JPH04249655A - Continuously variable transmission - Google Patents

Abstract

PURPOSE:To stabilize the output state of a planetary gear mechanism and improve durability in a continuously variable transmission which is equipped with a troidal type continuously variable transmission which can vary the speed in the engine output revolution continuously and a planetary gear mechanism which receives the output revolution of the continuously variable transmission and the engine output revolution and outputs the revolution difference. CONSTITUTION:A fluid coupling 3 is arranged between a carrier 15 in a planetary gear mechanism 5 and an engine output shaft 2a for transmitting the output of an engine 2 to the carrier 15, and the revolution variation of the engine 2 is absorbed by the fluid coupling 3, and the relative revolution between the planetary gear mechanism 5 and the engine 2 is permitted.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a continuously variable transmission, and more particularly, to a continuously variable transmission, which includes a continuously variable transmission means capable of steplessly changing the output rotation of an engine, and a system in which the output rotation of the continuously variable transmission means and the output rotation of the engine are inputted. The present invention relates to a continuously variable transmission having a differential mechanism that outputs a rotation difference between the two.

0002

2. Description of the Related Art As a type of continuously variable transmission that can steplessly change the speed of an engine output and transmit it to an output shaft, for example, as described in Japanese Patent Application Laid-Open No. 57-47063, an input disk that rotates integrally with the input shaft that is directly connected to the input disk; an output disk that faces the input disk and is loosely fitted on the input shaft; and an output disk that is disposed between the output disk and the input disk and that A toroidal device consisting of a plurality of rollers that rotate in contact with the disk and are tiltable, and is configured to steplessly change the speed of the rotation of the input disk and output the same to the output disk by tilting the rollers. It has a continuously variable transmission and a planetary gear mechanism that further changes the output of this toroidal type continuously variable transmission, and the operation of the planetary gear mechanism is controlled by a brake or clutch, and is suitable for moving from a forward state to a backward state. Continuously variable transmissions configured to obtain an infinitely large speed ratio are known.

0003

[Problems to be Solved by the Invention] By the way, as described above, a continuously variable transmission that combines a toroidal type continuously variable transmission and a planetary gear mechanism changes the engine output rotation at a large gear ratio (reduction ratio) and converts it into a planetary gear. In the case of output from a mechanism, that is, in a region where the gear ratio is infinite, the power is generated due to slight fluctuations in the engine speed due to changes in load, etc., or subtle changes in the output of the toroidal continuously variable transmission. The output state from the planetary gear mechanism fluctuates greatly, making it difficult to obtain stable output.

Furthermore, in the region where the reduction ratio is infinite as described above, the transmitted torque increases and a large load is applied to the planetary gear mechanism, which poses a problem in the durability of the planetary gear mechanism.

Accordingly, the present invention provides a continuously variable transmission means capable of steplessly changing the engine output rotation, and a differential transmission means for inputting the output rotation of the continuously variable transmission means and the engine output rotation and outputting the rotation difference between them. An object of the present invention is to stabilize the output state of the differential mechanism in a continuously variable transmission having a differential mechanism, and to improve the durability of the differential mechanism.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the present invention is characterized by the following structure.

That is, a continuously variable transmission means capable of changing the engine output rotation steplessly, an input section into which the output rotation of the continuously variable transmission means is input, and an input section into which the engine output rotation is input are provided. In a continuously variable transmission having a differential mechanism that outputs a rotation difference between the input parts, the input part of the differential mechanism and the engine or the continuously variable transmission are connected on one input path to the differential mechanism. The invention is characterized in that it is provided with a joint means that allows relative rotation of the two.

[0008]

[Operation] According to the above structure, a joint means is provided on one input path to the differential mechanism to allow relative rotation between the input part of the differential mechanism and the engine or the continuously variable transmission means. Therefore, when the engine output speed is changed with a large reduction ratio and output from the differential mechanism, that is, when the engine speed fluctuates due to changes in load etc. in a region where the reduction ratio is infinite, or Even when the output of the continuously variable transmission changes, fluctuations in engine rotation and changes in the output of the continuously variable transmission are absorbed by the coupling means, thereby suppressing fluctuations in the output of the differential mechanism. As a result, the output of the differential mechanism is always stable.

Furthermore, the above coupling means allows relative rotation between the input section of the differential mechanism and the engine or the continuously variable transmission means, so if an excessive load is applied, the differential Slippage occurs between the mechanism and the engine or the continuously variable transmission, thereby reliably preventing overload of the continuously variable transmission and improving the durability of the continuously variable transmission. become.

0010

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

As shown in FIG. 1, a vehicle 1 according to this embodiment includes a fluid coupling 3 connected to an output shaft 2a of an engine 2.
, a toroidal continuously variable transmission 4 similarly connected to the output shaft 2a, a planetary gear mechanism 5 to which the output of the toroidal continuously variable transmission 4 and the output of the fluid coupling 3 are transmitted, and this planetary gear mechanism. The output of the planetary gear mechanism 5 is input to the differential device 6, whereby the left and right axles 7, 7 connected to the differential device 6 are It is designed to be rotationally driven.

The fluid coupling 3 is connected to the output shaft 2 of the engine 2.
A pump 3b integrated with a casing 3a connected to a, a turbine 3c disposed opposite to the pump 3b, and a lock-up clutch 3d for integrally rotating the turbine 3c and the pump 3b as necessary. .

[0013] Furthermore, the toroidal continuously variable transmission 4 has the following features:
An input shaft 8 directly connected to the output shaft 2a of the engine 2, an input disk 9 that rotates integrally with the input shaft 8, and an output that is disposed opposite to the input disk 9 and loosely fitted onto the input shaft 8. A disc 10 is disposed between the output disc 10 and the input disc 9 at equal intervals in the circumferential direction around the input shaft 8 with the peripheral surface portions being in rolling contact with both the discs 10 and 9, and is tiltable. It has a plurality of rollers 11...11. Then, each roller 11 is in the state shown by the solid line in FIG.
When the rollers 11 are tilted, the rotation of the input disk 9 is decelerated and output to the output disk 10, and when each roller 11 is tilted as shown by the chain line in FIG.
The rotation speed of the input disk 9 is increased and outputted to the output disk 10.

The output disk 10 and the sun gear 12 constituting the planetary gear mechanism 5 are connected to each other, and a carrier 15 rotatably supports a plurality of pinion gears 14 . . . 14 meshing with the sun gear 12 and the ring gear 13. is connected to a turbine shaft 3e that rotates integrally with the turbine 3c. Therefore, as shown in FIG. 2, the sun gear 1 constituting the planetary gear mechanism 5
2, the output of the engine 2 whose speed has been changed by the toroidal continuously variable transmission 4 is inputted, and the output of the engine 2 is inputted to the carrier 15 constituting the planetary gear mechanism 5 via the fluid coupling 3. input, and the carrier 1
5 and the sun gear 12 drives the ring gear 13, and accordingly, the output gear 13a (see FIG. 1), which is provided integrally with the ring gear 13, drives the input gear 6b, which is integral with the casing 6a of the differential device 6. is designed to be rotationally driven.

Here, to briefly explain the speed change characteristics of the combination of the toroidal type continuously variable transmission 4 and the planetary gear mechanism 5, as shown in FIG. When the tilting angle is around 30°, the speed ratio (reduction ratio) is about 0.5, and from this state, each of the rollers 11 is tilted in the horizontal direction, and when the tilting angle is around 0°, a large reduction ratio, i.e. , an infinite reduction ratio can be obtained.

[0016] By tilting each of the rollers 11 in the opposite direction by more than 0°, the engine 2
The rotation of the rotation is decelerated and the rotation is outputted from the ring gear 13 in the planetary gear mechanism 5 in a reversed state.

According to the above configuration, the fluid coupling 3 that allows relative rotation between the carrier 15 of the planetary gear mechanism 5 and the engine 2 is provided on the power transmission path from the engine 2 to the planetary gear mechanism 5. When the rotation of the engine 2 is changed at a large reduction ratio and output from the planetary gear mechanism 5, that is, when the rotation speed of the engine 2 fluctuates due to changes in load etc. in a region where an infinite reduction ratio is obtained, or The above toroidal continuously variable transmission 4
Even when the output of the planetary gear mechanism 5 changes, fluctuations in the rotation of the engine 2 and changes in the output of the toroidal continuously variable transmission 4 are absorbed by the fluid coupling 3, thereby suppressing fluctuations in the output of the planetary gear mechanism 5. As a result, the output of the planetary gear mechanism 5 is always stable.

Furthermore, since the fluid coupling 3 allows relative rotation between the carrier 15 of the planetary gear mechanism 5 and the engine 2, if an excessive load is applied, the planetary gear mechanism 5 and the engine A slip occurs between the planetary gear mechanism 5 and the planetary gear mechanism 5.
In addition, overload of the toroidal continuously variable transmission 4 is reliably prevented, and its durability is improved.

4 and 5 show a second embodiment, and a vehicle 21 according to this embodiment includes an engine 22, a fluid coupling 23, a toroidal continuously variable transmission 24, and a planetary gear mechanism 25. The output of the engine 22 is input to the toroidal continuously variable transmission 24 via the output shaft 22a, and the output shaft 2 is input to the planetary gear mechanism 25.
The output of the engine 2 from 2a and the output of the toroidal continuously variable transmission 24 are inputted via the fluid coupling 23. The output of the planetary gear mechanism 25 is input to the differential device 26, whereby the left and right axles 27, 27 connected to the differential device 26 are rotationally driven.

The toroidal continuously variable transmission 24 includes an input shaft 28 directly connected to the output shaft 22a of the engine 22, an input disk 29 that rotates integrally with the input shaft 28, and an input disk 29 disposed opposite to the input disk 29. and the input shaft 28
An output disk 30 is loosely fitted onto the top, and both disks 30, 2 are connected between the output disk 30 and the input disk 29.
It has a plurality of rollers 31 . . . 31 which are arranged at equal intervals in the circumferential direction around the input shaft 28 in a state in which the peripheral surface portion is in rolling contact with the input shaft 28 and can be tilted. , when each roller 31 is tilted, the rotation of the input disk 29 is decelerated and output to the output disk 30.
When each roller 31 is tilted in the state shown by the chain line in , the rotation of the input disk 29 is accelerated and outputted to the output disk 30.

[0021] The fluid coupling 23 is connected to the output disk 3.
a pump 23 integrated with a casing 23a connected to 0;
b, and a turbine 23 arranged opposite to this pump 23b.
c, and a lock-up clutch 23d for integrally rotating the turbine 23c and the pump 23b as necessary.

The turbine 23c in the fluid coupling 23 and the sun gear 32 constituting the planetary gear mechanism 25 are integrally provided, and the sun gear 3
2 and a plurality of pinion gears 3 meshing with the ring gear 33
A carrier 35 that rotatably supports the motors 4...34 is provided integrally with the output shaft 22a of the engine 22. Therefore, as shown in FIG. 5, the output of the engine 2, whose speed has been changed by the toroidal continuously variable transmission 24, is transferred to the sun gear 32 constituting the planetary gear mechanism 25 through the fluid coupling 2.
3, and the planetary gear mechanism 2
The output of the engine 2 is directly input to the carrier 35 constituting the carrier 5 through the output shaft 22a.
The ring gear 33 is driven by the rotation difference between the sun gear 32 and the sun gear 32, and accordingly, the output gear 13a (see FIG. 4), which is provided integrally with the ring gear 33, drives the input gear 26b, which is integral with the casing 26a of the differential device 26. It is designed to be rotationally driven.

According to the above configuration, the relative rotation between the sun gear 32 of the planetary gear mechanism 25 and the output disk 30 of the toroidal type continuously variable transmission 24 occurs on the power transmission path from the toroidal type continuously variable transmission 24 to the planetary gear mechanism 25. By providing the fluid coupling 23 that allows the rotation of the engine 22 to be output from the planetary gear mechanism 25 by changing the rotation at a large reduction ratio, that is, in a region where an infinite reduction ratio is obtained, for example, the toroidal Even when the output of the continuously variable transmission 24 changes, the change in the output of the continuously variable transmission 24 is absorbed by the fluid coupling 23, thereby suppressing fluctuations in the output of the planetary gear mechanism 25. Therefore, the output of the planetary gear mechanism 25 is always stable.

Furthermore, since the fluid coupling 23 allows relative rotation between the sun gear 32 of the planetary gear mechanism 25 and the toroidal continuously variable transmission 24, if an excessive load is applied, Slippage occurs between the planetary gear mechanism 25 and the toroidal continuously variable transmission 24, thereby reliably preventing overload of the planetary gear mechanism 25 or the toroidal continuously variable transmission 24. The durability will be improved.

[0025] In the first and second embodiments above,
In areas other than the area where the reduction ratio is infinite, each fluid coupling 3, 2
It is possible to shift gears while the lock-up clutches 3d and 23d provided in the transmission gear 3 are engaged, and it is similar to an automatic transmission consisting of a conventional torque converter and a plurality of transmission gear mechanisms connected to the torque converter. In addition, it is no longer necessary to disengage the lock-up clutch every time the gear is changed.
This will improve fuel efficiency and the like.

[0026]

As described above, according to the present invention, there is provided a joint means on one input path to the differential mechanism that allows relative rotation between the input portion of the differential mechanism and the engine or the continuously variable transmission means. By providing a Even if the output of the continuously variable transmission changes, the fluctuation in engine rotation and the change in the output of the continuously variable transmission means will be absorbed by the coupling means, and as a result, the output of the differential mechanism will change. Since fluctuations are suppressed, the output of the differential mechanism can always be stabilized.

Furthermore, the above-mentioned coupling means allows relative rotation between the input section of the differential mechanism and the engine or the continuously variable transmission means, so if an excessive load is applied, the differential Slippage occurs between a mechanism and an engine or a continuously variable transmission, thereby reliably preventing overload of the continuously variable transmission, thereby improving the durability of the continuously variable transmission. Can be done.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic configuration diagram of a vehicle equipped with a continuously variable transmission according to a first embodiment.

FIG. 2 is a block diagram showing the overall configuration of a vehicle including a continuously variable transmission according to the first embodiment.

FIG. 3 is a graph showing the speed change characteristics of the continuously variable transmission.

FIG. 4 is an overall schematic configuration diagram of a vehicle equipped with a continuously variable transmission according to a second embodiment.

FIG. 5 is a block diagram showing the overall configuration of a vehicle including a continuously variable transmission according to a second embodiment.

[Explanation of symbols]

2,22 Engine 2a, 22a Output shaft 3,23 Fluid coupling

Claims (1)

[Claims] 1. A continuously variable transmission means capable of steplessly changing an engine output rotation, an input section into which the output rotation of the continuously variable transmission means is input, and an input section into which the engine output rotation is input. and a differential mechanism that outputs a rotation difference between the input parts, the input part of the differential mechanism and the engine or the continuously variable transmission being connected on one input path to the differential mechanism. A continuously variable transmission characterized by being provided with a joint means that allows relative rotation with the means.