Toroidal type continuously variable transmission

Abstract

To provide a toroidal type continuously variable transmission capable of preventing seizure or abrasion of a retainer of a bearing provided between a disk and a shaft rotatably supporting the disk.SOLUTION: A bearing 70 is provided between an output shaft 1A and an input side disk 2 (second disk), and the bearing 70 includes a plurality of rollers 71 rollable between the output shaft 1A and the input side disk 2, and a cylindrical retainer 72 rollably holding the plurality of rollers 71 and attached to the output shaft 1A. The retainer 72 is a retainer inside diameter guide or a roller guide.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a toroidal type continuously variable transmission that can be used in generators for automobiles and aircraft, or transmissions for various industrial machines, etc. [Background technology]

[0002] For example, a double-cavity toroidal type continuously variable transmission used as an automobile transmission is configured as shown in Figures 10 and 11. As shown in Figure 10, an input shaft 1 is rotatably supported inside a casing 50, and two input side discs 2, 2 and two output side discs 3, 3 are attached to the outer periphery of this input shaft 1. An output gear (transmission gear) 4 is rotatably supported on the outer periphery of a middle part of the input shaft 1. The output side discs 3, 3 are connected to cylindrical flanges 4a, 4a provided in the center of this output gear 4 by spline coupling. The input shaft 1 is rotated by a drive shaft 22 via a loading cam type pressing device 12 provided between the input side disc 2 located on the left side in Fig. 10 and a cam plate (loading cam) 7. The output gear 4 is supported in a casing 50 via a partition wall 13 formed by joining two members, which allows the output gear 4 to rotate around the axis O of the input shaft 1 while preventing displacement in the direction of the axis O.

[0003] The output side discs 3, 3 are supported rotatably about the axis O of the input shaft 1 by needle bearings 5, 5 interposed between them and the input shaft 1. The input side disc 2 on the left side in Fig. 10 is supported on the input shaft 1 via a ball spline 6, and the input side disc 2 on the right side in Fig. 10 is spline-connected to the input shaft 1, so that these input side discs 2 rotate together with the input shaft 1. Power rollers 11 (see Fig. 11) are rotatably sandwiched between inner surfaces (concave surfaces; also called traction surfaces) 2a, 2a of the input side discs 2, 2 and inner surfaces (concave surfaces; also called traction surfaces) 3a, 3a of the output discs 3, 3.

[0004] A step portion 2b is provided on the inner peripheral surface 2c of the input side disc 2 located on the right side in Fig. 10, and a step portion 1b provided on the outer peripheral surface 1a of the input shaft 1 abuts against this step portion 2b, and the back surface of the input side disc 2 (the right surface in Fig. 10) abuts against a loading nut 9 screwed into a threaded portion formed on the outer peripheral surface of the input shaft 1. This substantially prevents the input side disc 2 from being displaced in the direction of the axis O relative to the input shaft 1. In addition, a disc spring 8 is provided between the cam plate 7 and the flange portion 1d of the input shaft 1, and this disc spring 8 applies a pressing force (preload) to the contact portions between the concave surfaces 2a, 2a, 3a, 3a of the discs 2, 2, 3, 3 and the peripheral surfaces 11a, 11a of the power rollers 11, 11.

[0005] FIG. 11 is a cross-sectional view taken along line AA in FIG. 10. As shown in FIG. 11, a pair of trunnions 15, 15 are provided inside the casing 50, which swing about a pair of pivots 14, 14 that are in a twisted position relative to the input shaft 1. Note that the input shaft 1 is not shown in FIG. 11. Each trunnion 15, 15 has a pair of bent wall portions 20, 20 formed at both ends in the longitudinal direction (the vertical direction in FIG. 11) of the support plate portion 16, in a state of bending toward the inner surface side of the support plate portion 16. The bent wall portions 20, 20 form a concave pocket portion P in each trunnion 15, 15 for accommodating the power roller 11. In addition, the pivots 14, 14 are provided concentrically with each other on the outer surfaces of the bent wall portions 20, 20.

[0006] A circular hole 21 is formed in the center of the support plate portion 16, and a base end portion 23a of a displacement shaft 23 is supported in this circular hole 21. The inclination angle of the displacement shaft 23 supported in the center of each of the trunnions 15 can be adjusted by swinging each of the trunnions 15 about each of the pivots 14. The power rollers 11 are rotatably supported around the tip portion 23b of the displacement shaft 23 protruding from the inner surface of each of the trunnions 15, and each of the power rollers 11 is sandwiched between each of the input side disks 2 and each of the output side disks 3. The base end portion 23a and the tip portion 23b of each of the displacement shafts 23 are eccentric to each other.

[0007] The pivots 14, 14 of the trunnions 15, 15 are supported by a pair of yokes 23A, 23B so as to be swingable and displaceable in the axial direction (vertical direction in FIG. 11), and the horizontal movement of the trunnions 15, 15 is restricted by the yokes 23A, 23B. The yokes 23A, 23B are formed into a rectangular shape by pressing or forging a metal such as steel. Four circular support holes 18 are provided at the four corners of the yokes 23A, 23B, and the pivots 14 provided at both ends of the trunnions 15 are supported swingably in the support holes 18 via radial needle bearings 30. The yokes 23A, 23B are provided at the center in the width direction (horizontal direction in FIG. 11) with circular locking holes 19, and the inner peripheral surface of the locking holes 19 is a cylindrical surface, into which the spherical posts 64, 68 are fitted. That is, the upper yoke 23A is supported so as to be freely swingable by a spherical post 64 which is supported on the casing 50 via a fixed member 52, and the lower yoke 23B is supported so as to be freely swingable by a spherical post 68 and the upper cylinder body 56 of the drive cylinder 31 which supports it.

[0008] The displacement shafts 23, 23 provided on each trunnion 15, 15 are provided at positions 180 degrees opposite to each other with respect to the input shaft 1. The direction in which the tip end 23b of each of these displacement shafts 23, 23 is eccentric with respect to the base end 23a is the same as the direction of rotation of both disks 2, 2, 3, 3 (upside down in FIG. 11). The eccentric direction is approximately perpendicular to the direction in which the input shaft 1 is disposed. Therefore, each of the power rollers 11, 11 is supported so as to be slightly displaceable in the longitudinal direction of the input shaft 1. As a result, even if each of the power rollers 11, 11 tends to be displaced in the axial direction of the input shaft 1 due to elastic deformation of each component based on the thrust load generated by the pressing device 12, this displacement is absorbed without applying excessive force to each component.

[0009] Between the outer surface of the power roller 11 and the inner surface of the support plate portion 16 of the trunnion 15, a thrust ball bearing (thrust bearing) 24, which is a thrust rolling bearing, and a thrust needle bearing 25 are provided in this order from the outer surface side of the power roller 11. Of these, the thrust ball bearing 24 supports the thrust load applied to each power roller 11 while allowing each power roller 11 to rotate. Each thrust ball bearing 24 is composed of a plurality of balls (hereinafter referred to as rolling elements) 26, 26, an annular cage 27 that holds each of the rolling elements 26, 26 so that they can roll freely, and an annular outer ring 28. The inner ring raceway of each thrust ball bearing 24 is formed on the outer surface (large end surface) of each power roller 11, and the outer ring raceway is formed on the inner surface of each outer ring 28.

[0010] In addition, the thrust needle bearing 25 is sandwiched between the inner surface of the support plate portion 16 of the trunnion 15 and the outer surface of the outer ring 28. Such thrust needle bearing 25 supports the thrust load applied from the power rollers 11 to each outer ring 28, while allowing the power rollers 11 and the outer ring 28 to swing around the base end portion 23a of each displacement shaft 23.

[0011] Furthermore, a drive rod (trunnion shaft) 29, 29 is provided at one end of each trunnion 15, 15 (the lower end in FIG. 11), and a drive piston (hydraulic piston) 33, 33 is fixed to the outer circumferential surface of the middle part of each drive rod 29, 29. Each of these drive pistons 33, 33 is oil-tightly fitted into a drive cylinder 31 formed by an upper cylinder body 56 and a lower cylinder body 57. Each of these drive pistons 33, 33 and the drive cylinder 31 constitutes a drive unit 32 that displaces each of the trunnions 15, 15 in the axial direction of the pivots 14, 14 of the trunnions 15, 15.

[0012] In the case of a toroidal type continuously variable transmission configured in this manner, the rotation of the input shaft 1 is transmitted to the input side discs 2, 2 via a pressing device 12. The rotation of these input side discs 2, 2 is then transmitted to the output side discs 3, 3 via a pair of power rollers 11, 11, and the rotation of each of the output side discs 3, 3 is further taken out by the output gear 4.

[0013] When changing the rotational speed ratio between the input shaft 1 and the output gear 4, the pair of drive pistons 33, 33 are displaced in opposite directions. With the displacement of each of the drive pistons 33, 33, the pair of trunnions 15, 15 are displaced in opposite directions. For example, the power roller 11 on the left side of Fig. 11 is displaced downward in the same figure, and the power roller 11 on the right side of the same figure is displaced upward in the same figure. As a result, the direction of the tangential force acting on the contact portions between the peripheral surfaces 11a, 11a of the power rollers 11, 11 and the inner surfaces 2a, 2a, 3a, 3a of the input side disks 2, 2 and the output side disks 3, 3 changes. Then, with the change in the direction of the force, the trunnions 15, 15 swing (tilt) in opposite directions to each other about the pivots 14, 14 pivoted to the yokes 23A, 23B.

[0014] As a result, the contact position between the circumferential surface 11a, 11a of each power roller 11, 11 and each inner surface 2a, 3a changes, and the rotation speed ratio between the input shaft 1 and the output gear 4 changes. In addition, when the torque transmitted between the input shaft 1 and the output gear 4 fluctuates and the elastic deformation amount of each component changes, each power roller 11, 11 and the outer rings 28, 28 attached to each power roller 11, 11 rotate slightly around the base end portion 23a, 23a of each displacement shaft 23, 23. Since the thrust needle bearings 25, 25 are present between the outer surface of each outer ring 28, 28 and the inner surface of the support plate portion 16 constituting each trunnion 15, 15, the rotation is performed smoothly. Therefore, as described above, a small force is required to change the inclination angle of each displacement shaft 23, 23. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] JP 2003-4114 A Summary of the Invention [Problem to be solved by the invention]

[0016] In a toroidal type continuously variable transmission, a roller bearing or a cage and roller is placed between the disk (input disk or output disk) and the shaft, so that the disk is rotatably supported by the shaft. The disk and the shaft rotate in opposite directions, and the bearing between them must support the relative rotation. In a toroidal type continuously variable transmission for aircraft, which is used at high speeds, the relative rotation speed of the bearing can reach a maximum of about 30,000 rpm, and if the cage comes into contact with the guide surface, there is a concern that it may cause seizure or wear between the cage, which may ultimately lead to damage to the cage. If the cage breaks, the vibration of the disk and shaft will increase, causing the toroidal type continuously variable transmission to become out of sync and making it impossible to transmit power. In addition, when the cage breaks, it may impact surrounding parts, causing the disk and shaft to crack.

[0017] As shown in Fig. 12, in a conventional toroidal type continuously variable transmission for an aircraft (generator), the outer diameter surface of the retainer 72 of the needle bearing (bearing) 70 is configured to come into contact with (guide) the inner diameter surface 2c of the disk 2 (retainer outer diameter guide), but the inner diameter surface 2c of the disk is deformed inward due to the effect of the normal force from the power roller 11. The input side disk 2 for an aircraft rotates at approximately 20,000 rpm (300 Hz or more), and the above deformation occurs twice per disk rotation. For this reason, the inner diameter surface 2c of the disk, which is the guide surface of the retainer, deforms at a very high frequency, increasing concerns about seizure and wear on the outer diameter surface of the retainer. In a toroidal type continuously variable transmission for aircraft, the shaft designated by reference symbol 1A is an output shaft, and an input side disk 2 is rotatably supported by this output shaft 1A via a bearing 70.

[0018] The present invention has been made in consideration of the above circumstances, and has an object to provide a toroidal-type continuously variable transmission that can prevent seizure and wear of the retainer of the bearing that is provided between the shaft and the disk and rotatably supports the disk. [Means for solving the problem]

[0019] In order to achieve the above object, the toroidal type continuously variable transmission of the present invention comprises a shaft, a first disk and a second disk provided on the shaft so as to be rotatable concentrically with each other and integrally with the shaft with their inner surfaces facing each other, a power roller held between the two disks, and a bearing provided between the shaft and the second disk, the bearing includes a plurality of rollers capable of rolling between the shaft and the second disk, and a cylindrical cage that holds the plurality of rollers so as to be capable of rolling and is attached to the shaft; The cage is characterized in that it has a cage inner diameter guide or a roller guide.

[0020] Here, the cage inner diameter guide refers to a cage guide structure in which the cage is supported by the contact of the inner diameter surface of the cage with the shaft (outer diameter surface), and the roller guide refers to a cage guide structure in which the cage is supported by contact with the cylindrical rollers (see, for example, Patent Document 1). Also, the raceway ring guide refers to a cage guide structure in which the cage is supported by contact with the rolling rings (see, for example, Patent Document 2). The roller guide refers to a cage guide structure in which the cage is supported by contact with the cylindrical rollers (see, for example, Patent Document 1). Also, the raceway ring guide refers to a cage guide structure in which the cage is supported by contact with the rolling rings (see, for example, Patent Document 2). The roller guide refers to a cage guide structure in which the cage is supported by contact with the cylindrical rollers (see, for example, Patent Document 1). The roller guide refers to a cage guide structure in which the cage is supported by contact with the cylindrical rollers (see, for example, Patent Document 1). The roller guide refers to a cage guide structure in which the cage is supported by contact with the rollers, in which the rollers contact the inner diameter surface of the disk or the shaft (outer diameter surface) and the cage is supported.

[0021] In the present invention, the retainer is not a retainer outer diameter guide, as in the conventional case, but a retainer inner diameter guide or roller guide. Therefore, even if the inner diameter surface of the disk (retainer guide surface) deforms inward at high frequency due to the normal force from the power roller, the retainer outer diameter surface does not come into contact with the inner diameter surface of the disk. Furthermore, when the retainer inner diameter surface comes into contact (in the case of retainer inner diameter guide), no load that contributes to radial dimensional change acts on the shaft, thereby preventing seizure and wear of the retainer. In addition, since the radius from the center of rotation (center of rotation of the shaft) is smaller for the outer diameter surface of the shaft than for the inner diameter surface of the disk, the peripheral speed on the guide surface (outer diameter surface of the shaft) is smaller, and even if the inner diameter surface of the retainer comes into contact with the output shaft, the relative speed is small, which also helps to prevent seizure and wear of the retainer.

[0022] In the above-mentioned configuration of the present invention, when the cage is a cage inner diameter guide, If the outer diameter of the cage is D1, the inner diameter is D2, the inner diameter of the second disk is D3, and the outer diameter of the shaft is D4, It may be set as D3-D1>D2-D4.

[0023] In the above-mentioned configuration of the present invention, when the cage is a roller guide, The outer diameter of the cage is D1, the inner diameter is D2, the inner diameter of the second disk is D3, and the outer diameter of the shaft is D4. If the radial movement amount of the cage relative to the rollers is ΔS (the amount of movement from the position where the cage is arranged coaxially with the shaft to the radial direction (radial direction of the cage) relative to the rollers), then (D3-D1) / 2>ΔS, and (D2-D4) / 2>ΔS may be set to

[0024] In the above-described configuration of the present invention, a coating for improving sliding properties may be formed on at least the guide surface of the cage. Here, the coating may be, for example, copper plating, but is not limited to this.

[0025] According to this configuration, a coating that improves sliding properties is formed on at least the guide surface of the cage, so that seizure and wear of the cage can be more effectively prevented.

[0026] In the above-mentioned configuration of the present invention, a minute recess for oil reservoir may be formed on at least the guide surface of the cage.

[0027] According to this configuration, minute recesses for oil reservoirs are formed on at least the guide surface of the retainer, so that an oil film can be formed on the guide surface, and seizure and wear of the retainer can be more effectively prevented. Effect of the Invention

[0028] According to the present invention, it is possible to prevent seizure and wear of the cage of the bearing that is provided between the shaft and the disk and rotatably supports the disk. [Brief description of the drawings]

[0029] [Figure 1] 1 is a cross-sectional view of a main portion of a toroidal type continuously variable transmission according to a first embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 5 is an enlarged cross-sectional view of a main portion of a toroidal type continuously variable transmission according to a second embodiment of the present invention. [Figure 6] FIG. [Figure 7] FIG. 11 is a perspective view of a bearing of a toroidal type continuously variable transmission according to a third embodiment of the present invention. [Figure 8] FIG. 13 shows a first example of a toroidal type continuously variable transmission according to a fourth embodiment of the present invention, illustrating a perspective view of a bearing and a main portion. [Figure 9] FIG. 13 shows a second example of a toroidal type continuously variable transmission according to a fourth embodiment of the present invention, illustrating a perspective view of a bearing and a main portion. [Figure 10] FIG. 1 is a cross-sectional view showing an example of a conventional toroidal type continuously variable transmission. [Figure 11] FIG. 11 is a cross-sectional view taken along the line AA in FIG. [Figure 12] FIG. 1 is an enlarged cross-sectional view showing a main portion of an example of a conventional toroidal type continuously variable transmission for aircraft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (First embodiment) FIG. 1 is a cross-sectional view showing a main part of a toroidal type continuously variable transmission according to a first embodiment, and FIG. 2 is an enlarged cross-sectional view of the same. In the conventional technology shown in FIG. 10 and FIG. 11, the output side disk 3 is rotatably supported by the input shaft 1 via a bearing 5, but in this embodiment, the input side disk 2 is rotatably supported by the output shaft 1A via a bearing 70. However, the toroidal type continuously variable transmission according to this embodiment and the conventional toroidal type continuously variable transmission have the same configurations, such as a power roller 11 sandwiched between the input side disk 2 and the output side disk 3, and a pressing device 12 that presses one of the input side disk 2 and the output side disk 3, the disk 2(3), toward the other disk 3(2), and the like, and therefore the description thereof will be omitted. Also, hatching is omitted in FIG. 1.

[0031] The toroidal type continuously variable transmission of this embodiment is a double-cavity half-toroidal type continuously variable transmission for aircraft (generators), and is configured with an input side disc (second disc) 2 and an output side disc (first disc) 3 attached around an output shaft (shaft) 1A. The output side disc 3 is provided so as to be rotatable integrally with the output shaft 1A, and the input side disc 2 is provided so as to be rotatable relative to the output shaft A via a bearing 70. A power roller 11 is provided between the input side disc 2 and the output side disc 3, and the power roller 11 is sandwiched between the two discs 2, 3. In this embodiment, the output side disk 3 is pressed against the input side disk 2 by a pressing device 12.

[0032] As shown in Figures 2 and 3, the bearing 70 includes a plurality of cylindrical rollers 71 that can roll between the output shaft 1A and the input side disk 2, and a cylindrical retainer 72 that holds the rollers 71 in a rollable state and is attached to the output shaft 1A. A plurality of retaining holes 72d are formed at predetermined equal angular intervals on the outer peripheral surface (outer diameter surface) 72a of the retainer 72, opening in the radial direction of the retainer 72. Each retaining hole 72d is adapted to retain a roller 71 that rolls between the output shaft 1A and the input side disk 2 so as to be able to roll freely.

[0033] Such a bearing 70 is provided between the output shaft 1A and the input side disc 2. A retainer 72 of the bearing 70 is clamped in the axial direction by restricting members 75, 76, thereby restricting axial movement of the output shaft 1A. The restricting member 75 is restricted from moving leftward in the axial direction by a retaining ring 77 fixed to the inner diameter surface 2c of the input side disc 2, and the restricting member 76 is restricted from moving rightward in the axial direction by a member 78 inserted into the inner diameter side of the input side disc 2.

[0034] The retainer 72 is guided to an inner diameter of the retainer. The term "retainer inner diameter guide" refers to a retainer guide structure in which the retainer 72 is supported by an inner diameter surface 72c of the retainer 72 coming into contact with an outer diameter surface (outer peripheral surface) 1a of the output shaft 1A. Specifically, as shown in FIG. 4, if the outer diameter of the retainer 72 is D1, the inner diameter is D2, the inner diameter of the input side disc 2 is D3, and the outer diameter of the output shaft 1A is D4, then: It is set that D3-D1>D2-D4. In other words, the distance between the outer diameter surface 72a of the retainer 72 and the inner diameter surface 2c of the input side disk 2 is longer than the distance between the inner diameter surface 72c of the retainer 72 and the outer diameter surface 1a of the output shaft 1A.

[0035] Therefore, in this embodiment, even if the inner diameter surface (retainer guide surface) 2c of the input side disk 2 deforms inward at high frequency due to the effect of normal force from the power roller 11 (see Figures 1 and 2), the outer diameter surface 72a of the retainer 72 does not contact the inner diameter surface 2c of the input side disk 2, and further, since no load that contributes to radial dimensional change acts on the output shaft 1A with which the inner diameter surface 72c of the retainer 72 contacts, seizure and wear of the retainer 72 can be prevented. In addition, since the radius from the center of rotation (the center of rotation of the output shaft 1A) is smaller for the outer diameter surface 1a of the output shaft 1A than for the inner diameter surface 2c of the input side disk 2, the circumferential speed on the guide surface (outer diameter surface 1a) is smaller, and even if the inner diameter surface 72c of the retainer 72 comes into contact with the outer diameter surface 1a of the output shaft 1A, the relative speed is small, so that seizure and wear of the retainer 72 can be prevented in this respect as well.

[0036] Second Embodiment FIG. 5 is an enlarged view of a main portion showing the second embodiment. The second embodiment shown in FIG. 5 differs from the first embodiment shown in FIG. 2 etc. in that the retainer 72 is roller guided, and so this point will be explained below. In FIG. 5, the same components as those shown in FIG. 2 are given the same reference numerals and their explanation will be omitted.

[0037] The cage 72 is roller-guided. The roller guide refers to a cage guide structure in which the cage 72 is supported by the rollers 71 coming into contact with the inner diameter surface 2c of the input disk 2 or the outer diameter surface 1a of the output shaft 1A, as shown in FIG. Specifically, if the outer diameter of the retainer 72 is D1, the inner diameter is D2, the inner diameter of the input side disk 2 is D3, the outer diameter of the output shaft 1A is D4, and the radial movement amount of the retainer 72 relative to the rollers 71 is ΔS, ΔS is the movement amount in the radial direction (radial direction of the retainer 72) relative to the rollers 71 from the position where the retainer 72 is arranged coaxially with the output shaft 1A, and is set as follows. It is set as (D3-D1) / 2>ΔS and (D2-D4) / 2>ΔS. In other words, the distance between the outer diameter surface 72a of the retainer 72 and the inner diameter surface 2c of the input side disk 2 and the distance between the inner diameter surface 72c of the retainer 72 and the outer diameter surface 1a of the output shaft 1A are each longer than the radial movement amount ΔS of the retainer 72 relative to the rollers 71. Therefore, the outer diameter surface 72a and the inner diameter surface 72c of the retainer 72 do not come into contact with the inner diameter surface 2c of the input side disc 2 and the outer diameter surface 1a of the input shaft 1A, respectively. In FIG. 6, the cage 72 arranged coaxially with the output shaft 1A is hatched, and the cage 72 moved in the radial direction is indicated by a two-dot chain line.

[0038] Therefore, in this embodiment, as in the first embodiment, even if the inner diameter surface (retainer guide surface) 2c of the input side disk 2 deforms inward at high frequency due to the effect of a normal force from the power roller 11 (see Figures 1 and 2), the outer diameter surface 72a of the retainer 72 does not contact the inner diameter surface 2c of the input side disk 2, and further, even if the inner diameter surface 72c of the retainer 72 contacts the output shaft 1A due to an assembly error of the retainer 72, the output shaft 1A is not subjected to a load that contributes to a radial dimensional change, so that seizure and wear of the retainer 72 can be prevented. In addition, since the radius from the center of rotation (the center of rotation of the output shaft 1A) is smaller for the outer diameter surface 1a of the output shaft 1A than for the inner diameter surface 2c of the input side disk 2, the circumferential speed on the guide surface (outer diameter surface 1a) is smaller, and even if the inner diameter surface 72c of the retainer 72 comes into contact with the outer diameter surface 1a of the output shaft 1A, the relative speed is small, so that seizure and wear of the retainer 72 can be prevented in this respect as well.

[0039] (Third embodiment) FIG. 7 shows a third embodiment and is a perspective view of a bearing 70. In FIG. In this embodiment, a coating 80 for improving sliding properties is formed on at least the guide surface of the cage 72 of the bearing 70 . For example, in the case of the first embodiment, the cage 72 is guided along the inner diameter of the cage, and the inner diameter surface 72c serves as a guide surface. Therefore, at least this guide surface (inner diameter surface 72c) is formed with a coating 80 for improving sliding properties. The coating 80 may be, for example, copper plating, but is not limited thereto. Furthermore, the coating 80 may be formed on the outer diameter surface 72a of the cage 72 in addition to the inner diameter surface 72c, and may also be formed on the outer side surface 72e of the cage 72.

[0040] In addition, in this embodiment, the case where the retainer 72 is guided on the inner diameter of the retainer has been described. However, if the retainer 72 is guided on the outer diameter of the retainer as in the conventional case, the outer diameter surface 72a becomes the guide surface, and therefore the coating 80 may be formed on at least this outer diameter surface 72a, and further, the coating 80 may be formed on the inner diameter surface 72c and / or the outer surface 72e in addition to the outer diameter surface 72a.

[0041] In the second embodiment, the cage 72 is a roller guide. In this case, too, the coating 80 may be formed on the outer diameter surface 72a, the inner diameter surface 72c and the outer side surface 72e of the cage 72 as appropriate.

[0042] According to this embodiment, since the coating 80 for improving slidability is formed on at least the guide surface of the cage 72, seizure and wear of the cage 72 can be prevented more effectively.

[0043] (Fourth embodiment) 8 and 9 show a fourth embodiment, and are a perspective view and a view showing a main portion of a bearing 70, respectively. In this embodiment, at least the guide surface of the cage 72 is formed with minute recesses 81 for oil reservoirs. For example, in the case of the first embodiment, the cage 72 is guided along the inner diameter of the cage, and the inner diameter surface 72c serves as a guide surface. Therefore, at least this guide surface (the inner diameter surface 72c) is provided with minute recesses 81 for oil reservoirs.

[0044] A large number of minute recesses 81 are uniformly formed over the entire area of ​​the inner diameter surface 72c. As shown in Fig. 8, the surface shape of the minute recesses 81 may be elliptical or circular, or may be polygonal including a triangle or a rectangle. The cross-sectional shape of the minute recesses 81 may be triangular, polygonal including a rectangle, semicircular, or semielliptical. In addition, the diameter (diameter when the micro recess 81 is circular, the major axis when the micro recess 81 is elliptical, the longest length between the opposing corners and sides when the micro recess 81 is triangular, and the longest length between the opposing corners when the micro recess 81 is polygonal) and depth (depth of the deepest part) of the micro recess 81 are preferably, for example, about several μm to several mm.

[0045] 9, the minute recesses 81 may be groove-shaped. In this case, the groove-shaped minute recesses 81 may be formed to extend in the width direction of the inner diameter surface 72c (the axial direction of the cage 72), or may be formed to extend in a direction inclined with respect to the width direction. It is preferable to form a large number of minute recesses 81 at predetermined intervals in the circumferential direction of the inner diameter surface 72c. Furthermore, the cross-sectional shape of the minute recesses 81 may be triangular, or may be polygonal including quadrangular, semicircular, or semi-elliptical. Moreover, the groove width and depth (depth at the deepest part) of the minute recess 81 are preferably, for example, about several μm to several mm.

[0046] In addition, in this embodiment, the case where the retainer 72 is guided on the inner diameter of the retainer has been described. However, if the retainer 72 is guided on the outer diameter of the retainer as in the conventional case, the outer diameter surface 72a becomes the guide surface, and therefore the fine recesses 81 may be formed on at least this outer diameter surface 72a, and further, the fine recesses 81 may be formed on the inner diameter surface 72c and / or the outer surface 72e in addition to the outer diameter surface 72a.

[0047] In the second embodiment, the cage 72 is a roller guide. Even in this case, minute recesses 81 may be appropriately formed in the outer diameter surface 72a, the inner diameter surface 72c and the outer side surface 72e of the cage 72.

[0048] According to this embodiment, minute recesses 81 for oil collection are formed on at least the guide surface of the retainer 72, so that an oil film can be formed on the guide surface, and seizure and wear of the retainer 72 can be more effectively prevented.

[0049] Furthermore, in this embodiment, the present invention has been described with reference to a toroidal type continuously variable transmission for aircraft, but the present invention can also be applied to other applications (for example, automobile transmissions). In addition, in this embodiment, the present invention has been described taking as an example a case where it is applied to a double-cavity half-toroidal continuously variable transmission, but is not limited to this, and the present invention can also be applied to a double-cavity full-toroidal continuously variable transmission, and further, to a single-cavity half-toroidal continuously variable transmission, and a single-cavity full-toroidal continuously variable transmission.

[0050] Furthermore, in this embodiment, the case where the output side disc 3 is pressed by the pressing device 12 has been described as an example, but in a toroidal type continuously variable transmission, the input / output relationship between the input side disc and the output side disc may be reversed. Therefore, the present invention can also be applied to a case where the input side disc 2 is pressed by the pressing device 12. In other words, as shown in Figures 10 and 11, the present invention can also be applied to a toroidal type continuously variable transmission that includes an input shaft 1, an input side disc 2 that is splined to the input shaft 1 by a ball spline and rotates integrally with the input shaft 1, and an output side disc 3 that faces the input side disc 2 and is provided rotatably relative to the input shaft 1. [Explanation of symbols]

[0051] 1A Output shaft (shaft) 1a Outer diameter surface 2 Input disk (second disk) 3 Output disk (first disk) 11 Power Roller 70 Bearings 71 Around 72 Cage 72a Outer diameter surface 72c Inner diameter surface (guide surface) 80 Coating 81 Micro recess

Claims

1. A toroidal type continuously variable transmission comprising: a shaft; a first disk and a second disk rotatably mounted on the shaft, the first disk and the second disk being concentric with each other and rotatable integrally with the shaft with their inner surfaces facing each other; a power roller sandwiched between the first disk and the second disk; and a bearing mounted between the shaft and the second disk, the bearing includes a plurality of rollers that are capable of rolling between the shaft and the second disk, and a cylindrical cage that holds the plurality of rollers so as to be capable of rolling, is attached to the shaft, and is clamped in the axial direction by a restricting member whose movement to the left in the axial direction is restricted by a snap ring; A toroidal type continuously variable transmission, wherein the cage is guided by a cage inner diameter or a roller.

2. When the cage is a cage inner diameter guide, If the outer diameter of the cage is D1, the inner diameter is D2, the inner diameter of the second disk is D3, and the outer diameter of the shaft is D4, 2. The toroidal type continuously variable transmission according to claim 1, wherein D3-D1>D2-D4 is set.

3. When the cage is a roller guide, The outer diameter of the cage is D1, the inner diameter is D2, the inner diameter of the second disk is D3, and the outer diameter of the shaft is D4. If the radial movement amount of the cage relative to the rollers (the amount of movement in the radial direction (the radial direction of the cage) relative to the rollers from the position where the cage is disposed coaxially with the shaft) is ΔS, then (D3-D1) / 2>ΔS, and (D2-D4) / 2>ΔS 2. The toroidal type continuously variable transmission according to claim 1, wherein the toroidal type continuously variable transmission is set to:

4. 4. The toroidal type continuously variable transmission according to claim 1, wherein a coating for improving sliding properties is formed on at least the guide surface of the cage.

5. 4. The toroidal type continuously variable transmission according to claim 1, wherein at least a guide surface of the cage is formed with minute recesses for oil collection.

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