JP4702602B2 - 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.

  In some cases, a toroidal continuously variable transmission as schematically shown in FIGS. 3 and 4 is used as an automobile transmission. 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 in the circumferential direction on one side surface (the left side surface in FIGS. 3 and 4) of the cam plate 13, and the outer surface of the input side disk 2 (see FIGS. 3 and 4). 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. 3, 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 disk 2 and the outer periphery of the inner surface 4 a of the output 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 an 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 intermediate between those shown in FIGS. 3 and 4, an intermediate gear ratio can be obtained between the input shaft 1 and the output shaft 3.

FIG. 5 and FIG. 6 show an example of a more specific double cavity type toroidal continuously variable transmission. In addition, about the structural member which is common in FIG.3 and FIG.4, the same code | symbol is attached | subjected below and the detailed description or illustration is abbreviate | omitted.
As shown in FIG. 5, 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. In addition, the input side disk 2 located on the right side in FIG. 5 has its back surface (the right surface in FIG. 5) abutted against the loading nut 309 via a first plate spring 310 having a large elasticity.

  As shown in FIG. 6, 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. 5, 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, 2a of the input side disks 2, 2 and the inner side surfaces 4a, 4a of the output side disks 4, 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. .

  By the way, in such a toroidal type continuously variable transmission, since the bending stress of the input / output side disks 2 and 4 generated by the two-point pushing load from the power roller 11 is large, conventionally, the input / output side disk 2 , 4 are variously devised so as not to concentrate stress. For example, in Patent Document 1 and Patent Document 2, by providing a retaining ring on the input shaft 1 side to prevent the ball spline 96 from coming off, stress concentration caused by the retaining ring is caused on the input / output side disks 2 and 4 side. Is prevented from occurring.

  Also, without using a ball spline, the power transmission between the input shaft and the input side disk is performed from the cylinder member side of the hydraulic loading, and the assembly of the ball and the cage is made to move the input side disk relative to the input shaft. The structure performed by incorporating is also conventionally considered.

Japanese Patent No. 2997893 Japanese Patent No. 3042519

  However, conventionally, the strength of the input shaft 1 has not been considered so much, and the strength of the input shaft 1 sometimes becomes a problem in a toroidal continuously variable transmission having a large torque capacity. For example, when considering the relationship between the assembly of the ball attached to the input shaft 1 and the cage and the strength of the input shaft 1, in the case of an assembly in which the ball (rolling element) is held by the cage, In order to assemble the assembly between the input shaft 1 and the input side disk 2, conventionally, the outer diameter of one end portion of the input shaft 1 to which the assembly is assembled is set to the first plate spring 310 or the loading nut 309. It was necessary to make it larger than the outer diameter of the other end portion of the input shaft 1 on the opposite side to which is mounted. This is because if the former outer diameter is smaller than the latter outer diameter, the assembly, which is a single part in which the cage and the ball are integrated, cannot be assembled to the input shaft 1. Although accompanying the above request, considering the stress concentration, it is preferable to set the latter outer diameter larger than the former outer diameter in terms of securing the strength of the input shaft 1.

  That is, one end portion of the input shaft 1 to which the assembly is assembled normally does not need to be stepped or grooved, and therefore has a simple cylindrical surface, so there is almost no influence of stress concentration due to the shape. It is a part. In addition, since this part is a rolling surface of the ball of this assembly, it is heat-treated and ground, so that an abnormal layer or the like due to the heat-treatment does not remain and is an advantageous part in terms of strength. . On the other hand, the other end portion of the input shaft 1 on the opposite side to which the first plate spring 310 and the loading nut 309 are mounted requires a step, a spline, a screw, etc., and stress concentration occurs. Easy part. Therefore, rather than setting one end portion of the input shaft 1 to which the assembly is assembled, setting the outer diameter of the other end portion of the input shaft 1 where stress concentration is likely to occur to increase the strength of the input shaft 1. It can be said that this is important. However, as described above, in the case of an assembly that is a single part in which the cage and the ball are integrated, it is difficult to realize such advantageous dimension setting because of problems in the assembling work.

  The present invention has been made in view of the above circumstances, and is a toroidal continuously variable transmission capable of optimally assembling a rolling element between the input shaft and the input side disk while advantageously securing the strength of the input shaft. The purpose is to provide a machine.

In order to achieve the above object, a toroidal continuously variable transmission according to claim 1 includes an input shaft to which a rotational force from an engine is input and an input shaft coupled to the input shaft and integrally rotating with the input shaft. An input side disk that is movable relative to the input shaft; and provided between the input side disk and the input shaft, the input side disk being movable in the axial direction with respect to the input shaft. An output-side disk that receives the rotational force of the input-side disk at a predetermined speed ratio via a power roller provided between the rolling element and the input-side disk; and a trunnion that rotatably supports the power roller; a yoke for supporting the trunnion pivotally, and a support post which displaceably supports the yoke, cage holding the rolling elements is divided into a plurality, in the support posts, the holding And the rolling elements, characterized in that the retaining member to prevent the escape is provided from between the input shaft and the input side disk.

  In the invention described in claim 1, since the cage for holding the rolling element is divided into a plurality of parts, for example, the outer diameter of one end portion of the input shaft to which the rolling element and the cage are assembled is set. The rolling element and the cage can be assembled to the input shaft without having to be larger than the outer diameter of the other end portion of the input shaft on the opposite side to which a disc spring or a loading nut is mounted. Become. Therefore, optimal strength can be given to each part of the input shaft. In other words, dimensional restrictions associated with assembly are eliminated (shaft diameter design can be given a degree of freedom). For example, there is no need to form a step or a groove, which is advantageous in terms of strength. The outer diameter of the one end part of the shaft is set smaller than the outer diameter of the other end part of the input shaft, which is likely to cause stress concentration, which requires steps, splines or screws, etc., to optimize the strength distribution of the input shaft It becomes possible to do. As a result, the input shaft can be designed to be narrower than before. If the input shaft is thin, the minimum turning radius of the contact point between the input / output side disk and the power roller can be made smaller, so that the speed change range of the toroidal type continuously variable transmission can be made larger.

Further , since the support post is provided with a retaining member for preventing the retainer and the rolling element from coming off between the input side disk and the input shaft, the retainer and the rolling element can be prevented from coming off. Not only can it be effectively prevented, but also damage to the input shaft due to stress concentration can be prevented.

  In the toroidal-type continuously variable transmission of the present invention, the rolling element retainer interposed between the input shaft and the input side disk is divided into a plurality of parts, so that the input shaft is advantageously secured while ensuring the strength of the input shaft. And the rolling element can be optimally assembled between the disk and the input side disk.

  Embodiments of the present invention will be described below with reference to the drawings. The feature of the present invention lies in the assembly structure in which the rolling elements are assembled between the input shaft and the input side disk, and other configurations and operations are the same as the conventional configuration and operation described above. Only the characteristic part of the present invention will be referred to, and other parts will be simply described with the same reference numerals as in FIGS.

  FIG. 1 shows a moving mechanism 96A according to an embodiment of the present invention. As shown in the figure, the moving mechanism 96A includes a plurality of balls 320 as rolling elements (cylindrical rollers may be used in place of the balls) held by a brass cage 322. In this case, the cage 322 is divided into a plurality of parts in order to improve the assembling property with respect to the input shaft 1. The cage 322 may be made of resin.

  FIG. 2 shows a state in which the moving mechanism 96 </ b> A of FIG. 1 is assembled between the input shaft 1 and the input side disk 2. The moving mechanism 96 </ b> A holds the input side disk 2 concentrically with the input shaft 1 and enables the input side disk 2 to slide in the axial direction with respect to the input shaft 1. In this toroidal-type continuously variable transmission, power is not transmitted between the input shaft 1 and the input side disk 2 via a ball spline as in the prior art, but the rotational force from the engine is applied to the drive shaft on the engine side. 315 is transmitted to the input shaft 1 by nail engagement, and is transmitted from the input shaft 1 to the input disc 2 on the rear side (right side in FIG. 2) via the carrier 316 coupled to the input shaft 1, while the input shaft 1 1 is transmitted to the input side disk 2 on the front side (left side in FIG. 2) via a claw engagement between the cylinder 317 and the cylinder member 318. The cylinder member 318 and the input side disk 2 are fixed to each other by a method such as press-fitting or welding that can sufficiently withstand the transmission torque.

  The support post 20 a is provided with a retaining member 400 that prevents the retainer 322 and the ball 320 from slipping out between the input side disk 2 and the input shaft 1. In this case, the retaining member 400 may be integrated with or separate from the support post 20a. In the case of a separate body, the retaining member 400 is fixed to the support post 20a by screwing or press fitting. In the case of this embodiment, it is not necessary to form a large clearance between the retaining member 400 and the cage 322. This is because when the front side input side disk 2 located on the left side in FIG. 2 moves to the right due to elastic deformation of each part of the variator, the rear side input side disk 2 located on the right side in FIG. Is moved to the left, the input shaft 1 is also moved to the left by substantially the same amount, and as a result, the ball 320 and the holder 322 hardly change their positions.

  As described above, in the present embodiment, since the holder 322 that holds the ball 320 is divided into a plurality of parts, the outer diameter A of one end portion of the input shaft 1 to which the ball 320 and the holder 322 are assembled (FIG. 2). 2), the ball 320 and the cage 322 can be connected to the input shaft without the need to be larger than the outer diameter B (see FIG. 2) of the other end portion of the input shaft 1 on the opposite side to which a disc spring or a loading nut is mounted. 1 can be assembled. Specifically, the outer diameter A of the one end portion of the input shaft 1 that is advantageous in terms of strength without the need for forming a step or a groove is likely to cause stress concentration that requires a step, a spline, a screw, or the like. It is possible to optimize the intensity distribution of the input shaft 1 by setting it smaller than the outer diameter B of the other end portion of the input shaft 1. Accordingly, since the input shaft 1 can be designed to be thinner than the conventional one, the minimum turning radius of the contact point between the input / output side disks 2 and 4 and the power roller 11 can be made smaller, and the toroidal The shift range of the continuously variable transmission can be increased.

  Further, in the present embodiment, a retaining member 400 that prevents the retainer 322 and the ball 320 from coming off between the input side disk 2 and the input shaft 1 is provided not on the input shaft 1 side but on the support post 20a. Therefore, it is possible not only to effectively prevent the cage 322 and the ball 320 from coming off, but also to prevent the input shaft 1 from being damaged due to stress concentration.

  The present invention can be applied to a full toroidal continuously variable transmission having no trunnion in addition to a half toroidal continuously variable transmission such as a single cavity type or a double cavity type.

It is a perspective view of the moving mechanism which concerns on embodiment of this invention. It is sectional drawing which shows the state which assembled | attached the moving mechanism of FIG. 1 between the input shaft and the input side disk. 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 CC line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Input side disk 4 Output side disk 11 Power roller 20a Support post 320 Ball (rolling element)
322 Cage 400 Retaining member

Claims (1)

An input shaft to which the rotational force from the engine is input;
An input side disk coupled to the input shaft and rotating integrally with the input shaft, and movable relative to the input shaft;
A rolling element which is provided between the input side disk and the input shaft and which allows the input side disk to move in the axial direction with respect to the input shaft;
An output side disk that receives the rotational force of the input side disk at a predetermined gear ratio via a power roller provided between the input side disk; and
A trunnion that rotatably supports the power roller;
A yoke for swingably supporting the trunnion;
A support post for displacably supporting the yoke;
With
The cage for holding the rolling element is divided into a plurality of parts ,
A toroidal-type continuously variable transmission , wherein the support post is provided with a retaining member that prevents the retainer and the rolling element from slipping out between the input disk and the input shaft. .

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