JP2005226662A - Continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tensioner device for a continuously variable transmission having improved force transmitting efficiency between a tensioner arm and a piston rod while reducing the one-sided load of the piston rod on a bearing portion. <P>SOLUTION: The tensioner device 50 for thrusting a belt 15 of the continuously variable transmission to produce belt tension comprises a hydraulic cylinder 60 for energizing the rocking tensioner arm 53 on which a tension roller 51 is mounted. A pin 55 has one end journaled to the tensioner arm 53 and the other end inserted into a hollow portion 64a of the piston rod 64 with a gap and abutting on the piston rod 64 inside the hollow portion 64a. This abutting portion is arranged in an axial range L of the bearing portion 65 all over the stroke range of the piston rod 64, therefore reducing the one-sided load on the bearing portion 65. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a belt tension control device in a continuously variable transmission, particularly a V-belt type continuously variable transmission.

In Patent Document 1, a belt ratio is provided between a drive pulley and a driven pulley, and a gear ratio variable mechanism is provided that allows the gear ratio to be continuously variable by changing the pulley groove widths of both pulleys in opposite directions. A continuously variable transmission provided with a tensioner device that obtains belt tension by pressing a tension roller on the loose side of the belt has been proposed.
Known tensioner devices include a combination of a spring that urges the tensioner arm that supports the tension roller and an assist motor, a combination of a diaphragm actuator and a spring, and a combination of a hydraulic cylinder and a spring. ing.

Examples of auto tensioners using hydraulic pressure are described in Patent Documents 2 and 3.
In the auto tensioner described in Patent Document 2, one end of a tensioner arm is swingably supported on a fixed part, a tension roller is attached to the other end, and a piston rod of a hydraulic cylinder is pressed against the side surface of the tensioner arm. It has been made.
In the auto tensioner described in Patent Document 3, a tension roller is attached to one end portion of a tensioner arm, an intermediate portion of the tensioner arm is swingably supported on a fixed portion, and a hydraulic cylinder is connected to the other end portion of the tensioner arm. Yes.
In either case, the tensioner arm is swung by the action of the hydraulic cylinder, and the tension roller is pressed against the belt to absorb the looseness of the belt and to apply an appropriate tension.

In the case of the auto tensioner, basically, the position of the tension roller is almost constant, and the swing angle of the tensioner arm is very small. However, in the case of a tensioner device used in a continuously variable transmission, the position of the belt greatly changes depending on the gear ratio, and the swing angle of the tensioner arm also increases. Moreover, since the gear ratio changes frequently, the tensioner arm must also swing quickly. As a result, various problems occur in a continuously variable transmission using a hydraulic cylinder as an actuator for urging the tensioner arm.

7 and 8 show two examples of a continuously variable transmission using a hydraulic cylinder as an actuator of the tensioner device.
FIG. 7 shows a case where the piston rod 101 of the hydraulic cylinder 100 is brought into contact with the back surface of the tensioner arm 102 as in the case of Patent Document 2.
FIG. 8 shows a structure in which the piston rod 101 of the hydraulic cylinder 100 and the tensioner arm 102 are connected via a link 108.
In addition, 103 is a tension roller, 104 is a belt, 105 is a driving pulley, and 106 is a driven pulley.

7 and 8, when the tensioner arm 102 swings, the force transmission efficiency between the tensioner arm 102 and the piston rod 101 is deteriorated, and the bearing portion 107 that guides the piston rod 101 is used. There is a problem in that the unbalanced load increases. The reason for this is that the direction of the reaction force against the piston rod 101 changes as the tensioner arm 102 swings, and an oblique force is applied to the protruding end of the piston rod 101 that protrudes outward from the bearing portion 107. This is because not only an axial force but also a bending moment acts on the rod 101. As a result, the transmission efficiency of force between the piston rod 101 and the tensioner arm 102 is deteriorated, and there is a possibility that wear or oil leakage occurs in the bearing portion 107.
JP 2001-330099 A JP-A-10-184825 JP 2000-274502 A

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a continuously variable transmission including a tensioner device that can improve the transmission efficiency of force between the tensioner arm and the piston rod and reduce the bias load on the bearing portion of the piston rod. It is in.

In order to achieve the above object, according to the first aspect of the present invention, a belt is wound between a driving pulley and a driven pulley, and the pulley groove widths of both pulleys are changed in opposite directions to make the transmission ratio variable. In a continuously variable transmission provided with a variable gear ratio mechanism and a tensioner device that obtains belt tension by pressing the belt, the tensioner device is fixed to a tension roller that presses against the loose side of the belt, and one end is fixed. A tensioner arm that is swingably supported on the other end, the tension roller is attached to the other end, a piston rod that moves straight by fluid pressure, and that has a hollow portion that opens to one end, and slides the piston rod. A fluid pressure cylinder having a bearing portion that guides freely, and a transmission member that transmits force between the piston rod and the tensioner arm One end portion of the transmission member is inserted into the hollow portion of the piston rod with a gap, and is connected to the piston rod so as to contact with or rotate in the hollow portion, and the transmission member and the piston rod A continuously variable transmission is provided in which the abutting portion or the connecting portion is disposed within the axial range of the bearing portion in the entire stroke range of the piston rod.

The reaction force applied from the tensioner arm to the transmission member is transmitted to the piston rod via the contact portion or the coupling portion between the transmission member and the piston rod. Since the tensioner arm swings as the speed ratio changes, the transmission member tilts with respect to the piston rod. However, since the end of the transmission member is inserted with a gap in the hollow portion of the piston rod, the inclination of the transmission member can be allowed. Further, the reaction force from the tensioner arm to the transmission member becomes a force in an oblique direction with respect to the piston rod, and there is a possibility that an eccentric load is applied to the bearing portion. However, since the contact portion or connecting portion between the transmission member and the piston rod is disposed within the axial range of the bearing portion, the reaction force applied via the transmission member does not act as a bending moment on the piston rod, The power transmission efficiency is improved, and the offset load on the bearing portion can be reduced. Therefore, wear and oil leakage between the bearing portion and the piston rod can be prevented.
The fluid pressure cylinder of the present invention is not limited to a hydraulic cylinder but may be an air cylinder.

7 and 8, in the example of FIGS. 7 and 8, an oblique force is applied to the protruding end portion of the piston rod that protrudes from the bearing portion to the outside as the tensioner arm swings. Therefore, while a bending moment acts on the piston rod, in the present invention, since an oblique force is applied to the intermediate portion of the piston rod supported by the bearing portion, the bending moment hardly acts on the piston rod. Therefore, the transmission efficiency of the force between the piston rod and the tensioner arm becomes good, and the uneven load applied to the bearing portion can be reduced.

The concave or convex circular arc surface is formed on the bottom surface of the hollow portion of the piston rod, and the convex or concave circular arc surface is formed on one end of the transmission member. Is preferably in contact with the arc surface of the piston rod.
As a method for connecting the transmission member and the piston rod, there is also a method of connecting the transmission member and the piston rod so as to be rotatable, but the shaft must be arranged in the hollow portion of the piston rod, and the assembly of the shaft becomes difficult.
In contrast, if the end of the transmission member is brought into contact with the bottom surface of the hollow portion of the piston rod, there is no need to connect with a shaft, and only the end of the transmission member is inserted into the hollow portion of the piston rod. As it is good, assembly becomes easy. In addition, since the contact surface is an arc surface, force can be transmitted smoothly even if the angle between the transmission member and the piston rod changes.
The circular arc surface includes a spherical surface as well as a cylindrical surface. Further, the convex arc surface and the concave arc surface are not limited to the same radius of curvature, and the concave arc surface may have a radius of curvature larger than that of the convex arc surface.

As apparent from the above description, according to the present invention, in order to connect the tensioner arm and the piston rod of the fluid pressure cylinder, the piston rod is provided with a hollow portion opened on one end side, and the transmission member is provided in the hollow portion. One end part of the transmission member is inserted with a gap, and the transmission member and the piston rod are contacted or connected inside the hollow part, and the contact part or connection part between the transmission member and the piston rod is arranged in the entire stroke range of the piston rod. Since it arrange | positions in the axial direction range of a bearing part, the transmission efficiency of force improves and the eccentric load with respect to the bearing part of a piston rod can be reduced. As a result, the piston rod can operate smoothly, and wear and oil leakage between the bearing portion and the piston rod can be prevented.
Further, since the end of the transmission member is inserted into the piston rod, the total length from the fluid pressure cylinder to the tensioner arm can be shortened, and a small tensioner device can be realized.

Embodiments of the present invention will be described below with reference to examples.

1 to 6 show an example of a continuously variable transmission according to the present invention.
The continuously variable transmission of this embodiment is an FF horizontal type automobile transmission, which is roughly an input shaft 3 driven via a torsional damper 2 by an engine output shaft 1 and a drive shaft that supports a drive pulley 11. 10, a driven shaft 20 that supports the driven pulley 21, a drive pulley 11 and a dry V belt 15 wound around the driven pulley 21, a first reduction shaft 30, a second reduction shaft 31, and an output shaft 32 connected to the wheels. The transmission motor 40 (see FIGS. 2 and 3), the tensioner device 50, and the like. The input shaft 3, the drive shaft 10, the driven shaft 20, the first reduction shaft 30, the second reduction shaft 31, and the output shaft 32 are all non-coaxial and arranged in parallel. In FIG. 1, the drive pulley 11 is depicted above the driven pulley 21, but actually the drive pulley 11 is disposed below the driven pulley 21 as shown in FIG. 2.
The V-belt 15 used in this embodiment is a known dry type composite belt composed of a pair of endless tension bands and a large number of blocks locked to the tension bands in the length direction.

The input shaft 3 is rotatably supported by a transmission housing 6 via a bearing, and the input shaft 3 is integrally formed with an input gear 3a that meshes with a gear 10a provided at an end of the drive shaft 10 on the engine side. ing. By appropriately setting the reduction ratio between the input gear 3a and the gear 10a, the drive shaft 10 can be rotated at a reduction ratio suitable for belt driving.

The drive pulley 11 includes a fixed sheave 11a fixed on the drive shaft 10, a movable sheave 11b supported on the drive shaft 10 so as to be movable in the axial direction, and a stroke mechanism 12 provided behind the movable sheave 11b. The movable sheave 11b and the stroke mechanism 12 are disposed closer to the engine than the V belt 15. The stroke mechanism 12 of this embodiment is a ball screw mechanism that moves the movable sheave 11b in the axial direction by rotational input from the speed change motor 40. The female screw member 12b is supported on the movable sheave 11b via a bearing 12a so as to be relatively rotatable. And a male screw member 12c fixed to the housing 6, and a transmission gear 13 is fixed to the outer periphery of the female screw member 12b.

The driven pulley 21 includes a fixed sheave 21a fixed on the driven shaft 20, a movable sheave 21b supported on the driven shaft 20 so as to be axially movable, and a stroke mechanism 22 provided behind the movable sheave 21b. The movable sheave 21b and the stroke mechanism 22 are disposed on the opposite side of the engine from the V belt 15. The stroke mechanism 22 is also a ball screw mechanism having the same configuration as the stroke mechanism 12 of the drive pulley 11, and is fixed to the housing 6 and a female screw member 22 b that is supported on the movable sheave 21 b via a bearing 22 a so as to be relatively rotatable. The transmission gear 23 is fixed to the outer peripheral portion of the female screw member 22b.

A forward / reverse switching mechanism 24 is provided at a portion of the driven shaft 20 closer to the engine than the driven pulley 21, and a forward gear 25 and a reverse gear 26 are rotatably supported on both sides thereof. When the forward / reverse switching mechanism 24 is shifted to the left in FIG. 3, the forward (D) position is reached, and when it is shifted to the right, the reverse (R) position is reached. A start clutch 27 is provided at the shaft end of the driven shaft 20 on the engine side. The start clutch 27 connects and disconnects the hub 24 a of the forward / reverse switching mechanism 24 to the driven shaft 20. The forward gear 25 is engaged with the gear 30a of the first reduction shaft 30, the gear 30b of the first reduction shaft 30 is engaged with the gear 31a of the second reduction shaft 31, and the gear 31b of the second reduction shaft 31 is further connected to the differential device 33. Is engaged with the ring gear 33a. Further, the reverse gear 26 meshes with the gear 30 b of the first reduction shaft 30 through the idler gear 28. And the output shaft 32 connected with the wheel via the differential device 33 is driven.

The input gear 3a of the input shaft 3, the gear 10a of the drive shaft 10, the forward / reverse switching mechanism 24, the forward gear 25, the reverse gear 26, the start clutch 27, the first reduction shaft 30 (gears 30a and 30b), the second The reduction shaft 31 (gears 31a, 31b) and the differential device 33 are accommodated in a gear chamber 6a formed on the engine side of the housing 6. The gear chamber 6a is lubricated with oil.
On the other hand, the driving pulley 11 and the driven pulley 21 are disposed in a pulley chamber 6b of the housing 6 partitioned by the gear chamber 6a and the partition wall 6c. The pulley chamber 6b is a non-lubricated space and is air-cooled.

A speed change motor 40 (see FIG. 2) is attached to the outside of the housing 6. The output gear 41 of the speed change motor 40 is meshed with a reduction gear 45 a provided at one end of the first speed change shaft 45. The first transmission shaft 45 is provided across the pulley chamber 6b. A gear 45 b provided at the other end of the first transmission shaft 45 is a spur gear having a length corresponding to the moving stroke of the movable sheave 21 b of the driven pulley 21, and meshes with the transmission gear 23 provided on the driven pulley 21. Yes. When the gear 45b of the first speed change shaft 45 is rotated, the speed change gear 23 is rotated so that the movable sheave 21b can be moved in the axial direction by the action of the ball screw mechanism 22. That is, the pulley groove width (belt winding diameter) of the driven pulley 21 can be continuously changed by the speed change motor 40.

The transmission gear 23 of the driven pulley 21 is also meshed with a first idler gear 46 a of a second transmission shaft 46 provided over the housing 6, and the second idler gear 46 b of the second transmission shaft 46 is further engaged with the transmission gear 13 of the drive pulley 11. Are engaged. These idler gears 46a and 46b are also constituted by spur gears having a length corresponding to the moving stroke of the movable sheaves 11b and 21b, similarly to the gear 45b of the first transmission shaft 45. As shown in FIG. 2, the second transmission shaft 46 is disposed between the drive pulley 11 and the driven pulley 21 and in the circumference of the V belt 15. The rotational force of the speed change motor 40 is transmitted to the speed change gear 13 of the drive pulley 11 via the first speed change shaft 45, the speed change gear 23 of the driven pulley 21, and the second speed change shaft 46. Therefore, the movable sheave 11a of the driving pulley 11 and the movable sheave 21a of the driven pulley 21 are synchronized with each other, and can move in the axial direction while changing the pulley groove width (belt winding diameter) in the opposite direction.
As described above, the speed change motor 40, the stroke mechanism 12 of the drive pulley 11, the stroke mechanism 22 of the driven pulley 21, the first speed change shaft 45, the second speed change shaft 46, and the like constitute a speed change ratio variable mechanism.

Next, a mechanism for applying belt tension to the V-belt 15, that is, the tensioner device 50 will be described.
As described above, the pulley groove width (belt wrapping diameter) of the pulleys 11 and 21 is varied in the opposite direction by the speed change motor 40. However, the slippage between the V belt 15 and the pulleys 11 and 21 is caused by the transmission torque. Will occur. Therefore, a tensioner device 50 as shown in FIGS. 2 and 4 to 6 is provided in order to apply a belt tension sufficient to prevent the V belt 15 from slipping. The tensioner device 50 includes a tension roller 51 that presses the loose side of the V-belt 15 inward, and a swingable tensioner arm 53 that supports the tension roller 51 via a link 52. By pressing the V-belt 15 from the outside to the inside in this way, a predetermined belt tension is obtained, and the winding length of the V-belt 15 around the pulleys 11 and 21 is lengthened to increase the transmission efficiency.
Here, the tension roller 51 is attached to the tensioner arm 53 via the link 52, but it goes without saying that the tension roller 51 may be directly attached to the tensioner arm 53.
Further, the tension roller 51 is not limited to the one that presses against the V belt 15 from the outside, and may be the one that presses from the inside.

The base end of the tensioner arm 53, that is, the end opposite to the end to which the tension roller 51 is attached, is swingably attached to the transmission case 6 via a shaft 53a. A base end portion (the other end portion) of a pin 55 that is an example of a transmission member is rotatably attached to an intermediate portion of the tensioner arm 53 via a shaft 54. The shaft 54 may be provided with a wear-preventing bush. A rod-like tip portion (one end portion) 55a of the pin 55 is inserted into a hollow portion 64a of a piston rod 64 described later.

A hydraulic cylinder 60 is provided at a lower portion of the pulley chamber 6 b and corresponding to the rear surface of the tensioner arm 53. The hydraulic cylinder 60 includes a piston 63 that partitions the low pressure chamber 61 and the high pressure chamber 62, a piston rod 64 fixed to the piston 63, and a bearing portion 65 that guides the piston rod 64 in a slidable manner. The low pressure chamber 61 is connected to a drain tank 68, and the high pressure chamber 62 is supplied with control hydraulic pressure from a hydraulic control device 70 shown in FIG. By adjusting the hydraulic pressure of the high-pressure chamber 62, the rotational biasing force of the tensioner arm 53 can be controlled and adjusted to an optimum belt tension suitable for belt driving. A compression spring 66 is disposed in the high pressure chamber 62, and the piston 63 is pushed toward the low pressure chamber by the compression spring 66. Therefore, the tensioner arm 53 is urged to rotate in the direction in which the tension roller 51 presses the loose side of the V-belt 15 inward by the spring force of the compression spring 66. The spring force of the compression spring 66 is set to a spring force that can apply the minimum belt tension necessary for traveling even when the hydraulic pressure in the high-pressure chamber 62 fails.

A hollow portion 64 a is formed in the axial center portion of the piston rod 64, and the hollow portion 64 a opens at the projecting side end portion of the piston rod 64 that projects outward from the bearing portion 65. A concave-curved bush 67 is fitted on the bottom surface of the hollow portion 64a to reduce wear. The other end 55 a of the pin 55 inserted into the hollow portion 67 is formed as a convex arc surface, and this convex arc surface is in contact with the concave arc surface of the bush 67. Here, the bush 67 and the end 55a are formed as arcuate surfaces, but may be spherical. The other end portion 55a of the pin 55 is narrower than the inner diameter of the hollow portion 64a, and a predetermined gap is provided between the pin 55 and the hollow portion 64a. Therefore, even if the pin 55 is inclined with respect to the piston rod 64, the inclination can be allowed. Further, the end 55 a of the pin 55 having a convex arc surface contacts the bush 67 having a concave arc surface, so that force can be smoothly transmitted between the pin 55 and the piston rod 64. The contact portion between the pin 55 and the bush 67 is disposed within the axial range (indicated by L in FIGS. 5 and 6) of the bearing portion 65 in the entire stroke range of the piston rod 64.

As shown in FIG. 4, the hydraulic control device 70 adjusts the hydraulic pressure generated by the oil pump 71 to a constant pressure by the pressure regulating valve 72, adjusts this constant pressure by the electromagnetic valve 73, and supplies it to the high pressure chamber 62 of the hydraulic cylinder 60. By doing so, the rotational biasing force of the tensioner arm 53 is adjusted.
It is to be noted that the drain tank 68 connected to the low pressure chamber 61 is disposed above the low pressure chamber 61 and the end of the pipe connecting the low pressure chamber 61 and the tank 68 is always immersed in the oil in the tank 68. Good. The reason is that when the volume of the low pressure chamber 61 is changed by the operation of the piston 63, oil is sucked from the tank 68 by the breathing action, and the low pressure chamber 61 is always filled with oil. Therefore, the seal member 69 provided in the bearing portion 65 can be always lubricated with oil.
In this embodiment, the compression spring 66 is disposed inside the hydraulic cylinder 60 in order to apply the minimum tension to the belt 15. However, as described in Patent Document 1, the tensioner arm 53 is oscillated and biased. These springs may be arranged separately. In this case, a tension spring or a torsion spring may be used as the spring in addition to the compression spring.

The speed change motor 40 and the electromagnetic valve 73 are controlled by a controller 80 constituted by an electronic circuit. The controller 80 receives vehicle operation signals (engine speed, throttle opening, vehicle speed, shift position signal, input shaft 3 speed, output shaft 32 speed, etc.). A shift map and a tension control map are set in advance in the controller 80, and the shift motor 40 and the electromagnetic valve 73 are controlled according to the input signal and these control maps.

Here, the operation of the tensioner device 50, particularly the relationship between the piston rod 64 of the hydraulic cylinder 60 and the tensioner arm 53 will be described.
FIG. 5 shows a state in which the piston rod 64 is at the start position, and FIG. 6 shows a state in which the piston rod 64 is at the end position. The piston rod 64 and the tensioner arm 53 operate following each other. Such swinging of the tensioner arm 53 is caused by the gear ratio of the continuously variable transmission. That is, in the high speed ratio state or the low speed ratio state, the slack of the belt 15 wound around both the pulleys 11 and 21 is small, and the amount of the tension roller 51 between the pulleys 11 and 21 is small. Therefore, the tensioner arm 53 is located close to the hydraulic cylinder 60 as shown in FIG. On the other hand, in the intermediate gear ratio state, the slack of the belt 15 is increased, and the amount of depression of the tension roller 51 between the pulleys 11 and 21 is increased. Therefore, the tensioner arm 53 swings to a position away from the hydraulic cylinder 60 as shown in FIG.

Since the gear ratio of the continuously variable transmission changes frequently during traveling, the tensioner arm 53 also frequently swings between the positions of FIGS. 5 and 6, and the hydraulic cylinder 60 also operates quickly as the tensioner arm 53 swings. There is a need to. At this time, the piston 63 is pushed by the hydraulic pressure supplied to the high pressure chamber 62, and the piston rod 64 moves toward the tensioner arm 53. Therefore, the pin 55 that is in contact with the piston rod 64 on the circular arc surface is pushed, and a rotational biasing force is applied to the tensioner arm 53 via the shaft 54. Therefore, a predetermined belt tension proportional to the hydraulic pressure is applied.

Since a reaction force due to belt tension acts on the tensioner arm 53, the reaction force is transmitted to the piston rod 64 via the pin 55. That is, a force is transmitted between the pin 55 that is in contact with the circular arc surface and the bush 67 of the piston rod 64. Since the pin 55 is inserted into the hollow portion 64a of the piston rod 64 with a gap, even if there is an angle change between the pin 55 and the piston rod 64 as the tensioner arm 53 swings, the pin 55 and the hollow portion 64a There is no interference with the inner wall. In addition, since the contact point between the pin 55 and the piston rod 64 (bush 67) is always located within the axial range L of the bearing portion 65, the axial force of the pin 55 is efficiently transmitted to the piston rod 64. Thus, the bending moment hardly acts on the piston rod 64. As a result, the unbalanced load on the bearing portion 65 is reduced, wear of the bearing portion 65 and the piston rod 64 and oil leakage can be eliminated, and force transmission efficiency is improved.

The present invention is not limited to the above embodiments.
In the above embodiment, the pin 55 and the piston rod 64 are connected to each other by providing a concave arc surface on the bottom surface of the hollow portion 64a of the piston rod 64 and a convex arc surface on the end portion 55a of the pin 55. It may be reversed, or a curved surface with a constant curvature may be provided instead of the circular arc surface.
Further, the pin 55 and the piston rod 64 may be rotatably connected via an axis.
Furthermore, although the pin 55 and the tensioner arm 53 are connected via the shaft 54, the pin 55 and the tensioner arm 53 may be pivotally attached or brought into contact with each other by an uneven portion. In particular, it is effective when the pin 55 and the piston rod 64 are connected via a shaft.
In the above embodiment, the hydraulic cylinder 60 is used as the fluid pressure cylinder, but an air cylinder may be used.
In the above embodiment, the swing fulcrum of the tensioner arm is set in the transmission case on the outer peripheral side of the pulley. However, as shown in FIG. Therefore, the connecting portion between the pin and the tensioner arm does not have to be an intermediate portion of the tensioner arm, and may be one end portion of the tensioner arm.

It is an expanded sectional view of an example of a continuously variable transmission concerning the present invention. It is sectional drawing of the pulley chamber of the continuously variable transmission of FIG. FIG. 2 is a skeleton diagram of the continuously variable transmission of FIG. 1. It is the schematic which shows the control system of a tensioner apparatus. It is an enlarged view of the principal part of a tensioner apparatus. It is an enlarged view of the principal part at the time of the action | operation of a tensioner apparatus. It is the schematic of the comparative example of a tensioner apparatus. It is the schematic of the other comparative example of a tensioner apparatus.

Explanation of symbols

3 Input shaft 11 Drive pulley 15 Belt 21 Driven pulley 32 Output shaft 40 Shifting motor 50 Tensioner device 51 Tension roller 53 Tensioner arm 55 Pin (transmission member)
55a Convex arc surface end 60 Hydraulic cylinder 64 Piston rod 64a Hollow portion 65 Bearing portion 66 Spring 67 Concave arc surface bush

Claims (2)

A belt ratio is provided between the driving pulley and the driven pulley, and a gear ratio variable mechanism is provided for changing the gear ratio by changing the pulley groove widths of both pulleys in opposite directions. In a continuously variable transmission provided with a tensioner device for obtaining
The tensioner device is
A tension roller pressed against the loose side of the belt;
A tensioner arm, one end of which is swingably supported by the fixed part, and the tension roller is attached to the other end;
A fluid pressure cylinder having a piston rod that moves linearly by fluid pressure and has a hollow portion that opens to one end side, and a bearing portion that slidably guides the piston rod;
A transmission member for transmitting a force between the piston rod and the tensioner arm;
One end portion of the transmission member is inserted into the hollow portion of the piston rod with a gap, and is connected to the piston rod in the hollow portion so as to contact or turn freely,
The continuously variable transmission according to claim 1, wherein a contact portion or a connecting portion between the transmission member and the piston rod is disposed within an axial range of the bearing portion in the entire stroke range of the piston rod. A concave or convex arcuate surface is formed on the bottom surface of the hollow portion of the piston rod,
A convex or concave arc surface corresponding to the arc surface is formed at one end of the transmission member,
The continuously variable transmission according to claim 1, wherein the arc surface of the transmission member is in contact with the arc surface of the piston rod.

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