JP2008249117A - Toroidal type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toroidal type continuously variable transmission for reducing driving force to control the displacement of power rollers while reducing the dispersion of the tilting angles of the power rollers. <P>SOLUTION: In a variator 1 (the toroidal type continuously variable transmission), the displacement of the rotational centers of the power rollers 14A, 14B is controlled by a roller displacement control device 4 so that the power rollers 14A, 14B autonomously tilt to perform a variable speed. The roller displacement control device 4 consists of sun gears 25A, 25B, ring gears 26A, 26B, and power roller units 5A, 5B meshing with the sun gears and the ring gears and tiltingly and rotatably supporting the power rollers 14A, 14B. The ring gears 26A, 26B are fixed to a transmission case, and the sun gears 25A, 25B are rotationally driven to control the displacement of the power rollers 14A, 14B via the power roller units 5A, 5B. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a toroidal-type continuously variable transmission suitable for use in a continuously variable transmission mounted on an automobile, a work vehicle or the like, and more specifically, the inclination of the power roller with respect to both disks by controlling the movement of the power roller. The present invention relates to a toroidal continuously variable transmission that controls the angle and changes the contact radius between both disks and the power roller to enable continuously variable transmission.

  In recent years, development of a toroidal continuously variable transmission used for a continuously variable transmission mounted on an automobile, a working vehicle, or the like has been promoted. A toroidal-type continuously variable transmission is composed of an input disk, an output disk, and a power roller sandwiched between the two disks, and the gear ratio varies depending on the contact position (contact radius) with both disks based on the inclination of the power roller. can get. In such a toroidal-type continuously variable transmission, the inclination angle of the power roller is autonomously controlled by controlling the movement of the rotation center of the power roller with respect to the surface direction of both disks by a link mechanism connected to a hydraulic servo. Has been proposed, and the gear ratio is thereby changed (see Patent Document 1).

  The toroidal continuously variable transmission of Patent Document 1 will be briefly described with reference to FIGS. As shown in FIGS. 5A and 5B, the toroidal-type continuously variable transmission device includes an input disk 111, an output disk 112, and a power roller 113 sandwiched between the disks 111 and 112. The power roller 113 is supported by a carriage 116 so as to be rotatable about an axis P. The carriage 116 is connected to a piston of a hydraulic servo 115 at one end thereof. The power roller 113 rotates about the axis P in the ω1 direction based on the rotation of the input disk 111, and the output disk 112 is rotated in the ω3 direction based on this rotation. At this time, the traction force F11 is applied to the power roller 113 when torque is transmitted from the input disk 111, and the traction force F12 as a reaction force is applied when torque is transmitted from the power roller 113 to the output disk 112. Works. The traction forces F11 and F12 acting on the power roller 113 are balanced with the reaction force F13 acting on the carriage 116 by the pressing drive of the hydraulic servo 115.

  For example, when the reaction force F13 is weakened by the control of the hydraulic servo 115, the balance of force is lost and the position of the power roller 113 moves toward the hydraulic servo 115 as shown in FIGS. 6 (a) and 6 (b). 6B, the speed vector V′r of the power roller 113 does not change at the contact portion 117 between the output disk 112 and the power roller 113, but the speed vector V′d of the output disk 112 does not change. Therefore, the speed vector V′d of the output disk 112 and the speed vector V′r of the power roller 113 are not parallel to each other because the tangential direction of the contact portion 117 is obtained. Further, in the contact portion 117, a traction force F14 in the same direction as the difference between the velocity vector V′d and the velocity vector V′r is generated, and the traction force F14 acts on the power roller 113.

  On the other hand, a similar action occurs between the power roller 113 and the input disk 111, and a force opposite to the traction force F14 acts on the power roller 113. 7A and 7B, the shaft P of the power roller 113 is tilted by the action of the traction force and the traction force F14 generated between the power roller 113 and the input disk 111, that is, the input disk. The speed ratio (contact radius) of the output disk 112 with respect to 111 changes autonomously. Since the carriage 116 has a caster angle β with respect to a plane parallel to the input disk 111 and the output disk 112, the inclination is such that the velocity vector at the contact portion between the power roller 113 and both the disks 111 and 112 is parallel. Stable at the corners. As a result, the position of the power roller is moved and controlled by pressure control using a hydraulic servo, thereby enabling a stepless speed change.

  By the way, in the toroidal type continuously variable transmission of Patent Document 1 described above, for example, three power rollers are arranged between the input disk 111 and the output disk 112, and hydraulic servo or A link mechanism or the like for connecting the power rollers is required, which complicates the configuration and enlarges particularly in the radial direction.

  Therefore, the position control of the position of the power roller is made possible so that the sun gear disposed on the inner peripheral side of the power roller, the ring gear disposed on the outer peripheral side of the power roller, and the sun gear and the ring gear mesh with each other. And a roller position control device composed of a planet gear combined with a rotating shaft that supports the power roller in a tiltable and rotatable manner, and controls the rotation of the sun gear and the ring gear to control the rotation of the power roller. A toroidal continuously variable transmission that enables position movement control has been proposed (see Patent Document 2).

  The toroidal continuously variable transmission of Patent Document 2 will be briefly described with reference to FIG. As shown in FIG. 8A, a traction force F1 generated when torque is transmitted from an input disk (not shown) to the output disk 122 acts on the power roller 123. The traction force F1 is a sun gear 125 and a ring gear 126. It is balanced with the reaction forces F2 and F3.

  Here, as shown in FIG. 8B, for example, when the sun gear 125 and the ring gear 126 are rotationally driven in the ω4 direction so that the planet gear 127 moves in parallel, the position of the power roller 123 also moves. When the position of the power roller 123 moves, as shown in FIG. 8C, the contact portion between the output disk 122 and the power roller 123 deviates from the tangential direction as described above (see FIG. 6B). A traction force is generated and acts on the power roller 123. In addition, a traction force that deviates from the tangential direction is generated at the contact portion between the input disk and the power roller 123 and acts on the power roller 123. The rotation axis of the power roller 123 that is tiltably supported with respect to the planet gear 127 is tilted, that is, the speed ratio (contact radius) of the output disk 122 with respect to the input disk changes autonomously. Note that the support shaft of the planet gear 127 that rotatably supports the power roller 123 is arranged offset with respect to the rotation center of the power roller, and this has the same caster angle as described above. Therefore, the thing of patent document 2 enables the movement control of the position of the power roller similar to the thing of patent document 1 by carrying out rotation drive control of the sun gear and the ring gear, and makes it possible to change continuously.

JP 2006-292079 A International Publication No. WO 05/121602 A1

  In the toroidal-type continuously variable transmission of Patent Document 2, the sun gear and the ring gear rotate the planet gear while receiving the reaction force of the traction force acting on the power roller, and a large driving force is required. . For this reason, in a control device such as a hydraulic servo for rotationally driving the sun gear and the ring gear, there is a possibility that the control device is enlarged to prevent compactness in order to generate a large driving force.

  For example, the larger the caster angle, the larger the amount of movement of the planet gear (power roller) for changing the tilt angle of the power roller. However, the amount of movement of the power roller may be increased to avoid interference with the ring gear. It is not possible, that is, the caster angle cannot be increased. Therefore, the influence of the manufacturing error of the caster angle in the planet gear becomes large, and the inclination angle of the power roller easily varies with the movement of the power roller (planet gear), which is caused by the mismatch of the inclination angle of the power roller. There is a risk of adversely affecting the transmission efficiency.

  Further, since the amount of movement of the planet gear cannot be increased as described above, the sun gear and the ring gear that are moved by rotating the sun gear and the ring gear as in the above-mentioned Patent Document 2, for example, The amount of meshing movement between the planet gears and the amount of meshing movement between the ring gears and the planet gears are very small and are greatly affected by the pitch error of each gear, and the amount of movement of the planet gears (power rollers). There is also a problem that errors are likely to occur. If an error occurs in the amount of movement of the planet gear (power roller) as described above, the inclination angle of the power roller tends to vary with the movement of the power roller (planet gear), and the transmission efficiency is adversely affected. There was a fear.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a toroidal continuously variable transmission capable of reducing the driving force for controlling the movement of the power roller and reducing variations in the inclination angle of the power roller.

The present invention according to claim 1 includes a power roller (14A, 14B) sandwiched between both an input disk (11A, 11B) and an output disk (12);
A sun gear (25A, 25B) disposed on the inner peripheral side between the two disks (11A, 11B, 12);
A ring gear (26A, 26B) disposed on the outer peripheral side between the two disks (11A, 11B, 12);
A rotation / inclination support portion provided at the center of rotation of the power rollers (14A, 14B) and rotatably supporting the power rollers (14A, 14B) with respect to the disks (11A, 11B, 12). (31A, 31B),
It has a support shaft (32A, 32B) that supports the rotary tilt support portion (31A, 31B), and one end side of the support shaft (32A, 32B) meshes with the sun gear (25A, 25B) and the other end side thereof Planet gears (33A, 33B) meshing with the ring gears (26A, 26B),
Inclination of the power rollers (14A, 14B) is achieved by controlling the movement of the rotation / inclination support portions (31A, 31B) between the disks (11A, 11B, 12) via the planet gears (33A, 33B). The gear ratio of the output disk (12) with respect to the input disk (11A, 11B) is controlled by changing the contact radius between the disks (11A, 11B, 12) and the power roller (14A, 14B) by controlling the angle. In the toroidal-type continuously variable transmission (1) that enables continuously variable transmission control by controlling
The rotation of the ring gears (26A, 26B) is fixed, and the angle of the support shafts (32A, 32B) of the planet gears (33A, 33B) is changed by controlling the rotation of the sun gears (25A, 25B). The stepless speed change control is performed by controlling the movement of the rotating and tilting support portions (31A, 31B).
The toroidal-type continuously variable transmission (1) is characterized in that.

The present invention according to claim 2 is configured such that the support shaft (32A, 32B) supports the rotation inclination support portion (31A, 31B) so as to have a caster angle with respect to the rotation center.
According to the caster angle, the power roller (14A, 14B) has a full toroidal type in which the two disks (11A, 11B, 12) autonomously tilt in the rotational direction.
The toroidal-type continuously variable transmission (1) according to claim 1, wherein:

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

  According to the first aspect of the present invention, the rotation of the ring gear is fixed, the angle of the support shaft of the planet gear is changed by controlling the rotation of the sun gear, and the rotation and tilt support portion is moved and controlled, thereby continuously variable transmission. Since the control is performed, a part of the reaction force of the traction force acting on the power roller can be supported by the fixed ring gear, and the driving force for controlling the movement of the rotating and tilting support portion can be reduced. A control device such as a hydraulic servo can be reduced in size and can be reduced in size.

  Further, since the rotation of the planetary gear is controlled only by the rotation control of the sun gear while fixing the rotation of the ring gear, the sun gear and the gear are compared with the case where the movement of the planetary gear is controlled by rotating both the sun gear and the ring gear, for example. The amount of meshing movement with the planet gear can be increased. As a result, the influence of the pitch error of each gear can be reduced, variation in the inclination angle of the power roller accompanying the movement of the power roller (planet gear) can be reduced, and transmission efficiency can be improved. it can.

  According to the second aspect of the present invention, since the angle of the support shaft of the planet gear is changed by fixing the rotation of the ring gear and controlling the rotation of the sun gear, the power roller can be inclined even if the amount of movement of the planet gear is small. Since it is easy to occur, that is, the sensitivity of the inclination of the power roller with respect to the movement of the planet gear is increased, interference with the ring gear can be prevented even if the caster angle is increased accordingly. As a result, since the caster angle can be increased, it is possible to reduce the influence of the manufacturing error of the caster angle, to reduce the variation in the tilt angle of the power roller, and to improve the transmission efficiency. it can.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  A toroidal continuously variable transmission (hereinafter simply referred to as a variator) 1 according to an embodiment of the present invention is a full toroidal continuously variable transmission as shown in FIG. Input disks 11A and 11B, an output disk 12 having an output gear 16 on the outer peripheral side, and power rollers 14A and 14B sandwiched between the two input disks 11A and 11B and one output disk 12. Specifically, power roller units 5A and 5B described later are provided. The input disks 11A and 11B and the output disk 12 have circular arc-shaped grooves that form a part of a circle so as to face each other, and form double cavities 13A and 13B with two rows of power rollers interposed therebetween. Thus, it is configured to cancel the thrust force between the input disks.

  A plurality of power rollers 14A, 14B are arranged at substantially equal positions in the circumferential direction of the annular double cavities 13A, 13B (for example, three in one cavity). , 14B can be tilted and the center positions of the power rollers 14A, 14B are controlled to move on a plane parallel to the disks 11A, 11B, 12 described above. Further, the input disks 11A and 11B are pressed in a closed loop by the hydraulic servo 8, and the power rollers 14A and 14B are clamped, and the clamping pressure is controlled by the hydraulic pressure. The power rollers 14A and 14B are autonomously inclined by the movement control by the roller position control device 4 and the clamping pressure of the input disks 11A and 11B, so that the contact radius between the input disks 11A and 11B and the output disk 12 is increased. Is changed, and the speed continuously changes continuously. In the variator 1, since the output disk 12 is inverted with respect to the input disks 11A and 11B, the speed ratio is-(minus).

  The roller position control device 4 includes sun gears 25A and 25B disposed on the inner peripheral sides of the power rollers 14A and 14B and rotatably supported by the input shaft 2, and outer peripheral sides of the power rollers 14A and 14B. And ring gears 26A and 26B fixed to a transmission case (not shown), and the power roller units 5A and 5B.

  The power roller units 5A and 5B have the same configuration. As shown in FIG. 2, the power roller unit 5A (5B) is rotatable in the ω1 direction around the rotation center q and the power roller 14A (14B). A rotation / inclination support portion 31A (31B) that supports the rotation in the ω2 direction and a rotation / inclination support portion 31A (31B) on the support shaft 32A (32B) and an inner peripheral side (for example, a lower side in the drawing) A planet gear 33A (33B) that meshes with the sun gear 25A (25B) and has an outer peripheral side (for example, an upper side in the drawing) meshes with the ring gear 26A (26B).

  The planet gear 33A (33B) is formed in the shape of a fan in a side view by cutting out the movable range of the power roller 14A (14B) from the annular gear, and fixedly supports the rotation / inclination support portion 31A (31B) at the center portion. ing. Further, the support shaft 32A (32B) of the planet gear 33A (33B) is offset from the rotation center q of the power roller 14A (14B) (that is, the center of the rotation / inclination support portion 31A (31B)). Thereby, it is configured to have a caster angle.

  Next, the operation of the variator 1 will be described with reference to FIG.

  In the variator 1 mounted on the vehicle, the rotation of the input shaft 2 connected to the engine output shaft is transmitted to the input disks 11A and 11B of the variator 1. The power rollers 14A and 14B rotate based on the rotation of the input disks 11A and 11B, and based on this rotation, the output disk 12 is rotated in the ω3 direction as shown in FIG. Then, in the cavity 13A, a traction force F1 generated when torque is transmitted from the input disk 11A to the output disk 12 acts on the power roller 14A, and this traction force F1 is a reaction force F2 received by the sun gear 25A and the ring gear 26A. , F3. As described above, the ring gear 26A is fixed to a mission case (not shown), and a reaction force F2 of the traction force is received by the mission case.

  From this state, for example, when the sun gear 25A is rotationally driven in the ω4 direction that opposes the reaction force F3, the power roller unit 5A is opposite to the sun gear 25A together with the planet gear 33A as shown in FIG. , Ie, while changing the angle of the support shaft 32A of the planet gear 33A, the sun gear 25A moves toward the rotational direction. Then, at the contact portion 17 between the output disk 12 and the power roller 14A, the speed vector Vr of the power roller 14A is directed to the inner peripheral side with respect to the tangential direction of the output disk 12, and the speed vector Vd of the output disk 12 is the output disk 12 Therefore, the velocity vector Vd of the output disk 12 and the velocity vector Vr of the power roller 14A are not parallel. Further, in the contact portion 17, a traction force F4 in the same direction as the direction of the difference between the velocity vector Vd and the velocity vector Vr is generated, and the traction force F4 acts on the power roller 14A.

  On the other hand, a similar action occurs between the power roller 14A and the input disk 11A, and a traction force opposite to the traction force F4 acts on the power roller 14A. Due to the action of the traction force and the traction force F4 generated between the power roller 14A and the input disk 11A, as shown in FIG. 3C, the rotation shaft of the power roller 14A is tilted at the rotation / inclination support portion 31A. The transmission ratio (contact radius) of the output disk 12 with respect to the input disk 11A changes autonomously.

  In the above description, one power roller 14A in the cavity 13A has been described as an example. However, these actions simultaneously act on the three power rollers 14A in the cavity 13A, and similarly in the cavity 13B. A shift operation is performed by acting on the three power rollers 14B. The continuously variable speed rotation is output from the output gear 16 of the output disk 12.

  In the variator 1 described above, the power roller units 5A, 5B move together with the planet gears 33A, 33B while rotating (spinning) in the opposite direction to the sun gears 25A, 25B, and the power rollers 14A, 14B are moved. In order to change the angle so that the output disk 12 faces the outer peripheral side on the upstream side in the rotation direction, the speed control is performed so that the power roller moves approximately in parallel by rotating the sun gear and the ring gear as in Patent Document 2, for example. Compared to what is performed, the traction force is easily generated, and the power rollers 14A and 14B are easily inclined even with a small amount of movement, and the sensitivity is high. As a result, the power rollers 14A and 14B are easily tilted even with a small amount of movement, and the sensitivity is high. Therefore, even if the caster angle is increased, interference with the ring gears of the power rollers 14A and 14B can be prevented. And since a caster angle can be enlarged, the influence of the manufacturing error of a caster angle can be made small, and the dispersion | variation in the inclination angle of a power roller can be reduced.

  Further, in the variator 1 according to the present invention, the reaction force F2 acting on the power rollers 14A and 14B can be supported by the ring gears 26A and 26B fixed to a transmission case (not shown), and the rotation / inclination support portion 31A. , 31B can be reduced in driving force, and a control device such as a hydraulic servo can be reduced in size.

  Further, in the variator 1, the ring gears 26A and 26B are fixed and the movement of the planet gears 33A and 33B is controlled only by the rotation control of the sun gears 25A and 25B. Therefore, for example, the planet gears are driven by rotating both the sun gear and the ring gear. The amount of meshing movement between the sun gears 25A and 25B and the planet gears 33A and 33B can be increased as compared with the case where the movement control is performed. Thereby, the influence of the pitch error of each gear can be reduced, and variations in the inclination angles of the power rollers 14A and 14B accompanying the movement of the power rollers 14A and 14B (planet gears 33A and 33B) can be reduced.

  In the present embodiment, the ring gears 26A and 26B are fixed and the power rollers 14A and 14B are controlled by the sun gears 25A and 25B. However, the sun gears 25A and 25B are fixed and the ring gears 26A and 26B It is also conceivable to control the rollers 14A and 14B. However, as shown in FIGS. 4A and 4B, when the ring gear 26A is rotationally driven, the power roller 14A of the power roller unit 5A moves while rotating in the opposite direction to the case where the ring gear 26A is fixed. The traction force F5 in the same direction as the direction of the difference between the speed vector Vda and the speed vector Vra is also reversed. For example, when the vehicle suddenly decelerates due to sudden braking or the like, it becomes a force for shifting to a high-speed gear, and is not established as a transmission system.

  As a method of rotationally driving the sun gears 25A, 25B, for example, the sun gears 25A, 25B are connected through the input shaft 2 and the inner peripheral side of the output disk 12, and three power rollers are arranged in the cavity 13A. For example, an annular gear arranged in parallel with the ring gear 26A and the sun gear 25A are connected via a clearance 14A (so as not to interfere with the movable region of the power roller 14A), and the annular gear is connected to a rack and pinion mechanism or the like. It is conceivable that the sun gears 25A and 25B are configured to be rotationally driven by being driven and controlled by a hydraulic servo. Other than this, for example, the sun gears 25A, 25B and the pistons of the hydraulic servo may be connected via a joint, and so on as long as the sun gears 25A, 25B can be rotationally driven. The present invention can be applied to anything.

The skeleton figure which shows the toroidal type continuously variable transmission which concerns on this invention. The perspective view which shows a power roller unit. It is a schematic diagram showing a part of the toroidal continuously variable transmission, (a) is a diagram in which the force is suspended, (b) is a diagram in which the power roller is moved, (c) is a tilt of the power roller State diagram. It is explanatory drawing which shows a part of toroidal type continuously variable transmission, (a) is a figure of the state with which force was suspended, (b) is a figure which shows the effect | action concerning a power roller. It is the schematic diagram of the state with the force balance which shows the conventional toroidal type continuously variable transmission, (a) is a radial view, (b) is an axial view. It is a schematic diagram of the state which moved the power roller which shows the conventional toroidal type continuously variable transmission, (a) is radial direction view, (b) is axial direction view. The power roller which shows the conventional toroidal type continuously variable transmission is a schematic diagram of the state which inclined, (a) is radial direction view, (b) is an axial view. It is a schematic diagram showing a part of a conventional toroidal-type continuously variable transmission, (a) is a diagram showing a state where force is suspended, (b) is a diagram showing a state where a power roller is moved, (c) is a diagram showing a state where the power roller is The figure of the state which inclined.

Explanation of symbols

1 Toroidal continuously variable transmission (variator)
11A, 11B Input disk 12 Output disks 14A, 14B Power rollers 25A, 25B Sun gears 26A, 26B Ring gears 31A, 31B Rotating and tilting support portions 32A, 32B Support shafts 33A, 33B Planet gears

Claims (2)

A power roller sandwiched between both an input disk and an output disk;
A sun gear disposed on the inner peripheral side between the two disks;
A ring gear disposed on the outer peripheral side between the two disks;
A rotation / inclination support portion that is provided at the rotation center of the power roller and supports the power roller in a freely rotatable manner with respect to the both disks;
A planetary gear that has a support shaft that supports the rotary tilt support portion, and one end side of the support shaft meshes with the sun gear and the other end side meshes with the ring gear;
The rotation angle of the power roller is controlled by controlling the rotation and inclination support portion between the disks via the planet gear, and the input radius is changed by changing the contact radius between the disks and the power roller. In a toroidal continuously variable transmission that enables continuously variable transmission control by controlling the speed ratio of the output disk to the disk,
The rotation of the ring gear is fixed, the angle of the support shaft of the planet gear is changed by controlling the rotation of the sun gear, and the continuously variable transmission control is performed by controlling the movement of the rotating and tilting support portion.
A toroidal continuously variable transmission characterized by that. The support shaft is configured to support the rotation and inclination support portion so as to have a caster angle with respect to the rotation center,
According to the caster angle, the power roller is a full toroidal type that autonomously tilts in the rotational direction of the two disks.
The toroidal-type continuously variable transmission according to claim 1.

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