JP2006029354A - Toroidal continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toroidal continuously variable transmission with a power roller support shaft easily workable for supporting the oscillation of the power roller. <P>SOLUTION: In this toroidal continuously variable transmission, a shaft member 83 separate from the power roller support shaft is supported rotatably in a trunnion 6. The power roller support shaft consists of a first shaft port 80 supporting the power roller 11, and a second shaft part 81 coaxial with this first shaft part 80 and supported on the trunnion side 6. The second shaft part 81 is supported while being inserted in a shaft hole 84 provided in the shaft member 83 and deviated from the rotating shaft O1 of the shaft member 83. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  The use of a toroidal type continuously variable transmission as schematically shown in FIGS. 5 and 6 is partially implemented as a transmission for an automobile. This toroidal continuously variable transmission supports an input side disk 2 concentrically with an input shaft 1, and an output side disk 4 is fixed to an end of an output shaft 3 disposed concentrically with the input shaft 1. Inside the casing containing the toroidal-type continuously variable transmission, trunnions 6 and 6 are provided that swing around pivots 5 and 5 that are twisted with respect to the input shaft 1 and the output shaft 3. A power roller 11 is rotatably supported on each trunnion 6, 6, and each power roller 11, 11 is sandwiched (rolled) between both the input side and output side disks 2, 4. .

  The cross sections of the inner side surfaces 2a and 4a facing each other of the input and output side disks 2 and 4 each form a concave surface obtained by rotating an arc centering on the pivot 5 or a curve close to such an arc. ing. And the peripheral surface 11a, 11a of each power roller 11, 11 formed in the spherical convex surface is contact | abutted to each inner surface 2a, 4a.

  Between the input shaft 1 and the input side disk 2, a loading cam type pressing device 12 is provided. The pressing device 12 elastically presses the input side disk 2 toward the output side disk 4. The pressing device 12 includes a cam plate 13 that rotates together with the input shaft 1 and a plurality of (for example, four) rollers 15 held by a cage 14. Further, a cam surface 16 that is an uneven surface is formed on one side surface (the left side surface in FIGS. 5 and 6) of the cam plate 13 in the circumferential direction, and the outer surface (see FIGS. 5 and 5) of the input side disk 2. A similar cam surface 17 is also formed on the right side surface of FIG. The plurality of rollers 15 are supported so as to be rotatable about an axis extending in the radial direction with respect to the input shaft 1.

  In the toroidal type continuously variable transmission having such a configuration, when the input shaft 1 is rotated, the cam plate 13 is rotated along with the rotation of the input shaft 1, and the plurality of rollers 15, 15 are connected to the input side disk by the cam surface 16. 2 is pressed by the cam surface 17 provided on the outer side surface of the head. As a result, the input side disk 2 is pressed against the plurality of power rollers 11, 11, and at the same time, based on the pressing between the pair of cam surfaces 16, 17 and the rolling surfaces of the plurality of rollers 15, 15. The input side disk 2 rotates. Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 via the power rollers 11 and 11, and the output shaft 3 fixed to the output side disk 4 rotates.

  When the rotational speeds of the input shaft 1 and the output shaft 3 are changed, and when deceleration is performed between the input shaft 1 and the output shaft 3, the trunnions 6 and 6 are swung around the pivot shafts 5 and 5. As shown in FIG. 5, the peripheral surfaces 11 a and 11 a of the power rollers 11 and 11 are arranged near the center of the inner surface 2 a of the input side disk 2 and the outer periphery of the inner side surface 4 a of the output side disk 4. The displacement shafts 9 and 9 are inclined so as to abut each other.

  On the other hand, when the speed is increased, the trunnions 6 and 6 are swung so that the peripheral surfaces 11a and 11a of the power rollers 11 and 11 have the inner surface 2a of the input side disk 2 as shown in FIG. Each of the displacement shafts 9 and 9 is inclined so as to come into contact with the outer peripheral portion and the central portion of the inner side surface 4 a of the output side disk 4. If the inclination angle of each of the displacement shafts 9 and 9 is set intermediate between those shown in FIGS. 5 and 6, an intermediate gear ratio can be obtained between the input shaft 1 and the output shaft 3.

FIG. 7 and FIG. 8 show an example of a more specific double cavity type half toroidal type continuously variable transmission. In addition, about the structural member which is common in FIG.5 and FIG.6, the same code | symbol is attached | subjected below and the detailed description or illustration is abbreviate | omitted.
As shown in FIG. 7, the input shaft 1 is rotatably supported inside the casing 101. A circular transmission shaft 103 is supported on the outer periphery of the input shaft 1. In this case, the transmission shaft 103 is disposed concentrically with the input shaft 1 and can rotate with respect to the input shaft 1.

  The first and second input side disks 2 and 2 are respectively supported by ball splines 96 at both ends of the transmission shaft 103. In this case, the first and second input side disks 2 and 2 are concentrically arranged with their inner side surfaces 2a and 2a facing each other, and can rotate in synchronization with each other inside the casing 101. .

  Around the intermediate portion of the transmission shaft 103, first and second output side disks 4, 4 are supported via a sleeve 109. An output gear 110 is integrally provided on the outer peripheral surface of the intermediate portion of the sleeve 109. The output gear 110 is disposed concentrically with the transmission shaft 103 and has an inner diameter larger than the outer diameter of the transmission shaft 103. The output gear 110 is rotatably supported by a support wall 111 provided in the casing 101 via a pair of rolling bearings 112.

  The first and second output side disks 4 and 4 are splined to both ends of the sleeve 109. In this case, the output side disks 4 and 4 are arranged with their inner side surfaces 4a and 4a facing in opposite directions. Accordingly, the input side disk 2 and the output side disk 4 have their inner side surfaces 2a, 4a facing each other.

  As shown in FIG. 8, a pair of yokes 113a and 113b are supported inside the casing 101 and laterally of the output side disks 4 and 4 with both the disks 4 and 4 sandwiched from both sides. . The pair of yokes 113a and 113b are formed in a rectangular shape by pressing or forging a metal such as steel. In order to support the pivots 5 provided at both ends of the trunnion 6 to be described later in a swingable manner, circular support holes 118 are provided at the four corners of the yokes 113a and 113b, and the width direction of the yokes 113a and 113b. A circular locking hole 119 is provided at the center of the.

  The pair of yokes 113a and 113b are supported so as to be slightly displaceable by support posts 20a and 20b formed on portions of the inner surface of the casing 101 facing each other. These support posts 20a and 20b are respectively provided so as to face the first cavity 21 and the second cavity 22 between the inner side surface 2a of the input side disk 2 and the inner side surface 4a of the output side disk 4, respectively. Yes. The post 20 a is provided with a tilt stopper 150 that regulates the tilt amount of the trunnion 6.

  Accordingly, the yokes 113 a and 113 b are supported by the support posts 20 a and 20 b, and one end thereof faces the outer peripheral portion of the first cavity 21 and the other end faces the outer peripheral portion of the second cavity 22. is doing.

  Since the first and second cavities 21 and 22 have the same structure, only the first cavity 21 will be described below.

  The first cavity 21 is provided with a pair of trunnions 6. Concentric shafts 5 are provided concentrically at both ends of the trunnion 6, and these pivots 5 are supported by one end portions of a pair of yokes 113a and 113b so as to be swingable and axially displaceable. That is, the pivot 5 is supported by the radial needle bearing 26 inside the support hole 118 formed at one end of the yokes 113a and 113b. The radial needle bearing 26 includes an outer ring 27 whose outer peripheral surface is a spherical convex surface and whose inner peripheral surface is a cylindrical surface, and a plurality of needles 28.

  A circular hole 30 is provided in each intermediate portion of the trunnion 6. A displacement shaft 31 is supported in each circular hole 30. Each of the displacement shafts 31 includes a support shaft portion 33 and a pivot shaft portion 34 that are parallel to each other and eccentric. Among these, the support shaft portion 33 is supported inside the circular hole 30 via a radial needle bearing 35. The power roller 11 is supported around the pivot shaft 34 via another radial needle bearing 38.

  A pair of displacement shafts 31 provided for each of the first and second cavities 21 and 22 are 180 degrees opposite to the input shaft 1 and the transmission shaft 103 for each of the first and second cavities 21 and 22. Is located. In addition, the direction in which each pivot shaft 34 of the displacement shaft 31 is eccentric with respect to each support shaft 33 is the same as the rotational direction of the input disks 2, 2 and the output disks 4, 4. The eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 1 is disposed. Therefore, the power roller 11 is supported so that it can be slightly displaced along the longitudinal direction of the input shaft 1 and the transmission shaft 103. As a result, the power roller 11 tends to be displaced in the axial direction of the input shaft 1 and the transmission shaft 103 due to a variation in the amount of elastic deformation of the constituent members based on a variation in the torque transmitted by the toroidal continuously variable transmission. Even in this case, an excessive force is not applied to the component member, and the displacement can be absorbed.

  A thrust ball bearing 39 and a thrust bearing 40 such as a slide bearing or a needle bearing are provided between the outer peripheral surface of the power roller 11 and the inner peripheral surface of the trunnion 6 in order from the outer surface of the power roller 11. It has been. Among these, the thrust ball bearing 39 allows rotation of the power roller 11 while supporting a load in the thrust direction applied to the power roller 11. The thrust bearing 40 allows the pivot shaft 34 and the outer ring 41 to swing around the support shaft 33 while supporting a thrust load applied to the outer ring 41 of the thrust ball bearing 39 from the power roller 11. .

  A drive rod 42 is coupled to one end of the trunnion 6. A drive piston 43 is fixed to the outer peripheral surface of the intermediate portion of these drive rods 42. The drive piston 43 is oil-tightly fitted in the drive cylinder 44. The drive piston 43 constitutes an actuator for displacing the trunnion 6 in the axial direction.

  As shown in FIG. 7, a loading cam type pressing device 45 is provided between the input shaft 1 and one input side disk 2. The pressing device 45 includes a cam plate 46 and a plurality of rollers 48, and rotates one input-side disk 2 while pressing it toward the other input-side disk 2 based on the rotation of the input shaft 1. In this case, the cam plate 46 is spline-engaged with the intermediate portion of the input shaft 1, supported in a state where displacement in the axial direction is prevented, and rotates together with the input shaft 1. The plurality of rollers 48 are held by a holder 47 so as to be freely rollable.

  During operation of the toroidal continuously variable transmission configured as described above, the rotation of the input shaft 1 is transmitted to one input side disk 2 via the pressing device 45, and the input side disk 2 and the other input side disk are transmitted. The disk 2 rotates in synchronization with each other. The rotation of the input side disks 2 and 2 is transmitted to the output side disks 4 and 4 via the power roller 11. The rotation of the output side disks 4 and 4 is taken out by the output gear 110.

  When the rotational speed ratio between the input shaft 1 and the output gear 110 is changed, a pair is provided corresponding to the first and second cavities 21 and 22 based on switching of control valves (not shown). The drive piston 43 thus moved is displaced by the same distance in the opposite directions for each of the cavities 21 and 22. Along with the displacement of these drive pistons 43, a total of four trunnions 6 are displaced in the opposite direction, and one power roller 11 is displaced downward and the other power roller 11 is displaced upward. As a result, the tangential force acting on the contact portion between the peripheral surface of each power roller 11 and the inner side surfaces 2a and 2a of the input side disks 2 and 2 and the inner side surfaces 4a and 4a of the output side disks 4 and 4 The direction of changes. As the direction of the force changes, the trunnion 6 swings in the reverse direction around the pivot shaft 5 pivotally supported by the yokes 113a and 113b. As a result, the contact position between the peripheral surface of the power roller 11 and the input side disks 2 and 2 and the output side disks 4 and 4 changes, and the rotational speed ratio between the input shaft 1 and the output gear 110 changes. .

  As described above, in the toroidal type continuously variable transmission, the driving force from the input side disk 2 is transmitted to the output side disk 4 via the power roller 11. In addition, power transmission between the power roller 11 and the input / output side disks 2 and 4 is performed in a non-contact manner by a traction force through the oil film, so that surface damage is avoided. Here, a high pressing force for generating a traction force is applied between the input / output disks 2 and 4 and the power roller 11, and this load is applied to the toroidal continuously variable transmission in FIG. The above-mentioned rolling bearing (thrust ball bearing) 39 shown in FIG. Note that the rolling bearing has an inner ring formed by the power roller 11, an outer ring 41, and a rolling element 300 supported so as to be able to roll between them. The rolling element 300 is supported by a cage 302. Is retained.

  On the other hand, the traction force generated on the traction surface formed between the input / output side disks 2 and 4 and the power roller 11 acts in the radial direction of the power roller 11. Since it is difficult to support this radial force only by the thrust ball bearing 39 in the drawing, needle bearings 35, 38, and 40 as shown in FIG. 9 are provided to compensate for this.

  Moreover, as shown in FIG. 9, the displacement shaft 31 that supports the power roller 11 may be integrated with the outer ring 41 (see, for example, Patent Document 1 and Patent Document 2). In this case, the power roller 11 is rotatably supported by a pivot shaft portion (hereinafter referred to as a power roller support shaft) 34 of the displacement shaft 31, and a support shaft portion (hereinafter referred to as an offset) that is eccentric with respect to the pivot shaft portion 34. 33 is inserted into the trunnion 6. The power roller 11 is swung by the rotation of the offset shaft 33 and has a degree of freedom in a direction perpendicular to the paper surface of FIG. Since the power roller 11 and the input / output side disks 2 and 4 are deformed due to the increase of the pressing load, there is a risk that the geometric relationship at the time of design may be lost. It is possible to transmit power while maintaining.

JP 2000-304116 A JP-A-11-51140

  As described above, the power roller 11 for the toroidal-type continuously variable transmission is provided with the power roller support shaft 34 that supports the rotation of the power roller 11 and the offset shaft 33 that supports the swing of the power roller 11. However, since these are configured as an integral part, it is necessary to process the two shafts 34 and 33 whose axis centers are shifted. Becomes higher. Therefore, in order to reduce the cost, it is desirable to make the axes of the two shafts 34 and 33 coincide with each other. However, in order to swing the power roller 11, the rotation of the shaft 33 and the power roller 11 that guide the swinging is performed. An offset with the shaft 34 is inevitable.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a toroidal-type continuously variable transmission including a power roller support shaft that can be easily processed to support the swinging of the power roller.

  In order to achieve the above object, the toroidal continuously variable transmission according to claim 1 includes an input side disk supported concentrically and rotatably in a state in which respective inner peripheral surfaces face each other. The output side disk, a trunnion that swings around a pivot that is twisted with respect to the center axis of the input side disk and the output side disk, and a support shaft that is supported on the trunnion side are rotatably supported. In a toroidal-type continuously variable transmission comprising a power roller sandwiched between the input-side disk and the output-side disk, the trunnion has a shaft member separate from the support shaft. The support shaft includes a first shaft portion that supports the power roller, and a second shaft portion that is coaxial with the first shaft portion and supported on the trunnion side. Made, the second shaft section is characterized by being supported by being inserted into the shaft provided on member and the shaft hole which is eccentric from the axis of rotation of the shaft member.

  In the first aspect of the invention, since the first shaft portion and the second shaft portion are coaxial, the support shaft can be easily processed, and the cost can be reduced. In addition, since the second shaft portion is inserted into and supported by the eccentric shaft hole of the shaft member, the power roller can be allowed to swing and be supported.

  The toroidal continuously variable transmission according to a second aspect is the invention according to the first aspect, wherein the shaft member is supported by the trunnion via a tapered roller bearing.

  In the invention described in claim 2, since the bearing that supports the oscillation of the power roller is a tapered roller bearing, it is possible for the tapered roller bearing to receive an axial load that acts on the trunnion from the power roller. When a thrust needle bearing is provided, the burden on the needle bearing can be reduced. In addition, radial backlash between the power roller and the trunnion can be prevented by using the tapered roller bearing. Furthermore, since the direction of the load that acts on the trunnion from the shaft member acts toward the outside of the power roller (see the arrows in FIGS. 3 and 4 in the embodiments described later), deformation of the trunnion can be reduced. As described above, it is possible to increase the bearing life, reduce the bearing loss, improve the shift controllability, and the like.

  According to the toroidal type continuously variable transmission of the present invention, it is possible to provide a power roller support shaft that is easier to process than in the prior art, so that cost reduction can be expected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The feature of the present invention lies in the form of a shaft that supports the power roller 11, and other configurations and operations are the same as those of the conventional configuration and operations described above. Therefore, only the features of the present invention will be described below. Reference is made to the other portions, and the same reference numerals as in FIGS.

  1 and 2 show a first embodiment of the present invention. In the present embodiment, the power roller support shaft that pivotally supports the power roller 11 with respect to the trunnion 6 is a first shaft portion 80 (corresponding to the conventional power roller support shaft 34) that supports the radial load of the power roller 11. The first shaft portion 80 and the second shaft portion 81 concentric with each other. The first and second shaft portions 80 and 81 are formed integrally with the outer ring 41 of the power roller bearing (thrust ball bearing 39) (may be separate). A large-diameter shaft member 83 is inserted into the recess 82 formed in the trunnion 6.

  Further, the second shaft portion 81 is inserted into a shaft hole 84 (center shaft O2) provided at a position offset from the center O1 of the large-diameter shaft member 83. Therefore, the swinging motion of the power roller 11 can be realized by the rotation of the large-diameter shaft member 83 integrated with the power roller 11.

  In the present embodiment, in order to insert the large-diameter shaft member 83, the trunnion 6 must be provided with a relatively large recess 82. For this reason, the number of needle bearings 40 is increased as compared with the related art so that the shaft diameter of the large-diameter shaft member 83 is large so that the rigidity of the trunnion 6 does not decrease. In particular, in the present embodiment, the rigidity of the trunnion 6 is ensured by making the length of the needle bearing 40 shorter than before and making the recess 82 (shaft hole 84) shallow.

  Further, in the present embodiment, since the space for providing the thrust needle bearing 40 for supporting the axial load in the swing of the power roller 11 on the back surface of the outer ring 41 is narrow, the gap between the end surface of the large-diameter shaft member 83 and the trunnion 6 is reduced. Also, a thrust needle bearing 40 is provided. The thrust needle bearing 40 is provided on the plate 85 in parallel.

  As described above, in the present embodiment, since the first shaft portion 80 and the second shaft portion 81 are coaxial, it is easy to process the power roller support shaft, and the cost can be reduced. Further, since the second shaft portion 81 is inserted and supported in the eccentric shaft hole 84 of the shaft member 83, the power roller 11 can be allowed to swing and be supported.

  FIG. 3 shows a second embodiment of the present invention. Also in this embodiment, as in the first embodiment, the second shaft portion 81 extending from the back surface of the outer ring 41 has a shaft hole 84 (center axis O2) provided at a position offset from the rotation axis O1. It is inserted into a large-diameter shaft member 83A. Here, in this embodiment, the large-diameter shaft member 83 </ b> A inserted into the trunnion 6 has a tapered shape and is supported by a tapered roller bearing 86 so as to be rotatable (swing of the power roller 11).

  The shaft center O1 of the large-diameter shaft member 83A supported by the tapered roller bearing 86 is offset from the shaft center O2 of the first shaft portion 80 that supports the power roller 11, and the power roller 11 is rotated by the rotation of the shaft member 83A. Is swingable. A method of supporting the offset shaft member 83A with the tapered roller bearing 86 has already been proposed in Japanese Patent Application Laid-Open No. 2000-304116. Moreover, in this embodiment, it is the structure which receives the axial load which acts on the power roller 11 with the thrust needle bearing 40 like the conventional structure.

  Further, in this embodiment, since the tapered roller bearing 86 can receive a load in the axial direction, the thrust needle bearing 40 as applied in the first embodiment is installed on the end face of the large-diameter shaft member 83A. There is no need to do. Similarly to the general tapered roller bearing, the apex P of the tapered roller bearing 86 according to the present embodiment coincides with the apex P of the tapered shaft 83A (offset shaft) (shown by a broken line in FIG. 3). The structure is such that spin loss on the bearing surface can be avoided. Further, the shaft member 83A is provided with a flange 87 for receiving the axial force of the roller acting on the tapered roller bearing 86.

  As described above, in this embodiment as well, the first shaft portion 80 and the second shaft portion 81 are coaxial, as in the first embodiment, so that the processing of the power roller support shaft is easy. The cost can be reduced, and the second shaft portion 81 is inserted and supported in the eccentric shaft hole 84 of the shaft member 83A, so that the power roller 11 is allowed to swing and supported. Can do. Furthermore, in this embodiment, since the shaft member 83A is supported by the trunnion 6 via the tapered roller bearing, radial backlash is prevented and the radial rigidity is improved. On the other hand, in the conventional structure, since a gap is formed in the needle bearing portion provided between the trunnion 6 and the offset shaft 33 (see FIG. 9), radial backlash occurs, which causes a reduction in radial rigidity. It has become. In the present embodiment, as indicated by an arrow in FIG. 3, the direction of the load acting on the trunnion 11 from the shaft member 83 </ b> A acts toward the outside of the power roller 11, so that deformation of the trunnion 11 can be reduced. it can.

  FIG. 4 shows a third embodiment of the present invention. In the present embodiment, in addition to the configuration of the second embodiment, the first shaft portion 80 is tapered, and the power roller 11 rotates on the first shaft portion 80 via the tapered roller bearing 86. It is pivotally supported.

  According to such a configuration, the thickness of the power roller 11 is increased, and the power roller 11 is supported by the tapered roller bearing 86, so that radial play can be prevented. As a result, an increase in bearing life, a reduction in bearing loss, and an improvement in shift controllability can be expected. Further, in the present embodiment, since the power roller 11 is supported by the tapered roller bearing 86 only, the small size and low cost power roller can be realized.

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

It is principal part sectional drawing of the toroidal continuously variable transmission which concerns on the 1st Embodiment of this invention. It is the figure which looked at the toroidal continuously variable transmission of FIG. 1 from the inner side of the trunnion. It is principal part sectional drawing of the toroidal continuously variable transmission which concerns on the 2nd Embodiment of this invention. It is principal part sectional drawing of the toroidal continuously variable transmission which concerns on the 3rd Embodiment of this invention. It is a side view which shows the fundamental structure of the toroidal type continuously variable transmission conventionally known in the state at the time of maximum deceleration. It is a side view which shows the basic structure of the toroidal type continuously variable transmission conventionally known in the state at the time of maximum acceleration. It is sectional drawing which shows an example of the conventional concrete structure. It is sectional drawing which follows the AA line of FIG. It is sectional drawing of the conventional power roller part with which the outer ring | wheel and the displacement shaft were united.

Explanation of symbols

2 input side disk 4 output side disk 6 trunnion 11 power roller 80 first shaft portion 81 second shaft portion 83, 83A shaft member 84 shaft hole

Claims (2)

The input side disk and the output side disk that are supported concentrically and rotatably with the respective inner peripheral surfaces facing each other, and the position of twist with respect to the central axis of these input side disk and output side disk A trunnion that swings around a pivot shaft, and a power roller that is rotatably supported by a support shaft supported on the trunnion side and is sandwiched between the input side disk and the output side disk In a toroidal continuously variable transmission comprising:
A shaft member separate from the support shaft is rotatably supported by the trunnion,
The support shaft includes a first shaft portion that supports the power roller, and a second shaft portion that is coaxial with the first shaft portion and supported on the trunnion side, and the second shaft portion. Is a toroidal continuously variable transmission which is provided in the shaft member and inserted into and supported by a shaft hole which is eccentric from the rotation shaft of the shaft member.   The toroidal continuously variable transmission according to claim 1, wherein the shaft member is supported by the trunnion via a tapered roller bearing.

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