JP4706920B2 - 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. As shown in FIG. 2, 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. 3) is rotatable between the inner side surfaces (concave surfaces) 2a and 2a of the input side disks 2 and 2 and the inner side surfaces (concave surfaces) 3a and 3a of the output disks 3 and 3. It is pinched.

  A step 2b is provided on the inner peripheral surface 2c of the input disk 2 located on the right side in FIG. 2, 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. 2) 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.

  3 is a cross-sectional view taken along line BB in FIG. As shown in FIG. 3, 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 FIG. 3, the input shaft 1 is not shown. 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. 3) 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 in the center portion of the support plate portion 16, and a base end portion (first shaft 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 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.

  Further, 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. In addition, 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. 2). The inner peripheral surface of the locking hole 19 is a spherical concave 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 and 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 and 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, driving rods (trunnion shafts) 29 and 29 are provided at one end portions (lower end portions in FIG. 3) of the trunnions 15 and 15, respectively, and a driving 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. 3 is displaced downward in the figure, and the power roller 11 on the right side of FIG. 3 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 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 rotational speed 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.

  Incidentally, as described above, in such a toroidal-type continuously variable transmission, the thrust ball bearing 24 is used to support the load in the thrust direction applied to each power roller 11. The thrust ball bearing 24 that supports the thrust force applied to the power roller 11 is used in a very severe environment as compared with a normal thrust bearing. That is, the thrust ball bearing 24 is used at a high rotational speed of up to 10,000 rpm, and is exposed to a high temperature of the supplied oil temperature of 130 ° C. in an environment applied to a vehicle. Particularly in the case of a thrust load, a high load of up to 60000 N acts on the thrust ball bearing 24. Therefore, the surface pressure applied to the contact portion between the rolling element 26 and the inner ring (large end surface of the trunnion 11) and the outer ring 28 is considerably increased, and the heat generation at the contact portion becomes significant. Therefore, in general, a sufficient amount of lubricating oil is supplied into the thrust ball bearing 24 to suppress heat generation at the contact portion. For example, oil grooves are provided on both surfaces of the inner ring (large end surface of the trunnion 11) and the retainer 27 facing the outer ring 28 (surfaces related to the contact portion), and a sufficient amount of lubricating oil is supplied to the contact portion. (For example, refer to Patent Document 1 and Patent Document 2).

  Specifically, as shown in FIG. 4, the retainer 27 includes an annular main body 27a, and the main body 27a has a plurality of pockets (through holes) 120 that individually hold the rolling elements 26 so as to be able to roll. The central hole 122 is formed with an equal angular interval in the circumferential direction and through which the second shaft portion 23b of the displacement shaft 23 passes. The main body 27a of the retainer 27 has an outer facing surface 125 facing the outer ring 28 and an inner facing surface 127 facing the inner ring (large end surface of the trunnion 11). An oil groove 140 extending in the radial direction from the inner peripheral surface of the cage 27 toward the outer peripheral surface is formed so as to cross each pocket 120. That is, the oil groove 140 extends in the radial direction from the inner peripheral surface to the outer peripheral surface on both sides of the cage 27 and on both sides of each pocket 120.

Utility Model Registration No. 2603559 JP 2000-310308 A

  As can be seen from the above, the thrust ball bearing 24 can support a load with the entire rolling element 26 unlike the radial bearing, and thus can have a large capacity. However, since the retainer 27 is disposed in a limited space, the thickness thereof is limited. Therefore, if the oil groove 140 is provided in both the opposing surfaces 125 and 127 as disclosed in Patent Document 1 described above, the thickness of the cage 27 becomes thin.

  Further, since radial loads also act on the thrust ball bearing 24 (see, for example, FIGS. 12 and 13 of Japanese Patent Laid-Open No. 2003-113915), the rolling element 26 is delayed or advanced, and the cage 27 A large impact load is applied. For this reason, if a stress concentration site such as an oil groove exists in the vicinity of the pocket 120 of the cage 27, the strength decreases.

  In general, when the thrust ball bearing 24 is used under a high load and high rotation, heat generation between the rolling element 26 and the oil groove 140 or between the rolling element 26 and the cage 27 increases. Sufficient lubrication is required. In this case, what is important is to reliably supply the lubricating oil to the rolling elements 26 so that the “lubrication leakage” in which the lubricating oil flows to parts other than the rolling elements 26 does not occur. If this is not ensured, the amount of lubricating oil supplied from the pump must be increased in consideration of leakage of the lubricating oil, resulting in an increase in the size of the pump and a decrease in overall transmission efficiency. End up. The oil groove 140 described above is an effective means that can reliably supply the lubricating oil to the rolling elements 26, but as described above, the cage 27 is thinned.

  The present invention has been made in view of the above circumstances, and provides a toroidal continuously variable transmission including a thrust bearing that can efficiently and reliably supply lubricating oil to a rolling element without providing an oil groove. With the goal.

  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 disc, a trunnion that swings about a pivot that is twisted with respect to the center axis of the input side disc and the output side disc, and a displacement shaft that is supported by the trunnion and that is rotatably supported A power roller sandwiched between the input side disk and the output side disk, and a thrust bearing provided between the power roller and the trunnion for supporting a load in a thrust direction applied to the power roller. The thrust bearing includes a plurality of inner rings formed by the power roller, an outer ring, and a plurality of rollers that roll between the inner ring and the outer ring. A toroidal continuously variable transmission comprising a moving body and an annular retainer provided with a plurality of pockets for individually retaining the plurality of rolling elements in a freely rollable manner, wherein the retainer includes the outer ring A plurality of outer facing surfaces facing each other, and an inner facing surface facing the inner ring, and at least one of the outer facing surface and the inner facing surface is located between adjacent pockets on the radially inner side. The first projections are spaced apart from each other along the circumferential direction, and at least one of the outer facing surface and the inner facing surface is spaced radially apart from each other with a space between adjacent pockets. A plurality of second protrusions are provided along the circumferential direction.

  According to the toroidal-type continuously variable transmission of the present invention, the lubricating oil can be reliably guided into the pocket by the first and second protrusions, so that the lubricating oil flows to a portion other than the rolling elements. Thus, the lubricating oil can be reliably supplied to the rolling elements. Further, if the leakage of the lubricating oil can be reduced in this way, the pump discharge amount can be reduced, and the pump can be reduced in size and the efficiency of the entire transmission can be improved. Moreover, since the groove | channel is not provided in the holder | retainer, thickness reduction of a holder | retainer can also be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The feature of the present invention lies in the lubrication structure of the cage, and the other configurations and operations are the same as the conventional configurations and operations described above. Therefore, only the features of the present invention will be referred to below. The other parts are simply described with the same reference numerals as in FIGS.

  FIG. 1 shows an embodiment of the present invention. As shown in FIG. 1, the retainer 27 has an outer facing surface 125 that faces the outer ring 28 (see FIG. 3) and an inner facing surface 127 that faces the inner ring (power roller 11). A plurality of first protrusions 400 positioned between the adjacent pockets 120 and 120 are spaced apart from each other along the circumferential direction on the radially inner side of both the outer facing surface 125 and the inner facing surface 127. It has been. In addition, a plurality of second protrusions 300 that are spaced apart with a gap (space) S1 between the adjacent pockets 120 and 120 are provided in the circumferential direction on both radially outer sides of the outer facing surface 125 and the inner facing surface 127. It is provided along.

  Therefore, in such a configuration, as shown by an arrow in FIG. 1A, when lubricating oil is supplied through an oil supply path (not shown) on the radially inner side of the pocket 120, the lubricating oil is It goes to the pocket 120 through the gap S2 between the protrusions 400, and flows out from the radial direction through the gap S1 between the second protrusions 300 located on both sides thereof.

  As described above, in the present embodiment, the first and second protrusions 400 and 300 can reliably guide the lubricating oil into the pocket 120, so that the lubricating oil can be applied to parts other than the pocket 120 (the rolling element 26). The flowing “lubricant leakage” can be prevented, and the lubricating oil can be reliably supplied to the rolling elements 26. Further, if the leakage of the lubricating oil can be reduced in this way, the pump discharge amount can be reduced, and the pump can be reduced in size and the efficiency of the entire transmission can be improved. Moreover, in this embodiment, since the groove | channel is not provided in the holder | retainer 27, thickness reduction of the holder | retainer 27 can also be prevented.

  Needless to say, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the scope of the invention. For example, the material of the cage 27 can be arbitrarily set. For example, a copper alloy, resin, steel, or the like that is normally used may be used as the material of the cage 27. Further, the present invention can be applied not only to a pure thrust shaft but also to an angular type thrust bearing in which a rolling element has a contact angle. In the above-described embodiment, the first and second protrusions 400 and 300 are provided on both the outer facing surface 125 and the inner facing surface 127. However, the first and second protrusions 400 and 300 It may be provided only on one of the facing surface 125 or the inner facing surface 127.

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

(A) is an outer ring side plan view of a cage concerning an embodiment of the present invention, and (b) is a sectional view which meets an AA line of (a). 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 BB line of FIG. (A) is a plan view of the inner ring side of the conventional cage, (b) is a cross-sectional view of the cage, (c) is a plan view of the outer ring side of the cage, and (d) is a view in the direction of arrow C in (c). It is.

Explanation of symbols

2 Input side disk 3 Output side disk 11 Power roller (inner ring)
15 trunnion 24 thrust ball bearing 26 rolling element 27 cage 28 outer ring 120 pocket 125 outer facing surface 127 inner facing surface 300 second projection 400 first projection

Claims (1)

The input side disk and the output side disk supported concentrically and rotatably with the respective inner surfaces facing each other, and the twisted position with respect to the center axis of these input side disk and output side disk A trunnion swinging about a pivot, a power roller sandwiched between the input-side disk and the output-side disk in a state of being rotatably supported by a displacement shaft supported by the trunnion, and A thrust bearing provided between a power roller and the trunnion and supporting a load in a thrust direction applied to the power roller, the thrust bearing comprising an inner ring formed by the power roller, an outer ring, and the inner rings; A plurality of rolling elements that roll between the outer ring and the outer ring, and a plurality of pockets that individually hold the plurality of rolling elements in a freely rotatable manner. In the toroidal type continuously variable transmission comprising an annular cage which is provided,
The retainer has an outer facing surface facing the outer ring and an inner facing surface facing the inner ring,
A plurality of first protrusions positioned between adjacent pockets are provided apart from each other in the circumferential direction on the radially inner side of at least one of the outer facing surface and the inner facing surface,
A plurality of second protrusions spaced apart from each other with a space between adjacent pockets are provided along a circumferential direction on at least one radial outer side of the outer facing surface and the inner facing surface. A toroidal-type continuously variable transmission.

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