JP2005299752A - Toroidal type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toroidal type continuously variable transmission provided with a disc capable of ensuring sufficient strength for bending stress even by mere quenching and tempering treatment. <P>SOLUTION: In this toroidal type continuously variable transmission, an output side disc 4A is formed by quenching and tempering a high carbon steel material and has a traction face 4a coming into contact with a power roller 11 on both sides. In this case, the output side disc 4A is fitted into an input shaft 1 side without causing play in the radial direction. In this output side disc 4A, each traction face 4a, 4a on both sides comes into contact with the power roller 11 at the same phase. <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.

  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. On the inner side of the casing containing the toroidal type continuously variable transmission, trunnions 6 and 6 are provided that swing around pivots (tilting shafts) 5 and 5 that are twisted with respect to the input shaft 1 and the output shaft 3. It has been. 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.

FIGS. 5 and 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.

  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. Yes. 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. 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 5 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 tangents acting on the contact portions between the peripheral surfaces 11a and 11a 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 the direction force 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 positions of the peripheral surfaces 11a and 11a of the power roller 11 with the input side disks 2 and 2 and the output side disks 4 and 4 change, and the rotational speed ratio between the input shaft 1 and the output gear 110 is changed. Changes.

  By the way, in such a toroidal-type continuously variable transmission, power transmission between the power roller 11 and the input / output side disks 2 and 4 is non-contact by a traction force through an oil film in order to prevent damage to the surface of these members. Is done. Therefore, an oil film for transmitting torque in a non-contact manner can be formed between the peripheral surface (traction surface) 11a of the power roller 11 and the inner surfaces (traction surfaces) 2a and 4a of the input / output side disks 2 and 4. It is necessary to supply a sufficient amount of lubricating oil (traction oil).

  In such a toroidal-type continuously variable transmission, the disks 2 and 4 are in contact with the power roller 11 at two points (three points in the case of a three-roller type) as described above and receive a large force necessary for the traction drive. Cause large bending stress. In particular, the conventional disks 2 and 4 have a structure in which the traction surfaces 2a and 4a are only on one side and the opposite side is fixed in the axial direction with a small diameter portion, as can be seen from the above-described configuration. Therefore, when the power roller 11 is in contact with the outer periphery of the disks 2 and 4 (see, for example, the output side disk 4 shown in FIG. 3 or the input side disk 2 shown in FIG. 4), the bending moment increases, The bending stress generated in the disks 2 and 4 increases. Therefore, in the worst case, especially in a toroidal continuously variable transmission having a large torque capacity, the disks 2 and 4 may be damaged. For this reason, the disks 2 and 3 may be subjected to a carburizing process or a carbonitriding heat treatment that hardens the surface and softens the core part in order to impart toughness to the core part (see, for example, Patent Document 1).

JP 7-71555 A

  However, since the carbonitriding heat treatment is more complicated and expensive than quenching and tempering (so-called soaking), a disk capable of performing the soaking process is desired for large-scale production.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a toroidal continuously variable transmission including a disk that can secure sufficient strength against bending stress only by quenching and tempering. To do.

  In order to achieve the object, the toroidal continuously variable transmission according to claim 1 rotates concentrically with an input shaft to which rotational torque is input and each traction surface facing each other. An input disk and an output disk that are freely supported by the input shaft; and a power roller that is sandwiched between the traction surface of the input disk and the traction surface of the output disk. Is a toroidal continuously variable transmission in which the rotational force input to the input side disk is transmitted to the output side disk through a power roller at a predetermined speed ratio, wherein the input side disk or the output side disk is: It is formed by quenching and tempering high carbon steel material, and has traction surfaces on both sides that contact the power roller. And wherein the Rukoto.

  In the first aspect of the present invention, the input side disk or the output side disk has traction surfaces on both sides thereof. That is, the disk having the traction surface on both sides thereof constitutes an integrated disk structure in which disks having the traction surface only on one side are integrally coupled. Therefore, the disk can ensure sufficient strength against bending stress only by quenching and tempering. Moreover, since high carbon steel is easy to raise cleanliness, a material with few nonmetallic inclusions can be formed. Therefore, if the disc is made of a high carbon steel material as in the present claims, the durability of the disc can be improved.

  According to a second aspect of the present invention, the toroidal-type continuously variable transmission according to the first aspect of the invention is characterized in that the disk having traction surfaces on both sides thereof is free from backlash in the radial direction with the shaft fitted into the inner diameter. It is characterized by being fitted.

In the invention described in claim 2, since the disc having traction surfaces on both sides thereof is fitted to the shaft fitted to the inner diameter without any play in the radial direction, deformation of the disc is suppressed by the input shaft. Thus, it is possible to prevent a large stress from being generated in the disk.

  Further, the toroidal continuously variable transmission according to claim 3 is the invention according to claim 1 or 2, wherein the disk having traction surfaces on both sides has the same phase on each traction surface. It contacts with a power roller.

In the invention described in claim 3, since the power roller contacts the both sides of the disk at the same phase, for example, when the power roller contacts the outer periphery of the disk, The load cancels out relative to both sides of the disc. Therefore, it is not necessary to generate bending stress.

  In the toroidal type continuously variable transmission according to the present invention, the disk is made of a high carbon steel material and has traction surfaces on both sides thereof. Can be secured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The feature of the present invention lies in the shape and support form of the disk, and other configurations and operations are the same as the conventional configuration and operation described above. Therefore, only the features of the present invention will be described below. Other portions are denoted by the same reference numerals as those in FIGS. 3 to 6 and detailed description thereof is omitted.

  1 and 2 show an embodiment of a toroidal continuously variable transmission according to the present invention. As shown in FIG. 1, in the present embodiment, the output side disk 4 </ b> A is formed by quenching and tempering a high carbon steel material (for example, a steel type such as SUJ2 or SUJ3) and is in contact with the power roller 11. Traction surfaces 4a and 4a are provided on both sides thereof. That is, the output side disk 4A of the present embodiment has a configuration of an integrated disk in which conventional disks 4 and 4 (see FIG. 5) having a traction surface 4a only on one side are integrally coupled.

  Further, in the present embodiment, the output side disk 4A is fitted to the hollow shaft 300 fitted to the inner diameter thereof without backlash in the radial direction. Specifically, as shown in FIG. 2, the output side disk 4 </ b> A is a hollow that fits around the input shaft 1 by an inlay portion 302, a spline 304, and a collar 306 that are continuously provided along the axial direction. The shaft 300 is fitted with no backlash.

  Thus, in this embodiment, the output side disk 4A has the traction surfaces 4a, 4a on both sides thereof, and the integrated disk in which the disks 4, 4 having the traction surfaces only on one side are integrally coupled. It is composed of Therefore, the output side disk 4A can secure sufficient strength against bending stress only by quenching and tempering. Further, the output side disk 4A of the present embodiment is formed of a high carbon steel material. Since high carbon steel is easy to raise the cleanliness, non-metallic inclusions can be reduced. Therefore, if the output side disk 4A is made of a high carbon steel material, the durability of the output side disk 4A can be improved.

  In the present embodiment, since the integrated output side disk 4A has traction surfaces 4a and 4a on both sides thereof, these traction surfaces 4a and 4a have the same phase and power rollers under a predetermined condition. 11 will be contacted. That is, when the power roller 11 comes into contact with the outer peripheral diameter of the output side disk 4A (in the case of deceleration shown in FIG. 3), the force F1 applied from the power roller 11 is applied to the output side disk 4A as shown in FIG. Since both surfaces 4a and 4a cancel each other, bending stress is not generated in the disk 4A. In this decelerating state, the tangential force of the traction power transmission unit increases, so the normal force also increases considerably to transmit this, but the bending stress does not act on the disk 4A because the forces F1 cancel each other. That's it.

  On the other hand, when the power roller 11 is in contact with the center of the disk 4A (in the case of acceleration shown in FIG. 4), the direction of the force F2 applied from the power roller 11 to the traction surfaces 4a and 4a is different. These forces F2 do not cancel each other. However, in this embodiment, since the output side disk 4A is fitted to the hollow shaft 300 fitted to the inner diameter thereof without any backlash in the radial direction, the deformation of the disk 4A is suppressed by the input shaft 1, and the disk 4A Generation of large stress can be prevented.

  Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

  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 principal part sectional drawing of the toroidal type continuously variable transmission which concerns on embodiment of this invention. FIG. 2 is an enlarged cross-sectional view of a main part around an output side disk of the toroidal type continuously variable transmission of FIG. 1. 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Input side disk 2a Traction surface 4, 4A Output side disk 4a Traction surface 11 Power roller

Claims (3)

An input shaft to which rotational torque is input, an input-side disk and an output-side disk that are supported concentrically and rotatably on the input shaft in a state where the traction surfaces face each other, and the input disk A power roller sandwiched between the traction surface and the traction surface of the output side disk, and a rotational force input from the input shaft to the input side disk through the power roller at a predetermined speed ratio. In the toroidal type continuously variable transmission transmitted to the output side disk,
The input side disk or the output side disk is formed by quenching and tempering a high carbon steel material, and has a traction surface on both sides thereof in contact with a power roller. Continuously variable transmission.   2. The toroidal continuously variable transmission according to claim 1, wherein the disc having traction surfaces on both sides thereof is fitted to a shaft fitted to the inner diameter without any play in the radial direction.   3. The toroidal continuously variable transmission according to claim 1, wherein each of the disks having traction surfaces on both sides thereof is in contact with the power roller at the same phase.

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