JP5935473B2 - Toroidal continuously variable transmission - Google Patents

Description

  The present invention relates to an improvement in a toroidal type continuously variable transmission that is used as a transmission for an automobile or a transmission for adjusting the operating speed of various industrial machines such as a pump. Specifically, it is intended to realize a structure capable of preventing fretting wear based on the elastic deformation of the outer disk in the axial direction.

  The use of a toroidal continuously variable transmission as a transmission for an automobile is described in many publications such as Patent Documents 1 to 4 and partially implemented, and is well known. Further, a structure in which a toroidal type continuously variable transmission and a planetary gear mechanism are combined to widen the adjustment range of the gear ratio is also described in many publications such as Patent Document 5 and has been widely known. FIG. 4 shows a first example of a toroidal-type continuously variable transmission described in each of these patent documents and widely known. In the case of the first example of this conventional structure, a pair of input-side discs 2a and 2b around the portions near both ends of the input rotation shaft 1, with the inner surfaces each being a toroidal curved surface facing each other, The rotation synchronized with the input rotating shaft 1 is supported. An output tube 3 is supported around the intermediate portion of the input rotary shaft 1 so as to be rotatable with respect to the input rotary shaft 1. Further, on the outer peripheral surface of the output cylinder 3, an output gear 4 is fixed at the center in the axial direction, and a pair of output side disks 5, 5 are connected to both ends in the axial direction by spline engagement. The rotation synchronized with 3 is supported. In this state, the inner side surfaces of the output side disks 5 and 5, each of which is a toroidal curved surface, are opposed to the inner side surfaces of the input side disks 2 a and 2 b.

  Further, a plurality of power rollers 6 and 6 each having a spherical convex surface are sandwiched between the input disks 2 a and 2 b and the output disks 5 and 5. The power rollers 6 and 6 are rotatably supported by the trunnions 7 and 7, respectively, and rotate with the rotation of the two input side disks 2a and 2b. Power is transmitted to both output side disks 5 and 5. That is, when the toroidal-type continuously variable transmission is operated, one (the left side in FIG. 4) input side disk 2 a is rotationally driven via the pressing device 9 by the drive shaft 8. As a result, the pair of input-side disks 2a and 2b supported at both ends of the input rotation shaft 1 rotate synchronously while being pressed in a direction approaching each other. Then, this rotation is transmitted to the output side disks 5 and 5 through the power rollers 6 and 6 and is taken out from the output gear 4.

  Further, preload springs 10a and 10b 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 ends of the input rotary shaft 1, respectively. Even when the pressing device 9 is not in operation (when the drive shaft 8 is stopped), the peripheral surfaces of the power rollers 6 and 6 and the inner surfaces of the input side and output side disks 2a, 2b and 5 are provided. The surface pressure of the rolling contact part (traction part) is 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 10 a disposed on the inner diameter side of the pressing device 9. A preload spring 10b disposed between the loading nut 11 screwed to the tip of the input side rotating shaft 1 and the outer surface of the input side disk 2b alleviates the impact applied when the pressing device 9 is suddenly operated. And it can be omitted. When it is provided, it has a sufficiently large elasticity (so as not to be completely crushed even when a large torque is transmitted).

  In the case of the toroidal continuously variable transmission as described above, the work of adjusting the elasticity of the preload spring 10a for ensuring the minimum necessary surface pressure is troublesome. That is, in the case of the first example of the conventional structure, the elasticity of the preload spring 10a is adjusted by the tightening amount of the loading nut 11 screwed to the tip end portion of the input rotary shaft 1. On the other hand, Patent Documents 6 to 7 describe a structure using a locking ring called a cotter instead of a loading nut. FIG. 5 shows a second example of a conventional structure incorporating such a locking ring. In the case of the second example of this conventional structure, a locking groove 12 is formed over the entire periphery on the outer peripheral surface of the tip end portion of the input rotary shaft 1a, and a locking ring 13 is locked in the locking groove 12. Yes. Then, the inner side surface (left side surface in FIG. 5) of the locking ring 13 is brought into contact with the outer side surface of the input side disk 2b. When the pressing device 9 is not operated, the surface pressure of the rolling contact portion between the peripheral surface of each of the power rollers 6 and 6 (see FIG. 4) and the inner surface of each of the input and output side disks 2a, 2b and 5a is minimized. Adjustment of the elasticity of the disc spring 10a to ensure is achieved by selecting the locking ring 13 having an appropriate axial thickness dimension. Further, a retaining ring 14 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 14 is brought into contact with or close to the outer peripheral surface of the locking ring 13. The locking ring 13 is prevented from coming out of the locking groove 12. Such a retaining ring 14 prevents displacement in the axial direction by a retaining ring 15 locked to the tip end portion of the input rotary shaft 1a. In the case of the second example of the conventional structure, the entire toroidal continuously variable transmission is reduced in size and weight by using an integral output side disk 5a. 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, the input-side disk 2b on the distal end side is driven by the power rollers 6 based on the thrust generated by the pressing device 9 during operation. Based on the force received from 6, as shown in an exaggerated manner in FIG. 6, the portion near the outer diameter of the input side disk 2 b is elastically deformed in a direction (axial direction) approaching the locking ring 13 side. That is, the force applied to the input side disk 2b based on the thrust during operation is about 49 kN (5 tF) at the maximum during the operation of the toroidal continuously variable transmission, and is related to the axial direction of the input side disk 2b based on such a force. The amount of elastic deformation is a comma number of mm (a few tenths of a millimeter) and cannot be ignored. When the input side disk 2b is elastically deformed in the axial direction in this way, a portion closer to the inner diameter of the outer side surface (right side surface in FIG. 5) of the input side disk 2b and one side surface of the locking ring 13 are intermittently formed. By repeatedly coming into contact with each other, they rub against each other, and there is a possibility that fretting wear will occur at those portions. In particular, the circumferential position at which the input side disk 2b is elastically deformed always changes as the portions pressed by the power rollers 6 and 6 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. 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.
In order to prevent such fretting wear of the input side disk, Patent Document 8 describes a portion between the input side disk and a carrier connecting plate which is connected to the input side disk and constitutes a planetary gear type transmission. Describes a structure for holding a spacer made of a copper-based alloy. However, the structure described in Patent Document 8 is a toroidal-type continuously variable transmission (with the outer surface of the input side disk facing one side of the connecting plate of the carrier constituting the planetary gear type transmission). Not used).

JP 2003-214516 A JP 2007-315595 A JP 2008-25821 A JP 2008-275088 A JP 2004-169719 A JP 2000-205361 A JP 2009-041715 A JP 2005-249184 A

  The present invention has been invented to realize a structure capable of preventing the fretting wear of the outer disk regardless of the elastic deformation in the axial direction of the outer disk in view of the circumstances as described above.

A toroidal continuously variable transmission according to the present invention includes a rotating shaft, a pair of outer disks, an inner disk, a plurality of support members, the same number of power rollers as each of the support members, a pressing device, and a locking device. With a ring.
A pair of outer disks are supported by both ends of the rotating shaft so that they can rotate in synchronization with the rotating shaft in a state where the axial side surfaces of the outer disks face each other. Has been.
In addition, the inner disk rotates relative to the rotating shaft around the middle portion of the rotating shaft, with both axial side surfaces having a circular arc cross section facing one axial side surface of the outer disks. It is supported freely, and is formed as a single unit or a pair of elements.
Further, each of the supporting members is pivoted at a position twisted with respect to the rotating shaft, and a plurality of each of the supporting members is disposed between the axial side surfaces of the inner disk and the axial side surfaces of the outer disks. Oscillating displacement around the center is freely provided.
Each of the power rollers is rotatably supported by each of the support members, and each of the peripheral surfaces formed as spherical convex surfaces is formed on both sides in the axial direction of the inner disk and on one side in the axial direction of the outer disks. It is made to contact.
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.
The locking ring is locked in a locking groove formed on the outer peripheral surface of the rotating shaft, and one axial side surface of the locking ring abuts on the other axial side surface of the other outer disk. . This prevents the other outer disk from being displaced in a direction away from the one outer disk.

  In particular, in the case of the toroidal type continuously variable transmission according to the present invention, the lubricating oil is provided on at least one side surface of the other outer disk and the one axial side surface of the locking ring, which face each other. An oil retaining recess is provided to hold the oil.

Furthermore, in the case of the present invention , an O-ring is provided between one axial side surface of the retaining ring that prevents the locking ring from coming out of the locking groove and the other axial side surface of the other outer disk. Hold on. Thereby, the lubricating oil that lubricates the other axial side surface of the other outer disk and the one axial side surface of the locking ring is prevented from flowing out radially outward.
When implementing the present invention as described above, it is preferable to prevent fretting wear on at least one of the other axial side surface of the other outer disk and the one axial side surface of the locking ring. Apply surface treatment.

  According to the toroidal continuously variable transmission of the present invention configured as described above, fretting wear of the outer disk can be prevented regardless of the elastic deformation of the outer disk in the axial direction. That is, by providing an oil retaining recess on at least one of the axial side surface of the locking ring and the axially outer side surface of the outer disk facing the axial side surface of the locking ring, An oil film of lubricating oil can be effectively formed between both side surfaces (a sufficient and strong oil film). As a result, even when the both side surfaces rub against each other with the elastic deformation of the outer disk in the axial direction, it is possible to prevent the occurrence of significant fretting wear on both side surfaces.

The figure corresponded to the X section enlarged view of FIG. 5 which shows an example of embodiment of this invention. The perspective view which shows five examples of the oil retaining recessed part formed in the one side of a locking ring. The perspective view which shows the part which surface-treats about an outer side disk. Sectional drawing which shows the 1st example of a conventional structure. Sectional drawing which shows the 2nd example. The schematic diagram which exaggerates and shows the elastic deformation of an input side disk.

  1 to 3 show an example of an embodiment of the present invention. The features of the toroidal type continuously variable transmission and continuously variable transmission of the present invention including this example are irrespective of the elastic deformation of the input side disk 2b based on the thrust generated by the pressing device 9 (see FIG. 5). A structure capable of suppressing the occurrence of fretting wear between the outer side surface of the input side disk 2b (the right side surface in FIGS. 1 and 5) and one side surface of the locking ring 13 (the left side surface in FIGS. 1 and 5). It is in the point to realize. Since the structure and operation of other parts are the same as those of the conventionally known toroidal-type continuously variable transmission including the structure shown in FIG. 5 described above, the illustration and explanation of the equivalent parts are omitted or simplified. Hereinafter, the description will focus on the features of this example.

In the case of this example, an oil retaining recess for retaining lubricating oil (traction oil) is formed on at least one of the outer side surface of the input side disk 2b and one side surface of the locking ring 13. Yes.
Of such oil retaining recesses, a structure as shown in FIG. 2, for example, can be used as one formed on one side of the locking ring 13. Of these, the structure shown in (A) is a structure in which a plurality of radial grooves 16, 16 are formed on one side surface, and the structure shown in (B) is a circumferential groove in addition to the radial grooves 16, 16. The groove 17 is formed, the structure shown in (C) is the one in which a plurality of spiral concave grooves 18 and 18 are formed, and the structure in (D) is the one in which a large number of minute recesses 19 and 19 are formed. It is. Further, the structure shown in (E) is a structure in which radial grooves 16a and 16a are formed which are radially inward from a plurality of locations on the inner periphery of the circumferential groove 17.
Further, at least one of the outer side surface of the input side disk 2b and one side surface of the locking ring 13 is improved in lubricity at a portion that is in contact with each other (portion shown by hatching in FIGS. 2 to 3). For the surface treatment. Such surface treatment includes forming a coating layer of a solid lubricant such as molybdenum disulfide and PTFE, applying phosphate treatment such as manganese phosphate, zinc phosphate or zinc calcium phosphate, or Those subjected to electroless nickel plating can be used.

  Further, the locking ring 13 extends over the entire circumference on one side surface (the left side surface in FIG. 1) of the holding ring 14 supported so as not to come out of the locking groove 12 formed in the input rotary shaft 1a. 20 is formed, and the O-ring 21 is locked in the locking groove 20. The O-ring 21 is brought into contact with the outer surface of the opposing input side disk 2b over the entire circumference.

  In the case of this example, in order to supply lubricating oil (traction oil) to each sliding portion, an axial lubricating oil passage 22 (see FIG. 5) is provided inside the input rotary shaft 1a. Oil supply passages 23a to 23c are respectively provided in a direction from 22 to the sliding portions. Lubricating oil sent from an oil supply port 24 provided at the base end side opening of the input rotary shaft 1 a is sent to the sliding portions through the lubricating oil flow path 22. That is, a part of this lubricating oil passes through the oil supply passage 23a provided on the inner diameter side of one input side disk 2a (left side in FIG. 5) among the oil supply passages 23a to 23c. A ball spline 25 that supports the disc 2a with respect to the input rotary shaft 1a so as to be axially displaceable is provided through the oil supply passage 23b provided on the inner diameter side of the output disc 5a. The radial needle bearings 26 and 26 that are rotatably supported with respect to the rotary shaft 1a are lubricated. Similarly, a part of the lubricating oil passes through the oil supply passage 23c provided on the inner diameter side of the other input side disk 2b (the right side in FIG. 5) among the oil supply passages 23a to 23c. The spline engaging portion between the inner peripheral surface of the disk 2b and the outer peripheral surface of the tip end portion of the input rotary shaft 1a is lubricated.

  In the case of this example configured as described above, oil retaining recesses are formed on at least one side surface of the outer side surface of the input side disk 2b and one side surface of the locking ring 13. Lubricating oil can be effectively fed between the surfaces. That is, the lubricating oil flow path 22 is fed through the oil supply passage 23c to a spline engaging portion between the inner peripheral surface of the input side disk 2b and the outer peripheral surface of the tip end portion of the input rotating shaft 1a. Lubricate the joint. A part of the lubricating oil that has lubricated the spline engaging portion is sent to a portion between the outer side surface of the input side disk 2b and one side surface of the locking ring 13, and is collected in the oil retaining recess. The Lubricating oil collected in such an oil retaining recess oozes out between the opposite side surfaces as the input side disk 2b is elastically deformed in the axial direction. As a result, it is possible to effectively prevent the occurrence of oil film breakage that leads to fretting wear at the abutting portions between the opposite side surfaces (a sufficient and strong oil film can be formed).

  When the oil retaining recesses as described above are the radial recesses 16 and 16 shown in FIG. 2A, the oil film extends over the entire radial direction at the abutting portions between the opposite side surfaces. Can be easily formed. Similarly, in the case of the structure shown in (B), since the circumferential concave grooves 17 are formed in the circumferential direction in addition to the radial radial concave grooves 16, 16, not only in the radial direction but also in the circumferential direction. Even if it is, it can make it easy to form an oil film. Similarly, in the case of the spiral grooves 18 and 18 shown in (C), as in the case of the structure shown in (B), an oil film can be easily formed even in the radial direction and the circumferential direction, Further, the surface pressure per unit area can be suppressed by widening the area of the portion in contact with the outer surface of the input side disk 2b. In the case of the minute recesses 19 and 19 shown in (D), an oil film can be easily formed uniformly over the entire abutting portion between the opposite side surfaces. Similarly, in the case of the structure shown in (E), the radial grooves 16a, 16a are not opened at the outer peripheral edge of one side surface of the locking ring 13, so that the grooves 16a, 17 capture the grooves. The collected lubricant can be prevented from flowing out radially outward.

Further, in the case of this example, the O-ring 21 is provided between the outer side surface of the input side disk 2b and one side surface of the holding ring 14 on the outer side in the radial direction of the contact portions on both side surfaces facing each other. Is holding. Thereby, it is possible to prevent the lubricating oil that lubricates the contact portion between the outer side surface of the input side disk 2b facing each other and one side surface of the locking ring 13 from flowing out radially outward. . As a result, the lubricating oil can be sufficiently supplied to the abutting portions between the opposite side surfaces, and the lubricating oil can be easily collected in the oil retaining recess.
Furthermore, in the case of this example, at least one of the outer side surface of the input side disk 2b and the one side surface of the locking ring 13 facing each other is subjected to surface treatment for improving lubricity. Accordingly, it is possible to more effectively prevent fretting wear from occurring at the abutting portions between the two opposing side surfaces (even if temporary lubricating oil shortage occurs).

The present invention can be applied not only to the toroidal type continuously variable transmission of the half toroidal type as shown, but also to the toroidal type continuously variable transmission of the full toroidal type.
Further, the locking ring (cotter) is not limited to the one divided into three pieces as shown in the figure, but can be applied to ones divided into two pieces or four pieces or more.

DESCRIPTION OF SYMBOLS 1, 1a Input rotary shaft 2a, 2b Input side disk 3 Output cylinder 4 Output gear 5, 5a Output side disk 6 Power roller 7 Trunnion 8 Drive shaft 9 Pressing device 10a, 10b Preload spring 11 Loading nut 12 Locking groove 13 Locking Ring 14 Retaining ring 15 Retaining ring 16, 16a Radial concave groove 17 Circumferential concave groove 18 Helical concave groove 19 Micro concave portion 20 Locking concave groove 21 O-ring 22 Lubricating oil flow passage 23a-23c Oil supply passage 24 Oil supply port 25 Ball spline 26 Radial needle bearings

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 middle portion of the rotating shaft, the axially opposite side surfaces having a circular arc cross section are opposed to the axially one side surfaces of both outer disks, and are integrally supported to freely rotate relative to the rotating shaft. Or an inner disk formed by combining a pair of elements;
With respect to the axial direction, a plurality of oscillating displacements centering on the pivot axis that is twisted with respect to the rotating shaft are respectively provided at positions between both axial side surfaces of the inner disk and one axial side surface of the outer disks. A freely provided support member;
A power roller that is rotatably supported by each of these support members and has a spherical convex surface that is in contact with both axial side surfaces of the inner disk and axial side surfaces of the outer disks,
A pressing device that is provided between the rotating shaft and one of the outer disks and presses the one outer disk toward the other outer disk of the two outer disks;
The other outer disk is engaged with the other groove in the outer circumferential surface of the rotating shaft, and the other outer disk is brought into contact with the other outer disk in the axial direction. A toroidal continuously variable transmission with a locking ring that prevents displacement in a direction away from the outer disk of the
An oil retaining recess for retaining lubricating oil is provided on at least one side surface of the other outer disk in the axial direction and the one axial side surface of the locking ring facing each other ,
By holding an O-ring between one side surface in the axial direction of the holding ring and the other side surface in the axial direction of the other outer disk, which prevents the locking ring from coming out of the locking groove, the other side A toroidal continuously variable transmission characterized in that the lubricating oil that lubricates the other axial side surface of the outer disk and the one axial side surface of the locking ring is prevented from flowing outward in the radial direction .

Images