JP5082498B2 - Toroidal continuously variable transmission - Google Patents

Description

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

  For example, a double-cavity toroidal continuously variable transmission used as an automobile transmission is configured as shown in FIGS. As shown in FIG. 3, an input shaft 1 is rotatably supported inside the casing 50, and two input side disks 2, 2 and two output side disks 3 are disposed on the outer periphery of the input shaft 1. 3 is 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 driven to rotate by a drive shaft 22 via a loading cam type pressing device 12 provided between an input side disk 2 and a cam plate (loading cam) 7 located on the left side in the drawing. It has become. The output gear 4 is supported on a partition wall (intermediate wall) 13 formed by coupling two members via an angular ball bearing 107 and is supported in the casing 50 via the partition wall 13. Thus, while being able to rotate around the axis O of the input shaft 1, displacement in the direction of the axis O 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 is provided between the inner side surfaces (concave surface; also referred to as a traction surface) 2a and 2a of the input side disks 2 and 2 and the inner side surfaces (concave surface; also referred to as a traction surface) 3a and 3a of the output disks 3 and 3. 11 (see FIG. 4) is rotatably held.

  A step portion 2b is provided on the inner peripheral surface 2c of the input side disk 2 located on the right side in FIG. 3, and the step portion 1b provided on the outer peripheral surface 1a of the input shaft 1 is abutted against the step portion 2b. At the same time, the back surface (right surface in FIG. 3) of the input side disk 2 is abutted against a loading nut 9 screwed into a screw portion formed on the outer peripheral surface of the input shaft 1. 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.

  As shown in FIG. 4, which is a cross-sectional view taken along the line AA in FIG. 3, both the disks 3 and 3 are sandwiched from both sides inside the casing 50 and at the side positions of the output side disks 3 and 3. The pair of yokes 23A and 23B is supported in the state. The pair of yokes 23A and 23B are formed in a rectangular shape by pressing or forging a metal such as steel. In order to support pivots 14 provided at both ends of the trunnion 15 to be described later in a swingable manner, circular support holes 18 are provided at the four corners of the yokes 23A and 23B, and the width direction of the yokes 23A and 23B. A circular locking hole 19 is provided at the center of the.

  The pair of yokes 23A and 23B is supported by support posts 64 and 68 formed on the inner surface of the casing 50 so as to be able to swing around the support posts 64 and 68 as fulcrums. These support posts 64 and 68 are provided so as to face the first cavity 221 and the second cavity 222, respectively, between the inner side surface 2a of the input side disk 2 and the inner side surface 3a of the output side disk 3. Yes.

  Therefore, the yokes 23 </ b> A and 23 </ b> B are supported by the support posts 64 and 68, and one end thereof faces the outer peripheral portion of the first cavity 221, and the other end faces the outer peripheral portion of the second cavity 222. doing.

  Since the first and second cavities 221 and 222 have the same structure, only the first cavity 221 will be described below.

  As shown in FIG. 4, inside the casing 50, the first cavity 221 includes a pair of trunnions that swing around a pair of pivots (tilting axes) 14 and 14 that are twisted with respect to the input shaft 1. 15 and 15 are provided. In FIG. 4, the input shaft 1 is not shown. Each trunnion 15, 15 is a pair of bent portions formed in a state where the trunnions 15, 15 are bent toward the inner side surface of the support plate 16 at both ends in the longitudinal direction (vertical direction in FIG. 4) of the support plate 16. Wall portions 20 and 20 are provided. Then, the trunnions 15 and 15 form a pocket portion P that is a concave accommodation space for accommodating the power roller 11 by the bent wall portions 20 and 20. 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 in the central portion of the support plate portion 16, and a base end portion (first shaft portion) 23 a of a displacement shaft 23 as a support shaft 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 23 supported at the center of each trunnion 15, 15 can be adjusted. In addition, each power roller 11 is rotatably supported around the tip end portion (second shaft 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.

  As described above, the pivot shafts 14 and 14 of the trunnions 15 and 15 are supported so as to be swingable with respect to the pair of yokes 23A and 23B and displaceable in the axial direction (vertical direction in FIG. 4). The trunnions 15 and 15 are restricted from moving in the horizontal direction by the yokes 23A and 23B. As described above, four circular support holes 18 are provided at the four corners of each of the yokes 23A and 23B, and the pivot shafts 14 provided at both ends of the trunnion 15 are respectively provided in the support holes 18 with radial needle bearings ( A tilting bearing 30 is supported so as to be swingable (tiltable). Further, as described above, the circular locking hole 19 is provided in the central portion of the yokes 23A and 23B in the width direction (left and right direction in FIG. 4), and the inner peripheral surface of the locking hole 19 is cylindrical. Support posts 64 and 68 are internally fitted as surfaces. 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 (rolling elements) 26, 26, an annular retainer 27 that holds the balls 26, 26 in a freely rolling manner, and an annular outer ring 28. It consists of and. 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.

  Further, drive rods (shaft portions extending from the pivot shaft) 29 and 29 are respectively provided at one end portions (lower end portions in FIG. 4) of the trunnions 15 and 15, and outer peripheral surfaces of intermediate portions of the drive rods 29 and 29. The drive pistons (hydraulic pistons) 33, 33 are fixedly provided. 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 drive shaft 22 is transmitted to the input side disks 2 and 2 and the input shaft 1 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 (offset) in opposite directions. For example, the power roller 11 on the left side in FIG. 4 is displaced to the lower side in the figure, and the power roller 11 on the right side in the figure is displaced to the upper side 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 positions of the peripheral surfaces (traction surfaces) 11a and 11a of the power rollers 11 and 11 and the inner surfaces 2a and 3a change, and the rotational speed ratio between the input shaft 1 and the output gear 4 is changed. Change. 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, in such a toroidal-type continuously variable transmission, power transmission between the power roller 11 and the input / output side disks 2 and 3 is non-contact by a traction force through an oil film in order to prevent damage to the surface of these members. Is done. Therefore, a sufficient amount of lubricating oil (traction oil) that can form an oil film for transmitting torque in a non-contact manner is supplied to the traction surface formed between the power roller 11 and the input / output side disks 2 and 3. In addition, it is necessary to sufficiently lubricate the bearings (hereinafter also referred to as power roller bearings) that rotatably support the disks 2 and 3 and the power roller 11. Therefore, in Patent Document 1, for example, a mesh filter is attached to the displacement shaft 23 in the power roller bearing, and contamination (foreign matter) is removed immediately before the thrust ball bearing 24 having severe use conditions, thereby lubricating the bearing. Trying to do well.

JP 2004-324877 A (FIG. 10)

  However, in the structure as disclosed in Patent Document 1, since the filter is mounted on the displacement shaft 23, it is difficult to secure a large space for mounting the filter from the viewpoint of strength and rigidity, and only a small filter is mounted. Can not do it. For this reason, the filter may be clogged early.

  The present invention has been made in view of the above circumstances, and provides a toroidal continuously variable transmission that can reduce clogging of a filter for removing foreign matter in lubricating oil supplied to a power roller bearing. Objective.

  In order to achieve the above object, the toroidal continuously variable transmission according to claim 1 is characterized in that an input side disk and an output that are supported concentrically and rotatably with their respective inner surfaces facing each other. A side disk, a power roller sandwiched between the input side disk and the output side disk, a twisted position with respect to the rotation center axis of the input side disk and the output side disk, and concentrically with each other The thrust bearing includes a trunnion that swings about a pair of pivots provided and rotatably supports the power rollers, and a thrust bearing that supports a load in a thrust direction applied to the power rollers. An inner ring formed by the power roller; an outer ring; and a rolling element that rolls between the inner ring and the outer ring. Are provided with a pair of guide surface portions that are opposed to each other and extend along a direction perpendicular to the rotation center axis of the power roller, and when a tangential force in a direction along the pivot acts on the power roller, In the toroidal continuously variable transmission in which the outer peripheral surface of the outer ring can come into contact with the guide surface portion, the outer ring extends substantially perpendicularly from the outer ring main body portion forming the outer ring portion of the thrust bearing and the outer ring main body portion. And a shaft portion that rotatably supports the power roller, and the outer ring is provided with a recess that forms part of an oil passage for supplying lubricating oil to the thrust bearing. Is equipped with a filter for removing foreign substances in the lubricating oil.

  In the invention described in claim 1, when a tangential force is applied to the power roller, the outer peripheral surface of the outer ring and the guide surface portion of the trunnion come into contact with each other, and the power roller rolls on the guide surface portion. Since the pressing force is transmitted from the side disk to the output side disk, the shaft part of the outer ring becomes a part that does not contribute to strength, rigidity, and function, so by providing a recess in the outer ring, especially the shaft part By providing the concave portion, it is possible to ensure a large concave portion without hindering strength, rigidity, and function, and thus it is possible to attach a large filter to the concave portion. As a result, clogging of the filter can be reduced, and the weight of the outer ring can be reduced by the amount of the recess, so that the entire apparatus can be reduced in weight.

  According to a second aspect of the present invention, in the invention described in the first aspect, the concave portion extends in the axial direction from the outer ring main body portion to the shaft portion. To do.

  In the invention described in claim 2, since the concave portion extends in the axial direction from the outer ring main body portion to the shaft portion, the inner volume of the concave portion can be secured to the maximum, and the filter is clogged. Can be further reduced, and weight reduction of the entire apparatus can be promoted.

According to the present invention, since the outer ring having the shaft portion that supports the power roller is provided with the recess, and the oil filter is attached to the recess, the clogging of the oil filter can be reduced, and the weight of the entire apparatus can be reduced. Can also be planned.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The feature of the present invention lies in the lubricating oil supply structure for supplying the lubricating oil to the thrust bearing, and the other configurations and functions are the same as the conventional configurations and functions described above. Only the characteristic part of FIG. 4 is referred to, and other parts are simply described with the same reference numerals as those in FIGS.

  1 and 2 show an embodiment of the present invention. As shown in FIG. 1, in this embodiment, a structure that can smoothly swing and guide the power roller 11 with respect to the trunnion 15 while avoiding the offset of the shaft portion that supports the power roller 11 is adopted. Has been. More specifically, the outer ring 28 extends perpendicularly from the center of the substantially disc-shaped outer ring main body 28a forming the outer ring of the thrust ball bearing 24 and the inner side surface of the outer ring main body 28a, and rotates the power roller 11. The shaft portion 28b is supported so as to be able to be supported (the outer ring 28 having the conventional structure and the displacement shaft 23 are integrated in a so-called manner). The outer ring main body portion 28a has an outer peripheral surface 110 concentric with the rotation center axis of the power roller 11, that is, the rotation center axis of the shaft portion 28b. The outer peripheral surface 110 of the outer ring main body 28a is crowned.

  The outer ring 28 is accommodated in a concave pocket portion P inside the trunnion 15, and the trunnion 15 is opposed to each other at a position facing the outer peripheral surface 110 of the outer ring main body 28 a and the power roller 11 rotates. A pair of guide surface portions 120 and 120 extending along a direction perpendicular to the central axis (rotating axis) is formed. More specifically, the pair of guide surface portions 120, 120 extend along a direction orthogonal to the rotation center axis (rotation axis) of the power roller 11 and orthogonal to the pivot axis 14. Each guide surface portion 120 is formed by a tip surface (front surface) formed of a substantially rectangular flat surface of a protruding portion that slightly protrudes in a substantially square plate shape inward from the inner surface of the bent wall portion 20 of the trunnion 15. Each guide surface portion 120 is formed in the bent wall portion 20 of the trunnion 15 at a substantially central portion in the direction orthogonal to the rotation center axis (rotation axis) of the power roller 11. Each guide surface portion 120 is increased in hardness by induction hardening or the like, and the surface roughness is increased by grinding. The distance between the guide surface portions 120 and 120 is set slightly larger than the outer diameter of the outer ring main body portion 28a.

Further, at least one of the guide surface portions 120 and 120 and the outer peripheral surface 110 of the outer ring main body portion 28a of the outer ring 28 is subjected to a friction coefficient reduction process. As the friction coefficient reduction process, for example, a coating of polytetrafluoroethylene (PTFE) or molybdenum disulfide (MoS ₂ ) is formed on at least one of the guide surface portions 120 and 120 and the outer peripheral surface 110 of the outer ring main body portion 28a.

Further, between the trunnion 15 and the outer ring main body portion 28a, a thrust rolling bearing 130 for supporting a load in a thrust direction applied to the power roller 11 (a direction from the small end face side to the large end face side of the power roller 11) is interposed. Has been.
Further, a radial rolling bearing 140 is interposed between the shaft portion 28 b and the power roller 11.

  Therefore, in the above configuration, when a tangential force in the radial direction (the direction along the pivot 14 of the trunnion 15; the y direction in the figure) acts on the power roller 11, the power roller 11 is on one side of the pivots 14 and 14 (in the figure). Accordingly, the outer peripheral surface 110 of the outer ring main body portion 28 a is pressed against one of the guide surface portions 120, 120 of the trunnion 15. The outer ring main body portion 28a can roll on the guide surface portion 120. That is, the outer ring main body portion 28a and thus the power roller 11 can move in the direction twisted perpendicular to the rotation center axis of the power roller 11 with respect to the trunnion 15 (x direction in the figure).

  In the present embodiment, the trunnion 15 is formed with an oil supply path 200 for supplying the lubricating oil to a portion reaching the pocket P (opposite the outer ring 28). The oil supply path 200 extends from a drive rod 29 that communicates with the drive cylinder 31. An oil passage 202 communicating with the oil supply passage 200 is formed in the outer ring 28. The oil passage 202 extends in the axial direction from the end surface of the outer ring main body portion 28a facing the end portion of the oil supply passage 200 toward the end surface of the shaft portion 28b, and a part thereof (in this embodiment, the shaft portion 28b). The most part of the oil passage 202 excluding the vicinity of the end portion) is formed as a wide recessed space S that greatly expands in the radial direction. A filter 210 for removing foreign matter in the lubricating oil is mounted in the concave space S.

  In such a configuration, as shown in FIG. 2, the lubricant supplied from the oil supply path 200 has foreign matters removed by the large filter 210 mounted in the recessed space S of the outer ring 28, as indicated by the arrows. Thereafter, the oil flows from the shaft end of the oil passage 202 to the radial rolling bearing 140 through a gap between the shaft 28 b and the small end surface of the power roller 11, and is supplied to the thrust ball bearing 24 from here.

  As described above, in this embodiment, when a tangential force is applied to the power roller 11, the outer peripheral surface of the outer ring 28 and the guide surface portion 120 of the trunnion 15 come into contact with each other, and the power roller 11 is moved on the guide surface portion 120. , The pressing force is transmitted from the input side disk to the output side disk, and the shaft portion 28b of the outer ring 28 is a portion that does not contribute to strength, rigidity, or function. By providing S, particularly by providing a recess in the shaft portion 28b, it is possible to secure a large recess S without hindering strength, rigidity, and function, and therefore mounting a large filter 210 in the recess S. can do. As a result, clogging of the filter 210 can be reduced, and the weight of the outer ring 28 can be reduced by the amount of the recess S, so that the entire apparatus can be reduced in weight.

  Further, in the present embodiment, since the recess S extends in the axial direction from the outer ring main body portion 28a to the shaft portion 28b, the inner volume of the recess S can be secured to the maximum, and the filter 210 is further clogged. While being able to reduce, the weight reduction of the whole apparatus can be promoted.

  In the present embodiment, the trunnion 15 is provided with a pair of guide surface portions 120 and 120 that are opposed to each other and extend in the direction orthogonal to the rotation center axis (rotation axis) of the power roller 11. When a radial tangential force acts on one of the guide surface portions 120, 120, the outer peripheral surface 110 of the outer ring main body portion 28 a of the outer ring 28 contacts the outer ring main body portion 28 a on the guide surface portion 120. As a result, the outer ring 28 and thus the power roller 11 slide along the rotation center axis of the disks 2 and 3, so that the power roller 11 and the trunnion 15 are moved together with the outer ring 28 while avoiding the offset of the shaft portion supporting the power roller 11. Can be smoothly rolled and guided with a small frictional resistance, so that the input side disk 2 is pressed against the output side disk 3 It is possible to transmit a force smoothly. In addition, since such a function and effect can be realized simply by providing the pair of guide surface portions 120, 120 on the trunnion 15, the structure is simple, and it is not necessary to perform a large number of highly accurate processes (power rollers). Therefore, it is not necessary to offset the shaft portion that supports the material, so that the workability is good and the cost is low.

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

It is principal part sectional drawing of the toroidal type continuously variable transmission which concerns on embodiment of this invention. It is sectional drawing which shows the supply path | route of the lubricating oil in the structure of FIG. It is sectional drawing which shows an example of the specific structure of the toroidal type continuously variable transmission conventionally known. It is sectional drawing which follows the AA line of FIG.

Explanation of symbols

2 Input side disk 3 Output side disk 11 Power roller 14 Axis 15 Trunnion 24 Thrust ball bearing 28 Outer ring 28a Outer ring main body part 28b Shaft part 120 Guide surface part 202 Oil path 210 Filter S Recessed space (recessed part)

Claims (2)

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 swing about a pair of pivots concentrically with each other at a twisted position with respect to the rotation center axis of the input side disk and the output side disk, and the power rollers can be rotated freely. A trunnion for supporting, and a thrust bearing for supporting a load in a thrust direction applied to the power roller. The trunnion is opposed to each other and in a direction perpendicular to the rotation center axis of the power roller. A pair of guide surface portions extending in the direction of the outer ring, and when a tangential force in the direction along the pivot acts on the power roller, the outer peripheral surface of the outer ring can be brought into contact with these guide surface portions. In a step transmission,
The outer ring includes an outer ring main body portion that forms an outer ring portion of the thrust bearing, and a shaft portion that extends substantially perpendicularly from the outer ring main body portion and rotatably supports the power roller. The outer ring includes the thrust ring. A toroidal type characterized in that a recess for forming part of an oil passage for supplying lubricating oil to the bearing is provided, and a filter for removing foreign matter in the lubricating oil is mounted in the recess. Continuously variable transmission.   The toroidal continuously variable transmission according to claim 1, wherein the recess extends in the axial direction from the outer ring main body portion to the shaft portion.

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