JP4399922B2 - Toroidal continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toroidal continuously variable transmission in which a power roller is tiltably disposed between an input disk having a toroidal curved surface and an output disk, and the rotation of the input disk is continuously variable and transmitted to the output disk. About.
[0002]
[Prior art]
Conventionally, as a toroidal-type continuously variable transmission, an input disk driven by an input shaft, an output disk disposed opposite to the input disk and connected to the output shaft, and a power roller that frictionally contacts both disks, a toroidal transmission unit And changing the tilt angle of the power roller to change the rotation of the input disk steplessly and transmit it to the output disk.
[0003]
FIG. 3 is a cross-sectional view showing an example of a conventional double cavity toroidal continuously variable transmission in which two sets of toroidal transmission units 1 and 2 are arranged in parallel on the same axis. For the input shaft 13 to which torque output to the engine output shaft is input via a torque converter or the like, the toroidal transmission units 1 and 2 are respectively input disks 4 and 7 driven by the input shaft 13 and input. Output disks 5, 8 disposed opposite to the disks 4, 7 and connected to the output shaft 22, and disposed between the input disks 4, 7 and the output disks 5, 8 and both disks 4, 5, 7 , 8 are provided with a pair of power rollers 6, 6 and 9, 9 that frictionally engage the toroidal curved surface. Each power roller 6, 9 can rotate around its own rotation axis 10 and can tilt around a tilt axis 11 orthogonal to the rotation axis 10. By changing the tilt angles of the power rollers 6 and 9 simultaneously, the rotation of the input disks 4 and 7 is steplessly changed according to the tilt angles of the power rollers 6 and 9 and transmitted to the output disks 5 and 8. Is done.
[0004]
In the toroidal transmission 1, the input disk 4 is attached to one end of the main shaft 3 disposed on the same axis as the input shaft 13 via a ball spline 12, is movable in the axial direction of the main shaft 3, and 3 and can rotate together. The distal end portion 14 of the input shaft 13 is fitted and supported so as to be rotatable relative to a center hole 15 formed at one end of the main shaft 3 by, for example, a bearing. Further, the input flange portion 16 formed at the tip of the input shaft 13 and the loading cam 18 disposed to face the input flange portion 16 are provided with claw portions 17 and 19 that mesh with each other. A part of the torque from the engine is transmitted from the input shaft 13 to the input disk 4 through the engaging claws 17 and 19 and the loading cam 18. At the time of torque transmission, a thrust corresponding to the transmission torque is generated as a pressing force acting between the input disk 4, the power roller 6 and the output disk 5 by the action of the cam roller 36 of the loading cam 18.
[0005]
The input disk 7 of the toroidal transmission unit 2 is attached to the other end side of the main shaft 3 via a ball spline 28. Since the input disks 7 are respectively connected to the main shaft 3 via the ball splines 28, they rotate together with the main shaft 3, but are slidable in the thrust direction of the main shaft 3. The remaining torque from the input shaft 13 is transmitted to the input disk 7. As a reaction of the thrust force in the toroidal transmission unit 1 by the cam roller 36, a thrust reaction force according to the transmission torque is transmitted to the toroidal transmission unit 2 through the main shaft 3, and the input disk 7, power roller 9 and output of the toroidal transmission unit 2 are output. A pressing force is applied between the rotating elements of the disk 8. The power transmission between the input disks 4, 7 and the output disks 5, 8 is based on the shearing force of the oil sandwiched between the disks 4, 5, 7, 8 and the power rollers 6, 9. Done.
[0006]
The output disks 5 and 8 are connected to a cylindrical portion 22A provided on the opposite sides of the output shaft 22 by spline fitting or the like, and rotate integrally. The output shaft 22 is a hollow shaft fitted to the main shaft 3, and a sprocket 23 is integrally formed at an intermediate portion of the hollow shaft. The output disks 5, 8 are regulated in the axial direction by the casing 25 by being supported on the wall 26 of the casing 25 by ball bearings 24 that support the loads in the thrust direction and the radial direction through the output shaft 22. ing.
[0007]
The other end of the main shaft 3 is rotatably supported by the casing 25 via a bearing 27. A disc spring 29 is attached to the back side of the input disk 7 in a compressed state by tightening a nut 31 with the sun gear 30 as a spacer. The repulsive force of the disc spring 29 presses the input disk 7 against the output disk 8 via the power roller 9 in the toroidal transmission section 2, and urges the main shaft 3 to the right in FIG. 20 and a bearing 21 acting on the loading cam 18, and in the toroidal transmission unit 1, the input disk 4 is pressed against the output disk 5 through the power roller 6. Absorbs the gap.
[0008]
The power rollers 6 and 9 are rotatably supported on the trunnions 33 and 37 by rotating support shafts 34 and 38, respectively. The trunnions 33 and 37 are displaced in the axial direction of the tilt shaft 11 with respect to the casing 25 by a hydraulic actuator, which will be described later, and the power rollers 6 and 9 and the input / output disk 4 according to the axial displacement of the tilt shaft 11. , 5, 7, and 8, the tilting force is received from the input / output disks 4, 5, 7, and 8, so that it can rotate around the tilting shaft 11. When the power rollers 6 and 9 are tilted, the tilt angle displacement amount θ of the power rollers 6 and 9 is directly rotated about the tilt shaft 11 of the trunnions 33 and 37.
[0009]
The rotation of the output shaft 22 is transmitted, for example, from a sprocket 23 fixed to the output shaft 22 to a counter shaft through a chain transmission, and forward rotation is transmitted through an appropriate gear mechanism (not shown). ) Is output. The rotation of the input shaft 13 is output from the planetary gear mechanism (not shown) with a reverse clutch directly to the transmission output shaft from the main shaft 3 via the sun gear 30. The main shaft 3 has an oil passage 32 extending in the axial direction, and the oil passage 32 constitutes a passage for lubricating oil. The oil passage 32 branches to supply lubricating oil to the toroidal curved surfaces of the toroidal transmission units 1 and 2, the ball spline 12, the ball bearing 24, and the like.
[0010]
The input disks 4, 7 and the output disks 5, 8 are displaced in the axial direction of the main shaft 3 by changing the contact point between the power rollers 6, 9 and the input / output disks 4, 5, 7, 8. The reference for the axial position of the toroidal transmissions 1 and 2 is determined by the casing 25 in which the output disks 5 and 8 are supported by the ball bearings 24. The rotary support shafts 34 and 38 that rotatably support the power rollers 6 and 9 are eccentric shafts that are eccentric to the swing support shafts 35 and 39 (see FIG. 4) that are rotatably supported by the trunnions 33 and 37. Therefore, the displacement of the power rollers 6 and 9 in the axial direction of the main shaft 3 is absorbed by the swing motion of the power rollers 6 and 9 around the swing support shafts 35 and 39. When the thrust direction positions of the output disks 5, 8 are determined with respect to the casing 25, the thrust direction positions of the power rollers 6, 9 and both the input disks 4, 7 are determined. The disc spring 29 returns the disks 4, 7, 5, 8 to their original state when the transmission torque is lost in the toroidal transmission units 1, 2 and the thrust force disappears.
[0011]
Next, the toroidal transmission units 1 and 2 and their shift control will be described based on the description of FIG. FIG. 4 is a diagram in which cross-sectional views taken along lines AA and BB of the toroidal-type continuously variable transmission shown in FIG. 3 are juxtaposed. In order to displace the trunnions 33 and 37 in the direction of the tilt axis, hydraulic actuators 40 and 44 are disposed at the lower ends of the trunnions 33 and 37, respectively. The hydraulic actuators 40 and 44 include pistons 41 and 45 that extend around the tilt shaft 11 of the trunnions 33 and 37, and cylinders 42 that are formed in the casing 25 and slidably accommodate the pistons 41 and 45, respectively. 46. The cylinders 42 and 46 are respectively formed with deceleration side cylinder chambers 43A and 47A and acceleration side cylinder chambers 43B and 47B defined by pistons 41 and 45, respectively. When the hydraulic pressure Pd for deceleration is supplied from the spool valve 50 to the deceleration side cylinder chambers 43A and 47A through the oil passage 48A, the acceleration side cylinder chambers 43B and 47B are drained, and the acceleration side cylinder chambers 43B and 47B are drained through the oil passage 48B. When the speed increasing hydraulic pressure Pu is supplied, the deceleration side cylinder chambers 43A and 47A are drained, and a differential pressure is generated between the speed reduction side cylinder chambers 43A and 47A and the speed increase side cylinder chambers 43B and 47B. Moves together with the power rollers 6 and 9 in the axial direction of the tilting shaft 11 according to the differential pressure, and the transmission shifts to the deceleration side or the acceleration side.
[0012]
In the spool valve 50, a sleeve 51 is slidably provided in a valve body (valve case). A first spring 53 that abuts both ends of the sleeve 51 urges the sleeve 51 in a direction to hold the sleeve 51 in a neutral position. A spool 52 is slidably provided in the sleeve 51. The spool 52 is urged to the right in FIG. 4 by a second spring 54 disposed at one end, and the other end of the spool 52 abuts a later-described process cam 56 via a pivoted lever 55. An SA port and an SB port are formed at one end and the other end of the spool valve 50, respectively. A control hydraulic pressure PA is supplied to the SA port through a solenoid valve 57A, and a control hydraulic pressure PB is supplied to the SB port through a solenoid valve 57B. Is supplied. The spool valve 50 includes a PL port connected to the line pressure (hydraulic pressure source), an A port connected to the deceleration side cylinder chamber 43A via the oil passage 48A, and an acceleration side cylinder chamber 43B via the oil passage 48B. The B port communicated with the R port and the R port communicated with the reservoir.
[0013]
In the toroidal-type continuously variable transmission, shift information detected by various sensors 59 such as a vehicle speed v detected by a vehicle speed sensor and an accelerator depression amount sensor for detecting an accelerator pedal depression amount Acc is input to the controller 58. The controller 58 outputs a control signal corresponding to the target gear ratio calculated based on these gear shift information to the solenoid valves 57A and 57B. Solenoid valves 57A, 57B are output port C for outputting control oil pressures PA, PB to SA port and SB port of spool valve 50, drain port D, and oil pressure source port E communicating with control oil pressure source (pilot oil pressure source) PS. have. The solenoid valves 57A and 57B can be duty solenoid valves in which the time ratio of the valve operating position taken by the valve body can be changed by changing the duty ratio of the pulse current exciting the electromagnetic coil.
[0014]
Since the solenoid valves 57A and 57B are the same normally open solenoid valves, the controller 58 controls the solenoid valve 57A so that a differential pressure is generated between the SA port and the SB port corresponding to the target speed ratio. , 57B, the duty obtained by distributing the entire duty (100%) between the duty A and the duty B is obtained. The sleeve is controlled by controlling the time ratio at which the hydraulic pressure from the control hydraulic pressure source PS is supplied to the SA port and SB port of the solenoid valves 57A and 57B, or the time ratio at which the control hydraulic pressure at the SA port and SB port is released to the drain. 51 is moved in the axial direction according to the target gear ratio. The sleeve 51 is formed with communication holes corresponding to the ports PL, R, A, and B, and the ports PL and R communicate with the port A or the port B depending on the position of the spool 52. The sleeve 51 moves to a position representing the target gear ratio so that the differential pressure between the control hydraulic pressures PA and PB supplied to the ports SB and SA at both ends of the spool valve 50 is balanced with the spring force of the first spring 53.
[0015]
In the toroidal transmission unit 1, the recess cam 56 with which one end of the lever 55 abuts is attached to a shaft end extending along the tilt shaft 11 of one trunnion 33. The precess cam 56 detects the displacement amount of the trunnion 33 in the direction of the tilt axis Y and the combined displacement amount of the tilt angle displacement amount θ. The spool 52 of the spool valve 50 moves corresponding to the combined displacement amount. The spool valve 50 and the solenoid valves 57A and 57B receive the control signal regarding the target speed ratio from the controller 58 and the signal regarding the combined displacement amount from the recess cam 56 in order to control the speed ratio, and the hydraulic actuators 40 and 44. A gear ratio control valve that adjusts the hydraulic pressure is configured.
[0016]
In a state where the trunnions 33 and 37 are in a neutral position where the displacement amount Y in the tilt axis direction is zero, the tilt angle θ of the power rollers 6 and 9 is maintained at that time, and the gear ratio is constant at that time. The value of is held. That is, in this neutral position, the trunnions 33 and 37 are positioned in the direction of the tilt axis such that the rotation center lines of the input disks 4 and 7 and the output disks 5 and 8 intersect the rotation axis 10 of the power rollers 6 and 9. The power rollers 6 and 9 are rotated in a tilted state with a tilt angle displacement amount corresponding to the gear ratio. Further, the spool 52 moves following the sleeve 51 that is shifted corresponding to the target gear ratio, and is in a state where the A port and the B port are closed.
[0017]
The gear ratio is changed by displacing the trunnions 33 and 37 from the neutral position in the axial direction of the tilt shaft 11. That is, when the target gear ratio is changed during the rotation of both disks and the sleeve 51 is shifted, the A port or the B port communicates with the line pressure according to the relative movement amount generated between the sleeve 51 and the spool 52. Conducting to the PL port, the trunnions 33 and 37 are displaced in the direction of the tilt axis. The power rollers 6 and 9 are displaced in the tilt axis direction together with the trunnions 33 and 37, and the contact position between the power rollers 6 and 9 and the input disks 4 and 7 and the output disks 5 and 8 is displaced from the contact position at the neutral position. . As a result, the power rollers 6 and 9 receive the tilting force from both disks, and the displacement direction (that is, the direction of Y> 0 or Y <0) and the displacement amount (the absolute value of Y) along the tilting axis 11. ) Starts tilting around the tilting shaft 11 at a direction and speed according to (2), and the contact point between the two disks and the power roller is changed to start continuously variable transmission.
[0018]
The combined displacement amount of the tilt axis direction displacement amount Y and the tilt angle displacement amount θ of the trunnions 33 and 37 detected by the recess cam 56 acts on the other end of the spool 52 of the spool valve 50 via the lever 55, and the spool The spool 52 is moved against the spring force of the second spring 54 acting on one end side of the 52. Depending on the positional relationship between the sleeve 51 given as the target gear ratio and the spool 52 given by the recess cam 56, the A and B ports connected to the oil passages 48A and 48B are switched to the PL port or the R port. The displacement of the trunnions 33 and 37 in the direction of the tilt axis is controlled by the differential pressure between the hydraulic pressure Pd and the hydraulic pressure Pu introduced into the cylinder chambers 43A and 43B and 47A and 47B, and the tilt angle θ approaches the target tilt angle. When the displacement amount Y in the tilt axis direction of each trunnion 33, 37 approaches zero, the spool 52 representing the actual gear ratio approaches the position of the sleeve 51 representing the target gear ratio, gradually converges, and shift operation is performed. finish.
[0019]
By the way, each power roller 6 provided in a state of being opposed to the main shaft 3 is pressed against the input disks 4 and 7 and the output disks 5 and 8 by the loading cam 18 with a large force. The trunnions 33, 33 and 37, 37 that rotatably support 6 receive a force in a direction away from each other. In order to counteract this separation force, the ends of the pairs of trunnions 33, 33 and 37, 37 facing each other are connected by a yoke 60 to maintain the distance between the axes of the trunnions 33, 33, 37, 37. To be done.
[0020]
Each yoke 60 is fitted and supported by a post 61 erected integrally or fixed to the casing 25. The yoke 60 is a long member in which a fitting hole 62 is formed at a central position in the longitudinal direction, and circular holes 63 are formed at both ends. The yoke 60 can swing around the engaging portion 64 in a state in which the engaging portion 64 of the post 61 is fitted in the fitting hole 62 and the central position is constrained. Further, a bearing 66 for rotatably supporting the end portion 65 of each trunnion 33, 37 is fitted into the circular hole 63. The bearing 66 functions as a spherical bearing having a spherical surface on the outer peripheral side in order to maintain a fitted state with the end portions 65 of the trunnions 33 and 37 even when the yoke 60 is inclined with respect to the circular hole 63. At the same time, in order to rotatably support the end portions 65 of the trunnions 33 and 37, the inner peripheral side functions as a radial bearing holding a needle.
[0021]
FIG. 5 is an exploded perspective view showing the yoke and the post shown in FIG. Since the yoke 60 can only swing with respect to the post 61 in the plane including the tilting axes 11 and 11 of the trunnions 33 and 37, as shown in FIG. Planar chamfered portions 69 (only one is shown) are formed on both sides of the present engaging portion 64, and the chamfered portion 69 of the engaging portion 64 is engaged with the fitting hole 62 of the yoke 60. A flat inner surface 67 is formed, and an inner surface 68 that engages the spherical surface of the engaging portion 64 is formed. However, it is inevitable that the play occurs because the relative movement between the yoke 60 and the post 61 is allowed. Even if the backlash between the yoke 60 and the post 61 is kept small, each trunnion 33 (37) that fits into the circular hole 63 from the post 61 as compared to the width in the yoke longitudinal direction of the chamfered portions 69, 69 of the post 61. The distance due to the backlash is amplified and appears in the trunnion 33 (37).
[0022]
When the trunnions 33 and 37 are displaced from their original positions, the positional relationship between the power roller 6 and the input / output disks 4 and 5 and the positional relationship between the power roller 9 and the input / output disks 7 and 8 depend on the target gear ratio. Since it deviates from a predetermined position to be originally taken, the gear ratio may change or the durability of the power rollers 6 and 9 may be significantly impaired.
[0023]
A trunnion whose both ends are swing-supported by a link (yoke) through a support portion composed of a rolling bearing and a spherical joint is subjected to bending deformation due to a force during transmission. The clearance between the servo piston provided at one end of the trunnion and the guide hole that guides the servo piston is increased as the distance from the spherical joint increases, thereby preventing interference between the servo piston and the guide hole. A step transmission has been proposed (Japanese Patent Laid-Open No. 7-217716).
[0024]
In addition, the end portions of the trunnions arranged opposite to each other are supported by the casing of the transmission by support members, and one end of the trunnion is an expensive ball screw mechanism as an actuator that displaces the trunnion in the axial direction of the tilt shaft. There has been proposed one in which only the other end of the trunnion is supported by a post attached to the housing (Japanese Utility Model Publication No. 5-45302).
[0025]
Further, the ends of the trunnions arranged opposite to each other are supported by the casing of the transmission by support members, and one end of the trunnion is connected to a hydraulic actuator as an actuator for displacing the trunnion in the axial direction of the tilt shaft, A structure in which a protrusion formed on the other end of the trunnion is fitted in a recess formed in a casing has been proposed (Japanese Patent Laid-Open No. 63-130954). The details of the fitting state are unknown, but no special consideration is given to the bearings, etc., and if there is a large gap, there will be play, and if it is a small gap, smooth operation of the trunnion may be hindered. Further, as a means for solving the problem of the trunnion position restriction, there has been proposed one in which the trunnion is directly supported on the casing via a bearing without using a yoke or a post (Japanese Patent Laid-Open No. 10-274300).
[0026]
[Problems to be solved by the invention]
Thus, in the conventional structure, since the support of the trunnion is insufficient, there may be a problem in the speed change stability resulting from the operation of the trunnion and the durability of the support portion of the trunnion. Therefore, in a toroidal-type continuously variable transmission in which both ends of the trunnion shaft are swung by the yoke and supported by the casing, the trunnion is supported as a trunnion support means in addition to the support by the yoke that is swingable on the conventional post. By directly supporting the casing, the tilt shaft can be prevented from swinging and the operation of the trunnion can be stabilized, and the stable transmission performance and high durability as a transmission can be secured at a low cost. There are issues to be solved.
[0027]
[Means for Solving the Problems]
An object of the present invention is to solve the above-mentioned problem, and to support a trunnion that supports the power roller in a tiltable manner with respect to the casing at both ends in a stable and durable manner. It is an object of the present invention to provide a toroidal-type continuously variable transmission that can reliably perform a speed change operation and power transmission with a power roller, and can be mounted on a vehicle, particularly in a commercial vehicle having a long product life.
[0028]
The present invention relates to an input disk driven by an input shaft, an output disk disposed opposite to the input disk and connected to an output shaft, a tilting shaft disposed between the input disk and the output disk. A pair of power rollers that tilt around and shift the rotation of the input disk steplessly and transmit it to the output disk. The power rollers are rotatably supported and can be displaced in the axial direction of the tilting shaft. A pair of trunnions, an actuator disposed in the casing for displacing each trunnion in the axial direction of the tilt shaft, and the casing for supporting a force in a direction crossing the tilt shaft acting on the trunnion The post is attached to the post so that it can swing in a state where the position is regulated at the center, and the trunnions are opposed to each other at both ends. A yoke that connects the end portions so as to be swingable is provided, and in order to prevent rattling of the trunnions, rods provided on either end portion of each trunnion or one of the casings are provided on both ends of each trunnion. The present invention relates to a toroidal continuously variable transmission which is supported by a fitting portion provided on the other side of the casing and the casing via a radial bearing.
[0029]
Since the rods provided on either end of each trunnion and one of the casings are supported via radial bearings on the fittings provided on both ends of each trunnion and the other of the casing, the tilt shaft of each trunnion The position is regulated by the casing, and rattling is prevented. During torque transmission, each trunnion has a force in a direction crossing the tilting axis, that is, a separation force caused by a pressing force between the disks generated according to the transmission torque by the cam action of the loading cam, and a force in the main shaft direction. Act. However, the yoke is slidably fitted to the post attached to the casing in a state where the position is regulated at the center, and the opposite ends of both trunnions are slidably coupled at both ends. Therefore, the force acting on these power rollers is supported by the casing via the trunnion, the yoke and the post as in the conventional case, and the ratio of transmission through the rod and the fitting portion is small. The position of the tilting shaft of the trunnion is regulated by the rod and the fitting portion, and the radial bearing allows the trunnion to move in the tilting axis direction and rotate around the tilting shaft. The positional relationship is maintained. Therefore, the transmission ratio is stably maintained, and the contact portion of the power roller with the disk is held at a predetermined position.
[0030]
The radial bearing is preferably a sliding bearing because it is simple and inexpensive to manufacture as a structure that allows movement of the trunnion in the direction of the tilt axis and rotation around the tilt axis. Further, the rod is formed integrally extending from the both end portions of each trunnion, and the fitting portion is formed in the casing. The diameter of the rod is preferably smaller than the diameter of the end portion of the trunnion.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a toroidal continuously variable transmission according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an embodiment of a toroidal continuously variable transmission according to the present invention cut along a plane including a main shaft, and FIG. 2 shows a part including a yoke of the toroidal continuously variable transmission shown in FIG. FIG. The basic structure of the toroidal type continuously variable transmission shown in FIG. 1 is the same as that of the conventional toroidal type continuously variable transmission shown in FIG. A reference numeral is attached, and a duplicate description is omitted.
[0032]
In the toroidal-type continuously variable transmission shown in FIG. 1, rods 70 that are concentric with the tilt shaft 11 are integrally projected at upper and lower end portions 65, 65 of each trunnion 33, 37, preferably It is formed by integral molding. The shaft provided on one trunnion 33 of the toroidal transmission 1 and having the recess cam 56 disposed at the tip can be used as the rod 70 as it is. Each rod 70 is connected to a fitting portion 72 formed in the casing 25 of the transmission via a radial bearing 71 that permits the axial movement of the tilt shaft 11 and the rotation about the tilt shaft 11. It is supported. In other words, the trunnions 33 and 37 are supported on the casing 25 by the fitting portion via the radial bearing 71. With respect to the lower rod 70, the casing 25 is cylinders 42, 46. In this case, the oil in the hydraulic cylinder chambers 43A, 43B, 47A, 47B is not between the cylinders 42, 46 and the rod 70 so as not to leak outside. Is provided with a seal together with the radial bearing 71.
[0033]
Each trunnion 33, 37 is regulated in the axial center position of the tilting shaft 11 at the fitting portion 72. Therefore, the trunnions 33 and 37 do not rattle as conventionally existing with respect to the yoke 60. Due to the pressing force between the power rollers 6, 9 and the input / output disks 4, 5, 7, 8 generated by the loading cam 18 according to the transmission torque from the input shaft, The separation force for moving the trunnions 37 and 37 and the force in the direction of the main shaft 3 are applied. Since these forces are received by the corresponding posts 81 from the respective yokes 80 as in the prior art, the separation force and the shaft described above are used. The rate at which the directional force acts on the rods 70 attached to the trunnions 33 and 37 is small. The radial bearing 71 is a slide bearing from the viewpoint of being simple and low-cost as a structure that allows axial movement of the tilt shaft 11 of the trunnions 33 and 37 and rotation around the tilt shaft 11. Is preferred.
[0034]
Since the axial position of the tilting shaft 11 of the trunnions 33 and 37 is regulated without rattling to the casing 25 when the rod 70 is fitted to the fitting portion 72 via the radial bearing 71, the input / output disks 4, 5 , 7, 8 and the power rollers 6, 9 are maintained in a predetermined positional relationship. As a result, the transmission ratio of the toroidal continuously variable transmission is stably maintained, and the durability of the power rollers 6 and 9 is not lowered, and the durability reliability of the toroidal continuously variable transmission is increased. Since each rod 70 is set to be thinner than the shaft diameter of the end portion 65 of each trunnion 33, 37, the rod 70 supports a force such as a separating force acting on the trunnion 33, 37, and the trunnion 33, 37 is displaced. Small deformations and displacements that occur in the yoke 80 to cope with it are absorbed by the elastic deformation of the rod 70. In the trunnions 33 and 37, the rod 70 is regulated by the casing 25 via the radial bearing 71, but the function of the yoke 80 is not impaired by this.
[0035]
Further, as shown in FIG. 2, it is not necessary to regulate the position of the yoke 80 around the post 81 by the post 81 itself, so that the face 81 of the post 81 is formed to form a flat surface and the post 81 is attached to the casing 25. There is no need for time position restrictions. The shape of the central portion of the yoke 80 attached to the post 81 is also a fitting hole into which a spherical engaging portion 84 that is not chamfered is fitted from a conventional square hole having inner surfaces 67 and 68 shown in FIG. Similarly to the circular holes 83 at both ends, the circular holes 82 can be easily processed, and the processing costs of the yoke 80 and the post 81 can be reduced. The rod 70 may be provided on the casing 25 side, and the fitting portion 72 into which the rod 70 is fitted may be provided at the end portion 65 of the trunnions 33 and 37.
[0036]
【The invention's effect】
As described above, the toroidal-type continuously variable transmission according to the present invention attaches the rods provided at either end of each trunnion and one of the casings to the fitting portions provided at both ends of each trunnion and the other of the casing. Since it is supported via a radial bearing, each trunnion's tilting shaft position allows the tilting shaft position of each trunnion to move around the tilting shaft, and the fitting portion is composed of a rod, a radial bearing and a fitting portion. By using the casing, it is regulated by the casing, and rattling against the yoke is prevented. On the other hand, since the separating force acting on the opposing trunnion and the force applied in the main axis direction are supported by the yoke and the post via the trunnion as in the prior art, a large force does not act on the fitting portion. Since the trunnion tilting shaft position is regulated by the fitting portion, the input / output disk and the power roller are kept in a predetermined positional relationship, the transmission ratio can be maintained stably, and the power roller contacts the disk. The predetermined position of the power roller is held, and the predetermined position of the contact portion of the power roller with the disk is held, so that there is provided a continuously variable transmission with high durability and reliability that does not deteriorate the durability of the power roller. The Furthermore, since it is no longer necessary to regulate the position of the yoke post around the post, there is no need for surface chamfering of the post or position regulation when mounting the post, and the hole shape of the post mounting part of the yoke can be easily processed from the square hole. Since a round hole can be formed, the processing cost is also reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a toroidal continuously variable transmission according to the present invention.
2 is a perspective view showing a part including a yoke and a post of the toroidal-type continuously variable transmission shown in FIG.
FIG. 3 is a cross-sectional view showing a conventional toroidal-type continuously variable transmission.
4 is a cross-sectional view of the toroidal type continuously variable transmission shown in FIG. 3 cut along line AA and line BB.
5 is an exploded perspective view showing a yoke and a post of the toroidal-type continuously variable transmission shown in FIG. 4. FIG.
[Explanation of symbols]
1, 2 Toroidal transmission
4,7 input disk
5,8 output disk
6,9 Power roller
11 Tilt axis
13 Input shaft
25 casing
33, 37 trunnion
40, 44 Hydraulic actuator
65 End of trunnion
70 rod
71 Radial bearing
72 Insertion
80 York
81 post

Claims (4)

An input disk driven by an input shaft, an output disk disposed opposite the input disk and connected to an output shaft, and disposed between the input disk and the output disk and tilted about a tilt axis A pair of power rollers that continuously change the rotation of the input disk and transmit it to the output disk, and a pair of trunnions that rotatably support the power rollers and can be displaced in the axial direction of the tilting shaft. And an actuator disposed in the casing for displacing each trunnion in the axial direction of the tilt shaft, and attached to the casing for supporting a force in a direction crossing the tilt shaft acting on the trunnion. Fitted so as to be swingable in a state where the position is regulated at the center with respect to the post, and the opposite ends of both trunnions at both ends. In order to prevent rattling of the trunnions, rods provided on either end of each trunnion and one of the casings are provided on both ends of each trunnion and the casing. A toroidal-type continuously variable transmission which is supported by a fitting portion provided on the other side via a radial bearing. The toroidal continuously variable transmission according to claim 1, wherein the radial bearing is a sliding bearing. 3. The toroidal continuously variable transmission according to claim 1, wherein the rod is integrally formed from the both end portions of each trunnion, and the fitting portion is formed in the casing. . The toroidal continuously variable transmission according to any one of claims 1 to 3, wherein a diameter of the rod is smaller than a diameter of the end portion of the trunnion.

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