JP5817282B2 - 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 a transmission for an automobile is configured as shown in FIGS. 4 and 5 (two cavities 221 and 222 are shown in FIG. 4). As shown in FIG. 4, 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. Further, a power roller 11 (FIG. 5) is provided between the inner side surfaces (concave surfaces) 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 side disks 3 and 3. (See below) is rotatably held.

  A step 2b is provided on the inner peripheral surface 2c of the input disk 2 located on the right side in FIG. 4, 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. 4) 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. 5 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 5, a pair of trunnions 15, 15 that swing around 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 formed at a pair of ends formed in the longitudinal direction (vertical direction in FIG. 5) of the support plate 16 that supports the power roller 11 in a state of being bent toward the inner side of the support plate 16. It has the bent wall parts 20 and 20. 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 in the central portion of the support plate portion 16, and the 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 displaceable in the axial direction (vertical direction in FIG. 5) 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. In addition, a 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). The inner peripheral surface of the locking hole 19 is a cylindrical surface, and is a spherical post. 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.

  Further, drive rods (trunnion shafts) 29 and 29 are provided at one end portions (lower end portions in FIG. 5) 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. 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 in FIG. 5 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 position between the peripheral surfaces (traction 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. To do. 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 support structure that supports the power roller 11 by the crank type trunnion 15, for example, as disclosed in Patent Document 1, a pair of both ends of the support plate portion 16 and a pair of inner surfaces of the trunnion 15 are disclosed. A pair of step surfaces facing each other are provided in a continuous portion (bending wall portions 20 and 20) with the pivot shafts 14 and 14, and these step surfaces and the outer peripheral surface of the outer ring 28 are brought into contact with or in close proximity to each other. The traction force applied to the outer ring 28 from the roller 11 can be supported on any step surface.

  Further, in the support structure in which the power roller 11 is supported by the crank type trunnion 15, the trunnion 15 is bent and deformed inward when receiving a load in the thrust direction applied to each power roller 11, but such a bending deformation is caused. If this occurs, the outer ring 28 is sandwiched and the swinging is hindered. Therefore, in Patent Document 1, a gap is provided in the step surface receiving the traction force in order to prevent such a situation.

JP 2008-25821 A

  However, as disclosed in Patent Document 1, when a clearance is provided in the support portion that receives the traction force, the direction of the torque changes, and accordingly, when the direction of the traction force changes, the power roller is increased by the amount of the clearance. Is offset. Therefore, if a shift is performed in this state, an impact occurs on the vehicle.

  The present invention has been made in view of the above circumstances, and provides a toroidal continuously variable transmission that includes a trunnion support structure that receives a traction force without a gap and thereby can suppress an impact or the like during shifting. The purpose is to do.

In order to achieve the above object, the present invention provides an input side disk and an output side disk that are supported concentrically and rotatably in a state in which the respective inner surfaces face each other, the input side disk, Along with the axial direction of a pair of pivots provided concentrically with each other, the power roller sandwiched between the output side disk and a twisted position with respect to the central axis of the input side disk and the output side disk And a trunnion that tilts about the pivot and supports the power rollers in a rotatable manner, and the power roller surrounds a shaft portion that is tiltably supported with respect to the trunnions. The power low is supported between the trunnion and the power roller while supporting a load in the thrust direction applied to the power roller. A thrust ball bearing that allows rotation of the shaft portion is disposed around the shaft portion, and the thrust ball bearing includes a plurality of rolling elements, and a cage that holds the rolling elements in a freely rolling manner. A toroidal continuously variable transmission comprising an outer ring and an inner ring raceway of the thrust ball bearing formed on the outer surface of the power roller and an outer ring raceway on the inner side surface of the outer ring. When the tip convex portion of the shaft portion to be assembled is engaged with a concave groove formed on the inner surface of the central portion of the trunnion, the traction force applied to the outer ring from the power roller is received by the concave groove, and the shaft The portion is formed in a straight line shape, and the tip convex portion of the shaft portion is formed integrally with the shaft portion and in a concentric and coaxial cylindrical shape with the shaft portion .

  According to the above configuration, the center portion of the trunnion with a small amount of deformation is engaged with the concave groove formed on the inner surface of the trunnion by engaging the tip convex portion of the shaft portion assembled separately from the outer ring. Because the concave groove receives the traction force applied from the roller to the outer ring, a trunnion support structure that receives the traction force without any gap can be easily realized (there is no need to provide a gap in the support portion that receives the traction force). ). Accordingly, it is possible to suppress an impact at the time of shifting. Further, since the outer ring and the shaft portion are separated, the dimensional accuracy of the outer diameter of the shaft portion can be easily ensured by lathe processing or the like, and therefore the fitting gap between the tip convex portion of the shaft portion and the concave groove of the trunnion, The assembly tolerance between the outer ring and the shaft can be easily managed. This can also greatly contribute to a traction force support structure without a gap.

  According to the toroidal continuously variable transmission of the present invention, the front end convex portion of the shaft portion assembled separately from the outer ring at the center portion of the trunnion with a small amount of deformation is formed into the concave groove formed on the inner surface of the trunnion. By engaging, the trough force applied to the outer ring from the power roller is received by the concave groove, so that a trunnion support structure that receives the traction force without a gap can be easily realized, thereby allowing impact during shifting. Etc. can be suppressed.

It is a figure of the principal part of the toroidal type continuously variable transmission which concerns on embodiment of this invention, Comprising: (a) is a perspective view of trunnion single-piece | unit, (b) assembles an outer ring, a shaft part, and a power roller with respect to trunnion. It is a perspective view which shows a state. (A) is a perspective view of the state which assembles a shaft part to an outer ring, and (b) is a perspective view of a single outer ring. It is sectional drawing in alignment with the XX line of (b) of FIG. 2, (a) is sectional drawing of the state which assembles | attaches an outer ring | wheel and a shaft part, (b) assembles | attaches the axial part to which the outer ring was assembled | attached to a trunnion ( Sectional drawing of the state which engages the concave groove | channel of a trunnion with the front-end | tip convex part of a axial part, (c) is sectional drawing of an assembly completion state. 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.

Embodiments of the present invention will be described below with reference to the drawings.
The feature of the present invention is a trunnion support structure for receiving a traction force without a gap, and other configurations and operations are the same as the conventional configurations and operations described above. Only the characteristic part of FIG. 5 will be referred to, and other parts will be simply described with the same reference numerals as those in FIGS.

  FIG. 1 shows a trunnion support structure for a toroidal-type continuously variable transmission according to an embodiment of the present invention. As shown in the figure, the trunnion of the toroidal type continuously variable transmission according to the present embodiment is of a crank type having bent wall portions 20, 20, and the power roller 11 supported by the trunnion is supported by the trunnion 15. It is rotatably supported around a linear shaft portion 23A that is supported so as to be tiltable with respect to the plate portion 16. In this case, the small-diameter portion 23Ac of the shaft portion 23A is inserted into the center hole 11b of the power roller 11 with a radial needle bearing interposed therebetween, whereby the power roller 11 can be rotatably supported with respect to the shaft portion 23A.

  Further, between the trunnion 11 (support plate portion 16) and the power roller 11, a thrust ball bearing 24 that supports the rotation of the power roller 11 while supporting the load in the thrust direction applied to the power roller 11 is provided on the shaft portion 23A. It is arranged around the periphery. The thrust ball bearing 24 includes a plurality of rolling elements (not shown), a retainer 27 that holds these rolling elements in a freely rotatable manner, and an outer ring 28. Outer raceways are formed on the inner surface of the outer ring 28 on the outer surface of the power roller 11.

  In the present embodiment, the outer ring 28 and the shaft 23A are formed separately. Then, the front end convex portion 23Aa of the shaft portion assembled to the outer ring 28 is engaged with the concave groove 16b formed on the inner side surface of the central portion of the support plate portion 16 of the trunnion 15, so that the traction force applied from the power roller 11 to the outer ring 28 is achieved. Is received by the concave groove 16b.

  Specifically, as shown in FIGS. 2A and 3A, the large-diameter portion 23Ab on the distal end side of the shaft portion 23A is inserted into the circular central through hole 28a of the outer ring 28 on the rear surface side of the outer ring 28. For example, by press fitting. At this time, as shown in FIG. 2B, the tip convex portion 23Aa protruding from the tip of the large diameter portion 23Ab of the shaft portion 23A protrudes from the front surface of the outer ring 28. In this state, as shown in FIG. 3 (b), this time, the tip convex portion 23 Aa of the shaft portion 23 A that protrudes from the front surface of the outer ring 28 is formed on the inner surface of the central portion of the support plate portion 16 of the trunnion 15. Engage with the groove 16b. At this time, as shown in FIG. 3C, the substantially arcuate concave surface 28b formed on the front surface of the outer ring 28 is engaged with the substantially arcuate convex surface 16a on the inner surface of the support plate portion 16 having the concave groove 16b. Match. As a result, the outer ring 28 can swing with respect to the trunnion 15. Further, the concave groove 16b engaged with the shaft portion 23A has an elliptical shape or a long hole shape so that the shaft portion 23A can follow such swinging of the outer ring 28.

  As described above, in the present embodiment, the front end convex portion 23Aa of the shaft portion 23A that is assembled separately from the outer ring 28 at the center portion of the trunnion 15 with a small amount of deformation is connected to the inner surface of the trunnion 15. By engaging with the concave groove 16b formed on the outer ring 28, the tractive force applied to the outer ring 28 from the power roller 11 is received by the concave groove 16b. Therefore, the trunnion support structure that receives the traction force without any gap is easy. (There is no need to provide a gap in the bearing that receives the traction force). Accordingly, it is possible to suppress an impact at the time of shifting. Further, since the outer ring 28 and the shaft portion 23A are separated from each other, the dimensional accuracy of the outer diameter of the shaft portion 23A can be easily ensured by lathe processing or the like. Therefore, the tip convex portion 23Aa of the shaft portion 23A and the concave groove of the trunnion 15 The fitting clearance with 16b and the assembly tolerance between the outer ring 28 and the shaft portion 23A can be easily managed. This can also greatly contribute to a traction force support structure without a gap.

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

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Input side disk 3 Output side disk 11 Power roller 15 Trunnion 16a Convex surface 16b Concave groove 23A Shaft part 23Aa Tip convex part 24 Thrust ball bearing 28 Outer ring 28b Concave surface

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 move along the axial direction of a pair of pivots that are concentric with each other and are twisted with respect to the central axis of the input side disk and the output side disk and tilt about the pivot axis. And a trunnion that rotatably supports each of the power rollers, and the power roller is rotatably supported around a shaft portion that is tiltably supported with respect to the trunnion, and the trunnion and the power A thrust ball bearing that supports the rotation of the power roller while supporting a load in the thrust direction applied to the power roller is provided between the roller and the roller. The thrust ball bearing is disposed around the shaft portion, and the thrust ball bearing includes a plurality of rolling elements, a cage that holds the rolling elements in a freely rolling manner, and an outer ring. In the toroidal type continuously variable transmission in which the inner ring raceway is formed on the outer surface of the power roller and the outer ring raceway is formed on the inner side surface of the outer ring,
When the tip convex portion of the shaft portion assembled separately from the outer ring engages with a concave groove formed on the inner surface of the central portion of the trunnion, the traction force applied from the power roller to the outer ring is the concave shape. While being received in the groove ,
The shaft portion is formed in a linear shape, and the tip convex portion of the shaft portion is formed integrally with the shaft portion and in a cylindrical shape concentric with and coaxial with the shaft portion. Continuously variable transmission.   2. The outer ring can swing with respect to the trunnion by engaging a substantially arcuate concave surface of the outer ring facing the trunnion with a substantially arcuate convex surface of the trunnion having the concave groove. The toroidal type continuously variable transmission described in 1.   The toroidal continuously variable transmission according to claim 1 or 2, wherein the concave groove has an elliptical shape or a long hole shape.

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