JPH11280860A - Trunnion driving device of double cavity toroidal continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the impairing of the strength of a valve body and the workability by dividing the valve body at an output shaft side, when the valve body is mounted at the side same as the output shaft with respect to a torque input shaft for preventing the output shaft from penetrated through the valve body. SOLUTION: The trunnion sets respective comprising at least two trunnions 6 rotatably supporting at least two power rollers mounted around a torque input shaft 9, and tilting and rotating on their tilt rotary shafts 7, are respectively mounted in a front cavity and a rear cavity. A front valve body and a rear valve body respectively including a hydraulic driving part and a control valve are mounted in the direction same as an output shaft 5 with respect to a torque input shaft 9. The rear valve body is divided into two valve body members 220 for inhibiting the intereference with the output shaft 5, and these members 220 are respectively provided with a cylinder chamber 11 and a hydraulic piston 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-cavity toroidal type continuously variable transmission used as a transmission of an automobile, for example, to determine the inclination angle of the rotation axis of each power roller provided in two sets of toroidal type transmission mechanisms. The invention relates to a trunnion drive for adjusting.

[0002]

2. Description of the Related Art Toroidal-type continuously variable transmissions, which have been studied mainly as transmissions for automobiles, include an input disk and an output disk each having a concave section having an arc-shaped concave surface facing each other. A toroidal speed change mechanism having a structure combining a rotatable power roller sandwiched between two disks is provided. The input disk is drivingly coupled to the torque input shaft to allow movement in the direction of the torque input shaft, while the output disk is rotatable relative to the torque input shaft and away from the input disk. It is mounted opposite the input disk so that movement is restricted.

[0003] In the toroidal-type transmission mechanism described above,
When the input disk rotates, the output disk rotates reversely via the power roller, so that the rotational movement input to the torque input shaft is transmitted to the output disk as a rotational movement in the opposite direction, and rotates integrally with the output disk. Removed from output gear. At this time, the inclination from the torque input shaft to the output gear is increased by changing the inclination angle of the rotating shaft of the power roller so that the peripheral surface of the power roller comes into contact with the vicinity of the outer periphery of the input disk and the vicinity of the center of the output disk, respectively. Conversely, the torque input shaft is changed by changing the inclination angle of the rotation shaft of the power roller so that the peripheral surface of the power roller comes into contact with the vicinity of the center of the input disk and the vicinity of the outer periphery of the output disk, respectively. From the gear to the output gear. Further, an intermediate speed ratio between the two can be obtained almost steplessly by appropriately adjusting the inclination angle of the rotating shaft of the power roller.

[0004] The toroidal transmission mechanism has at least two power rollers symmetrically arranged about the torque input shaft on a plane orthogonal to the torque input shaft.
Each power roller is rotatably supported by one trunnion via a bearing. The trunnion is a member having a substantially U-shaped cross-sectional shape provided with a concave portion for accommodating the power roller at the center, and the power held in the concave portion around the tilt axis connected to both side surfaces. It is tilted and rotated integrally with the roller. Since this tilt axis is connected to the casing via a spherical ring, the trunnion is
A slight sliding in the direction along the tilt axis is possible. 2 arranged on the same plane orthogonal to the torque input shaft
The two or more trunnions are interconnected by a yoke that connects the ends of the tilting axes of adjacent trunnions to form an annular trunnion set.

Further, a double-cavity toroidal-type continuously variable transmission has been devised in which two sets of the above-described trunnion sets are provided to reduce the rotational torque of the power roller. In the toroidal type continuously variable transmission illustrated in FIG. 4, two working spaces of a front cavity and a rear cavity are formed around one output gear 3, and the toroidal disposed in each cavity is provided. Each of the mold transmission mechanisms 1 and 2 has one trunnion set. The output disks 1b and 2b of each toroidal type transmission mechanism are connected in parallel so that they face each other with the output gear 3 sandwiched therebetween, and the input disks 1b and 2b are input from the respective input disks 1a and 2a. After the drive torque is shifted by each power roller,
It is taken out from the drive gear 4 meshing with the output gear 3 via the output shaft 5. In this example, the valve body of the trunnion drive device is arranged on the same side as the output shaft 5 with respect to the torque input shaft 9.

Each of the trunnion sets includes a hydraulic drive unit for sliding the trunnion, a control valve for adjusting the supply hydraulic pressure to the hydraulic drive unit, a hydraulic setting unit for setting a target supply hydraulic pressure for the control valve, and a trunnion set. And a hydraulic control unit that feeds back the tilt angle of the trunnion to the control valve. By controlling the tilt rotation of the trunnion about the tilt axis by the trunnion drive device, the tilt angle of the power roller rotation shaft is adjusted, and an arbitrary speed ratio of the toroidal type continuously variable transmission can be obtained.

FIG. 5 shows an enlarged vertical cross-sectional structure of the rear cavity portion in the toroidal type continuously variable transmission of the type illustrated in FIG. Each hydraulic drive unit includes two sets of cylinder units arranged in a common valve body. Each of the cylinder units includes a cylinder chamber 11 and a hydraulic piston 12 fitted in the cylinder chamber 11, respectively. Consists of The hydraulic piston 12 of each cylinder unit is connected via a drive rod 13 to one end of each tilt shaft 7 provided on two adjacent trunnions 6 of the trunnion set, and is connected to a control valve (not shown). ), The trunnions 6 are driven in opposite directions along the tilt axis 7 by the pressure of the control oil supplied through the trunnions 6. The driving torque applied to the two adjacent trunnions 6 is equal to each other to the other trunnions constituting the same trunnion set by the action of the yoke 8 connecting the ends of the tilt shafts 7 to each other. Therefore, the entire trunnion set has a torque input shaft 9
Is caused to rotate in the circumferential direction around the center.

In the common valve body, a control valve is provided together with each hydraulic drive unit, and the oil supply hole of the control valve is opened and closed according to the tilting rotation of the trunnion, thereby controlling each cylinder of the hydraulic drive unit. The amount of oil flowing into the unit is increased or decreased. A hydraulic control unit for feedback-controlling the state of the oil supply hole based on the tilting and rotating movement of the trunnion is connected to the control valve, and a hydraulic setting unit for specifying a target hydraulic pressure for control by the control valve is controlled. It is connected to the end of the valve. The trunnion tilt angle is
For example, it is transmitted to the hydraulic control unit by a combination of a precess cam and a link mechanism for taking out the tilting and rotating motion of the trunnion and converting it into linear displacement. It is desirable that the control valve be disposed close to each cylinder unit in order to increase the accuracy of hydraulic control.

The valve body includes an upper body 14a located at an upper portion and a lower body 14 located at a lower portion.
b, which are fixed to each other by screws or the like in a state where they are vertically overlapped, and attached to the casing. These upper body 14a and lower body 14b
Are made of a single plate formed continuously from the front cavity side to the rear cavity side.
At positions corresponding to the respective trunnion tilting shafts 7a, a total of 4 for disposing the hydraulic piston 12 therein is provided.
One cylinder chamber 11 is bored. Upper body 1
Oil passages for supplying control oil to the respective cylinder chambers extend around the joint surface between the lower body 4a and the lower body 14b.

[0010]

In a general toroidal-type continuously variable transmission, an output shaft 5 for taking out a driving torque toward driving wheels is arranged in parallel with a torque input shaft 9. Occupies part of the space. Therefore, when the valve body of the trunnion drive device is disposed on the same side as the output shaft 5 with respect to the torque input shaft 9, the interference between the output shaft 5 and the rear cavity side of the valve body is taken into consideration. , The placement of each component must be determined. Conventionally, in such a type of double-cavity toroidal-type continuously variable transmission, the opening 15 is provided in advance.
This allows the output shaft 5 to penetrate the rear cavity side of the valve body, thereby preventing interference between the two.

However, it is not easy to provide an elongated opening 15 along the axial direction for allowing the output shaft 10 to pass through the upper body 14a and the lower body 14b, each of which is formed from a single plate. This greatly impairs the workability of the valve body. Opening 1
In the region where 5 is formed, a thin portion occurs due to a decrease in the effective dimension in the thickness direction, so that a local decrease in the strength of the valve body is inevitable. Further, in the thin portion, it is not possible to secure a large cross-sectional area of the oil passage for supplying the control oil to the cylinder chamber. On the other hand, when the thin portion is bypassed, the oil passage layout becomes complicated, It becomes difficult to keep the control oil pressure of each cylinder unit equal.

[0012] The present invention has been made in view of the above circumstances, and prevents the output shaft from penetrating the valve body even when the valve body is disposed on the same side as the output shaft with respect to the torque input shaft. Accordingly, an object of the present invention is to provide a trunnion drive device of a double-cavity toroidal-type continuously variable transmission that prevents a decrease in the strength of a valve body and a deterioration in workability and maintains uniformity of control hydraulic pressure.

[0013]

According to the present invention, there is provided at least two power rollers disposed around a torque input shaft, and the power rollers are rotatably supported and each of the power rollers is rotatable about a respective tilt axis. Each of the trunnion sets is incorporated in a double-cavity toroidal-type continuously variable transmission including a pair of trunnions each including a power roller and at least two trunnions that tilt and rotate integrally with each other in a front cavity and a rear cavity. A hydraulic drive unit having two sets of cylinder chambers and two hydraulic pistons fitted in the cylinder chambers, a control valve for adjusting the hydraulic pressure in each of the cylinder chambers, and a hydraulic pressure setting for setting a target hydraulic pressure for the control valves. The tilt angle of the trunnion and each trunnion is fed back to the control valve That by a hydraulic control unit, relates the trunnion driving device of a double cavity type toroidal continuously variable transmission to control the tilting rotational motion about the respective tilting axes of the trunnions, the object of the present invention,
A front valve body and a rear valve body each including the hydraulic drive unit and the control valve therein are arranged in the same direction as the output shaft with respect to the torque input shaft, and the front shaft without the output shaft is provided. A front valve body in the cavity is integrally formed, and a rear valve body in the rear cavity in which the output shaft is present is divided and formed by two valve body elements to avoid interference with the output shaft; This is achieved by providing the body element with one set of the cylinder chamber and the hydraulic piston.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A trunnion drive device for a double-cavity toroidal-type continuously variable transmission according to the present invention uses a hydraulic drive unit for sliding a trunnion and a hydraulic pressure supplied to the hydraulic drive unit, similarly to a conventional device. It has a control valve to adjust, a hydraulic pressure setting unit to set the target supply hydraulic pressure of the control valve, and a hydraulic control unit to feed back the tilt angle of each trunnion to the control valve,
It is arranged so as to be adjacent to each trunnion set. In addition, by controlling the tilt rotation of the trunnion about the tilt axis by these components in the same manner as in the related art, the tilt angle of the power roller rotary shaft is adjusted, and any speed change of the toroidal-type continuously variable transmission is performed. Ratio can be obtained.

FIGS. 1 and 2 show vertical cross-sectional structures of a rear cavity portion and a front cavity portion of a double-cavity toroidal type continuously variable transmission in which the trunnion drive device of the present invention is incorporated. FIG. 3 shows a horizontal cross-sectional structure of the entire valve body of the double-cavity toroidal continuously variable transmission shown in FIGS. 1 and 2. In each of these drawings, components denoted by the same reference numerals as those shown in FIGS. 4 and 5 have the same functions as those of the conventional trunnion drive device, and therefore, detailed description thereof will be omitted below. .

In the trunnion drive device of the present invention, the valve body in which the cylinder units of the hydraulic drive unit and the control valve are disposed is disposed on the same side as the output shaft 5 with respect to the torque input shaft 9, and The front valve body 21 is located in the cavity and the rear valve body 22 is located in the rear cavity. The front side valve body 21 and the rear side valve body 22 are, like the conventional valve body, overlapped with the upper body constituting the upper part and the lower body constituting the lower part, and fixed by screws or the like. It consists of. The drive gear 4 is disposed in a gap formed between the front valve body 21 and the rear valve body 22.

The cylinder chamber 1 is located at a position facing the trunnion tilting shaft 7 of the front valve body 21.
1 are formed, and constitute two sets of cylinder units together with the hydraulic piston 12 fitted in each cylinder chamber. Further, a post mounting hole 210 for inserting a post for fixing the yoke to the casing is provided at an intermediate portion between the two cylinder chambers 11. Each of the two sets of cylinder units is connected to a trunnion set in the front cavity via a driving rod 13.

On the other hand, the rear valve body 22 is composed of two valve body elements 220 distributed to both sides of the torque input shaft. One cylinder chamber 11 is formed in each of the two valve body elements 220, and a hydraulic piston 12 is fitted in each of the cylinder chambers 11 to form a cylinder unit. Each end of the two tilt shafts 7 of the trunnion set disposed in the rear cavity and the hydraulic piston 12 are connected by a drive rod 13. The output shaft 5 is accommodated in a gap formed between the two valve body elements.

With the above configuration, in the trunnion drive device of the present invention, even when the valve body of the trunnion drive device is disposed on the same side as the output shaft 5 with respect to the torque input shaft 9, the rear side in the rear cavity is formed. The valve body 22 and the output shaft 5 do not interfere. In addition, since the front valve body 21 and each valve body element 220 are independently fixed to the casing, alignment during assembly is facilitated.

[0020]

As described above, according to the trunnion drive apparatus of the double-cavity toroidal type continuously variable transmission of the present invention, the valve body is disposed on the same side of the torque input shaft as the output shaft. In addition, it is possible to prevent the output shaft from penetrating the valve body. As a result, it is not necessary to provide an opening on the rear cavity side, and workability is improved. Further, since the thin portion is not formed in the valve body, a local decrease in the strength of the valve body is eliminated, and the oil passage can be formed evenly and deeply. Uniformity is maintained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a structure of a rear cavity portion in a double-cavity toroidal type continuously variable transmission incorporating a trunnion drive device of the present invention.

FIG. 2 is a vertical sectional view showing a structure of a front cavity portion in the double-cavity toroidal type continuously variable transmission shown in FIG.

FIG. 3 is a horizontal sectional view showing the structure of the entire valve body in the double-cavity toroidal type continuously variable transmission shown in FIG. 1;

FIG. 4 is an axial sectional view showing an entire structure of a double-cavity toroidal type continuously variable transmission into which a conventional trunnion drive device is incorporated.

FIG. 5 is a vertical sectional view showing a structure of a rear cavity portion in the double-cavity toroidal-type continuously variable transmission shown in FIG. 4;

[Explanation of symbols]

 1, 2 toroidal transmission mechanism 1a, 2a input disk 1b, 2b output disk 3 output gear 4 drive gear 5 output shaft 6 trunnion 7 tilting shaft 8 yoke 9 torque input shaft 11 cylinder chamber 12 hydraulic piston 13 drive rod 14a upper body 14b Lower body 15 Opening 21 Front side valve body 22 Rear side valve body 210 Post mounting hole 220 Valve body element

Claims (1)

[Claims] At least two power rollers disposed around a torque input shaft and each of the power rollers are rotatably supported and tilted and rotated integrally with each of the power rollers about a respective tilt axis. A double-cavity toroidal-type continuously variable transmission having at least two trunnions and one set of trunnions in the front cavity and the rear cavity,
The hydraulic drive unit, which is disposed for each trunnion set, includes a cylinder chamber and two sets of hydraulic pistons fitted in the cylinder chambers, a control valve for adjusting the hydraulic pressure in each cylinder chamber, and a target hydraulic pressure of the control valve. A double-cavity toroidal type that controls the tilting rotation of each trunnion around each tilt axis by a hydraulic pressure setting unit to be set and a hydraulic control unit that feeds back the tilt angle of each trunnion to the control valve. In the trunnion drive device of the step transmission, the front-side valve body and the rear-side valve body each having the hydraulic drive unit and the control valve therein are arranged in the same direction as the output shaft with respect to the torque input shaft. Located in the front cavity where the output shaft does not exist. The rear valve body in the rear cavity in which the output shaft exists is divided into two valve body elements in order to avoid interference with the output shaft. A trunnion drive device for a double-cavity toroidal-type continuously variable transmission, wherein one set of the cylinder chamber and the hydraulic piston are provided in a valve body element.