JPH1163146A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toroidal type continuously variable transmission by which motive power transmitting efficiency is improved and the transmission can be downsized. SOLUTION: A variator 2 and a planetary gear mechanism 3 are provided, and the variator 2 is composed of a pair of mutually opposing input discs 10a and 10b to rotate by interlocking with an input shaft 6, a pair of output discs 11a and 11b and a power roller 12 rollingly connected between both discs so as to be freely tiltable, and the planetary gear mechanism 3 is composed of a sun gear 21 to rotate an output shaft 20, a ring gear 24 arranged around the sun gear 21 and plural planetary gears 22 rotatably supported between the sun gear 21 and the ring gear 24 by a carrier 23, and has a hydraulic piston 8 which is arranged between the input shaft and the input discs and presses the input discs to the output discs through the power roller, a counter shaft 16 to transmit rotation of the output discs to the carrier and a central shaft 19 to transmit rotation of the input discs to the ring gear.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal type continuously variable transmission used as a transmission for an automobile, for example.

[0002]

2. Description of the Related Art For example, a toroidal type continuously variable transmission used as a transmission for an automobile is disclosed in, for example, Japanese Patent Laid-Open No. 1-1691.
No. 69 is known. This toroidal-type continuously variable transmission includes a toroidal-type continuously variable transmission in which a power roller is tiltably contacted between an input disk and an output disk, and a planetary gear mechanism connected to the output disk. A planetary gear mechanism comprising: first and second planetary gear sets each having a sun gear connected to the output disk; and a predetermined element of the first planetary gear set fixed to rotate in a direction opposite to the output disk. A first power transmission mechanism for selectively taking out force and transmitting the force to the second planetary gear set and an output shaft; and a predetermined element of the second planetary gear set connected to the input disk, and the output disk And a second power transmission mechanism for selectively taking out a rotational force in the opposite direction and transmitting the rotational force to the output shaft.

That is, it is composed of a single-cavity toroidal type continuously variable transmission and a two-stage planetary gear set,
By operating the first power transmission mechanism to fix a predetermined element of the first planetary gear set, the rotational driving force of the output disk of the toroidal-type continuously variable transmission is output via the first planetary gear set. The shaft is transmitted to the shaft so as to rotate in a direction opposite to that of the input shaft to obtain the first mode in the forward state.

In the first mode, the first power transmission mechanism is deactivated while the toroidal-type continuously variable transmission is at the maximum speed increasing position. Is operated to fix a predetermined element of the second planetary gear set, so that the rotational driving force of the input shaft is directly transmitted to the output shaft via the second planetary gear set without passing through the toroidal type continuously variable transmission. A second mode is provided in which the power is transmitted and a part of the power is returned to the input shaft via the second planetary gear set and the toroidal-type continuously variable transmission.

[0005]

However, since the conventional toroidal type continuously variable transmission is a single-cavity type toroidal type continuously variable transmission, power transmission efficiency is poor and large torque is transmitted. There was a problem that it was not possible. Further, since the two-stage planetary gear set is used, there is a problem that the size of the apparatus is increased.

The present invention has been made in view of the above circumstances. It is an object of the present invention to control hydraulic pressure so that an appropriate thrust can always be given, and power circulation during high-speed running can be achieved. Can reduce the torque input to the variator, reduce the proportion of the torque burden in the entire variator, improve the durability of the components, and transmit a large torque through the double cavity toroidal stepless transmission It is to provide a device.

[0007]

In order to achieve the above object, the present invention provides an input shaft that is driven to rotate by a drive source, an output shaft that extracts power based on the rotation of the input shaft,
A variator and a planetary gear mechanism disposed between the input shaft and the output shaft, wherein the variator includes a pair of input disks facing each other that rotates in conjunction with the input shaft; and a pair of the input disks. A pair of output disks arranged coaxially between and rotating synchronously with each other, and a power roller rotatably contacted between the input disk and the output disk, wherein the planetary gear mechanism comprises:
A toroidal type comprising a sun gear for rotating the output shaft, a ring gear disposed around the sun gear, and a plurality of planetary gears rotatably supported by a carrier between the sun gear and the ring gear. In the continuously variable transmission, a hydraulic pressing mechanism provided between the input shaft and the input disk and pressing the input disk against the output disk via a power roller, and transmitting the rotation of the output disk to the carrier and A first power transmission mechanism for circulating the rotation to the output disk; and a second power transmission mechanism for transmitting the rotation of the input disk to the ring gear.

According to the toroidal-type continuously variable transmission configured as described above, the carrier of the planetary gear mechanism is connected to the ring gear during low-speed running, and the connection between the second power transmission mechanism and the ring gear is made. Switch the clutch to the released state. In this state, only the variator transmits power from the input shaft to the output shaft. During this low-speed traveling, the input side,
The operation itself when converting the transmission ratio between the two disks on the output side is the same as that of the conventional variator. Of course,
In this state, the speed ratio between the input shaft and the output shaft, that is, the speed ratio of the continuously variable transmission as a whole is proportional to the speed ratio of the variator. In this state, the torque input to the variator is equal to the torque applied to the input shaft.

On the other hand, during high-speed traveling, the second
Is connected to the ring gear and the clutch is switched to a state in which the connection between the carrier and the ring gear is released. As a result, the planetary gear mechanism transmits power from the input shaft to the output shaft. In this state, torque is transmitted from the carrier constituting the planetary gear mechanism to the output disk of the variator via the second power transmission mechanism. In this state, the speed ratio of the entire continuously variable transmission changes in accordance with the revolution speed of the planetary gear. Therefore, by changing the speed ratio of the variator and changing the revolution speed of the planetary gear, the speed ratio of the entire continuously variable transmission can be adjusted. That is, in this state,
As the speed ratio of the variator is changed to the speed reduction side, the speed ratio of the entire continuously variable transmission changes to the speed increasing side. In such a state at the time of high-speed running, the torque input to the variator decreases as the speed ratio of the variator is changed to the deceleration side in order to change the speed ratio of the entire continuously variable transmission to the speed increasing side. As a result, the torque input to the variator during high-speed running can be reduced, and the durability of the components of the variator can be improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram of a double-cavity toroidal type continuously variable transmission according to a first embodiment, and FIG. 2 is a graph showing the relationship between vehicle speed and power input to an input disk / engine power. In FIG. 1, reference numeral 1 denotes a toroidal type continuously variable transmission, which includes a variator 2 and a planetary gear mechanism 3. The variator 2 is rotatably supported by a fixed portion via a bearing or the like, and has a drive source 5 such as an engine at one end.
The input shaft 6 is connected to the input shaft 6.

The input shaft 6 is provided with a hydraulic piston 8 as a hydraulic pressing mechanism via a start clutch 7. The hydraulic piston 8 is connected to a hydraulic supply source (not shown) so that an arbitrary pressing force can be transmitted to the variator 2. The variator 2 includes a pair of input disks 10 a and 1 opposed to each other that rotate in conjunction with the input shaft 6.
0b is provided, and the pair of input disks 10a, 10
A pair of output disks 11a and 11b in a loosely fitted state with respect to the input shaft 6 are coaxially arranged between the input disks 6 and rotate in synchronization with each other.

Between the input disks 10a and 10b and the output disks 11a and 11b, there are provided a plurality of power rollers 12 which are rotatably contacted. Output disk 1
The reference numerals 1a and 11b are connected via a loose fitting shaft 13 which loosely fits on the input shaft 6. This variator 2 has an input shaft 6
The rotational driving force transmitted to the input disks 10a, 10
b, power roller 12 and output disks 11a, 11b
The speed ratio, that is, the rotation speed of the output disks 11a and 11b is transmitted to the
The value obtained by dividing by the rotation speeds 0a and 10b is
Is determined by the tilt angle.

That is, when the power roller 12 is in the horizontal state, the speed ratio becomes a neutral state, and when the output disks 11a and 11b of each power roller 12 tilt in the direction away from the input shaft 6, the power Accordingly, the speed ratio decreases, and conversely, the output disk 11 of each power roller 12
When the a and 11b sides tilt in the direction approaching the input shaft 6, the speed ratio increases accordingly. The loose fitting shaft 13 has a first
The first sprocket 14 is interlocked with a second sprocket 17 provided on a counter shaft 16 constituting a first power transmission mechanism via a chain 15. On the other hand, a center shaft 19 is provided on the other end side of the input shaft 6 via a high-speed clutch 18, and this center shaft 19 forms a second power transmission mechanism in conjunction with the planetary gear mechanism 3. I have.

The planetary gear mechanism 3 will be described. A sun gear 21 having an output shaft 20, a plurality of planetary gears 22 meshing with the sun gear 21, and a carrier 2 connecting the respective planetary gears 22 are connected.
3 and a ring gear 24 meshing with the planetary gear 22. The ring gear 24 is connected to the high-speed clutch 18 via the central shaft 19. Further, the ring gear 24
A reversing clutch 25 for allowing and restricting rotation of the ring gear 24 is provided between the planetary gear mechanism 3 and a housing (not shown) of the planetary gear mechanism 3. Further, between the carrier 23 and the ring gear 24, there is provided a low speed clutch 26 for connecting and disconnecting power transmission.

A first gear 27 is provided at the other end of the counter shaft 16 constituting the first power transmission mechanism, and a free-fit shaft that is loosely fitted to the output shaft 20 on the carrier 23 of the planetary gear mechanism 3. , And the loose fit shaft 28 has a first gear 2
A second gear 29 meshing with the gear 7 is provided.

Next, the operation of the first embodiment will be described.

Now, while the input shaft 6 is stopped, the variator 2 is at the maximum deceleration position, and the high-speed clutch 1
8. The low speed clutch 26 and the reverse clutch 25 are in the released state. In this state, when the starting clutch 7 is connected and the input shaft 6 is started to rotate in a predetermined direction by the drive source 5, the input disks 10a and 10b of the variator 2 are brought into the same state as the input shaft 6 with the rotation of the input shaft 6. Rotate at the same rotational speed in the same direction. At this time, since the power roller 12 is at the maximum deceleration position, the rotation of the input disks 10a and 10b is
The rotation is transmitted to the input shaft 11 b in a direction opposite to that of the input shafts 10 a and 10 b and at a lower speed than the input shaft 6.

Accordingly, the loose fitting shaft 13 rotates, and the power is transmitted to the first sprocket 14, the chain 15, and the second sprocket 17, and the first sprocket 14, the chain 15, and the first
The second gear 29 also rotates via the gear 27 of. However, in this state, the high-speed clutch 18, the low-speed clutch 26, and the reverse clutch 25 are in the disengaged state, and the planetary gear 22 and the carrier 23 only rotate freely.
The rotational force is not transmitted to the sun gear 21 connected to the output shaft 20, and the output shaft 20 maintains the rotation stopped state.

When the starting clutch 7 is connected, the low-speed clutch 26 is connected, and the high-speed clutch 18 and the reverse clutch 25 are released from the rotation stop state of the output shaft 20, the carrier 23 and the ring gear 24 are connected. The rotational force of the second gear 29 is transmitted to the loose fitting shaft 28, the carrier 23, and the ring gear 24. Therefore,
The sun gear 21 rotates via the planetary gear 22 to rotate the output shaft 2
0, and the first mode in the forward state in which the output shaft 20 rotates in the same direction as the input shaft 6 is obtained.

When the variator 2 is tilted in the direction of increasing the speed, that is, the power roller 12 is moved in the direction in which the output disks 11a and 11b approach the input shaft 6, while maintaining the first mode, the counter is operated in accordance with the tilt. The rotation speed of the shaft 16 increases, and accordingly, the rotation speeds of the ring gear 24 and the carrier 23 of the planetary gear mechanism 3 increase, so that the rotation speed of the output shaft 20 increases.
The overall speed ratio increases.

Next, when the high-speed clutch 18 is connected to release the low-speed clutch 26 and the reverse clutch 25 and the starting clutch 7 is connected, the rotation of the input shaft 6 is transmitted via the high-speed clutch 18 to the central shaft 19. And the rotation of the center shaft 19 is transmitted to the ring gear 24 of the planetary gear mechanism 3.
The rotation of the ring gear 24 is transmitted to the sun gear 21 via the plurality of planetary gears 22, and the output shaft 20 connected to the sun gear 21 rotates. When the ring gear 23 is on the input side, assuming that the carrier 23 supporting the planetary gear 22 is stopped, the speed increase is performed at a speed ratio corresponding to the number of teeth of the ring gear 23 and the sun gear 21. Do. However, the planetary gear 22 supported by the carrier 23 revolves around the sun gear 21, and the speed ratio of the entire continuously variable transmission changes according to the revolving speed of the planetary gear 22. Therefore, if the revolving speed of the planetary gear 22 is changed by changing the speed ratio of the variator 2, the speed ratio of the entire continuously variable transmission can be adjusted.

That is, the planetary gear 22 revolves in the same direction as the ring gear 24 during high-speed running. Then, the higher the revolution speed of these planetary gears 22, the higher the rotation speed of the output shaft 20 fixed to the sun gear 21. For example, if the revolution speed becomes equal to the rotation speed of the ring gear 24 (both angular velocities), the rotation speed of the ring gear 24 and the output shaft 20 becomes equal. On the other hand, if the revolution speed is lower than the rotation speed of the ring gear 24, the ring gear 24
The rotation speed of the output shaft 20 is higher than the rotation speed of the output shaft 20. On the contrary, if the revolution speed is higher than the rotation speed of the ring gear 24, the output shaft 1 is higher than the rotation speed of the ring gear 24.
9 becomes slower.

Therefore, during the high-speed running, the ring gear 24 of the planetary gear mechanism 3 is connected via the second power transmission mechanism.
A part of the torque transmitted to the output disk 1 from the planetary gear 22 via the carrier 23 and the first power transmission mechanism
1a and 11b. As the speed ratio of the variator 2 is changed to the deceleration side, the speed ratio of the entire toroidal type continuously variable transmission 1 is changed to the speed increasing side.

In such a state at the time of high-speed running, torque is applied to the variator 2 not from the input disks 10a and 10b but from the output disks 11a and 11b.
A so-called power circulation state occurs, but the input disks 10a, 10
When the torque to which the pressure b is applied is, for example, 30%, the pressing force can be varied by employing the hydraulic piston 8, so that the input discs 10a,
The force applied to the variator 2 can be reduced by pressing the variator 2 with a 30% force, and the load on the variator 2 can be reduced. As a result, as shown in FIG. 2, the torque input to the variator 2 during high-speed running can be reduced, and the durability of the components of the variator 2 can be improved.

Next, in order to move the vehicle backward, the output shaft 2
To reverse the rotation of 0, the low-speed clutch 26 and the high-speed clutch 18 are released, and the reverse clutch 25 is connected. As a result, the ring gear 24 of the planetary gear mechanism 3
Is fixed, and each planetary gear 22 revolves around the sun gear 21 while meshing with the ring gear 24 and the sun gear 21. Therefore, the sun gear 21 and the output shaft 20 fixed to the sun gear 21 rotate in a direction opposite to that at the time of the high-speed running and the low-speed running described above.

[0027]

As described above, according to the present invention, by controlling the hydraulic pressure, an appropriate thrust can always be given, and the thrust is input to the variator by power circulation during high-speed running. Torque can be reduced,
Further, the torque input to the variator can be reduced due to the power circulation during high-speed running, and the ratio of the torque burden to the entire variator can be reduced, so that the durability of the components can be improved. Further, the double cavity has an effect that a large torque can be transmitted.

Further, since a one-stage planetary gear mechanism is used, there is an effect that the whole toroidal type continuously variable transmission can be reduced in size and weight.

[Brief description of the drawings]

FIG. 1 is a system diagram of a toroidal-type continuously variable transmission according to a first embodiment of the present invention.

FIG. 2 is a graph showing a relationship between vehicle speed and power input to an input disk / engine power in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Variator 3 ... Planetary gear mechanism 5 ... Drive source 6 ... Input shaft 8 ... Hydraulic piston 10a, 10b ... Input disk 11a, 11b ... Output disk 12 ... Power roller 16 ... Counter shaft 18 ... High speed clutch 20 ... Output shaft 21 ... Sun gear 22 ... Planetary gear 23 ... Carrier 24 ... Ring gear 26 ... Low speed clutch

Claims (1)

[Claims] An input shaft rotatably driven by a drive source;
An output shaft for taking out power based on the rotation of the input shaft, a variator and a planetary gear mechanism disposed between the input shaft and the output shaft, wherein the variator rotates in conjunction with the input shaft. A pair of input disks opposed to each other, a pair of output disks coaxially arranged between the pair of input disks, and rotating in synchronization with each other; The planetary gear mechanism comprises a sun gear for rotating the output shaft, a ring gear disposed around the sun gear, and a carrier between the sun gear and the ring gear. A toroidal-type continuously variable transmission comprising a plurality of freely supported planetary gears, wherein an input disk provided between the input shaft and the input disk is power-lowered. A first power transmission mechanism that transmits the rotation of the output disk to the carrier and circulates the rotation of the carrier to the output disk, and the rotation of the input disk. A toroidal-type continuously variable transmission, comprising: a second power transmission mechanism that transmits the power to a ring gear.