JP2016211708A - Toroidal-type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fletching abrasion based on the elastic deformation of an input-side disc in an axial direction caused by the thrust of a pressing device while securing assembling workability.SOLUTION: A female spline part 13a is formed at an axial intermediate part out of an internal peripheral face of an input-side disc 2f, and a dis-side fitting face part 30 is formed at an axial outside end part. A male spline part 14a and a shaft-side fitting face part 31 are formed at an external peripheral face of an input rotating shaft 1b. Then, the female spline part 13 is spline-engaged with the male spline part 14a, and the disc-side fitting face part 30 is pressure-inserted into the shaft-side fitting face part 31. An interference between the disc-side fitting face part 30 and the shaft-side fitting face part 31 is set to a magnitude by which the input-side disc 2f is relatively displaced in an axial direction with respect to the input-side rotating shaft 1b by an elastic force which is exerted by a preload spring 11d.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an improvement in a toroidal continuously variable transmission that is used as a transmission for an automobile or an aircraft, or as a transmission for adjusting the operating speed of various industrial machines such as a pump.

  The use of a toroidal-type continuously variable transmission as an automobile transmission is described in, for example, publications such as Patent Document 1 and is partially implemented. A structure in which the adjustment range of the gear ratio is widened by combining a toroidal continuously variable transmission and a planetary gear mechanism has been described in publications such as Patent Document 2 and the like.

  FIG. 8 shows a first example of a conventional structure of a toroidal type continuously variable transmission described in each of these patent documents and conventionally known. In the case of the first example of this conventional structure, a pair of input-side discs 2a and 2b are disposed around the axially opposite ends of the input rotation shaft 1, and the inner side surfaces, each of which is a toroidal curved surface, face each other. These are supported via the ball splines 3 and 3 so as to be able to move forward and backward and to rotate in synchronization with the input rotary shaft 1. Further, an output cylinder 4 is supported around an intermediate portion in the axial direction of the input rotary shaft 1 so as to be able to rotate relative to the input rotary shaft 1. Further, an output gear 5 is fixed to the outer peripheral surface of the output cylinder 4 at the center in the axial direction, and a pair of output side disks 6 and 6 are connected to both ends in the axial direction by spline engagement. Rotation synchronized with 4 is supported. Further, in this state, the side surfaces of the two output side disks 6 and 6, each of which is a toroidal curved surface, are opposed to the inner side surfaces of the two input side disks 2a and 2b.

  Further, a plurality of power rollers 7 and 7 each having a spherical convex surface are sandwiched between the input disks 2a and 2b and the output disks 6 and 6. The power rollers 7 and 7 are rotatably supported by the trunnions 8 and 8, respectively, and rotate from the two input side disks 2a and 2b while rotating with the rotation of the two input side disks 2a and 2b. Power is transmitted to both output side disks 6, 6. That is, when the toroidal-type continuously variable transmission is operated, the drive shaft 9 rotates one input disk 2a (left side in FIG. 8) via the pressing device 10 (the structure shown is a loading cam type pressing device). To drive. As a result, the pair of input side disks 2a, 2b supported at both axial ends of the input rotating shaft 1 rotate synchronously while being pressed in a direction approaching each other. The rotation is transmitted to the output side disks 6 and 6 through the power rollers 7 and 7 and is taken out from the output gear 5.

  Also, preload springs 11a and 11b, each of which is a disc spring or the like having a large elasticity, are provided at positions where both the input side disks 2a and 2b are sandwiched from both sides in the axial direction in the vicinity of both axial ends of the input rotary shaft 1. Yes. Even when the pressing device 10 is not in operation (when the drive shaft 9 is stopped), the peripheral surfaces of the power rollers 7 and 7 and the side surfaces of the input side and output side disks 2a, 2b, and 6 are provided. The surface pressure of the rolling contact part (traction part) can be secured to the minimum necessary. Therefore, these rolling contact portions start power transmission without causing excessive slip immediately after the start of operation of the toroidal continuously variable transmission. The elasticity for securing the minimum necessary surface pressure is obtained by a preload spring 11 a disposed on the inner diameter side of the pressing device 10. The preload spring 11b disposed between the loading nut 12 screwed to the tip of the input rotary shaft 1 and the outer surface of the input side disk 2b alleviates the impact applied when the pressing device 10 is suddenly operated. It can be omitted. In the case where the preload spring 11b is provided, a sufficiently large elasticity is provided (so as not to be completely crushed even when a large torque is transmitted).

  In the case of the toroidal-type continuously variable transmission as described above, the work of adjusting the elasticity of the preload spring 11a for ensuring the necessary minimum surface pressure is troublesome. That is, in the case of the first example of the conventional structure, it is necessary to adjust the elasticity of the preload spring 11a by changing the tightening amount of the loading nut 12 screwed to the tip end portion of the input rotary shaft 1. It is.

  On the other hand, Patent Document 3 and the like describe a structure using a locking ring called a cotter instead of a loading nut. 9 to 12 show a second example of a conventional structure incorporating such a locking ring. In the second example of this conventional structure, of the pair of input disks 2c and 2d, the input side disk 2d disposed on the front end side of the input rotation shaft 1a is connected to the axially intermediate portion or outer end portion of the inner peripheral surface. A female spline portion 13 is formed in a range extending over (the right end portion in FIGS. 9 to 11), and the female spline portion 13 is engaged with a male spline portion 14 formed on the outer peripheral surface of the input rotary shaft 1a. Match. In addition, a locking groove 15 is formed over the entire circumference on the outer peripheral surface of the tip end portion of the input rotating shaft 1a at a portion that is axially removed from the male spline portion 14, and a plurality of locking grooves 15 are formed in the locking groove 15. The radially inner half of the locking ring 16 made up of (2 to 4) partially arcuate elements is locked. Then, a portion near the radially outer end of the side surface (the left side surface in FIGS. 9 to 10) of the locking ring 16 is brought into contact with the radially inner end portion of the outer side surface of the input side disk 2d.

  Further, when the pressing device 10a (the illustrated structure is a hydraulic pressing device) is not in operation, the peripheral surfaces of the power rollers 7, 7 (see FIG. 8) and the inner surfaces of the input and output disks 2c, 2d, 6a Adjustment of the elasticity of the preload spring 11c in order to ensure the necessary minimum surface pressure of the rolling contact portion is achieved by selecting the locking ring 16 having an appropriate axial thickness dimension. . Further, a retaining ring 17 having an L-shaped cross section is externally fitted to the tip of the input rotating shaft 1a, and the inner peripheral surface of the retaining ring 17 is brought into contact with or close to the outer peripheral surface of the locking ring 16. The locking ring 16 (each element constituting the locking ring 16) is prevented from coming out of the locking groove 15. Such a retaining ring 17 prevents axial displacement by a retaining ring 18 that is engaged with the tip of the input rotary shaft 1a.

  With the configuration as described above, the input side disk 2d is supported on the input rotary shaft 1a so as to freely rotate in synchronization with the input rotary shaft 1a. In the case of the second example of the conventional structure, the entire toroidal type continuously variable transmission is reduced in size and weight by using an integrated output side disk 6a. However, since the structure and operation of this portion are not related to the gist of the present invention, detailed description thereof is omitted.

  In the case of the toroidal-type continuously variable transmission according to the second example of the conventional structure as described above, during operation, the input side disk 2d disposed on the distal end side of the input rotary shaft 1a has a thrust generated by the pressing device 10a. As shown in an exaggerated manner in FIG. 13, based on the force received from each of the power rollers 7 and 7 based on the above, the direction closer to the outer diameter of the input side disk 2d (axial direction) approaches the locking ring 16 side. It is elastically deformed. That is, the force applied to the input side disk 2d based on the thrust during operation is about several tens kN to hundreds tens kN (several tF to several tens tF) at the maximum during operation of the toroidal type continuously variable transmission. The amount of elastic deformation in the axial direction of the input side disk 2d based on the force is a comma number of mm (a few tenths of a millimeter) and cannot be ignored. When the input side disk 2d is elastically deformed in the axial direction in this way, the outer side surface of the input side disk 2d and the side surface of the locking ring 16 are repeatedly abutted against each other to rub against each other. May cause fretting wear.

  In particular, the circumferential position at which the input side disk 2d is elastically deformed always changes as the portions pressed by the power rollers 7 and 7 change. For this reason, the frequency of the rubbing becomes considerably high (for example, hundreds of tens Hz), which is a severe condition in terms of occurrence of fretting wear. Further, in the case of the second example of the conventional structure, since the female spline portion 13 is provided in a range extending from the axially intermediate portion to the outer end portion of the inner peripheral surface of the input side disc 2d, the input side disc 2d. Are elastically deformed, the axially outer end edge of each female spline groove constituting the female spline portion 13 (the right end edge in FIGS. 9, 10 and 13) and the side surface of the locking ring 16 (FIG. 9). 10 and the left side surface of 13 and 13) repeatedly and abut against each other, and the outer edge of each female spline groove may tend to bite into the side surface of the locking ring 16. Therefore, it is a severe condition in which fretting wear is likely to occur. Such fretting wear may become a starting point of damage such as peeling, or the generated wear powder may contaminate the lubricating oil (traction oil), resulting in poor lubrication of each part.

JP 2003-214516 A JP 2004-169719 A JP 2000-205361 A

  In view of the circumstances as described above, the present invention provides a structure capable of preventing fretting wear between the outer disk and the locking member based on the thrust generated by the pressing device. The invention was invented to ensure the assembly workability of the machine.

The toroidal continuously variable transmission of the present invention includes a rotating shaft, a pair of outer disks, an inner disk, a plurality of power rollers, a pressing device, a preload applying member, and a locking member.
Both of these outer disks are supported in a freely rotating manner in synchronism with the rotating shaft at both ends of the rotating shaft in a state in which the respective axial side surfaces of each of the outer disks are arc-shaped. Has been.
In addition, the inner disk has a circular arc cross section around the axially intermediate portion of the rotating shaft, with the axially opposite sides facing the one axial side surface of the outer disks. It is supported by relative rotation freely, and is formed by integrating a single element or a pair of elements.
Each of the power rollers is supported by a swinging displacement centering on a pivot that is twisted with respect to the rotating shaft, and each circumferential surface having a spherical convex surface is formed on both side surfaces in the axial direction of the inner disk. And abutted against one side surface in the axial direction of the both outer disks.
For this purpose, with respect to the axial direction, a plurality of each is provided between the axial side surfaces of the inner disk and the axial side surfaces of the outer disks, and the pivot is located at a position twisted with respect to the rotational axis. Each of the power rollers can be rotatably supported by a support member (trunnion) that is provided with swinging displacement.
The pressing device is provided between the rotating shaft and one outer disk of the two outer disks, and the one outer disk faces the other outer disk of the two outer disks. Press. As such a pressing device, a mechanical or hydraulic structure can be adopted.
The preload applying member is provided between the rotating shaft and the one outer disk, and presses the one outer disk toward the other outer disk in the axial direction. Thus, even when the pressing device does not generate a pressing force, the both outer disks are pressed against the inner disk, and the rolling contact between the peripheral surfaces of the power rollers and the side surfaces of the outer disks and the inner disks is achieved. A surface pressure is applied to the part (traction part). As such a preload applying member, for example, a spring such as a disc spring or a coil spring, or an elastic member such as rubber can be used.
Further, the locking member is locked to an end portion (tip portion) on the side where the other outer disk is disposed in the axial direction of the rotating shaft, and the other outer disk is the one outer disk. Is prevented from moving in the direction away from the axial direction.

In particular, in the case of the toroidal type continuously variable transmission according to the present invention, a part in the axial direction of the inner peripheral surface of the other outer disk (for example, the female spline portion or the inner peripheral surface side uneven portion of the female serration portion) A part in the axial direction of the outer peripheral surface of the rotating shaft (for example, an outer peripheral surface side uneven portion such as a male spline portion or a male serration portion) is engaged so as not to be relatively rotatable by, for example, an uneven engagement. Yes.
At the same time, the axially other side (locking member side) of the inner peripheral surface of the other outer disk, which is engaged with the outer peripheral surface of the rotating shaft so as not to be relatively rotatable (inner peripheral surface side uneven portion). A portion (outer peripheral surface side uneven portion) engaged with the inner peripheral surface of the other outer disk in the axial direction in the outer peripheral surface of the rotating shaft and the locking member. It press-fits directly or via another member between the locked parts.
With such a structure, the other outer disk is supported with respect to the rotating shaft so as to freely rotate in synchronization with the rotating shaft (allowing transmission of power between the other outer disk and the rotating shaft). ing.
Furthermore, in the case of the toroidal-type continuously variable transmission according to the present invention, the preload is determined by the size of the tightening margin at the press-fitting portion between the inner peripheral surface of the other outer disk and the outer peripheral surface of the rotary shaft. Based on the elasticity exerted by the imparting member, the other outer disk is restricted to a size that allows the other outer disk to be displaced in the axial direction relative to the rotating shaft (the rotating shaft can be pulled out from the outer disk in the axial direction). ing.

When implementing the toroidal type continuously variable transmission according to the present invention, for example, a locking ring called a cotter can be used as the locking member. This locking ring is formed as a whole by combining a plurality of (for example, 2 to 4) partial arc-shaped elements, and is engaged with a locking groove formed on the rotating shaft. Stopped. Then, the locking ring has a portion close to the outer diameter on the side surface in the axial direction (a portion exposed from the locking groove) abutting against (abuts) the other side surface in the axial direction of the other outer disk, The other outer disk is prevented from being displaced away from the one outer disk.
Alternatively, a loading nut can be used as the locking member. The loading nut is further screwed into a male thread formed at the end of the rotating shaft. Then, the loading nut is brought into contact with (abuts) the other axial side surface of the other outer disk, either directly or via another member (a preload spring or the like). Is prevented from moving away from the one outer disk.

According to the toroidal type continuously variable transmission of the present invention configured as described above, fretting wear occurs between the outer disk (the other outer disk) and the locking member based on the thrust generated by the pressing device. A structure that can prevent this can be achieved while ensuring the assembly workability of the toroidal type continuously variable transmission.
That is, in the case of the present invention, of the inner peripheral surface of the outer disk, a portion adjacent to the other side in the axial direction (locking member side) of the portion engaged with the outer peripheral surface of the rotating shaft so as not to be relatively rotatable. Directly between the portion of the outer peripheral surface of the rotating shaft engaged with the inner peripheral surface of the outer disk in a non-rotatable manner with respect to the axial direction and the portion where the locking member is locked. Or it press-fits through another member.
For this reason, the support rigidity with respect to the said rotating shaft of the axial direction other end part (end part by the side of a locking member) among the said outer side disks can be made high. Further, the rigidity in the reduced diameter direction of the other axial end portion of the inner peripheral surface of the outer disk can be increased. Therefore, based on the thrust generated by the pressing device, it is possible to suppress the tendency of the other end portion in the axial direction of the inner peripheral surface of the outer disk to be elastically deformed in the direction of reducing the diameter. It is possible to suppress elastic deformation of the outer disk near the outer diameter in the axial direction (the amount of elastic deformation of the outer disk in the axial direction can be reduced). As a result, it can be prevented that the other side surface of the outer disk and the side surface of the locking member are rubbed against each other and significant fretting wear occurs on both side surfaces.

  Further, in the case of the present invention, an end edge of a portion that is formed on a part of the inner peripheral surface of the outer disk in the axial direction and engages with the outer peripheral surface of the rotating shaft so as not to rotate relative to the outer peripheral surface; Are separated from each other in the axial direction. Therefore, even if the outer disk is elastically deformed in the axial direction based on the thrust generated by the pressing device, the end edge does not tend to bite into the side surface of the locking member. Also from this surface, fretting wear can be prevented from occurring between the outer disk and the locking member.

  Further, in the case of the present invention, the size of the tightening allowance in the press-fitting portion between the inner peripheral surface of the outer disk and the outer peripheral surface of the rotating shaft is based on the elasticity exerted by the preload applying member, The outer disk is restricted to a size that allows the outer disk to be displaced relative to the rotating shaft in the axial direction (the input rotating shaft is pulled out of the input disk). For this reason, during the assembly work of the toroidal type continuously variable transmission, the outer disk is directed toward the locking member based on the elasticity exerted by the preload applying member without strictly managing the assembly position of the outer disk. The outer disk can be positioned by pressing it. Therefore, according to the present invention, the assembly workability of the toroidal type continuously variable transmission can be improved.

Sectional drawing of the toroidal type continuously variable transmission which shows the 1st example of embodiment of this invention. FIG. 2 is an end view showing the state seen from the left side of FIG. 1. The left part enlarged view of FIG. 1 similarly. The X section enlarged view of FIG. 1 similarly. Similarly, a cross-sectional view (A) showing the state of the inner end in the axial direction, and a cross-sectional view (B) showing the state of the intermediate portion in the axial direction, among the engaging portions of the input side disk on the tip side and the input rotation shaft, Sectional drawing (C) which shows the state of an axial direction outer end part. Sectional drawing equivalent to FIG. 4 shown in order to demonstrate the problem which arises when the magnitude | size of a fastening margin remove | deviates from the range of this invention. The figure equivalent to FIG. 4 which shows the 2nd example of embodiment of this invention. Sectional drawing which shows the 1st example of the toroidal type continuously variable transmission of conventional structure. Sectional drawing which shows the 2nd example. Similarly, the upper right half enlarged view (A) of FIG. 9 and the Y part enlarged view (B) of (A). The perspective view which takes out and shows the input side disk of the front end side. Sectional drawing which shows the state of the engaging part of this input side disk of this front end side, and an input rotating shaft. The schematic diagram which exaggerates and shows the elastic deformation of this input side disk of the front end side.

  1 to 5 show a first example of an embodiment of the present invention. The toroidal-type continuously variable transmission of this example has a pair of outer disks described in the claims around a portion near both ends in the axial direction of the input rotating shaft 1b corresponding to the rotating shaft described in the claims. A pair of corresponding input-side disks 2e and 2f are supported in a state where the inner side surfaces, each of which is a toroidal curved surface, face each other, and rotate in synchronization with the input rotation shaft 1b. Further, an output side disk 6b corresponding to the inner disk described in the claims is supported around an intermediate portion in the axial direction of the input rotation shaft 1b so as to be capable of relative rotation with respect to the input rotation shaft 1b. In this state, both side surfaces of the output side disk 6b, each of which is a toroidal curved surface, are made to face the inner side surfaces of the input side disks 2e and 2f. In the case of the structure shown in the figure, only the input side disk 2e provided on the base end side of the input rotation shaft 1b among these both input side disks 2e, 2f is rotated by this input via the ball spline 3. It is supported by the shaft 1b and enables the two discs 2e and 2f to move in the near and far directions. In the present specification, the inner side surface of the input side disk corresponds to one side surface in the axial direction of the outer side disk described in the claims.

  Further, a plurality of power rollers 7 and 7 (see FIG. 8) each having a spherical convex surface are sandwiched between the input disks 2e and 2f and the output disk 6b. These power rollers 7 and 7 are rotatably supported by trunnions 8 and 8 (see FIG. 8), respectively, and rotate while the both input side disks 2e and 2f rotate, Power is transmitted from 2e, 2f to the output side disk 6b. That is, when the toroidal-type continuously variable transmission is operated, the input side disk 2e corresponding to one of the outer disks described in the claims is pressed by the drive shaft by the pressing device 10b (the structure shown is a hydraulic pressing device). It is driven to rotate through. As a result, the pair of input-side disks 2e and 2f supported at both axial ends of the input rotation shaft 1b rotate synchronously while being pressed toward each other. Then, this rotation is transmitted to the output side disk 6b via the power rollers 7 and 7 and is taken out from the output gear formed on the outer peripheral surface. Each of the trunnions 8, 8 has a plurality of positions in the axial direction between the inner side surfaces of the two input side disks 2e, 2f and both side surfaces of the output side disk 6b. The power rollers 7 and 7 are rotatably supported with respect to the trunnions 8 and 8. The power rollers 7 and 7 are supported by the trunnions 8 and 8.

  As shown in FIG. 3, the pressing device 10b has a so-called double piston type structure in which a pair of pistons are arranged in parallel with each other in the force transmission direction. The pressing device 10 b includes a first cylinder housing 19, a first piston 20, a first hydraulic chamber 21, a first pressure oil supply / discharge passage 22, a second cylinder housing 23, a second piston 24, Two hydraulic chambers 25 and a second pressure oil supply / discharge passage 26 are provided.

  Of these, the first cylinder housing 19 is configured in a petri dish as a whole, and is fitted on the base end portion of the input rotary shaft 1b with an interference fit so as to ensure oil tightness. Further, the first cylinder housing 19 is moved away from the input side disk 2e by abutting a portion closer to the inner diameter of the first cylinder housing 19 against a flange formed on the outer peripheral surface of the base end portion of the input rotary shaft 1b. It is designed not to be displaced in the direction of moving away. At the same time, the thrust force applied to the first cylinder housing 19 in the leftward direction in FIGS. 1 and 3 as the pressure oil is fed into the first hydraulic chamber 21 can be transmitted to the input rotary shaft 1b.

  The first piston 20 has a ring shape as a whole, and an oil is formed between the inner peripheral surface of the first cylinder housing 19 and the outer peripheral surface near the base end of the input rotary shaft 1b. It is closely and oil-tightly fitted so as to be capable of displacement in the axial direction (left-right direction in FIGS. 1 and 3). The first hydraulic chamber 21 is provided between the first cylinder housing 19 and the first piston 20 combined in this way. Then, the first hydraulic oil supply / discharge passage 22 provided in a portion facing the inner diameter side of the first hydraulic chamber 21 near the base end of the input rotary shaft 1b is pressurized into the first hydraulic chamber 21. Oil can be freely supplied and discharged.

  The second cylinder housing 23 has a cylindrical shape and is provided on the outer peripheral edge of the input side disk 2e so as to protrude to the outer surface side (left side in FIGS. 1 and 3) of the input side disk 2e. Yes. In the illustrated example, the second cylinder housing 23 is formed integrally with the input side disk 2e on the outer peripheral edge of the outer surface of the input side disk 2e. The second piston 24 has an L-shaped cross section and is formed in an annular shape as a whole. The second piston 24 is oil-tightly fitted to a portion near the base end of the input rotary shaft 1a, and the inner diameter side of the second cylinder housing 23 The second cylinder housing 23 is fitted in an oiltight manner so as to be capable of axial displacement.

  The second hydraulic chamber 25 is provided between the outer surface of the input side disk 2 e and the second piston 24 on the inner diameter side of the second cylinder housing 23. Then, the pressure in the second hydraulic chamber 25 is increased by the second pressure oil supply / discharge passage 26 provided at a portion near the base end of the input rotary shaft 1b and facing the inner diameter side of the second hydraulic chamber 25. Oil can be freely supplied and discharged.

  The second pressure oil supply / discharge passage 26 and the first pressure oil supply / discharge passage 22 are connected to an oil supply pump (not shown) via a center hole 27 of the input rotary shaft 1b and a hydraulic control valve (not shown). Leading to the discharge port. During operation of the toroidal continuously variable transmission, pressure oil of a predetermined pressure is fed into the first hydraulic chamber 21 and the second hydraulic chamber 25 based on switching of the hydraulic control valve. Then, a force is generated in the hydraulic chambers 21 and 25 in the direction in which the axial dimensions of the hydraulic chambers 21 and 25 increase. The forces generated in these hydraulic chambers 21 and 25 both press the input side disk 2e toward the output side disk 6b, and the input rotating shaft 1b is moved to the base end side (the left side in FIGS. 1 and 3). ) And the other input side disk 2f is applied as a force in the direction of pressing the output side disk 6b.

  Further, in the case of this example, the preload applying member according to claim 1, wherein elastic force in a direction away from each other is applied to the first cylinder housing 19 and the first piston 20 in the first hydraulic chamber 21. 11d corresponding to a preload spring (disc spring) is provided. Accordingly, even when the pressure device 10b is not in operation (when the drive shaft is stopped) in which no hydraulic pressure is introduced into the hydraulic chambers 21 and 25, the peripheral surfaces of the power rollers 7 and 7; A pressing force (surface pressure) more than the minimum necessary for power transmission is applied to the rolling contact portions (each traction portion) with the side surfaces of the input side and output side discs 2e, 2f, 6b, and the same pressure. It prevents the structural members from rattling with no oil supplied. Specifically, the input side disk 2e is pressed against the output side disk 6b by the elasticity exerted by the preload spring 11d, and the input rotary shaft 1b is moved to the base end side (left side in FIGS. 1 and 3). The other input side disk 2f is pressed against the output side disk 6b. Therefore, in the case of this example, each rolling contact portion starts power transmission without causing excessive slip immediately after the start of operation of the toroidal continuously variable transmission.

In the case of this example, as shown in FIGS. 4 and 5, the input side disk 2f corresponding to the other outer disk described in the claims is placed next to the tip of the input rotating shaft 1b. It is supported by such a configuration.
That is, a central hole 28 is formed in the central portion of the input side disk 2f so as to penetrate the input side disk 2f in the axial direction. And the female spline part 13a is formed only in the axial direction intermediate part of the internal peripheral surface of this center hole 28. FIG. In addition, a disk side cylindrical surface portion 29 is formed in a portion of the inner peripheral surface of the center hole 28 adjacent to the axially inner side (left side in FIG. 4) of the female spline portion 13a, and this female spline 13a. A disc-side fitting surface portion 30 is formed in a portion adjacent to the outer side in the axial direction (right side in FIG. 4).

In the disk-side cylindrical surface portion 29, the cross-sectional shape related to a virtual plane orthogonal to the center axis of the input-side disk 2f is a regular circle centered on the center axis of the input-side disk 2f. The inner diameter d ₂₉ of the disk-side cylindrical surface portion 29 is constant in the axial direction and is larger than the root diameter (maximum inner diameter) d _{max of the} female spline portion 13a (d ₂₉ > d _max ). On the other hand, the disk-side fitting surface portion 30 has a cross-sectional shape with respect to a virtual plane orthogonal to the central axis of the input-side disk 2f having a regular circle centered on the central axis of the input-side disk 2f. Further, the inner diameter _{d 30} of the disk-side fitting surface 30 is constant over the axial direction, the tip diameter (minimum inner _diameter) of the female spline portion 13a is smaller than _{d min (d 30 <d min} ).

On the other hand, a male spline portion 14a that is spline-engaged with the female spline portion 13a is formed in a portion closer to the tip (portion closer to the right end in FIGS. 1 and 4) of the outer peripheral surface of the input rotary shaft 1b. And the cross-sectional shape regarding the virtual plane orthogonal to the central axis of this input rotating shaft 1b is formed in this input rotating shaft in the part adjacent to the front end side rather than this male spline part 14a among the outer peripheral surfaces of the said input rotating shaft 1b. A shaft-side fitting surface portion 31 that is a regular circle centered on the central axis 1b is formed. Outer diameter _{D 31} of the shaft-side fitting surface 31 is constant over the axial direction, the root circle diameter of the male spline portion 14a (minimum outer _diameter) smaller than _{D min (D 31 <D min} ). The outer diameter of the shaft-side fitting surface portion 31 in a free state (a state before the input-side disc 2f is press-fitted into the input rotary shaft 1b) is larger than the inner diameter of the disc-side fitting surface portion 30 in a free state. Set slightly larger.

More specifically, between the disc-side fitting surface portion 30 and the shaft-side fitting surface portion 31, which corresponds to the difference between the inner diameter of the disc-side fitting surface portion 30 and the outer diameter of the shaft-side fitting surface portion 31. press-fit portion in interference of the size of (| D 31 _{-d 30 |)} and based on the elastic force the preload spring 11d exerts, the input side disk 2f in the axial direction with respect to the input rotary shaft 1b The size is regulated so as to be relatively displaced (the input rotary shaft 1b can be pulled out in the axial direction from the input side disk 2f). In other words, the magnitude of the elasticity exerted by the preload spring 11d is pulled out from the input side disk 2f to the base end side (moved to the left side of FIGS. 1, 3 and 4). Is set to be larger than the pull-out force that is affected by the tightening allowance (elasticity> pull-out force).

  Further, in the outer peripheral surface of the input rotary shaft 1b, a locking groove 15a is formed over the entire circumference in a portion adjacent to the tip side from the shaft-side fitting surface portion 31. And in this latching groove | channel 15a, the inner diameter side half part of the latching ring (cotter) 16a which consists of a several (2-4 pieces) partial arc-shaped element corresponded to the latching member described in the claim Is locked. Then, the radially outer end portion of the side surface of the locking ring 16a (the left side surface in FIGS. 1 to 4) is brought into contact with the radially inner end portion of the outer surface of the input side disk 2f. Yes.

  In order to assemble the input side disk 2f to the front end portion of the input rotary shaft 1b, the preload spring 11d is elastically contracted (compressed), and the front end portion of the input rotary shaft 1b is moved to the input side disc 2f. The input side disk 2f is inserted into the center hole 28 from the inner side in the axial direction. Then, the male spline portion 14a is spline-engaged with the female spline portion 13a, and the shaft-side fitting surface portion 31 is press-fitted into the disk-side fitting surface portion 30 (it is fitted with an interference fit). In this state, the locking ring 16a is locked in the locking groove 15a, and the side surface of the locking ring 16a is brought into contact with (abuts against) the outer surface of the input side disk 2f. In this state, a retaining ring 17a having an L-shaped cross section is fitted on the tip of the input rotary shaft 1b, and the inner peripheral surface of the retaining ring 17a is in contact with or close to the outer peripheral surface of the locking ring 16a. While making it oppose, the retaining ring 18a is latched to the front-end | tip part of the said input rotating shaft 1b. This prevents the locking ring 16a (each element constituting the locking ring 16a) from coming out of the locking groove 15a.

  With the configuration as described above, the input-side disk 2f is prevented from being displaced toward the tip end side of the input rotary shaft 1b, and the input-side disk 2f is separated from the input rotary shaft 1b with the input rotary shaft 1b. Synchronized rotation is supported freely (allowing transmission of power between the input side disk 2f and the input rotation shaft 1b). In the case of this example, a portion of the outer peripheral surface of the input rotary shaft 1b adjacent to the base end side with respect to the male spline portion 14a and the disc-side cylindrical surface portion 29 are fitted with a gap.

In the case of the toroidal type continuously variable transmission of this example configured as described above, fretting wear occurs between the input side disk 2f and the locking ring 16a based on the thrust generated by the pressing device 10b. Can be prevented, and the assembly workability can be secured well.
That is, in the case of the second example of the conventional structure described above, a female spline portion 13 is provided in a range extending from the axially intermediate portion to the outer end portion of the inner peripheral surface of the input side disk 2d. The male spline portion 14 formed on the outer peripheral surface near the tip of the input rotary shaft 1a is engaged. For this reason, when the portion near the outer diameter of the input side disk 2d is elastically deformed outward in the axial direction (the right side in FIG. 13) based on the thrust generated by the pressing device 10, it approaches the outer end in the axial direction of the female spline portion 13. The portion is pressed against the outer peripheral surface of the input rotary shaft 1a, and is easily elastically deformed in a direction of reducing (reducing) the inner diameter thereof.

  On the other hand, in the case of this example, of the portion between the inner peripheral surface of the center hole 28 of the input side disk 2f and the outer peripheral surface of the input rotating shaft 1b, The disc-side fitting surface portion that is adjacent to the axially inner side (left side in FIG. 4) of the contact portion with the side surface of the locking ring 16a has a circular cross-sectional shape and is fitted by an interference fit. 30 and the shaft side fitting surface part 31 are provided. Therefore, the support rigidity of the input side disk 2f with respect to the input rotation shaft 1b at the axially outer end can be made higher than in the second example of the conventional structure. Further, the rigidity in the diameter-reducing direction of the outer end in the axial direction of the inner peripheral surface of the center hole 28 of the input side disk 2f can be increased, and the input side disk 2f is based on the thrust generated by the pressing device 10b. However, it is possible to suppress a tendency to elastically deform the portion near the outer end in the axial direction of the center hole 28 in the direction of reducing the diameter. As a result, the portion closer to the outer diameter of the input side disk 2f is elastically deformed outward in the axial direction. (The amount of elastic deformation in the axial direction of the portion near the outer diameter of the input side disk 2f can be reduced). For this reason, it is possible to prevent the outer side surface of the input side disk 2f and the side surface of the locking ring 16a from rubbing with each other to cause significant fretting wear on both side surfaces.

  Further, in the case of the structure of this example, the axial outer end edge of each female spline groove constituting the female spline portion 13a formed in the axially intermediate portion of the inner peripheral surface of the center hole 28, and the locking The side surfaces of the ring 16a are separated from each other in the axial direction. For this reason, even if the portion near the outer diameter of the input side disk 2f is elastically deformed outward in the axial direction based on the thrust generated by the pressing device 10b, each of the female spline portions 13a is configured. The outer edge in the axial direction of the female spline groove does not tend to bite into the side surface of the locking ring 16a. From this surface, fretting wear can be prevented from occurring between the input side disk 2f and the locking ring 16a.

  Furthermore, in the case of this example, between the disc-side fitting surface portion 30 formed on the inner peripheral surface of the input-side disc 2f and the shaft-side fitting surface portion 31 formed on the outer peripheral surface of the input rotating shaft 1b. Based on the elastic force exerted by the preload spring 11d, the input disk 2f can be displaced relative to the input rotary shaft 1b in the axial direction (input rotary shaft 1b). Is pulled out from the input side disk 2f). For this reason, at the time of assembling the toroidal-type continuously variable transmission, the input-side disk 2f is engaged with the engagement side based on the elasticity exerted by the preload spring 11d without strictly managing the assembly position of the input-side disk 2f. The input side disk 2f can be positioned by pressing against the retaining ring 16b (moving the input rotary shaft 1b in the direction of pulling out from the input side disk 2f). Therefore, according to the structure of this example, the assembly workability of the toroidal type continuously variable transmission can be improved.

In addition, as a comparative example, when the size of the tightening margin is set to such a large value that the input-side disk cannot be displaced in the axial direction relative to the input rotation axis regardless of the elasticity exerted by the preload spring, This will be described with reference to FIG. In the case of the comparative example, the input side disk 2f cannot be pressed against the locking ring 16a (the input rotary shaft 1b is pulled out from the input side disk 2f) depending on the elasticity exerted by the preload spring. For this reason, if the input side disk 2f is mistakenly moved to one axial side (left side in FIG. 6) from the normal assembly position (position where it abuts against the locking ring 16a) during assembly work, the input side disk It is necessary to apply an external force to 2f from the opposite side, pull it out from the input rotary shaft 1b, and perform the press-fitting operation again. For this reason, the assembling workability of the toroidal type continuously variable transmission is deteriorated. Further, when the operation of the toroidal continuously variable transmission is started without noticing that the input side disk 2f is assembled on one side in the axial direction from the regular assembly position, the input side disk 2f Until a large axial force is applied, the input-side disk 2f cannot be moved in the axial direction (moved to the proper assembly position). For this reason, the surface pressure acting on the rolling contact portion between the peripheral surface of the power roller and the side surface of each disk on the input side and the output side becomes excessive, and the preload spring is excessively elastically deformed. there is a possibility.
On the other hand, according to the structure of this example, the input side disk 2f can be relatively displaced in the axial direction with respect to the input side rotating shaft 1b based on the elasticity of the preload spring 11d. You do n’t have to.

In the case of this example, when the tip end of the input rotary shaft 1b is inserted into the center hole 28 of the input side disk 2f, the inside of the center hole 28 in the axial direction which is the front side of the input rotary shaft 1b is inserted. the end portion is provided with a disc-side cylindrical surface portion 29 having an inner diameter larger than the root circle diameter d _max of the female spline portion 13a. Therefore, in the initial stage of the assembling operation, the input side disk 2f and the input rotation are inserted into the disk side cylindrical surface part 29 by fitting the shaft side fitting surface part 31 to the male spline part 14a with gap fitting. Centering with the shaft 1b can be performed. For this reason, the assembling work of the toroidal type continuously variable transmission can be facilitated also from this aspect.

  In the case of this example, the disk-side cylindrical surface portion 29 formed at the inner end in the axial direction of the inner peripheral surface of the center hole 28 of the input-side disc 2f is included in the outer peripheral surface of the input rotary shaft 1b. The outer side of the male spline portion 13a is adjacent to the base end side with a clearance fit. However, in this portion, a shaft-shaped cylindrical surface portion that is a circular shape centered on the central axis of the input rotation shaft 1b and whose outer diameter does not change in the axial direction is formed, and the outer diameter of the shaft-side cylindrical surface portion in a free state is formed. Is slightly larger than the inner diameter of the disk-side cylindrical surface portion 29 in the free state, and the disk-side cylindrical surface portion 29 is press-fitted into the shaft-side cylindrical surface portion (externally fitted by an interference fit). good. If the disc side and shaft side cylindrical surface portions 29 are fitted together by interference fit, the concentricity of the input side disc 2f and the input rotating shaft 1b can be improved (the amount of eccentricity and the inclination angle between the center shafts are reduced). Therefore, various performances of the toroidal-type continuously variable transmission can be further improved (for example, the swinging motion of the input side disk 2f can be reduced to reduce vibration and improve the accuracy of the gear ratio control). When such a configuration is adopted, the press-fitting portion between the disc-side cylindrical surface portion 29 and the shaft-side cylindrical surface portion, and the disc-side fitting surface portion 30 and the shaft-side fitting surface portion 31 The tightening allowance at each of the press-fit portions is set so that the elasticity exerted by the preload spring 11d is larger than the total pull-out force generated at each of the press-fit portions.

[Second Example of Embodiment]
FIG. 7 shows a second example of the embodiment of the present invention. In the case of this example, the input side disk 2g and the input rotating shaft 1c are indirectly press-fitted through an annular intermediate member 32. More specifically, the intermediate member 32 is press-fitted into a shaft-side fitting surface portion 31a formed near the tip of the input rotary shaft 1c. Further, a disc side fitting surface portion 30a formed at the other axial end portion (the right end portion in FIG. 6) of the inner peripheral surface of the input side disc 2g is press-fitted into the outer peripheral surface of the intermediate member 32. In the case of this example, an annular recess 33 having an inner diameter larger than the root diameter of the female spline portion 13a is formed over the entire circumference at the axially outer end of the inner peripheral surface of the input side disk 2g. The bottom surface of the annular recess 33 is the disk-side fitting surface portion 30a. The side surface of the annular recess 33 is in contact with the side surface of the intermediate member 32.

In the case of this example having the above-described configuration, based on the contact between the side surface of the intermediate member 32 and the side surface of the annular recess 33, the intermediate member 32 is rotated with respect to the input side disk 2g. Relative displacement to the base end side of the shaft 1c is prevented. Therefore, in the case of this example, a tightening margin between the disk-side fitting surface portion 30a and the outer peripheral surface of the intermediate member 32 is set small, and the input-side disk 2g is lightly press-fitted into the intermediate member 32. ing. On the other hand, the fastening allowance between the inner peripheral surface of the intermediate member 32 and the shaft-side fitting surface portion 31a is the same as that in the first example of the embodiment, as shown in FIG. The intermediate member 32 (input-side disk 2g) is regulated within a range in which the intermediate member 32 (input-side disk 2g) can be relatively displaced in the axial direction with respect to the input rotation shaft 1c.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

  In each example of the above-described embodiment, the case where a locking ring called a cotter is used as a locking member for preventing the input side disk from being displaced outward in the axial direction has been described. As a locking member constituting the toroidal type continuously variable transmission of the invention, a loading nut as shown in FIG. 8 can be used. Further, the present invention is not limited to the half toroidal type as shown in the figure, but can be implemented by a full toroidal type toroidal continuously variable transmission.

DESCRIPTION OF SYMBOLS 1, 1a-1c Input rotary shaft 2a-2g Input side disk 3 Ball spline 4 Output cylinder 5 Output gear 6, 6a, 6b Output side disk 7 Power roller 8 Trunnion 9 Drive shaft 10, 10a, 10b Pressing device 11a-11d Preload Spring 12 Loading nut 13, 13a Female spline part 14, 14a Male spline part 15, 15a Locking groove 16, 16a Locking ring 17, 17a Retaining ring 18, 18a Retaining ring 19 First cylinder housing 20 First piston 21 First Hydraulic chamber 22 First pressure oil supply / discharge passage 23 Second cylinder housing 24 Second piston 25 Second hydraulic chamber 26 Second pressure oil supply / discharge passage 27 Center hole 28, 28a Center hole 29 Disc side cylindrical surface portion 30, 30a Disc side Fitting surface portion 31, 31a Shaft side fitting surface portion 32 Intermediate member 33 Annular recess

Claims (1)

A rotation axis;
A pair of outer disks supported so as to be freely rotatable in synchronization with the rotating shaft, with each axial side surface having a circular arc shape facing each other;
Around the intermediate portion in the axial direction of the rotating shaft, relative rotation with respect to the rotating shaft is supported freely with both axial side surfaces having an arcuate cross section facing one axial side surface of the outer disks. An inner disk formed by combining one or a pair of elements;
The circumferential surfaces of the spherically convex surfaces are supported in a freely oscillating displacement centered on a pivot that is twisted with respect to the rotating shaft, and both the axial sides of the inner disk and the axial direction of the outer disks A power roller in contact with one side surface;
A pressing device that is provided between the rotating shaft and one outer disk of the two outer disks and presses the one outer disk toward the other outer disk of the two outer disks;
Even if the outer disk is provided between the rotating shaft and the one outer disk, and the one outer disk is pressed against the other outer disk, the pressing device does not generate a pressing force. A preload applying member that presses the inner disk toward the inner disk;
The rotating shaft is locked to the end portion on the side where the other outer disk is arranged in the axial direction, and the other outer disk is prevented from being displaced in the axial direction from the one outer disk. A toroidal continuously variable transmission comprising: a locking member;
A part in the axial direction of the inner peripheral surface of the other outer disk and a part in the axial direction of the outer peripheral surface of the rotating shaft are engaged with each other in a relatively non-rotatable manner, and among the inner peripheral surfaces of the other outer disk, The portion adjacent to the other axial side of the portion engaged with the outer peripheral surface of the rotating shaft so as not to rotate relative to the outer peripheral surface of the rotating shaft is the inner peripheral surface of the other outer disk in the axial direction. By press-fitting the other outer disk with respect to the rotation shaft, either directly or via another member, between the part engaged with the relative rotation impossible and the part where the locking member is locked. The pre-load is determined by the size of the interference in the press-fitting portion between the inner peripheral surface of the other outer disk and the outer peripheral surface of the rotary shaft. Based on the elasticity exerted by the applying member, the other outer disk is Regulates the size that is allowed to relative displacement in the axial direction with respect to the axis, the toroidal type continuously variable transmission, wherein a thing.

Images