JP4706960B2 - 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 (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, the power roller 11 (see FIG. 4) 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 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 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.

  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 23 </ b> A and 23 </ b> B are supported so as to be slightly displaceable by support posts 64 and 68 formed on portions of the inner surface of the casing 50 facing each other. 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. is 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 is provided with 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. It has been. In FIG. 4, the input shaft 1 is not shown. Each trunnion 15, 15 is a pair of bent portions formed at both ends in the longitudinal direction (vertical direction in FIG. 4) of the support plate portion 16 that is the main body portion so as to be bent toward the inner side surface of the support plate portion 16. Wall portions 20 and 20 are provided. 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 a base end portion (first shaft portion) 23 a of a displacement shaft (support 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, 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 23 </ b> A and 23 </ b> B. It is supported so as to be able to swing through. 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 spherical. Support posts 64 and 68 are internally fitted as concave 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 23A is composed of the spherical post 68 and the cylinder supporting the same. 31 is supported by the upper cylinder body 61 so as to be swingable.

  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 allows the rotation of the power roller 11 while supporting the load in the thrust direction applied to the power roller 11. Such a thrust ball bearing 24 includes a plurality of balls 26, an annular retainer 27 that holds the balls 26 in a freely rolling manner, a power roller 11 as an inner ring, and an annular outer ring 28. It is composed of 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 28b. Such a thrust needle bearing 25 supports the thrust load applied from the inner ring 28 a to the outer ring 28 b, and allows the inner ring 28 a and the outer ring 28 b to swing around the base end portion 23 a of each displacement shaft 23.

  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 in directions opposite to each other. 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 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.

  As examples of the toroidal type continuously variable transmission, those described in Patent Document 1 and Patent Document 2, for example, are known. Furthermore, Patent Document 3 describes a cage made of synthetic resin.

JP 2000-310308 A Utility Model Registration No. 2603559 Japanese Patent No. 3532663

  By the way, the thrust ball bearing 24 for supporting the power roller 11 is for axial load and rotational support, and unlike the radial bearing, it can support the load with all the balls, and therefore has a large capacity. Although the ring-shaped cage that holds the ball so as to roll freely is disposed in a limited space (a space between the inner ring (power roller 11) and the outer ring 28), the thickness is Therefore, it is difficult to increase the thickness in order to improve the strength. For this reason, when the oil groove is provided on both surfaces of the cage 27 as in the case of the above-mentioned Patent Document 1, the thickness of the portion becomes thin and there is a possibility of breakage. Therefore, like the one described in Patent Document 2, it is necessary to devise such as making the cross section of the oil groove (lubricating oil flow path) formed on both surfaces of the cage into a single arc shape, for processing the cage. It will take time.

  Further, in the resin cage described in Patent Document 3, when forming the cross-sectional shape of the pocket formed in the cage on the circular arc surface and the continuous cylindrical surface, the mold is removed. Thus, the diameter of the cylindrical surface can be made smaller than the diameter of the sphere formed by the arc surface. When the ball is inserted into the circular arc surface portion of the cage pocket, the ball can be pushed in from the cylindrical surface side, and the inserted ball can be held while preventing its dropout. However, in a cage made of steel other than synthetic resin, if the diameter of the cylindrical surface is made smaller than the diameter of the sphere formed by the arc surface, a ball cannot be inserted, so the diameter of one cylindrical surface is formed by the arc surface. In order to prevent the ball from falling off or protruding after insertion of the ball by making it approximately equal to or slightly larger than the diameter of the sphere, the cylindrical entrance formed by the cylindrical surface is caulked. Therefore, the surface having the “caulking” of the cage may come into contact with the inner ring or the outer ring, and the cage is likely to be seized or worn, which is not preferable.

  Furthermore, as the size of the toroidal-type continuously variable transmission is further reduced, the space for arranging the cage is further reduced. Accordingly, the cage needs to be thinned, and the cage may be damaged. . In addition, since the cage is disposed between the inner ring and the outer ring, if the cage approaches either the inner ring or the outer ring, there is almost no gap between the cage and the inner ring or the outer ring. , The lubricity is impaired, and the durability varies.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a toroidal continuously variable transmission that can prevent contact between a retainer of a thrust bearing and an inner ring and an outer ring.

In order to solve the above problems, the toroidal-type continuously variable transmission according to claim 1 includes an input-side disk and an output that are supported concentrically and rotatably with each inner surface facing each other. A side disc, a trunnion that tilts about a pivot that is twisted with respect to the central axis of the input side disc and the output side disc, and the input side disc that is rotatably supported by the trunnion. A power roller sandwiched between the output side disk and a thrust bearing provided between the power roller and the inner surface of the trunnion for supporting a load in a thrust direction applied to the power roller; The bearing includes an inner ring formed by the power roller, an outer ring, and a plurality of rolling elements that roll between the inner ring and the outer ring. In the toroidal type continuously variable transmission and a cage holding the plurality of rolling elements these, respectively between the inner ring and the outer ring and the retainer, and the retainer and the inner ring and the outer ring Are provided separately from the cage, the inner ring, and the outer ring .

  Here, the material of the cage may be steel or synthetic resin that is generally used. The rotation support member may be a bearing such as a rolling bearing or a sliding bearing, and may be a low friction material such as a fluororesin.

In the first aspect of the present invention, since the rotation support members are provided between the cage and the inner ring and the outer ring, the rotation support members contact the cage with the inner ring and the cage. Contact with the outer ring can be prevented. Therefore, seizure and wear of the cage can be suppressed, and the lubricity is not impaired and the durability is excellent.
Further, since it is not necessary to devise such as making the cross section of the oil groove (lubricating oil flow path) formed on both surfaces of the cage into a single arc shape, the cage can be easily processed.
Further, since the clearance is secured by the presence of the rotation support member between the cage and the inner ring and the outer ring, it is not necessary to apply “caulking” to the entrance of the pocket of the cage. For this reason, it becomes easy to process the cage, and it is possible to prevent seizure and wear of the cage caused by the surface having the “caulking” of the cage coming into contact with the inner ring or the outer ring.

  According to a second aspect of the present invention, the toroidal continuously variable transmission according to the first aspect of the present invention is characterized in that the rotation support member is provided closer to the inner diameter side of the cage than the rolling element position.

  In the invention according to claim 2, since the rotation support member is provided on the inner diameter side of the cage from the rolling element position, the peripheral speeds of the inner ring and the outer ring with respect to the rotation support member can be kept small. Loss due to the rotation support member can be reduced.

  The toroidal type continuously variable transmission according to claim 3 is the invention according to claim 1 or claim 2, wherein the pocket of the cage for holding the rolling element has an inner peripheral surface thereof in an axial direction of the pocket. It is characterized by parallel straight holes.

  In the invention according to claim 3, since the rotation support member is provided between the cage and the inner ring and the outer ring respectively, and the pocket of the cage is a straight hole, the rolling elements provided in the straight hole There is no need to restrain the cage in its axial direction. Therefore, since the cage can be made as thin as possible, the cage can be miniaturized. Further, since the pocket is a straight hole, the pocket can be easily processed and the processing accuracy is improved.

A toroidal continuously variable transmission according to a fourth aspect is the invention according to any one of the first to third aspects, wherein the rotation support member is a bearing.
The bearing may be any bearing such as a rolling bearing or a sliding bearing.

  In the invention according to claim 4, since the rotation support member is a bearing, the cage, the inner ring, and the outer ring can be relatively easily rotatably supported.

  According to the toroidal type continuously variable transmission of the present invention, the rotation support members are provided between the cage and the inner ring and the outer ring, respectively, so that these rotation support members contact the cage and the inner ring. In addition, contact between the cage and the outer ring can be prevented. Therefore, seizure and wear of the cage can be suppressed, and the durability is excellent, and further, the cage is easily processed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is characterized in the form of a thrust bearing in a toroidal type continuously variable transmission, and other configurations are the same as those of the prior art. Therefore, illustration and description of common parts are omitted, and the thrust bearing will be described. .

(First embodiment)
FIG. 1 shows a first embodiment of the present invention.
The thrust ball bearing (thrust bearing) 24 includes a power roller 11 as an inner ring, an outer ring 28 provided coaxially with the power roller 11, and a plurality of balls that roll between the power roller 11 and the outer ring 28. (Rolling element) 26 and a cage 27 that holds these balls. The inner ring raceway of the thrust ball bearing 24 is formed on the outer side surface (large end surface) of the power roller 11, and the outer ring raceway is formed on the inner side surface of the outer ring 28. The cage 27 is formed in an annular plate shape, and holds each ball 26 in a freely rollable manner in each pocket 27a formed at equal angular intervals in the circumferential direction. The pocket 27a is a straight hole whose inner peripheral surface is parallel to the axial direction of the pocket 27a. Further, the diameter of the pocket 27 a is slightly larger than the diameter of the ball 26. The pocket 27a may be circular or rectangular in plan view.

  A rotation support member 40 is provided between the cage 27 and the power roller 11, and a similar rotation support member 40 is also provided between the cage 27 and the outer ring 28. The rotation support member 40 makes the cage 27, the power roller 11, and the outer ring 28b relatively rotatable. In the present embodiment, the rotation support member 40 is a thrust bearing using a cylindrical roller. The rotation support member 40 is provided on the outer peripheral side from the position of the ball 26 of the cage 27.

In the thrust ball bearing 24 as described above, the rotation support member 40 is provided between the retainer 27 and the power roller 11 and the outer ring 28b, and therefore the retainer 27 and the inner ring 28a are separated by the rotation support member 40. And the contact between the cage 27 and the outer ring 28b can be prevented. Therefore, seizure and wear of the cage 27 can be suppressed, and the lubricity is not impaired and the durability is excellent.
Further, since it is not necessary to devise such as making the cross section of the oil groove (lubricant oil flow path) formed on both surfaces of the cage 27 into a single arc shape, the cage 27 can be easily processed.
Furthermore, since the gaps between the cage 27 and the power roller 11 and the outer ring 28b are each held constant by the presence of the rotation support member 40, it is necessary to apply “caulking” to the entrance of the pocket 27a of the cage 27. There is no. For this reason, processing of the cage 27 is facilitated, and seizure and wear of the cage due to the surface of the cage 27 having “caulking” coming into contact with the inner ring or the outer ring can be prevented.

In addition, since the pocket 27a of the cage 27 is a straight hole, it is not necessary to restrain the cage 27 in the axial direction by the balls 26 provided in the straight hole. Therefore, since the cage 27 can be made as thin as possible, the cage 27 can be downsized. Moreover, since the pocket 27a is a straight hole, the hole of the pocket is easy and the processing accuracy is improved.
Further, since the rotation support member 40 is a thrust bearing, the retainer 27, the power roller 11, and the outer ring 28b can be relatively easily rotatably supported.

(Second Embodiment)
FIG. 2 shows a second embodiment of the present invention. The thrust ball bearing 24 shown in this figure is different from the thrust ball bearing 24 shown in FIG. 1 in the arrangement position of the rotation support member 40. Therefore, this point will be described below, and other common parts have the same reference numerals. The description is omitted.

  As shown in FIG. 2, the rotation support member 40 is provided on the inner diameter side of the cage 27 from the position of the ball 26. The rotation support member 40 positioned between the cage 27 and the inner ring 28a is a thrust bearing, and a plurality of cylindrical rollers constituting the thrust bearing are tracks formed on the large end surface (outer surface) of the power roller 11. 41 can be rolled. Similarly, the rotation support member 40 positioned between the cage 27 and the outer ring 28 is also a thrust bearing, and a plurality of cylindrical rollers constituting this thrust bearing are formed on a track 41 formed on the inner surface of the outer ring 28. It is possible to roll along.

  In the present embodiment, the same effect as in the first embodiment can be obtained, and the rotation support member 40 is provided on the inner diameter side of the cage 27 from the position of the ball 26, so that the rotation support is provided. The peripheral speed of the power roller 11 and the outer ring 28 with respect to the member 40, that is, the peripheral speed of the thrust ball bearing 24 can be suppressed to be small, and the loss due to the rotation support member 40 can be reduced.

  In this embodiment, the rotation support member 40 is provided on the inner diameter side of the cage 27 from the position of the ball 26. In addition to this, the rotation support member 40 is further arranged on the outer diameter of the cage 27 from the position of the ball 26. It may be provided on the side. In this way, a gap can be reliably secured between the retainer 27 and the power roller 11 and the outer ring 28, so that the rotation of the power roller 11 and the outer ring 28 becomes smoother.

In the above two embodiments, a thrust bearing is used as the rotation support member 40. However, any bearing such as a rolling bearing or a sliding bearing may be used as long as it is a bearing.
Further, a low friction material such as a fluororesin may be used in place of the bearing. In this case , a member coated with a low friction material or a member formed of a low friction material may be provided between the cage 27, the power roller 11, and the outer ring 28.

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

1 shows a toroidal continuously variable transmission according to a first embodiment of the present invention, and is a longitudinal sectional view of a thrust ball bearing portion. FIG. The toroidal type continuously variable transmission which concerns on the 2nd Embodiment of this invention is shown, and is a longitudinal cross-sectional view of a thrust ball bearing part. It is sectional drawing which shows an example of the conventional toroidal type continuously variable transmission. 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 (inner ring)
14 Axis 15 Trunnion 24 Thrust Ball Bearing (Thrust Bearing)
26 balls (rolling elements)
27 Cage 27a Pocket 28 Outer ring 40 Rotation support member

Claims (4)

The input side disk and the output side disk supported concentrically and rotatably with the respective inner side 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 that tilts about a pivot, a power roller that is rotatably supported by the trunnion, and is sandwiched between the input-side disk and the output-side disk, and the power roller and the trunnion A thrust bearing provided between the inner surface 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 ring and the outer ring A toroidal stepless variable motor comprising a plurality of rolling elements that roll between and a cage that holds the plurality of rolling elements. In the machine,
Respectively between the inner ring and the outer ring and the retainer, the retainer and the inner ring and the rotation support member is said retainer to the outer ring rotatable relative each, the inner ring and the outer ring and another member toroidal type continuously variable transmission, characterized in that provided in the.   The toroidal continuously variable transmission according to claim 1, wherein the rotation support member is provided closer to the inner diameter side of the cage than the rolling element position.   The toroidal continuously variable transmission according to claim 1 or 2, wherein a pocket of the cage for holding the rolling element is a straight hole having an inner peripheral surface parallel to an axial direction of the pocket. .   The toroidal continuously variable transmission according to any one of claims 1 to 3, wherein the rotation support member is a bearing.

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