JP4605495B2 - Toroidal continuously variable transmission - Google Patents

Description

  The present invention relates to a toroidal continuously variable transmission that can be used for transmissions of automobiles and various industrial machines.

  FIG. 3 shows an example of a conventional toroidal continuously variable transmission that can be used as a transmission for an automobile. This toroidal type continuously variable transmission is a so-called double cavity type high torque toroidal type continuously variable transmission. Two input side disks 2 and 2 and two output side disks 3 and 3 are connected to the input shaft 1. It is attached to the outer periphery. An output gear 4 is rotatably supported on the outer periphery of the intermediate portion of the input shaft 1. Output side discs 3 and 3 are connected to cylindrical flange portions 4a and 4a provided at the center of the output gear 4 by spline engagement.

  The input shaft 1 is rotationally driven by a drive shaft 22 on the engine side via a loading cam type pressing device 12 provided between the input side disk 2 and the cam plate 7 located on the left side in the drawing. It is like that. Further, the output gear 4 is supported in the housing 14 via a partition wall 13 formed by coupling two members, whereby the output gear 4 can be rotated around the axis O, while the displacement in the axis O direction is reduced. It is blocked.

  The output side disks 3 and 3 are supported by needle bearings 5 and 5 interposed between the input shaft 1 so as to be rotatable about the axis O of the input shaft 1. Further, the input side disks 2 and 2 are supported on both ends of the input shaft 1 via ball splines 6 and 6 so as to rotate together with the input shaft 1. Further, as shown in FIG. 4, the power roller 11 is freely rotatable between the inner surfaces (concave surfaces) 2a, 2a of the input side disks 2, 2 and the inner surfaces (concave surfaces) 3a, 3a of the output disks 3, 3. Is sandwiched between.

  A first disc spring 8 is provided between the input side disk 2 and the cam plate 7 located on the left side in FIG. 3, and between the input side disk 2 and the loading nut 9 located on the right side in FIG. Is provided with a second disc spring 10. These disc springs 8 and 10 include concave surfaces 2a, 2a, 3a and 3a of the disks 2, 2, 3 and 3 and peripheral surfaces (traction surfaces) 11a and 11a of the power rollers 11 and 11 (see FIG. 4). A pressing force is applied to the contact portion.

  Therefore, in the continuously variable transmission configured as described above, when rotational force is input from the drive shaft 22 to the input side disk 2 located on the left side via the pressing device 12, the input side located on the right side via the input shaft 1 is input. The rotational force is also transmitted to the disk 2, and the rotation is transmitted to the output side disks 3, 3 by the power rollers 11, 11 at a constant speed ratio. The rotation of the output side disks 3 and 3 is transmitted from the output gear 4 to the output shaft 17 via the transmission gear 15 and the transmission shaft 16.

  By the way, in such a toroidal type continuously variable transmission, power is transmitted by the shearing force of oil between the input / output side disks 2 and 3 and the power roller 11. Therefore, it is necessary to apply a large load to the contact point between the input / output side disks 2 and 3 and the power roller 11.

  As a method of applying the load, there are a case where the above-described loading cam type pressing device 12 that mechanically generates a load proportional to an input torque and a case where a hydraulic type pressing device is used (for example, Patent Documents). 1). When only the loading cam type pressing device 12 is used, a thrust (pushing force of the input side disk) proportional to only the input torque is generated. Therefore, depending on the gear ratio, the contact portion between the disk and the roller may be excessive. May cause a reduction in transmission efficiency and durability. On the other hand, when a hydraulic pressing device is used, an optimum pressing force can be applied in accordance with the speed change, the oil temperature, the rotation speed, etc., so that the transmission is more efficient than the loading cam type pressing device. It becomes possible.

  Further, in the toroidal type continuously variable transmission, a certain preload is also required. Therefore, in a loading cam type pressing device, a disc spring is often provided in order to generate a predetermined pressing force. On the other hand, in the hydraulic pressing device, the minimum pressing force can be given by determining the minimum hydraulic pressure. However, it is considered that the hydraulic pressure may not catch up at the start of the engine, etc. Thus, an initial preload is applied (see, for example, Patent Document 2).

JP 2001-12573 A Japanese Patent Laid-Open No. 2003-21111

  As described above, when an initial preload is applied by an elastic member in a hydraulic pressing device, it is necessary to pay attention to the relationship between the thrust generated by the pressing device and the thrust generated by the elastic member. If these relationships form a parallel relationship, that is, if the thrust relationship is set so that the elastic member expands as the supply pressure to the pressing device increases, the change in load by the elastic member is large. turn into. For this reason, if the oil pressure is not determined in anticipation of the load, the efficiency is reduced due to an excessive load, or slipping due to an excessive load occurs. Further, since the amount of deflection of the elastic member is large, fatigue failure of the spring is also a problem. Furthermore, if the elastic member is extended too much, the elastic member may fall off the mounting position. In such a case, when the thrust of the pressing device is reduced, the required thrust setting value can be generated. There is a risk of disappearing.

  The present invention has been made in view of the above circumstances, and is a toroidal stepless machine including a hydraulic pressing device capable of appropriately applying a predetermined preload by an elastic member without causing an excessive change in thrust. An object is to provide a transmission.

  In order to achieve the above object, a toroidal continuously variable transmission according to claim 1 includes an input shaft to which a rotational force from an engine is input, and an input side that is coupled to the input shaft and rotates integrally with the input shaft. An output-side disk that receives the rotational force of the input-side disk at a predetermined speed ratio via a power roller provided between the disk and the input-side disk; and the input-side disk disposed on the back surface of the input-side disk A hydraulic pressing device that presses the shaft in the axial direction, and the pressing device includes a first cylinder portion that is provided integrally with the input shaft, and a second portion that is provided integrally with the input side disk. And a first piston part and a second piston part disposed between the first cylinder part and the second cylinder part so as to be movable in the axial direction. The first piston part comprises: 1st hydraulic pressure between 1 cylinder part And the second piston part forms an air chamber with the first piston part, and forms a second hydraulic chamber with the second cylinder part, and enters the first hydraulic chamber. With the introduction of the oil, the first piston part and the first cylinder part move in the axial direction so as to be separated from each other, the first piston part comes into contact with the second cylinder part, and the second A toroidal-type continuously variable transmission in which the second piston portion and the second cylinder portion move in the axial direction so as to be separated from each other in accordance with the introduction of oil into the hydraulic chamber. An elastic member for applying a preload is interposed between the first cylinder portion and the second cylinder portion.

  In the toroidal-type continuously variable transmission according to claim 1, the thrust of the elastic member serves as a preload, but even when oil is supplied to the first hydraulic chamber and the second hydraulic chamber to increase the pressing force. Since the first piston part and the second cylinder part come into contact with each other, the amount of compression of the elastic member is limited (the elastic member is prevented from being excessively contracted), so that the change in thrust can be kept small. That is, it is possible to suppress a change in the pressing force, and it is possible to prevent the thrust from the pressing device from becoming excessive or excessive. As a result, it is possible to prevent the efficiency and durability of the toroidal-type continuously variable transmission from decreasing. Moreover, since the amplitude of the elastic member becomes small, it is possible to suppress fatigue of the elastic member.

  The toroidal type continuously variable transmission according to claim 2 is the toroidal type continuously variable transmission according to claim 1, wherein the elastic member is disposed in a state of being in constant contact with the input side disk. It is characterized by.

  In the toroidal-type continuously variable transmission according to claim 2, since the elastic member is always in contact with the input side disk, the axial dimension of the pressing device can be kept small. It is possible to reduce the size of the device (prevent the increase in size of the pressing device).

According to a third aspect of the present invention, there is provided a toroidal-type continuously variable transmission including an input shaft to which rotational force from an engine is input, an input side disk coupled to the input shaft and rotating integrally with the input shaft, and an input side disk An output side disk that receives the rotational force of the input side disk at a predetermined speed ratio via a power roller provided between the input side disk and the back side of the input side disk and presses the input side disk in the axial direction. A hydraulic pressing device, wherein the pressing device includes a first cylinder portion provided integrally with the input shaft, a second cylinder portion provided integrally with the input side disk, The first and second piston portions are arranged between the first cylinder portion and the second cylinder portion so as to be movable in the axial direction. The first piston portion is connected to the first cylinder portion. A first hydraulic chamber is formed between them and a second pin is formed. The ton portion forms an air chamber with the first piston portion and a second hydraulic chamber with the second cylinder portion. With the introduction of oil into the first hydraulic chamber, The first piston part and the first cylinder part move in the axial direction so as to be separated from each other, and the first piston part comes into contact with the second cylinder part, so that the oil into the second hydraulic chamber A toroidal-type continuously variable transmission that moves in the axial direction so that the second piston portion and the second cylinder portion are separated from each other with the introduction of the input shaft and the second cylinder in the air chamber. An elastic member for applying a preload is interposed between the piston and the piston.

  In the toroidal-type continuously variable transmission according to claim 3, the thrust of the elastic member serves as a preload, but even when the pressure is increased by supplying oil into the first hydraulic chamber and the second hydraulic chamber. Since the first piston part and the second cylinder part come into contact with each other, the amount of compression of the elastic member is limited (the elastic member is prevented from being excessively contracted), so that the change in thrust can be kept small. That is, it is possible to suppress a change in the pressing force, and it is possible to prevent the thrust from the pressing device from becoming excessive or excessive. As a result, it is possible to prevent the efficiency and durability of the toroidal-type continuously variable transmission from decreasing. Moreover, since the amplitude of the elastic member becomes small, it is possible to suppress fatigue of the elastic member.

  In the toroidal continuously variable transmission pressing device according to the present invention, even when the pressing force is increased, the compression amount of the preload elastic member is limited by the contact between the first piston portion and the second cylinder portion. Is done. Therefore, a predetermined preload can be appropriately given by the elastic member without causing an excessive change in thrust.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The feature of the present invention lies in the preload application configuration in the hydraulic pressing device, and the other configurations and operations are the same as the conventional configurations and operations described above. Therefore, only the features of the present invention will be described below. Reference is made to the other parts, and the same reference numerals as those in FIGS.

  FIG. 1 shows a cross-sectional view of a main part (a peripheral part of a pressing device) of a toroidal type continuously variable transmission according to an embodiment of the present invention. The toroidal continuously variable transmission according to the present embodiment is a so-called double cavity type high torque toroidal continuously variable transmission, and includes two input side disks 2 and two output side disks (see FIG. 3). It is attached to the outer periphery of the input shaft 1 (FIG. 1 shows only the input side disk 2 on the input side to which power is input from the engine (prime mover)). A power roller is interposed between the input side disk 2 and the output side disk to transmit the rotational force of the input side disk 2 to the output side disk at a predetermined speed ratio. An output gear is rotatably supported on the outer periphery of the intermediate portion of the input shaft 1 as in the conventional configuration shown in FIG. The output side disk is connected by spline engagement to a cylindrical flange portion provided at the center of the output gear. The configuration on the power output side is the same as the configuration in FIG.

  Between the input shaft 1 and an unillustrated engine-side drive shaft 22 (see FIG. 3), a power transmission portion 52 as a coupling portion is provided. A hydraulic pressing device 30 that presses the input side disk 2 in the axial direction is provided on the back surface 2b of the input side disk 2 (input side disk 2 shown in FIG. 1) located on the input side of the input shaft 1. ing. The pressing device 30 includes a first cylinder part 41 integral with the input end 1a of the input shaft 1, a second cylinder part 59 integral with the input side disk 2, and a first annular body (first piston). Part) 61 and a second annular body (second piston part) 60.

  The first cylinder part 41 is engaged with the outer periphery of the second cylinder part 59, and is arranged in a state of facing the back surface 2 b of the input side disk 2. The second cylinder part 59 is formed in a cylindrical shape and extends from the outer peripheral edge of the input side disk 2 toward the first cylinder part 41.

  The second annular body 60 has an inner peripheral surface fitted to the outer peripheral surface of the input shaft 1, and an outer peripheral surface fitted to the inner peripheral surface of the second cylinder part 59. It is arranged in a state facing the back surface 2b of the. The first annular body 61 has an inner peripheral surface fitted to the outer peripheral surface of the input shaft 1, and an outer peripheral surface fitted to the inner peripheral surface of the first cylinder portion 41, The annular body 60 and the first cylinder part 41 are arranged.

  A space surrounded by the inner surface of the first cylinder portion 41, the first annular body 61, and a part of the outer peripheral surface of the input shaft 1 constitutes a first hydraulic chamber (oil chamber) 70. . The first hydraulic chamber 70 is kept fluid tight (liquid tight and air tight) by seal members 71 and 72 attached to the outer peripheral portion and the inner peripheral portion of the first annular body 61. In addition, the space surrounded by the inner peripheral surface of the second cylinder part 59, the second annular body 60, the back surface 2b of the input side disk 2, and a part of the outer peripheral surface of the input shaft 1 is a second space. The hydraulic chamber (oil chamber) 67 is configured. The second hydraulic chamber 67 is kept fluid tight by a seal member 68 attached to the outer periphery of the second annular body 60. In addition, on the inner peripheral side of the second cylinder part 59, a space 75 located between the second annular body 60 and the first annular body 61 is an air chamber. The air chamber 75 is kept fluid-tight by a plurality of seal members 68 and 72. The second cylinder 59 has a gap S that functions as a communication groove for communicating the air chamber 75 to the outside. The second cylinder 59 has the first annular body 61 through which the first cylinder 61 is connected. It can come into contact with the annular body 61. A disc spring 100 for applying a preload is interposed between the first annular body 61 and the second cylinder portion 59. In this case, the disc spring 100 is arranged in a state in which it is always in contact with the second cylinder portion 59 by the preload adjusting plate 102.

  In order to supply oil to each of the hydraulic chambers 67 and 70, an oil passage is formed in the drive shaft 22 on the engine side. Specifically, an inner hole 1 b coaxial with the axis O is formed in the input end 1 a of the input shaft 1 along the longitudinal direction, and a drive shaft coupled to the input shaft 1 is formed in the inner hole 1 b. 22 extension parts are inserted and inserted. The extending portion is formed with an oil passage extending along the longitudinal direction and an oil hole extending in the radial direction so as to be orthogonal to the oil passage. The input shaft 1 is formed with oil holes 82 and 80 that connect the oil holes and the hydraulic chambers 67 and 70, respectively.

  The first oil hole 80 that communicates with the first hydraulic chamber 70 extends in the radial direction so as to be orthogonal to the axis O of the input shaft 1, and the second oil hole 82 that communicates with the second hydraulic chamber 67. Extends obliquely with respect to the axis O of the input shaft 1.

  In such a configuration, when pressure oil is supplied into the second hydraulic chamber 67, the pressure oil is applied to the input side disk in a direction in which the second annular body 60 and the back surface 2 b of the input side disk 2 are separated from each other. Move 2a. Thereby, the input side disk 2 is pressed toward the output side disk. On the other hand, when pressure oil is supplied into the first hydraulic chamber 70, the pressure oil moves the first cylinder portion 41 in a direction in which the first annular ring 61 and the first cylinder portion 41 are separated from each other. . As a result, the input shaft 1 integrated with the first cylinder portion 41 moves to the engine side, and the input side disk 2 on the opposite side located far from the engine is moved via the loading nut 9 (see FIG. 3). It is pressed toward the output side disk. Thus, the traction portions of the respective power rollers are brought into rolling contact with both the input / output side disks 2 and 3, and the rotational driving force of the input side disk 2 is transmitted to the output side disk 3 at a desired reduction ratio.

  Further, at the time of such a pressing operation (when pressure oil is supplied into the first hydraulic chamber 70 and the second hydraulic chamber 67), the first annular body 61 is filled with the second gap S so as to fill the gap S. The disc spring 100 interposed between the second cylinder portion 59 and the second cylinder portion 59 is compressed, but the first annular body 61 and the second cylinder portion 59 abut against each other. The amount of compression of the spring 100 is limited to the length corresponding to the gap S.

  As described above, in the present embodiment, the disc spring 100 as an elastic member for applying a preload is interposed between the first annular body 61 and the second cylinder portion 59. Even when oil is supplied into the hydraulic chamber 70 and the second hydraulic chamber 67 to increase the pressing force, the first annular body 61 and the second cylinder portion 59 come into contact with each other, so that the disc spring 100 Since the amount of compression is limited (the disc spring 100 is prevented from being excessively contracted), the change in thrust can be suppressed to a small level. That is, it is possible to suppress a change in the pressing force, and it is possible to prevent the thrust from the pressing device from becoming excessive or excessive. As a result, it is possible to prevent the efficiency and durability of the toroidal-type continuously variable transmission from decreasing. In addition, since the amplitude of the disc spring 100 is reduced, fatigue of the disc spring 100 can be suppressed.

  Moreover, in this embodiment, since the disc spring 100 is arrange | positioned in the state always contacted with respect to the input side disk 2 (2nd cylinder part 59), the axial direction dimension of a press apparatus can be restrained small, The pressing device can be reduced in size (preventing an increase in the size of the pressing device).

FIG. 2 shows a cross-sectional view of a main part (a peripheral part of the pressing device) of a toroidal type continuously variable transmission according to another embodiment of the present invention.
In the embodiment of FIG. 1 described above, a disc spring 100 for applying preload and a preload adjusting plate 102 are interposed between the first annular body 61 and the second cylinder portion 59. However, in the present embodiment, instead of this, in the air chamber 75, the disc spring 100 for applying a preload between the step portion of the input shaft 1 and the second annular body 60 and the preload adjustment are provided. A plate 102 is inserted. The other configuration of the present embodiment is the same as the configuration of the embodiment of FIG.

In the present embodiment, at the time of pressing operation (when pressure oil is supplied into the first hydraulic chamber 70 and the second hydraulic chamber 67), it is inserted between the input shaft 1 and the second annular body 60. The disc spring 100 is compressed. However, since the first annular body 61 and the second cylinder portion 59 abut, the compression amount of the disc spring 100 is such that the first annular body 61 and the second cylinder 59 are compressed. Only the length of the gap S between the two stays.
As described above, in the present embodiment, the disc spring 100 as an elastic member for applying a preload is inserted between the input shaft 1 and the second annular body 60, but in the first hydraulic chamber 70 and Even when oil is supplied into the second hydraulic chamber 67 to increase the pressing force, the compression amount of the disc spring 100 is limited by the contact between the first annular body 61 and the second cylinder portion 59. (The plate spring 100 is prevented from being excessively contracted), so that the change in thrust can be suppressed small. Moreover, in this Embodiment, the freedom degree of design of the disc spring 100 becomes high.

  The present invention can be applied to a full toroidal continuously variable transmission that does not have a trunnion, in addition to a half-toroidal continuously variable transmission such as a double cavity type.

It is a principal part expanded sectional view of the toroidal type continuously variable transmission which concerns on embodiment of this invention. It is a principal part expanded sectional view of the toroidal type continuously variable transmission which concerns on other embodiment of this invention. It is sectional drawing of the conventional double cavity type toroidal type continuously variable transmission. FIG. 3 is an enlarged cross-sectional view of the toroidal continuously variable transmission of FIG. 2 clearly showing an enlarged state in which a power roller is provided between an input side disk and an output side disk.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Input side disk 3 Output side disk 11 Power roller 30 Pressing device 41 1st cylinder part 59 2nd cylinder part 60 2nd annular body (2nd piston part)
61 1st annular body (1st piston part)
67 Second hydraulic chamber 70 First hydraulic chamber 100 Belleville spring (elastic member)

Claims (3)

  The input shaft is connected to the input shaft through which a rotational force from the engine is input, the input disc coupled to the input shaft and rotating integrally with the input shaft, and a power roller provided between the input disc. An output-side disk that receives a rotational force at a predetermined speed ratio; and a hydraulic-type pressing device that is disposed on a back surface of the input-side disk and presses the input-side disk in an axial direction. A first cylinder part provided integrally with the shaft, a second cylinder part provided integrally with the input side disk, and an axial direction between the first cylinder part and the second cylinder part The first and second piston portions are movably disposed in the first piston portion. The first piston portion forms a first hydraulic chamber between the first cylinder portion and the second piston portion. Forms an air chamber between the first piston part In addition, a second hydraulic chamber is formed between the second cylinder portion and the first piston portion and the first cylinder portion are separated from each other with the introduction of oil into the first hydraulic chamber. And the first piston part comes into contact with the second cylinder part, and with the introduction of oil into the second hydraulic chamber, the second piston part and the second cylinder part Are toroidal-type continuously variable transmissions that move in the axial direction so as to be separated from each other, and an elastic member for applying a preload is interposed between the first piston and the second cylinder part. A toroidal-type continuously variable transmission.   The toroidal continuously variable transmission according to claim 1, wherein the elastic member is arranged in a state in which the elastic member is always in contact with the input side disk. The input shaft is connected to the input shaft through which a rotational force from the engine is input, the input disc coupled to the input shaft and rotating integrally with the input shaft, and a power roller provided between the input disc. An output-side disk that receives a rotational force at a predetermined speed ratio; and a hydraulic-type pressing device that is disposed on a back surface of the input-side disk and presses the input-side disk in an axial direction. A first cylinder part provided integrally with the shaft, a second cylinder part provided integrally with the input side disk, and an axial direction between the first cylinder part and the second cylinder part The first and second piston portions are movably disposed in the first piston portion. The first piston portion forms a first hydraulic chamber between the first cylinder portion and the second piston portion. Forms an air chamber between the first piston part In addition, a second hydraulic chamber is formed between the second cylinder portion and the first piston portion and the first cylinder portion are separated from each other with the introduction of oil into the first hydraulic chamber. And the first piston part comes into contact with the second cylinder part, and with the introduction of oil into the second hydraulic chamber, the second piston part and the second cylinder part Are toroidal-type continuously variable transmissions that move in the axial direction so as to be separated from each other, and an elastic member for applying a preload is interposed between the input shaft and the second piston in the air chamber. A toroidal-type continuously variable transmission characterized by the above.

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