cam device 21 receives torque transmission via the forward / reverse switching mechanism 11 and transmits torque to the torque transmission shaft 4. Further, a pressing force corresponding to the input torque is generated to press the toroidal transmission mechanism 30 in the x-axis direction.

(Details of toroidal transmission mechanism)
The toroidal transmission mechanism 30 includes a first transmission unit 31 and a second transmission unit 32. The first transmission unit 31 includes a first input disk 33, a first power roller 39a, and a first output disk 35 in this order from the negative x-axis direction. Toroidal surfaces 33a and 35a are provided on the x-axis negative direction surface.

  The first power roller 39a is sandwiched between the first input disk 33 and the first output disk 35 on the toroid surfaces 33a and 35a. The first input disk 33 is connected to the torque transmission shaft 4 via a ball spline 37a, and the first output disk 35 is rotatably supported by the torque transmission shaft 4.

  The second transmission unit 32 includes a second output disk 36, a second power roller 39b, and a second input disk 34 in order from the negative x-axis direction. Also in the second transmission unit 32, toroid surfaces 34a and 36a are provided on the x-axis negative direction surface of the second input disk 34 and the x-axis positive direction surface of the second output disk 36, and the toroid surfaces 34a and 36a are provided with the first toroid surfaces 34a and 36a. The two power rollers 39b are sandwiched between the second input / output disks 34 and 36.

  The second input disk 34 is connected to the torque transmission shaft 4 via a ball spline 37b, and the second output disk 36 is rotatably supported by the torque transmission shaft 4. Further, a disc spring 22 is provided at the end of the torque transmission shaft 4 in the x-axis positive direction, and the second input disk 34 is biased in the x-axis negative direction.

(Torque transmission path)
Torque from the torque converter 2 is transmitted to the torque transmission shaft 4 via the forward / reverse switching mechanism 11 and the loading cam device 21, and is transmitted to the first and second input disks 33 and 34 via the ball splines 37a and 37b. . At that time, the loading cam device 21 generates a pressing force according to the transmission torque.

  The loading cam device 21 presses the first input disk 33 in the positive x-axis direction and presses the second input disk 34 in the negative x-axis direction via the torque transmission shaft 4, the loading nut 72, and the disc spring 22. The disc spring 22 generates a preload by tightening the loading nut 72 and presses the second input disk 34 in the negative x-axis direction, and also via the loading nut 72, the torque transmission shaft 4 and the loading cam device 21. The first input disk 33 is pressed in the positive x-axis direction.

  Therefore, the toroidal speed change mechanism 30 receives a pressing force from the loading cam device 21 and the disc spring 22, and the first and second power rollers 39a and 39b are clamped by the first and second input / output disks 33, 34 and 35, 36. Is done.

  By being pinched, each input / output disk and each power roller transmit torque by shearing the oil film, and torque is transmitted to the first and second input disks 33 and 34 as the torque transmission shaft 4 rotates, and is pinched. Torque is transmitted to the first and second output disks 35 and 36 by rotating the first and second power rollers 39a and 39b. At this time, the rotational axis of each power roller is tilted, and the rotational radius of the contact point with each disk is made different between the input side and the output side, thereby performing a shift.

  Torque transmitted to the first and second output disks 35 and 36 is transmitted to the output shaft 60 via the output gear 52, the counter gear 55, and the counter shaft 57.

[Detailed section of toroidal transmission mechanism]
FIG. 2 is a radial cross-sectional view (AA cross-sectional view) of the first transmission unit 31 in the toroidal transmission mechanism 1 shown in FIG. Since the 2nd transmission part 32 is the structure similar to the 1st transmission part 31, only the 1st transmission part 31 is demonstrated. Moreover, since the 1st transmission part 31 is substantially symmetrical with respect to the BB line, only the area | region of a z-axis negative direction rather than a BB line is demonstrated.

  The first power roller 39a is rotatably supported by the first trunnion 40, and a first servo piston 61 is provided at the end of the first trunnion 40 in the negative y-axis direction. The first power roller 39a tilts with the axis O2 as the rotation axis and the axis O3 parallel to the y axis as the tilt axis. The rotation axis O2 and the tilt axis O3 are orthogonal to each other, and the first servo piston 61 is provided coaxially with the tilt axis O3.

  The first servo piston 61 is positioned by the upper link 71 and the lower link 70. In addition, it has a third servo piston insertion hole defining portion 61 a extending in the radial direction, and is slidably fitted into the first servo piston body 62. The first servo piston body 62 has a third servo piston insertion hole 67 for accommodating the third servo piston insertion hole defining portion 61a of the first servo piston 61, and the third servo piston insertion hole 67 is a third servo piston. The first and second working pressure chambers 68 and 69 are defined by the piston insertion hole defining portion 61a.

  The first servo piston 61 is provided with a plurality of circumferential grooves, and an O-ring 64 is fitted in each groove. The O-ring 64 comes into contact with the inner peripheral surfaces of first and second servo piston insertion holes 65 and 66 provided in the first servo piston body 62. Also, a groove is provided at the outer diameter end portion of the third servo piston insertion hole defining portion 61a, and comes into contact with the outer diameter end surface of the third servo piston insertion hole 67 through an O-ring 64 fitted in the groove. As a result, the first and second working pressure chambers 68 and 69 are kept liquid-tight.

  When the first trunnion 40 is moved in the y-axis direction, oil is introduced into the first and second working pressure chambers 68 and 69, and the volume of the third servo piston insertion hole is changed to change the first servo piston 61. The trunnion 40 is moved by moving in the y-axis direction. Thus, by driving the trunnions of the first and second transmission units 31 and 32 in the same phase, the radial contact position between each power roller and each input / output disk is changed, so Shifting is performed by continuously changing the rotation speed ratio, that is, the gear ratio.

[Cross section of power roller at low speed]
FIG. 3 is a sectional view around the tilt axis of the first transmission unit 31 at the time of the lowest shift, that is, when the tilt angle of the first power roller 39a is minimum, and FIG. It is a schematic diagram of the positions of the hole centers 65a and 66a of the second servo piston insertion hole 65 and the hole center 67a of the third servo piston insertion hole 67. Since the first and second transmission units 31 and 32 are symmetrical, only the first transmission unit 31 will be described.

  No pressing force is generated by the loading cam device 21 and no preload is generated by the disc spring 22 because the loading nut 72 is not tightened, that is, a thrust force is generated on the first power roller 39a. In such a state, the hole centers 65a and 66a of the first and second servo piston insertion holes 65 and 66 and the hole center 67a of the third servo piston insertion hole 67 are the first input / output disks 33 and 34 at the lowest speed. To the first power roller 39a is provided in an eccentric direction opposite to the thrust force F applied thereto.

  Since this thrust force F acts in the normal direction of the first power roller 39 a, that is, in the direction of the rotation axis O 2, the hole centers 65 a and 66 a of the first and second servo piston insertion holes 65 and the third servo piston insertion hole 67. The hole center 67a is eccentric on the rotation axis O2 in the direction opposite to the thrust force F, that is, on the torque transmission shaft 4 side and on the first output disk 35 side.

The amount of eccentricity at the center of each hole is defined by t1 and t2 as the amount of eccentricity of the hole centers 65a and 66a of the first and second servo piston insertion holes 65, and t3 as the amount of eccentricity of the hole center 67a of the third servo piston insertion hole 67. >t3> t2
Is set to be That is, the amount of eccentricity is increased as the distance from the first power roller 39a increases.

  When the first servo piston 61 is tilted by the thrust force, the first servo piston 61 moves larger as it is away from the first power roller 39a. Therefore, when the first servo piston 61 is inclined by increasing the amount of eccentricity as it is farther from the first power roller 39a, the first and second axes of the first servo piston 61 and the first servo piston body 62 are first and second. Decreasing the sealing performance due to uneven wear by reducing the bias of the surface pressure applied to the O-ring 64 by bringing the servo piston insertion holes 65, 66 and the third servo piston insertion holes 67 close to the hole centers 65a, 66a, 67a. To avoid.

  These eccentric amounts are set to values that do not interfere with the first servo piston 61 and the first servo piston body 62 even when the inclination angle of the first servo piston 61 becomes maximum.

[Relationship between power roller tilt angle and thrust force]
FIG. 5 is a diagram showing the relationship between the forces acting on the first power roller 39a, and FIG. 6 is a diagram showing the relationship between the tilt angle φ of the first power roller 39a and the thrust force F. If the intersection of the power roller rotation axis O2 and the power roller tilting axis O3 is Q and the contact points of the first input / output disks 33 and 35 and the first power roller 39a are A and B, respectively, the power roller half apex angle θ is 2θ = ∠AQB
Is required. Therefore, if the force in the normal direction at the contacts A and B is Fc, the thrust force F acting on the first power roller 39a from the first input / output disks 33 and 35 is F = 2Fc · cosθ (1)
It is. If the pressing force applied to the first input disk 33 by the loading cam device 21 is Fa, Fa = 2Fc · sinφ (2)
Therefore, from the above equations (1) and (2), F = Fa · (cosθ / sinφ) (3)
It becomes. Since the power roller half apex angle θ is a constant value, the thrust force F is a function of the tilt angle φ if the pressing force Fa is the same value from the equation (3). Therefore, as shown in FIG. 6, the thrust force F increases as the tilt angle φ decreases, and the thrust force F becomes maximum at the lowest shift where the tilt angle φ is minimum.

[Contrast of the effects of the conventional example and the embodiment of the present application]
In the prior art, the servo piston lower outer diameter is reduced, or the servo piston insertion hole inner diameter is increased to increase the clearance between the servo piston lower outer periphery and the servo piston insertion hole inner periphery. Thus, even if the servo piston is inclined, interference between the lower outer periphery of the servo piston and the inner periphery of the servo piston insertion hole is avoided. Also, the same member as the servo piston is arranged on the inner periphery of the servo piston insertion hole, or the same member as the servo piston insertion hole is arranged on the outer periphery of the lower part of the servo piston, so that the same member slides inside the insertion hole. The peripheral surface is protected.

  However, in the above prior art, it is difficult to ensure a sufficient clearance from the servo piston insertion hole due to the presence of the seal ring. When the inclination of the servo piston becomes large, the periphery of the seal ring groove becomes the servo piston insertion hole. There is a problem of interference with the inner peripheral surface. Also, when the clearance between the periphery of the seal ring groove and the servo piston insertion hole is increased, the pressure receiving area in the seal ring is increased, the surface pressure on the side surfaces of the seal ring and the seal ring groove is increased, and the amount of wear is increased. At the same time, the uneven wear of the seal ring pressure-receiving surface caused by the tilting of the servo piston is a major factor for reducing the sealing performance. Furthermore, when the same member as the servo piston is disposed on the inner periphery of the servo piston insertion hole, or when the same member as the servo piston insertion hole is disposed on the outer periphery of the lower portion of the servo piston, there is a problem that the number of parts and man-hours increase. .

  On the other hand, in the embodiment of the present application, the first and second servo piston insertion holes in the first servo piston 61 in a state where the thrust force F is not generated from the first input / output disks 33 and 35 to the first power roller 39a. The hole centers 65a, 66a, and 67a of the 65, 66 and the third servo piston insertion hole 67 are provided eccentric to the torque transmission shaft 4 side with respect to the tilt axis O3 so as to be in the direction opposite to the thrust force generation direction. Thereby, even if the first servo piston 61 is inclined by the thrust force, it is possible to reliably avoid the interference between the first servo piston 61 and the first servo piston body 62.

  Further, by decentering each hole center 65a, 66a, and 67a toward the torque transmission shaft 4 with respect to the tilt axis O3, when the first servo piston 61 is inclined, the axis of the first servo piston 61 and the center of each hole 65a, 66a and 67a can be brought close to each other, and the unevenness of the surface pressure applied to the O-ring 64 can be alleviated to prevent the deterioration of the sealing performance due to uneven wear. Moreover, since it is not necessary to provide another member separately, it is possible to reduce the number of parts and man-hours. The above effect is an effect on the first servo piston 61 and the first servo piston body 62, but the same effect can be obtained by adopting the same configuration for the other servo pistons and servo piston bodies. Corresponds to item 1.)

  Further, the hole centers 65a and 66a of the first and second servo piston insertion holes 65 and the hole center 67a of the third servo piston insertion hole 67 are provided eccentric to the first output disk 35 side with respect to the tilt axis O3. It was decided. As a result, even if the thrust force changes according to the tilt angle φ of the first power roller 39a and the tilt amount of the first servo piston 61 changes, the first servo piston 61 and the first servo piston body 62 may Interference can be reliably avoided.

  Further, by decentering each hole center 65a, 66a and 67a toward the first output disk 35 with respect to the tilt axis O3, when the first servo piston 61 is inclined, the axis of the first servo piston 61 and each hole The centers 65a, 66a, and 67a can be brought close to each other, and the uneven surface pressure applied to the O-ring 64 can be alleviated to prevent deterioration of the sealing performance due to uneven wear. The same effect can be obtained by adopting the same configuration for other servo pistons and servo piston bodies (corresponding to claim 2).

  Further, assuming that the eccentric amounts of the hole centers 65a and 66a of the first and second servo piston insertion holes 65 are t1 and t2, and the eccentric amount of the hole center 67a of the third servo piston insertion hole 67 is t3, t1> t2. It was decided to be set. Thus, when the first servo piston 61 is inclined, the axial center of the first servo piston 61 and the hole centers 65a and 66a of the first and second servo piston insertion holes 65 and 66 in the first servo piston body 62 are obtained. It becomes possible to approach, the unevenness of the surface pressure applied to the O-ring 64 can be reduced, and the deterioration of the sealing performance due to uneven wear can be avoided. By adopting the same configuration, the same effect can be obtained for other servo pistons and servo piston bodies (corresponding to claim 3).

  Further, in the embodiment of the present application, the eccentric amount of the hole center 67a of the third servo piston insertion hole 67 is set to t3, and t1> t3> t2 is set. Accordingly, the eccentric amount is sequentially increased as the distance from the first power roller 39a is increased, and when the first servo piston 61 is inclined, the first and second shafts of the first servo piston 61 and the first and second servo piston bodies 62 are arranged. The servo piston insertion holes 65 and 66 and the third servo piston insertion holes 67 can be made closer to the hole centers 65a, 66a, and 67a, and the effect of claim 3 can be further ensured.

(Other examples)
Although the best mode for carrying out the present invention has been described based on the first embodiment, the specific configuration of the present invention is not limited to each embodiment and does not depart from the gist of the present invention. Any changes in the design of the range are included in the present invention.

  In the present embodiment, the disk pressed by the loading cam device is the input disk, but the output disk may be pressed. In this case, the same operation and effect as in the present embodiment can be obtained by decentering each hole center of each servo piston insertion hole toward the input disk.

  In the present embodiment, the relationship between the eccentric amounts t1, t2, and t3 of the hole centers 67a of the first and second servo piston insertion holes 65 and 66 and the third servo piston insertion hole 67 is set to satisfy t1> t3> t2. T1 = t3 or t2 = t3. The same applies to other servo pistons.

It is a skeleton figure of an automatic transmission to which the present toroidal type continuously variable transmission is applied. It is radial direction sectional drawing of the 1st transmission part in a toroidal transmission mechanism. FIG. 6 is a sectional view around the tilt axis of the first transmission unit when the tilt angle of the first power roller is minimum. It is a schematic diagram of the position of the hole center of the 1st, 2nd servo piston insertion hole with respect to a 1st power roller tilting axis, and the hole center of a 3rd servo piston insertion hole. It is a figure which shows the relationship of the force which acts on a 1st power roller. It is a figure which shows the relationship between the tilt angle of a 1st power roller, and thrust force.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toroidal transmission mechanism 2 Torque converter 3 Input shaft 4 Torque transmission shaft 11 Forward / reverse switching mechanism 12 Planetary gear mechanism 13 Forward clutch 14 Reverse brake 15 Double pinion 16 Pinion carrier 17 Ring gear 18 Sun gear 21 Loading cam device 22 Belleville spring 30 Toroidal transmission mechanism 31 1st transmission part 32 2nd transmission part 33 1st input disk 34 2nd input disk 35 1st output disk 36 2nd output disk 33a-36a Toroid surface 37a, 37b Ball spline 39a 1st power roller 39b 2nd power roller 40 first trunnion 52 output gear 55 counter gear 57 counter shaft 60 output shaft 61 first servo piston 61a third servo piston insertion hole defining portion 62 first servo piston body 64 O-ring 6 5 First servo piston insertion hole 65a First servo piston insertion hole center 66 Second servo piston insertion hole 66a Second servo piston insertion hole center 67 Third servo piston insertion hole 67a Third servo piston insertion hole center 68 First operating pressure Chamber 69 Second working pressure chamber 70 Lower link 71 Upper link 72 Loading nut

Claims (3)

An input disk and an output disk arranged opposite to each other on the rotation axis;
A power roller capable of being tilted by being sandwiched between opposing surfaces of the input disk and the output disk;
A trunnion that supports the power roller so as to be rotatable around a power roller rotation axis and to be capable of reciprocating in the direction of the power roller tilting axis;
A servo piston coupled to the trunnion and reciprocating the trunnion in the direction of the power roller tilt axis;
A servo piston body having a servo piston insertion hole through which the insertion portion of the servo piston is inserted, and forming a working pressure chamber for reciprocating the servo piston together with the insertion portion of the servo piston;
Toroidal-type continuously variable transmission comprising
A toroidal continuously variable transmission, characterized in that the hole center of the servo piston insertion hole is eccentrically arranged on the rotating shaft side with respect to the axis center of the servo piston. The toroidal continuously variable transmission according to claim 1,
A pressing force urging means for urging the pressing force for clamping the power roller to either the input disk or the output disk;
A toroidal continuously variable transmission characterized in that the hole center of the servo piston insertion hole is eccentrically arranged on the other disk side different from the one disk with respect to the axis center of the servo piston. In the toroidal continuously variable transmission according to claim 1 or 2,
The working pressure chamber is formed of a first working pressure chamber that operates the trunnion in the forward direction and a second working pressure chamber that operates the trunnion in the backward direction,
The servo piston insertion hole is
A first servo piston insertion hole provided with a seal member that fluidly defines the first working pressure chamber and the outside between the insertion portion of the servo piston;
A second servo piston insertion hole provided with a seal member that fluidly defines the second working pressure chamber and the outside between the insertion portion of the servo piston;
Between the servo piston insertion portion, a third servo piston insertion hole provided with a seal member that fluidly defines the first working pressure chamber and the second working pressure chamber,
The eccentric amount of the hole center of the first servo piston insertion hole with respect to the axial center of the servo piston is larger than the eccentric amount of the hole center of the second servo piston insertion hole with respect to the axial center of the servo piston. Toroidal continuously variable transmission.

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