JPH08247241A - Toroidal continuously variable transmission - Google Patents

Abstract

PURPOSE: To reduce the load on an angular bearing, to reduce the power loss, and to reduce the calorific power by receiving the thrust load to be exerted between output gears to transmit different power by a thrust bearing and the angular bearing. CONSTITUTION: The power is independently taken out from input disks 4a, 4b to output disks 6a, 6b through power rollers 7a, 7b, and the power is transmitted from the output disks 6a, 6b to output shafts 10a, 10b through output gears 3a, 3b. A thrust bearing 20 is arranged between the output gears 3a, 3b, the thrust loads generated in the output gears 3a, 3b corresponding to the power to be shared by toroidal change gear parts 1a, 1b are received by the thrust bearing 20, and the thrust load to be received by angular bearings 8a, 8b to support the output gears 3a, 3b by a case 5 is reduced.

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 which is applied to an automobile or the like and can independently take out power by arranging two sets of toroidal transmission parts on the same axis.

[0002]

2. Description of the Related Art Generally, a toroidal type continuously variable transmission has a toroidal transmission mechanism including an input disc, an output disc, and a power roller arranged between the two discs.
It has a configuration in which it is arranged on the set coaxial. The power transmission between the power roller and both discs depends on the shearing force of oil under high pressure, that is, the traction force (adhesive friction force). Therefore, a large pressing force, that is, a pressing force or a pressure contact force is required.

Regarding the toroidal type continuously variable transmission,
Two sets of toroidal speed change parts are arranged facing each other on the same axis,
The power can be independently taken out from the output gears respectively fixed to the two sets of output disks, and for example, the independently taken out power can be transmission-coupled to the front wheels and the rear wheels to form a four-wheel drive vehicle. A toroidal type continuously variable transmission is known (see, for example, JP-A-5-157151).

As the toroidal type continuously variable transmission as described above, the one shown in FIG. 2 is known. The toroidal type continuously variable transmission is composed of two sets of toroidal transmission parts 1a and 1b which independently take out power from an input shaft 2 to which power from an engine is transmitted, and two sets of toroidal transmission parts 1a and 1b. Are arranged to face each other on the input shaft 2. The toroidal transmission units 1a and 1b are input discs 4a and 4b rotatably mounted on the input shaft 2 via needle bearings 12a and 12b, and input discs 4a and 4a.
Needle bearings 12a, 12 on the input shaft 2 in opposition to 4b.
output discs 6a and 6b rotatably arranged via b, tiltable power rollers 7a and 7b for transmitting torque from the input discs 4a and 4b to the output discs 6a and 6b, and the respective output discs 6a and 6b. And a pair of output gears 3a, 3b, which are fixed to each other and take out power independently of each other, and output gears 3a, 3b.
And a pair of angular bearings 8a and 8b for supporting the transmission case 5 on the transmission case 5, respectively.

The power rollers 7a and 7b are rotatably provided on rotary shafts 15a and 15b on a tilt shaft fixed to a case (not shown). The power rollers 7a and 7b themselves are disc-shaped and are configured to receive torque from the input disks 4a and 4b, rotate, and transmit the torque to the output disks 6a and 6b. Angular bearing 8a,
8b are separated by a snap ring 13 fitted in a recess formed in the transmission case 5. Output shaft 10
a, 10b to the gear 9 via the keys 14a, 14b.
a and 9b are fixed respectively. Output gears 3a, 3
b is transmission-coupled to the output shafts 10a and 10b via gears 9a and 9b, respectively. The respective output shafts are a front wheel output shaft 10a and a rear wheel output shaft 10b.

The input shaft 2 is rotatably supported by the transmission case 5 by a pair of bearings 21 while restricting its axial movement. Input shaft 2 to input disks 4a, 4
The torque input to b is transmitted by the loading cams 16a and 16b which change the pressure contact force of the power rollers 7a and 7b according to the magnitude. The input disks 4a and 4b and the output disks 6a and 6b are rotatably supported by needle bearings 12a and 12b, respectively. Flange portions 11a and 11b are provided at both ends of the input shaft 2, respectively. Flange part 11
Loading cams 16a and 16b as pressing means are provided between a and 11b and the input disks 4a and 4b.

The toroidal type continuously variable transmission is constructed as described above and operates as follows. When torque is input to the input shaft 2 as the engine is driven, the torque is transmitted to the input disk 4a via the flange portion 11a formed at one end of the input shaft 2 and the loading cam 16a, and at the other end. Is transmitted to the input disc 4b via the flange portion 11b and the loading cam 16b, and the input disc 4a and the input disc 4b rotate independently of each other. The torque input to the input disks 4a and 4b is transmitted to the output disk 6 via the power rollers 7a and 7b.
It is independently transmitted to a and 6b. At this time, the gear ratios corresponding to the tilt angles of the power rollers 7a and 7b are independently obtained without any step between the input disks 4a and 4b and the output disks 6a and 6b. The torque transmitted to the output disk 6a is transmitted through the output gear 3a to the front wheel output shaft 1
The torque transmitted to the output wheel 0a and to the output disk 6b is transmitted to the rear wheel output shaft 10b via the output gear 3b.

[0008]

In the toroidal type continuously variable transmission, the angular bearings 8a and 8b are
The output disks 6a and 6b are supported by the case 5,
Toroidal transmission 1a, 1 for obtaining traction force
It receives the thrust load generated in each b. In the speed change by the toroidal speed change parts 1a and 1b, the power rollers 7a and 7b sandwiched between the input / output disks are tilted about the center of the arc forming the toroidal surface of the input / output disk as the axis (tilt axis), and This is performed by changing the ratio of the radius gyrations of the contact points with the power rollers 7a and 7b. A method of tilting the power rollers 7a and 7b is generally performed by displacing the power rollers 7a and 7b in the tilt axis direction.

However, in the above toroidal type continuously variable transmission, the thrust loads received by the two sets of output disks 6a, 6b are absorbed by the angular bearings 8a, 8b, so that the angular bearings 8a, 8b have a very large thrust load. Causes a large power loss. Moreover, the efficiency of the entire apparatus is lowered due to the power loss, and heat is generated in the angular bearings 8a and 8b. In some cases, the snap ring 13 arranged between the angular bearings 8a and 8b may be broken, and the angular bearings 8a and 8b cannot be supported by the case 5, resulting in damage.

An object of the present invention is to solve the above-mentioned problems. For example, it has two sets of toroidal transmissions for independently transmitting power to front wheels and rear wheels, and their output disks are The thrust load received is not absorbed only by the angular bearings, but is applied to the thrust bearings arranged between the output gears fixed to the output disc, and the thrust loads respectively applied to the output gears opposed by the thrust bearings are offset each other. A toroidal type that can improve fuel efficiency by reducing the load on the angular bearings by reducing the load on the angular bearings by making only the difference in the thrust load applied to each output gear on the angular bearings. It is to provide a gear transmission.

[0011]

In order to achieve the above object, the present invention is configured as follows. That is,
The present invention relates to an input shaft penetrating a casing, a pair of input disks rotatably supported on the input shaft, and a pair of input disks arranged to face each of the input disks and rotatably supported on the input shaft. Pair of output discs,
Tiltable power rollers arranged between a pair of the input disk and the output disk facing each other and transmitting power independently from the input disk to the output disk, fixed to the output disk and mutually A pair of opposed output gears that independently take out power, a pair of angular bearings that respectively support the output gears in a case, output shafts that are transmission-coupled to the output gears, respectively.
And a thrust bearing which is arranged between the facing surfaces of the output gear and receives a thrust load generated in the output gear in response to the power shared by the toroidal speed changer, and a toroidal type continuously variable transmission. Regarding

One of the output shafts is a front wheel output shaft, and the other output shaft is a rear wheel output shaft.

Further, the thrust loads applied to the thrust bearings cancel each other out, and the thrust loads applied to the angular bearings are only the differences in the thrust loads applied to the output gears.

[0014]

Since the toroidal type continuously variable transmission according to the present invention is constructed as described above, it operates as follows. In this toroidal type continuously variable transmission, tiltable power rollers arranged between a pair of input disks and a pair of output disks respectively take out power from the input disks to the output disks independently of each other, The power is transmitted from the independent output disk to the output shaft via the output gear, the thrust bearing is arranged between the facing surfaces of the output gear, and the output is output in accordance with the power shared by the toroidal transmission unit by the thrust bearing. Since the thrust loads generated in the gears are respectively received, the thrust load received by the angular bearings that support the output gear in the case can be reduced. This toroidal type continuously variable transmission can be applied to, for example, a four-wheel drive vehicle that independently transmits power to the front wheels and the rear wheels, and the output discs according to the power shared by the two toroidal transmission units. Thrust loads are generated in the thrust bearings, but the thrust loads applied to the thrust bearings oppose each other, so the thrust loads that oppose each other cancel each other out, and only the difference between the thrust loads applied to the output discs and thus the output gears, respectively. Is applied to the angular bearing, and the thrust load that the angular bearing bears is significantly reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view showing an embodiment of a toroidal type continuously variable transmission according to the present invention. The structure of the toroidal type continuously variable transmission according to the present invention has basically the same structure as the toroidal type continuously variable transmission shown in FIG. 2, and parts having the same actions as those shown in FIG. Are given the same reference numerals.

This toroidal type continuously variable transmission comprises a front wheel output shaft 10a for driving front wheels and a rear wheel output shaft 1 for driving rear wheels.
The present invention can be applied to a four-wheel drive vehicle having 0b and has a pair of input disks 4a, 4b rotatably supported on the input shaft 2 and arranged to face each of the input disks 4a, 4b. A pair of output discs 6a, 6b rotatably supported with respect to 2, a pair of opposing input discs 4a, 4b and output discs 6a, 6b arranged between the input discs 4a, 4b to the output disc 6
Power roller 7 capable of tilting to transmit torque to a and 6b
a, 7b and the pair of input disks 4a, 4b, respectively, and the power roller 7 depending on the magnitude of the input torque.
Loading cam 16 for changing the pressure contact force of a and 7b
a and 16b.

Engine torque is input to the input shaft 2 via, for example, a torque converter. The toroidal speed change parts 1a and 1b include needle bearings 12a and 12 on the input shaft 2.
input disks 4a and 4b rotatably attached via b, and needle bearings 12a and 12 to the input shaft 2.
an output disc 6 which is rotatably attached via b and is arranged to face the input discs 4a and 4b.
a, 6b, and a pair of power rollers 7a, 7b arranged between the disks 4a and 6a and 4b and 6b, respectively. The power rollers 7a and 7b rotate on rotating shafts 15a and 15b that are tiltably provided with respect to tilting shafts fixed to a case (not shown). The power rollers 7a and 7b themselves are disc-shaped and are configured to receive torque from the input disks 4a and 4b, rotate, and transmit the torque to the output disks 6a and 6b.

The toroidal transmission unit 1a and the toroidal transmission unit 1b are arranged on the input shaft 2 and have the output disks 6a and 6b.
They are arranged so that they face each other. Output disc 6
a and the output disc 6b are the front wheel output shaft 10a and the rear wheel output shaft 10 via the output gears 3a and 3b and the gears 9a and 9b.
output shafts 10a, 10b, which are independently fixed to b.
Rotate independently of each other. The output gears 3a and 3b are supported by the case 5 via angular bearings 8a and 8b, respectively. The angular bearings 8a and 8b can receive the thrust load and the radial load applied to the output gears 3a and 3b, and the snap ring 13 is interposed therebetween. At both ends of the input shaft 2, flange portions 11a, 1
1b are formed respectively. Flange 11a, 1
Between the 1b and the input disks 4a, 4b, loading cams 16a, 16b as pressing means are provided, respectively.

In this toroidal type continuously variable transmission, the thrust bearing 20 is arranged especially between the facing surfaces of the output gears 3a and 3b in the above structure. The thrust bearing 20 abuts against the end faces of the output gears 3a and 3b and rotates independently with the output gears 3a and 3b, and the bearing rings 18a and 18b, and the bearing rings 18a and 18b.
It is composed of rolling elements 17 such as rollers and balls that roll between b and b. The thrust bearing 20 includes the toroidal transmission unit 1.
The thrust loads generated in the output gears 3a and 3b can be received corresponding to the powers shared by a and 1b, respectively. Therefore, the thrust loads applied to the thrust bearing 20 from the output gears 3a and 3b cancel each other out, and the thrust loads applied to the angular bearings 8a and 8b are only the difference between the thrust loads applied to the output gears 3a and 3b, respectively. The thrust load carried by the angular bearings 8a, 8b is greatly reduced.

The toroidal type continuously variable transmission is constructed as described above and operates as follows. When torque is input to the input shaft 2 as the engine is driven, the torque is applied to the flange portion 11 a formed at one end of the input shaft 2.
Is transmitted to the input disc 4a via the loading cam 16a and is transmitted to the input disc 4b via the flange portion 11b formed at the other end of the input shaft 2 and the loading cam 16b. And rotate independently of each other.

The torque input to the input disk 4a is
It is transmitted to the output disk 6a via a pair of power rollers 7a. On the other hand, the torque input to the input disk 4b is transmitted to the output disk 6b via the power roller 7b. At this time, the power rollers 7a and 7b have gear ratios corresponding to their tilt angles between the input disk 4a and the output disk 6a and between the input disk 4b and the output disk 6a.
It is obtained steplessly between b and b. Output disc 6
The torque transmitted to a and 6b is further transmitted to the output gears 3a and 3b.
It is transmitted to the front wheel output shaft 10a and the rear wheel output shaft 10b via b and the gears 9a and 9b, respectively.

At the time of gear shifting, the two sets of toroidal gear shifting sections 1a and 1b need independent sharing of power, but a thrust load generated according to the power to be carried is output from the output disks 6a and 6b. It acts on 3a and 3b. These thrust loads are received by the thrust bearing 20 and the angular bearings 8a and 8b. At this time, the thrust load applied to the thrust bearing 20 is offset by the thrust bearing 20 by the same thrust load because the bearing ring 18a and the bearing ring 18b face each other and the rolling elements 17 are interposed therebetween. Therefore, the thrust load La generated in the toroidal transmission unit 1a
And the thrust load Lb generated in the toroidal transmission unit 1b
Only the difference ΔL (= La−Lb) from the angular bearing 8
a, 8b will be loaded. Therefore, the thrust load ΔL applied to the angular bearings 8a, 8b is significantly reduced, and not only the durability of the angular bearings 8a, 8b but also the snap ring arranged between the angular bearings 8a, 8b. No damage such as breakage occurs in 13, and in particular, because the relative rotational difference between the output gear 3a and the output gear 3b that transmits power to the front wheel output shaft 10a and the rear wheel output shaft 10b is very small, it is caused by the thrust load. The power loss is very small and the heat generation of the toroidal transmission can be reduced.
Fuel efficiency can be improved.

[0023]

Since the toroidal type continuously variable transmission according to the present invention is configured as described above, it has the following effects. That is, according to this toroidal type continuously variable transmission, thrust bearings are arranged between the output gears fixed to the output disks of the two sets of toroidal transmissions, and the thrust load received by the output disks is absorbed only by the angular bearings. Instead, the thrust bearings are loaded, and the thrust loads applied to the output gears facing each other by the thrust bearings are offset to each other, and only the difference in the thrust loads applied to the output disks is loaded to the angular bearings. It is possible to reduce the load on the vehicle, reduce power loss and heat generation, and improve fuel efficiency.

Therefore, this toroidal type continuously variable transmission is
The power loss that would occur with the angular bearing of a conventional toroidal type continuously variable transmission is significantly reduced, and the power loss in the thrust bearing is also extremely small, so the transmission efficiency of the toroidal type continuously variable transmission is greatly improved. Therefore, it is possible to provide a toroidal type continuously variable transmission that is capable of improving power performance and operating fuel efficiency, can reduce the amount of heat generated in the toroidal transmission unit, and is durable and has a long life.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a toroidal type continuously variable transmission according to the present invention.

FIG. 2 is a sectional view showing an example of a conventional toroidal type continuously variable transmission.

[Explanation of symbols]

 1a, 1b Toroidal speed changer 2 Input shaft 3a, 3b Output gear 4a, 4b Input disk 5 Case 6a, 6b Output disk 7a, 7b Power roller 8a, 8b Angular bearing 10a, 10b Output shaft 17 Rolling element 18a, 18b Bearing ring 20 Thrust bearing

Claims (3)

[Claims] 1. An input shaft penetrating a casing, a pair of input disks rotatably supported with respect to the input shaft, arranged to face each of the input disks and rotatable with respect to the input shaft. A pair of supported output discs, a tiltable power roller disposed between a pair of opposed input discs and the output discs and independently transmitting power from the input discs to the output discs, A pair of opposed output gears that are fixed to the output disks and independently extract power, a pair of angular bearings that respectively support the output gears in a case, output shafts that are transmission-coupled to the output gears, and the output Thrust which is arranged between the facing surfaces of the gears and which is generated in each of the output gears in response to the power shared by the toroidal transmission unit. Thrust bearing,
A toroidal-type continuously variable transmission characterized by comprising. 2. One of the output shafts is a front wheel output shaft,
The toroidal type continuously variable transmission according to claim 1, wherein the other output shaft is a rear wheel output shaft. 3. The toroidal according to claim 1, wherein the thrust loads applied to the thrust bearings cancel each other out, and the thrust loads applied to the angular bearings include only the difference between the thrust loads applied to the output gears. Type continuously variable transmission.