JP2012159115A - Troidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively achieve efficient supply of lubricant to a radial needle bearing rotatably supporting a power roller with respect to a trunnion, reduction of lubricant stirring resistance by a needle (roller), and an increased discharge property of lubricant by the radial needle bearing.SOLUTION: The radial needle bearing 99 which rotatably supports the power roller 11 with respect to a shaft part 23 supported with the trunnion comprises: a retainer 90 composed by connecting a pair of annular rim parts 97a, 97b with a plurality of pillars 91; and a plurality of rollers 92 rotatably supported with respective pockets 94 formed between the pillars 91 of the retainer. The inner and outer surfaces of the retainer 90 are formed as smooth surfaces, the wall thickness d of the pillar 91 of the retainer 90 is set to be a half or more of the diameter D of the roller 92, and a cross-section area by a clearance X between the outer surface of the retainer and the power roller 11 is larger than the cross-section area by a clearance Y between the inner surface of the retainer 90 and the shaft part 23.

Description

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

  For example, a double-cavity toroidal continuously variable transmission used as a transmission for an automobile is configured as shown in FIGS. As shown in FIG. 6, an input shaft (center shaft) 1 is rotatably supported inside the casing 50, and two input side disks 2, 2 and two outputs are provided on the outer periphery of the input shaft 1. Side disks 3 and 3 are attached. An output gear 4 is rotatably supported on the outer periphery of the intermediate portion of the input shaft 1. Output side disks 3 and 3 are connected to cylindrical flange portions 4a and 4a provided at the center of the output gear 4 by spline coupling.

  The input shaft 1 is rotationally driven by a drive shaft 22 via a loading cam type pressing device 12 provided between an input side disk 2 and a cam plate 7 located on the left side in the drawing. . The output gear 4 is supported in the casing 50 via a partition wall 13 formed by coupling two members, so that the output gear 4 can rotate around the axis O of the input shaft 1 while the axis O. Directional displacement is prevented.

  The output side disks 3 and 3 are supported by needle bearings 5 and 5 interposed between the input shaft 1 so as to be rotatable about the axis O of the input shaft 1. Further, the left input side disk 2 in the figure is supported on the input shaft 1 via a ball spline 6, and the right side input disk 2 in the figure is splined to the input shaft 1. Rotates with the input shaft 1. A power roller 11 (see FIG. 7) is rotatable between the inner side surfaces (concave surfaces) 2a, 2a of the input side disks 2, 2 and the inner side surfaces (concave surfaces) 3a, 3a of the output side disks 3, 3. Is sandwiched between.

  A step 2b is provided on the inner peripheral surface 2c of the input side disk 2 located on the right side in FIG. 6, and the step 1b provided on the outer peripheral surface 1a of the input shaft 1 is abutted against the step 2b. At the same time, the back surface (the right surface in FIG. 6) of the input side disk 2 is abutted against the loading nut 9. Thereby, the displacement of the input side disk 2 in the direction of the axis O with respect to the input shaft 1 is substantially prevented. Further, a disc spring 8 is provided between the cam plate 7 and the flange 1d of the input shaft 1, and this disc spring 8 is a concave surface 2a, 2a, 3a of each disk 2, 2, 3, 3. , 3a and the contact surface between the peripheral surfaces 11a and 11a of the power rollers 11 and 11 are applied with a pressing force.

  FIG. 7 is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 7, a pair of trunnions 15, 15 that swing about a pair of pivots 14, 14 that are twisted with respect to the input shaft 1 are provided inside the casing 50. In addition, illustration of the input shaft 1 is abbreviate | omitted in FIG. Each trunnion 15, 15 is a pair of bent wall portions 20, 20 formed at both ends in the longitudinal direction (vertical direction in FIG. 7) of the support plate portion 16 so as to be bent toward the inner surface side of the support plate portion 16. have. The bent wall portions 20 and 20 form concave pocket portions P for accommodating the power rollers 11 in the trunnions 15 and 15. Further, the pivot shafts 14 and 14 are concentrically provided on the outer side surfaces of the bent wall portions 20 and 20, respectively.

  A circular hole 21 is formed at the center of the support plate portion 16, and a base end portion 23 a of the displacement shaft 23 is supported in the circular hole 21. Then, by swinging each trunnion 15, 15 about each pivot 14, 14, the inclination angle of the displacement shaft (shaft) 23 supported at the center of each trunnion 15, 15 can be adjusted. It has become. In addition, each power roller 11 is rotatably supported via a radial needle bearing 99 around the distal end portion 23b of the displacement shaft 23 protruding from the inner surface of each trunnion 15, 15. 11 is sandwiched between the input disks 2 and 2 and the output disks 3 and 3. In addition, the base end part 23a and the front-end | tip part 23b of each displacement shaft 23 and 23 are mutually eccentric.

  The pivot shafts 14 and 14 of the trunnions 15 and 15 are supported so as to be swingable and axially displaceable with respect to the pair of yokes 23A and 23B, respectively. The horizontal movement of the trunnions 15 and 15 is restricted by 23B. Each yoke 23A, 23B is formed in a rectangular shape by pressing or forging a metal such as steel. Four circular support holes 18 are provided at the four corners of each of the yokes 23 </ b> A and 23 </ b> B, and the pivot shafts 14 provided at both ends of the trunnion 15 swing through the radial needle bearings 30. It is supported freely. Further, a circular locking hole 19 is provided in the central portion of the yokes 23A and 23B in the width direction (the left-right direction in FIG. 6). 64 and 68 are fitted inside. That is, the upper yoke 23A is swingably supported by the spherical post 64 supported by the casing 50 via the fixing member 52, and the lower yoke 23B is supported by the spherical post 68 and the drive for supporting the same. The upper cylinder body 61 of the cylinder 31 is swingably supported.

  The displacement shafts 23 and 23 provided in the trunnions 15 and 15 are provided at positions 180 degrees opposite to the input shaft 1. Further, the direction in which the distal end portion 23b of each of the displacement shafts 23, 23 is eccentric with respect to the base end portion 23a is the same direction as the rotational direction of both the disks 2, 2, 3, 3 (in FIG. (Reverse direction). Further, the eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 1 is disposed. Accordingly, the power rollers 11 and 11 are supported so that they can be slightly displaced in the longitudinal direction of the input shaft 1. As a result, even if each power roller 11, 11 tends to be displaced in the axial direction of the input shaft 1 due to elastic deformation of each component member based on the thrust load generated by the pressing device 12, each component This displacement is absorbed without applying an excessive force to the member.

  Further, 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 24 that is a thrust rolling bearing, and a thrust needle bearing, in order from the outer surface side of the power roller 11. 25. Among these, the thrust ball bearing 24 supports the rotation of each power roller 11 while supporting the load in the thrust direction applied to each power roller 11. Each of such thrust ball bearings 24 includes a plurality of balls (hereinafter referred to as rolling elements) 26, 26, an annular retainer 27 that holds the rolling elements 26, 26 in a freely rolling manner, And an annular outer ring 28. Further, the inner ring raceway of each thrust ball bearing 24 is formed on the outer side surface (large end surface) of each power roller 11, and the outer ring raceway is formed on the inner side surface of each outer ring 28.

  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 a thrust needle bearing 25 supports the thrust load applied to each outer ring 28 from the power roller 11, while the power roller 11 and the outer ring 28 swing around the base end portion 23 a of each displacement shaft 23. Allow.

  Furthermore, drive rods (trunnion shafts) 29 and 29 are provided at one end portions (lower end portions in FIG. 7) of the trunnions 15 and 15, respectively, and a drive piston ( Hydraulic pistons) 33, 33 are fixed. Each of these drive pistons 33 and 33 is oil-tightly fitted in a drive cylinder 31 constituted by an upper cylinder body 61 and a lower cylinder body 62. The drive pistons 33 and 33 and the drive cylinder 31 constitute a drive device 32 that displaces the trunnions 15 and 15 in the axial direction of the pivots 14 and 14 of the trunnions 15 and 15.

  In the case of the toroidal continuously variable transmission configured as described above, the rotation of the input shaft 1 is transmitted to the input side disks 2 and 2 via the pressing device 12. Then, the rotation of the input side disks 2 and 2 is transmitted to the output side disks 3 and 3 via the pair of power rollers 11 and 11, and the rotation of the output side disks 3 and 3 is further transmitted to the output gear 4. It is taken out more.

  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. As the drive pistons 33 and 33 are displaced, the pair of trunnions 15 and 15 are displaced in directions opposite to each other. For example, the power roller 11 on the left side of FIG. 7 is displaced downward in the figure, and the power roller 11 on the right side of FIG. 7 is displaced upward in the figure. As a result, the peripheral surfaces 11a and 11a of the power rollers 11 and 11 act on contact portions of the input side disks 2 and 2 and the inner side surfaces 2a, 2a, 3a and 3a of the output side disks 3 and 3, respectively. The direction of the tangential force changes. As the force changes, the trunnions 15 and 15 swing (tilt) in opposite directions around the pivots 14 and 14 pivotally supported by the yokes 23A and 23B.

  As a result, the contact position between the peripheral surfaces 11a and 11a of the power rollers 11 and 11 and the inner surfaces 2a and 3a changes, and the gear ratio between the input shaft 1 and the output gear 4 changes. Further, when the torque transmitted between the input shaft 1 and the output gear 4 fluctuates and the amount of elastic deformation of each component changes, the power rollers 11 and 11 and the outer rings attached to the power rollers 11 and 11 will be described. 28 and 28 slightly rotate around the base end portions 23a and 23a of the displacement shafts 23 and 23, respectively. Since the thrust needle bearings 25 and 25 exist between the outer side surfaces of the outer rings 28 and 28 and the inner side surfaces of the support plate portions 16 constituting the trunnions 15 and 15, respectively, the rotation is performed smoothly. Is called. Therefore, as described above, the force for changing the inclination angle of each displacement shaft 23, 23 can be small.

  By the way, the radial needle bearing 99 that rotatably supports the power roller 11 with respect to the distal end portion 23b of the displacement shaft 23 includes a plurality of needles (rollers) and a holder that holds these needles in a freely rolling manner. In this case, the efficient supply of the lubricating oil to the radial needle bearing 99, the reduction of the lubricating oil stirring resistance by the needle, and the improvement of the discharging performance of the lubricating oil by the radial needle bearing 99 are achieved by the rotation of the power roller 11. This is important for improving performance and cooling efficiency. Therefore, conventionally, a smooth flow of the lubricating oil in the radial needle bearing 99 is ensured by devising the shape of the cage and the like (for example, see Patent Documents 1 to 3).

JP 2004-346980 A JP 2009-58044 A Japanese Patent No. 2627885

  However, it has been difficult to say that the proposed means can always obtain a sufficient effect.

  The present invention has been made in view of the above circumstances, and efficiently supplies lubricating oil to a radial needle bearing that rotatably supports a power roller with respect to a trunnion, and reduces lubricating oil stirring resistance by a needle (roller). Another object of the present invention is to provide a toroidal-type continuously variable transmission that can effectively improve the lubricating oil discharge performance by a radial needle bearing.

  In order to achieve the above object, the invention according to claim 1 is directed to an input side disk and an output side disk that are supported concentrically and rotatably with the respective inner surfaces facing each other, and A power roller sandwiched between the input-side disk and the output-side disk, tilting about a pivot that is twisted with respect to the center axis of the input-side disk and the output-side disk, and In a toroidal continuously variable transmission including a trunnion that rotatably supports a power roller via a radial needle bearing, the radial needle bearing rotatably supports the power roller with respect to a shaft portion supported by the trunnion. And a cage formed by connecting a pair of annular rim portions by a plurality of columns, and a cage formed between the columns of the cage. A plurality of cylindrical rollers that are rotatably held in the pockets, the inner and outer surfaces of the cage are formed as smooth surfaces, and the thickness of the pillar of the cage is It is set to be more than half of the diameter of the roller, and the cross-sectional area due to the gap between the outer surface of the cage and the power roller is larger than the cross-sectional area due to the gap between the inner surface of the cage and the shaft portion. Features.

  In the first aspect of the present invention, the inner and outer surfaces of the cage are formed as smooth surfaces, and the thickness of the columns of the cage is set to be more than half of the diameter of the roller. Since the surface of the cage that becomes the flow path of the roller becomes smooth and the roller is largely covered by the column of the cage, the lubricating oil stirring resistance by the cage and the roller can be effectively reduced, and Since the cross-sectional area due to the gap between the outer surface of the cage and the power roller is larger than the cross-sectional area due to the gap between the inner surface of the cage and the shaft, it is possible to effectively discharge the lubricating oil by the radial needle bearing. (If the lubricating oil is poorly discharged, the bearing is filled with oil, leading to an increase in oil agitation resistance). In addition, when comparing the temperature of the power roller and the shaft during operation, the power roller having a traction surface is higher, so the cross-sectional area due to the gap between the outer surface of the cage and the power roller is the same as the inner surface of the cage. By making it larger than the cross-sectional area due to the gap between the shaft part, the power roller can be cooled more actively, which can improve the durability life and the traction coefficient and thereby improve the cooling efficiency. it can. Therefore, efficient supply of the lubricating oil to the radial needle bearing can be realized.

  According to a second aspect of the present invention, in the first aspect of the present invention, a spiral groove is formed on the outer surface of the retainer column.

  In the second aspect of the present invention, since the spiral groove is formed on the outer surface of the retainer column, the lubricating oil discharging performance by the radial needle bearing can be improved more effectively. In addition, it is preferable that the formation direction (inclination direction) of the spiral groove is directed in such a direction that the lubricating oil is easily discharged to the outside of the cage when the cage is rotated.

  The invention described in claim 3 is the invention described in claim 1 or 2, characterized in that a spiral groove is formed on the surface of the rim portion of the cage.

  In the third aspect of the present invention, since the spiral groove is formed on the surface of the rim portion of the cage, the lubricating oil discharging performance by the radial needle bearing can be improved more effectively. In particular, when the spiral groove is formed on the outer surface of the retainer column as in the invention described in claim 2, the retainer receives a reaction force from the lubricating oil slightly, so that the rim portion of the retainer is Although the friction loss may increase due to contact with the opposing member, such an increase in friction loss can be suppressed if a spiral groove is formed on the surface of the rim portion.

  According to the toroidal continuously variable transmission of the present invention, efficient supply of lubricating oil to a radial needle bearing that rotatably supports a power roller with respect to a trunnion, reduction of lubricating oil stirring resistance by a needle (roller), and Further, it is possible to effectively improve the lubricating oil discharge performance by the radial needle bearing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the 1st Embodiment of this invention, Comprising: (a) is sectional drawing of the structure part by which a power roller is rotatably supported by the displacement shaft of a trunnion via a radial needle bearing, (b) is radial. The perspective view of a needle bearing, (c) is a sectional view similar to (a). The 2nd Embodiment of this invention is shown, (a) is a perspective view of a radial needle bearing, (b) is a side view of a radial needle bearing, FIG. 3 is a cross-sectional view for explaining the flow direction of lubricating oil in the configuration of FIG. 2. It is a side view for demonstrating the assembly direction of the holder | retainer in the structure of FIG. It is a figure for demonstrating the assembly direction of the holder | retainer in the 3rd Embodiment of this invention, Comprising: (a) is a side view, (b) is a top view. It is sectional drawing which shows an example of the specific structure of the half toroidal type continuously variable transmission conventionally known. It is sectional drawing which follows the AA line of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The feature of the present invention lies in the structure of the radial needle bearing that rotatably supports the power roller with respect to the trunnion, and other configurations and operations are the same as the conventional configurations and operations described above. Only the characteristic part of the present invention will be referred to, and other parts will be simply described with the same reference numerals as those in FIGS.

  FIG. 1 shows a first embodiment of the present invention. As shown in FIGS. 1A and 1C, in this embodiment, the displacement shaft 23 is integrated with the outer ring 28, and the distal end portion 23 b of the displacement shaft 23 does not penetrate the power roller 11. It terminates inside the roller 11. Further, as shown in FIG. 1B, a radial needle bearing 99 that rotatably supports the power roller 11 with respect to the displacement shaft (shaft portion) 23 of the trunnion 15 includes a pair of annular rim portions 97a, A retainer 90 formed by connecting 97b by a plurality of pillars 91, and a plurality of cylindrical rollers (needle) that are rotatably held in respective pockets 94 formed between the pillars 91 of the retainer 90. 92. Here, the cage 90 is formed of a material such as brass or resin, for example.

  In the present embodiment, the inner surface and the outer surface of the cage 90 are formed as smooth surfaces, and the thickness d of the column 91 of the cage 90 is set to be more than half the diameter D of the roller 92. Further, the cross-sectional area formed by the gap X between the outer surface of the cage 90 and the power roller 11 is larger than the cross-sectional area formed by the gap Y between the inner surface of the cage 90 and the tip 23b of the displacement shaft 23. Is also set larger.

  Thus, according to the present embodiment, the inner surface and the outer surface of the cage 90 are formed as smooth surfaces, and the thickness d of the column 91 of the cage 90 is set to be half or more of the diameter D of the roller 92. In other words, the surface of the cage 90 serving as a flow path for the lubricating oil becomes smooth, and the roller 92 is largely covered by the column 91 of the cage 90. Therefore, the lubricating oil by the cage 90 and the roller 92 is used. Stirring resistance can be effectively reduced. Further, since the cross-sectional area due to the gap X between the outer surface of the cage 90 and the power roller 11 is larger than the cross-sectional area due to the gap Y between the inner surface of the cage 90 and the displacement shaft 23, lubrication by the radial needle bearing 99 is performed. The oil discharging ability can be effectively improved (if the lubricating oil discharging ability is poor, the inside of the bearing 99 is filled with oil, leading to an increase in oil stirring resistance). Further, when the temperatures of the power roller 11 and the displacement shaft 23 in operation are compared, the power roller 11 having a traction surface is higher, so that the cross-sectional area due to the gap X between the outer surface of the cage 90 and the power roller 11. Is made larger than the cross-sectional area due to the gap Y between the inner surface of the cage 90 and the displacement shaft 23, the power roller 11 can be more actively cooled, and the durability life and the traction coefficient can be improved. As a result, the cooling efficiency can be improved. Therefore, an efficient supply of lubricating oil to the radial needle bearing 99 can be realized.

  2 to 4 show a second embodiment of the present invention. As shown in FIG. 2, in this embodiment, a spiral groove 105 is formed on the outer surface of the column 91 of the cage 90. In this case, the formation direction (inclination direction) of the spiral groove 105 is directed to a direction in which the lubricating oil is easily discharged to the outside of the cage 90 when the cage 90 rotates. Specifically, as shown in FIG. 4, the radial needle bearing 99 is incorporated so that the first rim portion 97 a faces the retainer 27 of the thrust ball bearing 24. As indicated by an arrow in a), the lubricating oil flowing from the outer ring 28 side toward the power roller 11 side through the oil passage 109 penetrating the center of the displacement shaft 23 and the end surface of the distal end portion 23b of the displacement shaft 23 and the power roller The spiral groove 105 so that it flows through the radial needle bearing 99 in the direction opposite to the inflow direction (direction P in which oil is desired to be discharged) through the gap with the screw 11 and smoothly exits horizontally through the thrust ball bearing 24. Is extending obliquely from the second rim portion 97b toward the first rim portion 97a in the direction opposite to the rotation direction Q of the retainer 90. 3B shows a modified structure in which the displacement shaft 23 protrudes through the power roller 11 and a washer 119 is attached to the protruding opening, unlike FIG. 3A. There is no change in the shape of the spiral groove 105 and the oil flow direction.

  As described above, according to the present embodiment, since the spiral groove 105 is formed on the outer surface of the column 91 of the cage 90, the discharge performance of the lubricating oil by the radial needle bearing 99 can be improved more effectively. Can do. The spiral groove 105 may be formed on the inner surface of the column 91.

  FIG. 5 shows a third embodiment of the present invention. As illustrated, in this embodiment, in addition to the configuration of the second embodiment, a spiral groove 129 is formed on the surface of the second rim portion 97b of the cage 90. When the spiral groove 105 is formed on the outer surface of the column 91 of the retainer 90 as in the second embodiment, the retainer 90 receives a reaction force F from the lubricating oil slightly. (In this embodiment, the second rim portion 97b) comes into contact with the opposing member (the power roller 11 in the configuration of FIG. 3A and the washer 109 in the configuration of FIG. 3B) to cause friction loss. However, if a spiral groove 129 is formed on the surface of the rim portion (second rim portion 97b in this embodiment), such an increase in friction loss can be suppressed, and the radial needle can be suppressed. Lubricating oil discharging performance by the bearing 99 can be improved more effectively.

  The present invention can be applied to various half-toroidal continuously variable transmissions such as a single cavity type and a double cavity type.

2 Input side disk 3 Output side disk 11 Power rollers 15, 15 Trunnion 23 Displacement shaft (shaft)
90 Cage 91 Column 92 Roller 94 Pocket 97a, 97b Rim 99 Radial needle bearing 105, 129 Spiral groove

Claims (3)

An input side disk and an output side disk that are supported concentrically and rotatably with their inner side surfaces facing each other, and a power roller sandwiched between the input side disk and the output side disk And a trunnion that tilts about a pivot that is twisted with respect to a central axis of the input side disk and the output side disk, and that rotatably supports the power roller via a radial needle bearing. Toroidal-type continuously variable transmission with
The radial needle bearing includes a retainer that rotatably supports the power roller with respect to a shaft portion supported by a trunnion, and a pair of annular rim portions connected by a plurality of columns, and the retainer Comprising a plurality of cylindrical rollers that are rotatably held in respective pockets formed between the columns,
The inner surface and the outer surface of the cage are formed as smooth surfaces, and the thickness of the pillar of the cage is set to be more than half of the diameter of the roller, between the outer surface of the cage and the power roller. A toroidal continuously variable transmission, wherein a cross-sectional area due to the gap is larger than a cross-sectional area due to the gap between the inner surface of the cage and the shaft portion.   The toroidal continuously variable transmission according to claim 1, wherein a spiral groove is formed on an outer surface of the retainer column.   The toroidal continuously variable transmission according to claim 1 or 2, wherein a spiral groove is formed on a surface of a rim portion of the cage.

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