JP5534307B2 - 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.

The use of a toroidal continuously variable transmission as shown in FIGS. 4 and 5 has been implemented as a transmission for automobiles.
As shown in FIG. 4, 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 be rotated 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, 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. 5, a pair of yokes 113 a and 113 b are supported inside the casing 101 and on the side positions of the output side disks 4 and 4 with both the disks 4 and 4 being 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. Then, in order to support the pivots 5 provided at both ends of the trunnion 6 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.
Therefore, 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. Both ends of the trunnion 6 are provided with pivots 5 which are concentrically twisted with respect to the input shaft 1, and these pivots 5 swing at one end of the pair of yokes 113a and 113b and are displaced in the axial direction. It is supported freely. That is, the pivot 5 is supported by the radial needle bearing 26 inside a 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. Further, the power roller 11 is supported around the pivot shaft 34 via another radial needle bearing 38 and is sandwiched (rolled) between both the input side and output side disks 2 and 4. Yes.

  The cross sections of the inner side surfaces 2a, 4a of the input side and output side discs 2, 4 facing each other 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 surfaces 11a and 11a of each power roller 11 and 11 formed in the spherical convex surface are contact | abutted to each inner surface 2a and 4a.

  A pair of displacement shafts 31 provided for each of the first and second cavities 21 and 22 is 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. Further, the directions in which the respective pivot shaft portions 34 of the displacement shaft 31 are eccentric with respect to the respective support shaft portions 33 are the same with respect to the rotation directions of the input disks 2 and 2 and the output disks 4 and 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.
The post 20 a is provided with a tilt stopper 150 that regulates the tilt amount of the trunnion 6.

  As shown in FIG. 4, 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 changing the rotational speed ratio between the input shaft 1 and the output gear 110, a pair is provided for each of 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 5 pivotally supported by the yokes 113a and 113b. As a result, the contact position between the circumferential 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, power transmission between the power roller 11 and the input / output side disks 2 and 4 is non-contact by traction force through an oil film in order to prevent damage to the surface of these members. (Hereinafter, the interface between the power roller 11 formed by the oil film and the input / output side disks 2 and 4 is referred to as a traction surface). Therefore, a sufficient amount of lubricating oil (traction oil) capable of forming an oil film for non-contact transmission of torque is supplied to the traction surface formed between the power roller 11 and the input / output side disks 2 and 4. There is a need to.

  As a lubricating structure of the toroidal continuously variable transmission, there are toroidal continuously variable transmissions described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-163854) and Patent Document 2 (Japanese Patent Laid-Open No. 2008-032084).

  The toroidal continuously variable transmission described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-163854) swings and moves the intermediate portion of a trunnion support yoke fixed to the inner surface of the casing of the toroidal continuously variable transmission. Lubricating oil is supplied to substantially the entire traction surface of the input side disk and the output side disk from a lubrication post provided at the tip of a support post that is displaceably supported along the axial direction of the pivot.

  A toroidal continuously variable transmission described in Patent Document 2 (Japanese Patent Laid-Open No. 2008-032084) is provided between a positioning member that is provided on both sides of an output side disk and positions and supports the output side disk, and an output side disk. A support plate that is inserted and supports the output side disk is provided, and the lubricating oil supplied through the input shaft is guided to the traction surface of the output side disk by an oil passage provided in the support plate.

  In the toroidal continuously variable transmission, the relationship between the traction force Ft and the pressing force Fc is expressed as Ft = μ · Fc. Here, μ is a traction coefficient. If the pressing force is constant, the higher the traction force, the greater the transmitted traction force. In order to transmit power efficiently, it is necessary to set the pressing force Fc as small as possible and μ as large. Further, when Fc increases, the spin loss of the traction contact portion increases, and the load load of the bearing that supports the power roller axial component of the pressing force increases, resulting in power loss.

By the way, the traction coefficient has a limit value called a maximum traction coefficient, and the maximum traction coefficient decreases as the temperature of the oil increases. On the other hand, to reduce the temperature of the oil, it is conceivable to increase the capacity of the radiator, or to increase the pump and increase the cooling flow rate. In this case, however, the loss of the hydraulic system increases. The power transmission efficiency of the device will be reduced.
Therefore, in order to increase the power transmission efficiency, it is necessary to efficiently cool with a small flow rate, and a cooling method for the toroidal type continuously variable transmission is described in Patent Document 3 (Japanese Patent Laid-Open No. 2007-154952). There are toroidal continuously variable transmissions.

  A toroidal-type continuously variable transmission described in Patent Document 3 (Japanese Patent Application Laid-Open No. 2007-154952) includes a first oil passage that supplies lubricating oil to the trunnion, and a trunnion. A second oil passage for supplying lubricating oil in the oil passage to a traction surface formed between the input side disk and the output side disk and the power roller, a trunnion and a displacement shaft; A third oil passage that supplies the lubricating oil in the oil passage to a bearing that supports a load in the thrust direction applied to the power roller, and from the discharge port provided in the second oil passage, Lubricating oil is discharged toward the extended line in the circumferential direction of the contact point of the power roller in contact with the output side disk.

JP 2005-163854 A JP 2008-032084 A JP 2007-154952 A

  However, in the above Patent Documents 1 to 3, various lubrication (cooling) means have been proposed, but the amount of lubrication (cooling) oil is not mentioned.

  Further, the axial force generated by the pressing force generator (such as a hydraulic piston or a mechanical cam mechanism) passes through the disk on the pressing force generator side, is input to the power roller, and is transmitted to the disk on the opposite side. At this time, as shown in FIG. 6, a frictional force due to the axial force component of the power roller is generated, and the pressing force is expressed by the following equation (Equation 1) as shown in the following formula (Equation 1). The pressing force Fco is smaller than the pressing force Fci on the pressing force generator side.

If the traction coefficient of each input / output disk is the same value, if the necessary pressing force is secured on the counter-pressing force generator side where the pressing force decreases, the pressing force is excessive on the opposite pressing force generator side. Therefore, in such an overpressed state, the power transmission efficiency is reduced.
An object of the present invention is to change the lubricating oil film temperature on the traction surface by adjusting the lubricating oil distribution amount and the like in order to enhance the power transmission performance of the toroidal type continuously variable transmission.

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. An output-side disk; a power roller sandwiched between the input-side disk and the output-side disk; and a pressing device that presses the input-side disk toward the output-side disk, the power roller and the input In the toroidal continuously variable transmission in which power is transmitted by the traction force through the lubricating oil film formed on the traction surface that is the interface between the side disk and the output side disk, the oil film temperature of the traction surface is: This toroidal-type continuously variable transmission is characterized in that the pressing device side> the anti-pressing device side in the entire transmission range .

A toroidal continuously variable transmission according to a second aspect of the present invention is the toroidal-type continuously variable transmission according to the first aspect of the present invention, wherein the nozzle hole for supplying a lubricating liquid to the traction surface of the input side disk and the traction surface of the output side disk are provided. The nozzle holes for supplying the lubricating liquid are respectively provided with a throttle, and the size of the through hole of the throttle of the nozzle hole for supplying the lubricating liquid to the traction surface of the input side disk is the traction surface of the output side disk. The nozzle hole for supplying the lubricating liquid is set to be smaller than the size of the through hole of the restrictor, whereby the oil film temperature of the traction surface is higher on the pressing device side than on the counter pressing device side.
Further, the toroidal continuously variable transmission according to claim 3 is the invention according to claim 1, wherein the nozzle hole for supplying a lubricating liquid to the traction surface of the input side disk and the traction surface of the output side disk are provided. A throttle is provided only in the nozzle hole for supplying the lubricating liquid to the traction surface of the input side disk among the nozzle holes for supplying the lubricating liquid to the oil pressure on the pressing device side. It is characterized by being higher than the side.

  According to the present invention, since it is possible to operate without excessive pressing on the pressing force generating device side, the load loss of the bearing supporting the spin loss of the traction contact portion and the power roller axial component of the pressing force can be reduced. Loss can be reduced, and the lubrication supply amount is distributed so that the traction transmission performance can be maximized in each part, so the total lubrication flow rate can be reduced efficiently and power loss is reduced by the hydraulic system. Is also possible.

It is principal part sectional drawing concerning Example 1 of this invention. It is principal part sectional drawing which concerns on Example 2 of this invention. It is principal part sectional drawing which concerns on Example 3 of this invention. It is sectional drawing which shows an example of the conventional toroidal type continuously variable transmission. It is AA sectional drawing in FIG. It is a mechanism figure explaining pressing force.

  FIG. 1 shows a first embodiment of the present invention. On the inner surface of the casing 101 (see FIG. 5) that houses the toroidal-type continuously variable transmission, an intermediate portion of the trunnion support yoke 113a is supported so as to be swingable and displaceable in the axial direction of the pivot shafts 5 and 5. The support post 20a is fixed. The lubrication post 200 is coupled and fixed by a coupling screw 202 to the center of the inner surface of the yoke 113a at the tip of the support post 20a. Further, an outer flange-shaped holding bar 236 having an outer diameter larger than that of the proximal end portion is formed at the distal end portion of the lubrication post 200.

  The coupling screw 202 is screwed and fastened to a support plate 237 whose tip is fixed to the inner surface of the casing 101 in a state of passing through the support post 20a and the lubrication post 200, and the head 238 is held down and brought into contact with the flange 236. Yes. In this state, the support post 20 a and the lubrication post 200 are sandwiched between the support plate 237 and the head 238 and are fixed to the inner surface of the casing 101 via the support plate 237.

  The downstream ends of the nozzle holes 239 are opened at four positions at equal intervals in the circumferential direction on the outer peripheral surface of the holding collar 236. Of these four nozzle holes 239, two nozzle holes 239 have their downstream ends opened on opposite sides in the diametrical direction. Of these two nozzle holes 239, the downstream end of one nozzle hole 239 opens toward the inner side surface 2 a of the input side disk 2. On the other hand, the downstream end of the other nozzle hole 239 opens toward the inner side surface 4 a of the output side disk 4. Further, the downstream ends of the remaining two nozzle holes 239 open toward the peripheral surface 11 a of each power roller 11.

  When the toroidal continuously variable transmission is operated, the four nozzle holes 239 as described above are provided in the lubricating oil supply groove formed on the inner surface of the casing 101 and the coupling screw 202 by an oil feeding pump (not shown) and coupled to this. Traction oil is fed through the oil supply passage 242 and the nozzle hole 239 that are open to the front end surface of the screw 202 and the outer peripheral surface near the head 238. In this case, a restriction is provided in the nozzle hole 239 to supply lubricating oil to the traction surfaces of the input side disk 2 and the output side disk 4. Then, as a diaphragm, a screw provided with a through hole in the axial direction is screwed into the nozzle hole 239. At this time, the size of the through hole of the throttle 242 facing the input side disk is set to the throttle 241 facing the output side disk so that the flow rate of the lubricating oil becomes the counter pressing force generator side> the pressing force generator side. Smaller than the size of the through hole.

  FIG. 2 shows a second embodiment of the present invention. As shown in the figure, in the present embodiment, the downstream end of the nozzle hole 239 is opened at the position of the counter pressing force generating device on the outer peripheral surface of the restraining collar 236, that is, the output side disk and the power roller, and the restraining collar No nozzle hole is opened at the position of the pressing force generator on the outer peripheral surface of 236, that is, the input disk.

  FIG. 3 shows a third embodiment. Cylindrical shape is formed only at the downstream end of the nozzle hole 239 opened toward the input side disk 2 by opening the downstream end of the nozzle hole 239 at four circumferentially equidistant positions on the outer peripheral surface of the holding collar 236. A diaphragm 243 may be provided.

  In addition, the capacity of the radiator installed in the lubrication supply line to the counter-pressing force generator side is made larger than the capacity of the radiator installed in the lubrication supply line on the side of the pressing force generator, and the lubricating oil temperature is reduced to the counter-pressing force generator side < It is good also as the pressing force generator side.

  In addition, it cannot be overemphasized that this invention can carry out various deformation | transformation in the range which does not deviate from the summary, The structure where the oil film temperature of a traction surface becomes a pressing device side> anti-pressing device side, and lubricating oil supply means It is important to use it, and it is not particularly limited to the configuration given in the examples.

  The present invention is a toroidal type continuously variable transmission and can be used as a cooling method thereof.

1 Input shaft
2 Input disk
2a Inner side of the input disc
4 Output disk
4a Inner side of the output disk
5 Axis
6 Trunnion
8 Trunnion
9 Axis
11 Power roller
11a Power roller circumference
20a Support post
20b support post
21 First cavity
22 Second cavity
26 Radial needle bearing
27 Outer ring
28 needle
30 hole
31 Displacement axis
33 Support shaft
34 Pivot shaft
35 radial needle
38 radial needle
39 Thrust ball bearing
40 Thrust bearing
41 outer ring
42 Drive rod
43 Drive piston
44 Drive cylinder
45 Pressing device
46 Cam plate
47 Cage
48 Laura
96 ball spline
101 casing
103 Transmission shaft
109 sleeve
110 Output gear
111 Supporting wall
112 Rolling bearing
113a York
113b York
118 Support hole
119 Locking hole
150 Tilt stopper
200 Lubrication post
202 coupling screw
236 restraining collar
237 Support plate
238 head
239 nozzle hole
241 aperture
242 Aperture
243 aperture

Claims (3)

Power held between the input side disk and the output side disk, and the input side disk and the output side disk supported concentrically and rotatably with the respective inner peripheral surfaces facing each other. A lubricating oil film formed on a traction surface which is an interface between the power roller and the input side disk and the output side disk, comprising a roller and a pressing device that presses the input side disk toward the output side disk In the toroidal continuously variable transmission to which power is transmitted by the traction force via
A toroidal continuously variable transmission characterized in that the oil film temperature of the traction surface is higher on the pressing device side than on the non-pressing device side in the entire transmission region of the toroidal continuously variable transmission. The nozzle holes for supplying the lubricating liquid to the traction surface of the input side disk and the nozzle holes for supplying the lubricating liquid to the traction surface of the output side disk are respectively provided with a restriction, and the traction surface of the input side disk is lubricated. The size of the throttling through hole of the nozzle hole for supplying liquid is set smaller than the size of the throttling through hole of the nozzle hole for supplying lubricating liquid to the traction surface of the output side disk, thereby The toroidal continuously variable transmission according to claim 1, wherein the oil film temperature of the traction surface is higher on the pressing device side than on the counter pressing device side . Among the nozzle holes for supplying the lubricating liquid to the traction surface of the input side disk and the nozzle holes for supplying the lubricating liquid to the traction surface of the output side disk, the lubricating liquid is supplied to the traction surface of the input side disk. 2. The toroidal continuously variable transmission according to claim 1, wherein a throttle is provided only in the nozzle hole, whereby an oil film temperature of the traction surface is higher on the pressing device side than on the non-pressing device side.

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