JPH04366048A - Continuously variable transmission - Google Patents

Abstract

PURPOSE:To provide a continuously variable transmission in which a speed change roller is interposed between input and output disks under the press fit condition to be always pressed against both disks with a fixed force. CONSTITUTION:An input disk 2 and output disk 3 opposed to each other are supported by an input shaft 1, and a roller support device 4 for supporting a disk-like roller 5 pressed against bent surfaces 2a, 3a of these disks is slantingly interposed between the disks. Also, the roller support device 4 is formed with a hydraulic actuator 12 for pressing the roller 5 against both disks 2, 3, so that the roller 5 is always pressed against both disks with a fixed force by the hydraulic actuator 12 whatever the inclination of the roller may be.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a half-wheel drive system in which a speed-changing roller is interposed between disks on the input side and output side in a press-contact state, and the inclination of the speed-changing roller is changed by hydraulic pressure to perform stepless speed changes. Regarding a toroidal continuously variable transmission.

0002

[Prior Art] In a conventional toroidal type continuously variable transmission of this type, a power roller is interposed in pressure contact between an input disk and an output disk having curved surfaces facing each other. A hydraulic chamber is attached to one side of the disk, which urges the disk in the direction of pressure contact with the power roller, and this controlled hydraulic pressure causes the disk to press against the power roller, reducing the frictional force at the contact area between the two. It is designed to increase. (Refer to Japanese Patent Application Laid-Open No. 1-250657)

0003

However, the end of the power roller comes into contact with the curved surface of the input and output disk in an inclined state, and the pressing force of the disk acts on the end of the power roller in the direction of the input axis. The component force of the above pressing force on the inclined contact surface is that the component force perpendicular to the contact surface that is effective for frictional force is small, and the component force in the direction along the contact surface is large, so that the end of the power roller is against the disk. Becomes slippery.

[0004] Therefore, as the power roller tilts and the inclination increases, the pressing force of the disk becomes less effective against the frictional force with the power roller, resulting in a problem of a reduction in transmitted torque and damage to the traction section. .

[0005]

[Means for Solving the Problems] In order to solve the problems of the prior art described above, the present invention has the following features as shown in FIGS.
An input disk 2 and an output disk 3 are pivotally supported on the input shaft 1 so as to face each other, and disk-shaped rollers 5 and 17 are pressed against the respective curved surfaces 2a and 3a between the disks 2 and 3, In a half-toroidal continuously variable transmission in which a roller support device 4, 15 that supports the rollers 5, 17 is installed in a tiltable manner, the rollers 5, 7 are connected to both disks 2, , 3 curved surfaces 2a, 3a
It is equipped with hydraulic actuators 12 and 21 for pressing the cylinder.

Further, the present invention provides that the hydraulic actuator 21 of the roller support device 15 is provided with a cylinder portion 19 into which the cylindrical portion 16 formed on the roller 17 is fitted, and that the cylindrical portion 16 of the roller 17 and the cylinder portion are provided. A hydraulic chamber 20 is formed between the hydraulic pressure chamber 19 and the hydraulic pressure chamber 20.

[0007]

[Operation] The hydraulic actuators 12 and 21 provided in the roller support devices 4 and 15 insert the rollers 5 and 17 into the curved surfaces 2a and 3a of the output disks 2 and 3, respectively.
Regardless of the tilt angle of 7, it can be pressed substantially vertically and with a constant force. Therefore, normal transmitted torque can always be obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of a first embodiment of the apparatus of the present invention. Reference numeral 1 denotes an input shaft, which is connected to a drive shaft of an engine 13 via a clutch 14 shown in FIG. An input disk 2 and an output disk 3 are supported on the input shaft 1 so as to face each other. The input disk 2 is spline-fitted to the input shaft 1 and is attached so that it cannot rotate and cannot move in the axial direction, and the output disk 3 is attached via a bearing so that it can rotate but cannot move in the axial direction.

Reference numeral 4 denotes a roller support device, which supports both the disks 2 mentioned above.
, 3 so as to be tiltable about a tilting axis A perpendicular to the plane of the paper by a tilting means (not shown). Further, the roller support device 4 includes curved surfaces 2a of both the disks 2 and 3,
3a, a disc-shaped roller 5 that presses the circumferential ends 5a and 5b forming curved pressure contact surfaces, and a central shaft 6 that is fitted into a hole at the center of the roller 5 through a bearing 6a are provided protrudingly. a cylinder portion 7 having a disk shape having an outer diameter approximately equal to that of the roller 5; and a piston portion 8 having a bearing 8a that is fitted into the cylinder portion 7, protrudes from the center, and into which the central shaft 6 is loosely fitted. , a plurality of ball bearings 9 interposed between the roller 5 and the piston part 8, a hydraulic chamber 10 formed between the cylinder part 7 and the piston part 8, and a hydraulic pressure chamber 10 formed in the cylinder part 7. Room 1
0 and an oil passage 11 that leads to a hydraulic actuator (not shown). Components for pressing the roller 5, namely a ball bearing 9, a piston part 8,
Hydraulic chamber 10, oil passage 11, hydraulic actuator and cylinder section 7
forms a hydraulic actuator 12 in the roller support device 4.

A plurality of roller support devices 4 are installed as shown in FIG. 3, and are interposed between the output disks 2 and 3. When the engine 13 is started and the input shaft 1 is rotated via the clutch 14, the input disks are first 2 rotate together. This rotation of the input disk 2 causes the roller 5 to rotate around the central axis 6 through the frictional force caused by the pressure contact with the peripheral end 5a of the roller 5, that is, the pressing force of the roller 5. This roller 5 has a peripheral edge 5
b is brought into pressure contact with the output disk 3, and the output disk 3 is rotated through the frictional force. Note that the rotation of the roller 5 is absorbed by the ball bearing 9, and the piston portion 8 does not rotate.

The pressing force of the roller 5 is obtained by the magnitude of the hydraulic pressure introduced into the hydraulic chamber 10, and the hydraulic pressure is transmitted from the piston section 8 through the ball bearing 9 to the roller 5, and this roller 5 Press 2 and 3. Moreover, the hydraulic pressure is controlled so that the pressing force of the roller 5 is constant no matter what tilt angle of the roller support device 4, that is, the gear ratio r1/r2. Note that r1 and r2 are the respective distances from the central axis l of the input shaft 1 to each pressure contact point 5a', 5b'.

In other words, the pressing force of the roller 5 is proportional to the input torque and the gear ratio, and therefore the frictional force between the roller 5 and both disks 2 and 3 is proportional to the input torque and the gear ratio. It is expected that the torque transmission will always be stable and the life of the traction section will be extended without slipping.

FIG. 2 is a sectional view of a second embodiment of the device according to the invention. Components that are the same as those in the first embodiment shown in FIG. 1 will be described using the same reference numerals. The roller support device 15, which is rotatably interposed between the input disk 2 and the output disk 3, has peripheral edges 17a and 17b formed with curved pressure contact surfaces on the curved surfaces 2a and 3a of both disks 2 and 3, respectively. A roller 17 is provided in which a piston portion 16 is formed by pressing the roller 17, and a cylinder portion 19 is fitted onto the piston portion 16 of the roller 17 via a plurality of cylindrical bearings 18. A hydraulic chamber 20 is formed between the hydraulic pressure chamber 19 and the hydraulic pressure chamber 20 .

The components for pressing the roller 17, that is, the piston section 16, the hydraulic chamber 20, the hydraulic actuator (not shown) that supplies hydraulic pressure to the hydraulic chamber 20, and the cylinder section 19 are the hydraulic actuator 21 in the roller support device 15. is formed. That is, in this embodiment, unlike the first embodiment, there is no ball bearing 9 on the back surface of the roller 17, and the hydraulic chamber 20 is provided directly, and the roller 17 is in a floating state. Therefore, as in the case of the first embodiment, the roller 17 is pressed by the hydraulic actuator 21 against both disks 2 and 3 with their circumferential ends 17a and 17b, respectively, and as the input disk 2 rotates, the roller 17 is moved as indicated by the chain line. The output disk 3 is rotated around the center line B shown by , and the output disk 3 is rotated at the same time. Note that since the rotation of the roller 17 is absorbed by the oil in the hydraulic chamber 20 and the bearing 18, the cylinder portion 19 does not rotate.

Therefore, regardless of the tilting angle of the roller support device 15, that is, regardless of the gear ratio, a constant pressing force of the roller 17 is always obtained, and as in the first embodiment, the rotation by the ball bearing 9 is There is no loss and the transmission efficiency is improved, and problems such as failure of the bearing 8a are eliminated, and reliability is improved, and weight reduction, size reduction, and cost reduction are expected due to the reduction in the number of parts.

[0016]

[Effects of the Invention] According to the present invention, a roller supporting device is provided between the input and output disks, which is provided with a roller that presses against each of these curved surfaces, and which forms an actuator for pressing the roller, which is rotatably installed. Therefore, regardless of the tilt angle of the roller, the actuator can press the roller against the input and output disks with a constant force. Therefore, it has the characteristic that stable torque transmission can always be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a second embodiment of the present invention.

FIG. 3 is an overall configuration diagram of the present invention.

[Explanation of symbols]

1 Input shaft 2 Input disk 2a Curved surface 3 Output disk 3a Curved surface 4 Roller support device 5 Roller 12 Hydraulic actuator 15 Roller support device 16 Cylindrical part 17 Roller 19 Cylinder part 21 Hydraulic actuator

Claims (2)

[Claims] 1. An input disk and an output disk are pivotally supported on an input shaft so as to face each other, and a disk-shaped roller is pressed against the curved surface of each disk between the two disks, and a roller that supports the roller is provided. A half-toroidal continuously variable transmission in which a support device is installed in a tiltable manner, characterized in that the roller support device is provided with a hydraulic actuator for pressing the rollers against the curved surfaces of both disks. gearbox. 2. The hydraulic actuator of the roller support device is provided with a cylinder portion into which a piston portion formed on the roller is fitted, and a hydraulic chamber is formed between the piston portion and the cylinder portion of the roller. The continuously variable transmission according to claim 1.