JPH0819998B2 - Friction car type continuously variable transmission - Google Patents

Description

The present invention relates to a friction wheel type continuously variable transmission.

(B) Conventional Technology As a conventional continuously variable transmission, there is, for example, one disclosed in JP-A-61-119865. The continuously variable transmission shown therein has an input disc, an output disc, a friction roller arranged in frictional contact with both discs in a toroidal groove formed by the discs, and a friction roller that is rotatable. And a roller support member that is rotatable about an axis orthogonal to the rotation axes of both discs and is movable in the axial direction of the shaft, and a hydraulic cylinder for moving the roller support member in the axial direction. And a shift control valve that controls the hydraulic pressure supplied to the hydraulic cylinder, and a cam that transmits the movement of the roller support member in the rotational direction to the shift control valve. By adjusting the axial position of the roller support member by the hydraulic cylinder, the inclination of the friction roller can be adjusted to continuously change the gear ratio between the input disc and the output disc.

(C) Problems to be Solved by the Invention However, in the continuously variable transmission, the hydraulic cylinders are arranged on both the upper side and the lower side of the friction roller supporting member,
Since a space for these is required, the size of the entire apparatus becomes large, and the oil passage for supplying the hydraulic pressure to the hydraulic cylinder becomes long and complicated. Therefore, Japanese Patent Application No. 61-177558, filed by the present applicant, discloses a structure in which a double-acting hydraulic cylinder is arranged on one side of a roller supporting member. However, in this case, there are the following problems. That is, the position of the bearing support member on the side where the hydraulic cylinder is provided is regulated by the post having a rectangular cross section in the central portion thereof, and the bearing support member is movable only in the lateral direction. On the other hand, the position of the bearing support member on the opposite side is regulated by a post having a spherical surface so that the bearing support member can rotate but does not move laterally. One of the bearing support members is movable in the horizontal direction because the bearing support member moves in the horizontal direction when an error occurs due to the mounting accuracy of each member, the processing accuracy of the disc, the friction roller, etc. This is because it is automatically adjusted to balance in a mechanically stable position. However, when the adjustment is performed by moving the bearing support member in this manner, there arises a problem that the operation of the piston of the hydraulic cylinder becomes unsmooth. That is, the clearance between the piston of the hydraulic cylinder and the inner diameter of the cylinder is determined by the functional necessity of the seal member and is relatively small. For this reason, when the bearing support member largely moves and the piston tilts, a large frictional force is generated between the cylinder inner diameter portion and the piston, which causes a malfunction. The present invention aims to solve such problems.

(D) Means for Solving the Problems The present invention is directed to an input disk, an output disk, and a pair of friction rollers arranged in a toroidal groove formed by the disks in frictional contact with the disks. And a roller support member that rotatably supports each friction roller and that is rotatable about an axis perpendicular to the rotation axis of both disks and that is movable in the axial direction of this axis, and one end side of the roller support member. A double-acting hydraulic cylinder that is arranged in the axial direction and is movable in the axial direction, and a first bearing support member that rotatably supports the rotary shaft portions at one end sides of both roller support members via bearings. A second bearing support member that rotatably supports the rotary shaft portions on the other end sides of both roller support members via bearings, and a central position outside the first bearing support portion is a casing or this. Friction wheel type continuously variable transmission having a first link post for supporting a member integrated with the casing and a second link post for supporting the central position of the second bearing support member for the casing or a member integral with the casing. In the machine, the second link post on the side where the hydraulic cylinder is arranged supports the second bearing support member in a structure that allows rotation of the second bearing post but does not allow movement of the second link post in the direction orthogonal to the axis, and the other side. The first link post of (1) supports the first bearing support member in a structure that allows only movement in a direction orthogonal to the axis of the first link post and connecting both roller support members.

(E) Action The second link post on the side where the hydraulic cylinder is arranged is connected to the second bearing support member by, for example, a spherical surface, and the second bearing support member is centered on the second link post and is the shaft of the roller support member. Although it swings in the direction, it does not move in the direction orthogonal to the axis of the second link post. On the other hand, the first bearing support member on the opposite side is orthogonal to the axis of the first link post and is movable in the direction connecting both roller support members, but since it is far from the hydraulic cylinder, the piston of the hydraulic cylinder falls. Has a relatively small effect on. As a result, the concentricity of the piston of the hydraulic cylinder with respect to the cylinder is maintained, and smooth operation can be obtained.

(F) Embodiment FIG. 4 shows the structure of the entire continuously variable transmission. Torque converter 12 on drive plate 10 integrated with engine output shaft
Are connected. The torque converter 12 is equipped with a lockup clutch 12a, and by controlling the hydraulic pressure in the lockup oil chamber 12b, a pump impeller on the input side is provided.
12c and the turbine runner 12d on the output side can be mechanically connected or disconnected. Torque converter 12 cover 12
The oil pump drive shaft 87 is connected to e. The oil pump drive shaft 87 is connected to the oil pump 15 and can drive it. The oil pump 15 is arranged on the opposite side of the torque converter 12 with a friction wheel type continuously variable transmission mechanism 16 described later interposed therebetween. Further, the turbine runner 12d of the torque converter 12 is connected to the hollow input shaft. Input shaft 14
A friction wheel type continuously variable transmission mechanism 16 is connected to. The friction wheel type continuously variable transmission 16 includes an input disc 18 and an output disc.
It has 20 and a friction roller 22 that transmits the rotational force between them. The contact surfaces of the input disk 18 and the output disk 20 with the friction roller 22 are toroidal surfaces. Friction roller
The inclination of the shaft 24 of 22 can be adjusted by a mechanism described later shown in FIG. An input disk 18 is connected to the input shaft 14, while a gear 26 is provided on the output disk 20 so as to rotate integrally therewith. The gear 26 meshes with a gear 30 integral with the idler shaft 28. The idler shaft 28 is provided with a gear 32 that always rotates integrally with the idler shaft 28 and a gear 34 that is rotatably supported by the idler shaft 28. The gear 34 can be connected by a reverse clutch 36 so as to rotate integrally with the gear 30. The idler shaft 28 is rotated only in the forward direction by the one-way clutch 31 attached to the casing, and is not rotated in the reverse direction. This is to prevent the friction wheel type continuously variable transmission mechanism 16 from rotating in the direction opposite to the engine rotation direction due to the reverse driving force from the wheel side. A gear 40 is rotatably supported on another idler shaft 38 disposed in parallel with the idler shaft 28, and a gear 42 is connected so as to always rotate integrally. The gear 40 can be connected by a forward clutch 44 so as to rotate integrally with the idler shaft 38. The gear 40 meshes with the gear 32. The gear 42 meshes with the above-mentioned gear 34 via a reverse idler gear, which is not shown in the sectional view of the drawing. The gear 42 is always meshed with the final gear 48. The final gear 48 has a pair of pinion gears 52 and 54 constituting a differential device 50 attached thereto. The pinion gears 52 and 54 and the pair of side gears 56 and 58 are meshed with each other, and the side gears 56 and 58 respectively output. The axes are connected. With such a configuration, when the forward clutch 44 is engaged, the output shafts 60 and 62 rotate in the forward direction, and when the reverse clutch 36 is engaged, the output shafts 60 and 62 rotate in the backward direction. In addition, friction wheel type continuously variable transmission 16
By controlling the contact state of the friction roller 22 with the input disk 18 and the output disc 20, the gear ratio can be continuously changed.

FIG. 3 shows the friction wheel type continuously variable transmission mechanism 16 in detail. The input shaft 14 is rotatably supported by a casing 67 via a ball bearing 65 and a needle bearing 66. A spacer is placed between the input shaft 14 and the ball bearing 65.
68 are provided. A disc spring 70 is provided between the spacer 68 and the loading nut 69 screwed onto the input shaft 14.
Is provided. As a result, the reaction force of the disc spring 70
14 acts to the right in the figure. The loading nut 69 is prevented from loosening by a pin 71 whose tip enters the groove 14a of the input shaft 14. A plurality of holes 69a for receiving the pins 71 are provided, and a plurality of grooves 14a for the input shaft 14 are also provided. By combining the two, the fixing position of the loading nut 69 can be finely adjusted. The pin 71 is prevented from coming off by a screw 72. An output disk 20 is rotatably supported on the input shaft 14 via a bearing 73. The output disk 20 is provided with output gears 26 so as to rotate integrally via the keys 74 arranged at two symmetrical positions. The gear 26 is supported by the casing 67 via a ball bearing 75. Further, an input disk 18 is provided on the input shaft 14 via a bearing 76 so as to be rotatable and axially movable. A cam flange 77 is provided on the back side of the input disk 18, that is, on the side opposite to the side facing the output disk 20. The cam flange 77 is splined with the input shaft 14 and the shoulder 78 of the input shaft 14 is provided.
This prevents movement to the left in FIG. A cam roller 79 is provided between the cam surfaces 18a and 77a of the input disk 18 and the cam flange 77 which face each other. The cam surfaces 18a and 77a and the cam roller 79 are in a shape so that a force for pressing the input disk 18 to the right in FIG. 1 is generated when the cam flange 77 and the input disk 18 rotate relative to each other. A friction roller 22 arranged in a toroidal groove formed by the surfaces of the input disk 18 and the output disk 20 facing each other is rotatably supported by a shaft 80 via a bearing 81. Further, the friction roller 22 is supported in the thrust direction by a ball bearing 82. The ball bearing 82 is supported by the roller support member 83. Friction roller 22, ball bearing 82,
The roller support member 83 is prevented from coming off by snap rings 84 and 85 provided at both ends of the shaft 80. A sleeve 86 is inserted in the inner diameter portion of the input shaft 14 and is prevented from coming off by a snap ring 97. The diameter of the sleeve 86 is smaller than the inner diameter of the input shaft 14 except for both ends where the O-rings 96 and 95 are provided, respectively, and an oil passage 88 is formed by a clearance having an annular cross section therebetween. The input shaft 14 is provided with radial holes 94, 93, 92 and 91 communicating with the oil passage 88. Further, the input shaft 14 is provided with a groove 101 and a hole 102 for receiving oil from the hole 90 of the casing 67.
The groove 101 is sealed by a seal ring 103.
The oil pump drive shaft 87 passes through the inner diameter of the sleeve 86. An oil passage 89 for the lockup control hydraulic pressure of the torque converter 12 is formed by a clearance having an annular cross section between the inner diameter portion of the sleeve 86 and the outer diameter portion of the oil pump drive shaft 87.

FIG. 1 shows a cross section taken along line I-I of FIG. The above-mentioned roller support member 83 is supported by the spherical bearings 110 and 112 on the upper and lower rotary shaft portions 83a and 83b so as to be rotatable and movable in the vertical direction. The spherical bearing 110 is held by the first bearing support member 114, and the first bearing support member 114 is supported by the first link post 116 fixed to the casing 67. As shown in FIG. 2, the first link post 116 fits in the rectangular hole of the first bearing support member 114 at the rectangular cross section. Therefore, the first bearing support member 114 is movable in the left-right direction in FIG. 2, that is, only in the direction connecting both roller support members 83 and in the direction orthogonal to the axis of the first link post 116, by the clearance of the rectangular portion. is there. The spherical bearing 112 is also supported by the second bearing support member 118, and the second bearing support member 118 is supported by the second link post 120 fixed to the upper control valve body 200. The second link post 120 supports the second bearing support member 118 at its spherical portion. Therefore, the second bearing support member 118 can rotate but cannot move in the lateral direction (direction orthogonal to the axis of the second link post 120). The upper control valve body 200 is attached to the casing 67. The roller support member 83 is an extension shaft portion 83c provided concentrically with the rotation shaft portion 83b.
have. The extension shaft portion 83c is configured by integrally fixing another member to the rotation shaft portion 83b. Extension shaft
A piston 124 is provided on the outer circumference of 83c. Piston 12
4 is fitted in a cylinder 126 provided in the upper control valve body 200. An oil chamber 128 is formed above the piston 124, and an oil chamber 130 is formed above and below the piston 124. The oil chamber 130 on the right side of the figure is a hole provided in the piston 124.
302, a clearance 304 between the piston 124 and the small diameter portion of the extension shaft portion 83c, holes 306 and 308 provided in the roller support member 83 (note that the opening of the hole 306 is closed by the ball 310) It communicates with the opening of 308. Also,
The race 312 of the bearing 82 is provided with a hole 314.
The roller support member 83 on the left side of the drawing has substantially the same oil passages (hole 302, clearance 304, holes 306 and 308), but the hole 302 communicates with the upper oil chamber 128. To do. Also, holes 306 and 308 are connected by an annular groove 316. The left and right pistons 124 have the same shape except that the positions of the holes 302 are different. The upper end of the piston 124 is in contact with the roller support member 83 via the spacer 132,
Further, the lower end of the piston 124 is provided with a cam 136 through a spacer 134.
Is in contact with. The cam 136 is attached by a bolt 138 so as to rotate integrally with the extension shaft portion 83c. The cam 136 is attached to the extension shaft portion 83c on the right side in FIG. 1, and is not provided on the extension shaft portion 83c on the left side. The left and right friction rollers 22, the roller support member 83, etc. are basically symmetrical with respect to other points. The portion 80a of the shaft 8 that supports the friction roller 22 and the portion 80b that is supported by the roller support member 83 are eccentric. The cam 136 has a slope 140, which allows the cam 13 to
The swing shaft 1 in which the link 142 is supported by a part of a lower control valve body 144 described later by rotating 6
It can be swung around 42a. Separate plate 200 on the bottom of the upper control valve body 200
The lower control valve body 144 is attached via the, and an oil pan 146 is attached to the casing 67 so as to accommodate the valve body 144, the cam 136, and the like. The lower control valve Oddie 144 is provided with a shift control valve 150. The shift control valve 150 includes a drive rod 154 that is rotationally driven by a shift motor 152, a sleeve 156, a spool 158 that is fitted in the inner diameter portion of the sleeve 156, and a spring 160 that presses the spool 158 to the right in the figure. have. The drive rod 154 has a threaded portion 154a at its tip, and this is engaged with the female threaded portion 156a of the sleeve 156. Sleeve 156 is axially grooved 1
The groove 162b has a pin 162 fixed to the lower control valve body 144. This allows the sleeve 156 to move axially without rotating. The end 158a of the spool 158 on the side opposite to the side in contact with the spring 160 is pressed by the above-mentioned link 142 by the force of the spring 160. The spool 158 has lands 158b and 158c, by which the opening degree of the ports communicating with the oil passages 166 and 168 can be adjusted. In the stable state, the spool 158 is always in a predetermined axial position with respect to the sleeve 156 as shown in the drawing, supplies hydraulic pressure of the same pressure to the oil passages 166 and 168, and
In the unstable state, the spool 158 has an oil passage 164 depending on its position.
The line pressure supplied from is distributed to the oil passages 166 and 168. The oil passage 168 includes an oil chamber 128 on the right side in the figure and an oil chamber 13 on the left side in the figure.
Connected to 0. Further, the oil passage 166 is the oil chamber 13 on the right side of the drawing.
0 and the oil chamber 128 on the left side in the figure.

Next, the operation of this embodiment will be described. When the input shaft 14 is stopped, the force of the disc spring 70 acts on the input disk 18 as an initial thrust. When the rotation of the input shaft 14 increases, the input disk 18 rotates following the cam flange 77 by the action of the cam roller 79, and at the same time, generates a thrust corresponding to the input torque of the input shaft 14. As a result, the friction roller 22 is sandwiched between the input disk 18 and the output disk 20 and rotates without slipping, and power is transmitted from the input disk 18 to the output disk 20. For example, when the gear ratio is changed to the larger side, the drive rod 154 is rotated by the gear change motor 152, and the sleeve 156 is moved rightward in FIG. 1 by the engagement between the male thread 154a and the female thread 156a. Spool 158 does not move immediately, so spool 1
The relative relationship between 58 and the sleeve 156 is changed, and the clearance leading from the oil passage 164 to the oil passage 168 is reduced, and conversely, the clearance leading from the oil passage 164 to the oil passage 166 is enlarged. This allows oil passage 168
Oil pressure of the oil passage 166 decreases, and the oil pressure of the oil passage 166 increases. The oil pressure in the oil passage 166 is supplied to the right oil chamber 130, and the oil pressure in the oil passage 168 is supplied to the right oil chamber 128, so that the right piston 124 tries to move it upward. Receive the power to do. On the other hand, for the oil chambers 128 and 130 on the left side, the oil passage 168
Since the connection state with the oil passage 166 and the oil passage 166 is opposite to that described above, the left piston 124 receives a force to move it downward in the drawing. As a result, the roller support member 83 on the right side moves upward, and the roller support member 83 on the left side moves downward. Since the direction of the tangential force acting on the friction roller 22 changes accordingly, the left and right roller support members
83 rotates in opposite directions about the rotating shaft portions 83a and 83b, respectively. This allows the input disc 18 of the friction roller 22 to
The radius of the contact position with the output disk 20 becomes smaller, and the radius of the contact position with the output disk 20 becomes larger. That is, the gear ratio changes to the large side. The rotation of the roller support member 83 is transmitted to the cam 136 via the extension shaft portion 83c, and when the cam 136 further rotates, the link 142 swings and the tip of the link 14 moves to the right in FIG. As a result, the spool 158 is pushed by the force of the spring 160 and similarly moves to the right. spool
Oil passage 168 and oil passage 166 as 158 moves to the right in the figure.
The hydraulic pressures of and approach the same hydraulic pressure, and finally stabilize in the state where the hydraulic pressure values are the same. As a result, the speed ratio increases by a predetermined amount in accordance with the rotation of the speed change motor 152, and that state is maintained. Even when the gear ratio is changed to the smaller side, the basic operation is the same except that the rotation direction of the gear change motor 152 is reversed.

During the shifting operation as described above, the first bearing support member 114 always automatically moves to the left and right so that the left and right friction rollers 22 are balanced and in a stable state. The influence of the movement of the first bearing support member 114 on the piston 124 is significantly smaller than that of the conventional one. This will be described from the geometrical relationship shown in FIG. In FIG. 5, points A, B, C, D, E, F, G, H, and I respectively indicate the following positions.

A: Center of the first link post 116 B: Center of the left spherical bearing 110 C: Center of the right spherical bearing 110 D: Intersection point of the center line of the shaft 80 and a vertical line passing through B E ... Point of intersection of the center line of shaft 80 and vertical line passing through C F ... Point on center axis of left piston 124 G ... Point on center axis of right piston 124 H ... Left spherical bearing Center of 112 I ... Center of right spherical bearing 112 If points D and E in FIG. 5 are moved rightward by S ₁ , points F and G are centered at points H and I, respectively. Move S ₂ left.

S ₂ = S ₁ · (l ₂ / l ₂ ) l ₁・ ・ ・ Distance between DH l ₂・ ・ ・ Distance between HF, S ₂ is smaller than S ₁ , and is based on the movement of the friction roller 22. The movement amount of the piston 124 becomes small. When a link post having a rectangular cross section is arranged on the side where the piston 124 is arranged as in the conventional case, the geometrical relationship is as shown in FIG. 6, and the points A, B and C do not move. , D point and E point move by S _1, respectively, F point and G point become S ₃ = S ₁ · (l ₄ / l ₃ ), and S ₃ becomes larger than S ₁ . For this reason, this occurs in the piston 124, which hinders smooth operation.

(G) Effect of the Invention As described above, according to the present invention, the laterally movable bearing support member is arranged on the side far from the hydraulic cylinder, so that the tilting of the piston due to the movement of the bearing support member is reduced. It is possible to obtain smooth operation of the hydraulic cylinder.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention (a sectional view taken along line I-I in FIG. 3), FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. FIG. 4 is a diagram showing a continuous variable transmission mechanism, FIG. 4 is a diagram showing the entire continuously variable transmission, FIG. 5 is a diagram showing a geometrical relationship of an embodiment of the present invention, and FIG. 6 is a geometry of a conventional device. It is a figure which shows a physical relationship. 18 …… input disc, 20 …… output disc, 22 …… friction roller, 67 …… casing, 83 …… roller support member, 12
4 …… Piston, 114 …… First bearing support member, 116
...... First link post, 118 ...... Second bearing support member, 120 ...... Second link post.

Claims (1)

[Claims] 1. An input disk, an output disk, a pair of friction rollers arranged in frictional contact with both disks in a toroidal groove formed by the disks, and rotatably supporting each friction roller. And a roller support member that is rotatable about an axis perpendicular to the rotation axis of both discs and that is movable in the axial direction of this axis, and that is arranged on one end side of the roller support member and that moves in the axial direction. A double-acting hydraulic cylinder that can be driven, a first bearing support member that rotatably supports the rotary shaft portions at one end sides of both roller support members via bearings, and a first bearing support member at the other end sides of both roller support members. A second bearing support member that rotatably supports the rotary shaft portion via a bearing, and a first bearing support member that supports the central position of the first bearing support member with respect to the casing or a member integrated with the casing. In a friction wheel type continuously variable transmission having a link post and a second link post that supports the central position of the second bearing support member with respect to the casing or a member integrated with the casing, The second link post supports the second bearing support member with a structure that allows rotation of the second link post but does not allow movement of the second link post in the direction orthogonal to the axis, and the first link post on the opposite side supports the first bearing support member. A friction wheel type continuously variable transmission characterized by being supported by a structure which is orthogonal to the axis of the first link post and allows only movement in a direction connecting both roller support members.