JPH0587704B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a toroidal continuously variable transmission, particularly a toroidal continuously variable transmission with a direct coupling device that can perform direct drive without going through a toroidal transmission section during forward movement. It's about machines.

Conventional technology and its problems Conventionally, multiple power rollers are arranged between input and output disks that are arranged facing each other on the same axis, and the toroidal type continuously variable speed is achieved by changing the inclination of the power rollers. A machine is shown in, for example, Japanese Patent Publication No. 47-1242.

By the way, in the case of a toroidal type continuously variable transmission, the power transmission efficiency of the toroidal transmission part is low, so when driving at high speeds, which are the most frequently used and do not require much shifting, the power transmission is transmitted through a direct coupling mechanism such as gears without going through the toroidal transmission part. In terms of fuel efficiency, it is preferable to transmit power by However, in the case of the above publication, since the engine power is input from one end of the transmission and output from the other end, it is difficult to provide a direct coupling mechanism, and even if a direct coupling mechanism could be provided, it would be difficult to provide a direct coupling mechanism. However, the axial dimension is unnecessarily large, making it difficult to install in front-wheel drive vehicles.

OBJECT OF THE INVENTION The present invention has been made in view of these conventional problems, and its purpose is to provide a toroidal continuously variable transmission that can configure a direct drive path with a compact configuration and is particularly suitable for front-wheel drive vehicles. There is a particular thing.

Structure of the Invention In order to achieve the above object, the present invention includes an input shaft and an output shaft arranged in parallel, an input/output disk arranged facing each other on the input shaft, and a plurality of power rollers arranged between the two disks. a toroidal transmission section consisting of a toroidal transmission section, a drive gear supported on an input shaft or an output disk, a starting clutch that connects and connects the drive gear with respect to the output disk, and a counter shaft that transmits power from the drive gear to the output shaft; A loading cam device that is installed behind the input disk and adds thrust to the input disk according to the input torque of the input shaft, a direct drive gear that is installed behind the input disk and connected to the input shaft, and an output shaft. It is equipped with a direct-coupled driven gear that is supported on the top and meshes with the direct-coupled drive gear, and a direct-coupling clutch that connects and disconnects the direct-coupled driven gear with respect to the output shaft.

DESCRIPTION OF THE EMBODIMENTS The drawing shows an example of a toroidal continuously variable transmission suitable for a front-wheel drive vehicle, which roughly includes an input shaft 10, a toroidal transmission section 20, a starting clutch 30, and an output shaft 4.
0, a forward/reverse switching mechanism 41, a differential device 50, and a direct coupling clutch 60, and these components are covered by casings 1, 2, and 3.

A crankshaft 4 of the engine is connected to an input shaft 10 via a flywheel 5 and a torsional damper 6 for absorbing engine torque fluctuations. The boss portion 6a of the torsional damper 6 is a gear type oil pump 7 for circulating mineral oil.
The oil pump 7 is spline-coupled to drive the oil pump 7. There are two bearings 1 on the left side of the oil pump 7.
1 and 12 are arranged adjacent to each other, the bearing 11 supports the thrust load acting on the input shaft 10 in the left direction in the figure, and the bearing 12 supports the thrust load in the right direction in the figure acting on the output disk 22 of the toroidal transmission section 20, which will be described later. Supports thrust loads.

The toroidal transmission section 20 includes an input disk 21 and an output disk 22 that are rotatably arranged on the input shaft 10, and two power rollers that are arranged between the opposing annular surfaces 21a and 22a of both the disks 21 and 22. By changing the inclination of the power roller 23, the points of contact with the annular surfaces 21a and 22a are changed, and power is transmitted from the input disk 21 to the output disk 22 at a variable speed. In addition, in the figure, the upper half from the input shaft 10 shows a low speed ratio state, and the lower half shows a high speed ratio state. A loading cam device 24 is provided behind the input disk 21 to apply a thrust force (thrust load) to the input disk 21 according to the input torque of the input shaft 10 . This loading cam device 24 is
Cam surface 21 formed on the back surface of input disk 21
b, a cam surface 25a formed on the side surface of the cam disk 25 spline-coupled to the input shaft 10;
It is composed of a cam roller 26 that is rotatably arranged between both cam surfaces 21b and 25a, and as the input torque increases, the power roller 23 and the annular surface 21a,
The contact pressure between 22a is increased, and power transmission without slipping is performed. A direct drive gear 25b is integrally formed on the outer periphery of the cam disc 25,
Further, a gear type oil pump 27 for circulating traction oil is provided at the left end of the input shaft 10.

A wet starting clutch 30 is disposed between the toroidal transmission section 20 and the bearings 11, 12, and a clutch drum 31 of the starting clutch 30 is connected to the output disk 22 by splines. A clutch hub 33, which is connected to and connected to the clutch drum 31 through a clutch plate 32, is connected to a drive gear 34 rotatably disposed on the output disk 22.

A counter shaft 35 arranged parallel to the input shaft 10
, a driven gear 36 that meshes with the drive gear 34 is provided.
are connected by splines. Further, the counter shaft 35 is provided with a forward drive gear 37 and a reverse drive gear 3.
8 are integrally formed.

The output shaft 40 is also arranged parallel to the input shaft 10, and the output shaft 40 is provided with a forward/reverse switching mechanism 41. The forward/reverse switching mechanism 41 includes a forward driven gear 42 that meshes with the forward drive gear 37.
, a reverse driven gear 43 that meshes with the reverse drive gear 38 via an idler gear (not shown), a spline hub 44, and a switching sleeve 45, and by sliding the switching sleeve 45 in the axial direction. Performs forward/reverse switching. An output gear 46 is integrally formed at the right end of the output shaft 40, and this output gear 46 meshes with a ring gear 51 of a differential device 50 to transmit power to an axle 52.

The left end portion of the output shaft 40 is extended to the left by approximately the same length as the input shaft 10, and a direct coupling clutch 60 is disposed in this extended portion at a position corresponding to the input disk 21. A clutch drum 61 of the direct coupling clutch 60 is spline connected to the output shaft 40, and a clutch hub 63, which is connected to the clutch drum 61 via a clutch plate 62, is coupled to a direct coupled driven gear 64. The directly coupled driven gear 64 is rotatable with respect to the output shaft 40 and meshes with the directly coupled drive gear 25b integrally formed with the cam disk 25. Note that although the drawing is a developed cross-sectional view, both gears 25b and 64 are separated, but they actually mesh. Furthermore, the power roller 23 of the toroidal transmission section 20 is actually close to the output shaft 40 as shown by the two-dot chain line in the figure, but the direct coupling clutch 60 corresponds to the input disk 21 of the toroidal transmission section 20. Since the power roller 23 and the direct coupling clutch 60 are arranged in such a position that there is no possibility that the power roller 23 and the direct coupling clutch 60 will interfere with each other.

The toroidal transmission section 20 and the direct coupling clutch 6
0, the bearings 11 and 12, the forward/reverse switching mechanism 41, and the differential device 50.
A chamber 71 containing a gear mechanism such as the above is separated by a partition wall 2a provided in the casing 2,
Both chambers 7 are sealed by oil seals 72, 73, 74.
Oil leakage between 0 and 71 is prevented. The bearings 11 and 12 and the gear mechanism are the oil pump 7.
The toroidal transmission section 20 and the direct coupling clutch 60 are lubricated with the traction oil discharged by the oil pump 27. In other words, for the bearings 11 and 12 and the gear mechanism where friction loss is to be reduced as much as possible, gear oil with excellent lubricity or mineral oil such as ATF is used, and for the toroidal transmission section 20 that performs traction drive, traction oil with a high traction coefficient is used. oil is used. Therefore, the power loss of the bearings 11, 12 and the gear mechanism can be reduced, and the power transmission efficiency of the toroidal transmission section 20 is not reduced in any way.

The operation of the toroidal continuously variable transmission having the above configuration will be explained. First, when starting, the direct coupling clutch 60 is disconnected, and the starting clutch 30 is gradually engaged to start the vehicle. As a result, the power of the input shaft 10 is transmitted from the toroidal transmission unit 20, starting clutch 30, drive gear 34, counter shaft 35, forward/reverse switching mechanism 41, and output gear 46 to the differential device 50, and the toroidal transmission In the section 20, power is transmitted while being continuously variable. When the gear ratio of the toroidal transmission section 20 reaches or near the maximum speed ratio, the starting clutch 30 is disconnected and the direct coupling clutch 60 is disconnected.
are coupled, and the power of the input shaft 10 is transmitted to the cam disc 25, the direct-coupled driven gear 64, the direct-coupling clutch 60, and the output gear 4 without passing through the toroidal transmission section 20.
6 to the differential device 50, and the power is transmitted at a constant transmission ratio. During this direct drive, the power is transmitted efficiently without passing through the toroidal transmission section 20.

In general, the power transmission efficiency of toroidal continuously variable transmissions is lower than that of other continuously variable transmissions (e.g. V-belt continuously variable transmissions), and is usually estimated to be around 80-85%. According to experiments conducted by the present inventors, by using mineral oil with excellent lubricity, which is different from traction oil, for the bearings 11, 12 and the gear mechanism, an efficiency improvement of 5% or more could be achieved. Further, by transmitting power through the direct gears 25b and 64 during high-speed ratio running, it was possible to further improve efficiency by about 5%. As a result, it is possible to achieve power transmission efficiency that is comparable to other continuously variable transmissions, and the toroidal type continuously variable transmission has a shorter distance between the input and output shafts than V-belt type continuously variable transmissions. Since it can be shortened, a compact and highly practical continuously variable transmission can be realized.

Note that the present invention is not limited to the structure of the embodiment, and for example, the input disk 21 may be arranged closer to the engine than the output disk 22, and it is not necessary to provide the starting clutch 30 and the drive gear 34 on the output disk 22. However, if the output disk 22 is placed closer to the engine than the input disk 21 as in the embodiment and the starting clutch 30 and drive gear 34 are provided on the output disk 22, then the power transmission path from the output disk 22 to the output shaft 40 In addition, the bearings 11 and 12, which receive the thrust loads of the input/output disks 21 and 22, can be placed adjacent to each other in one place. The parts numbered 11 and 12 are connected to input shaft 1.
0 can be placed very efficiently.

Furthermore, in the above embodiment, the loading cam device 2
Since the direct drive gear 25b is integrally provided on the cam disk 25 of No. 4, and one drive gear 34 for speed change is provided on the input shaft 10, the input shaft 10
The upper gear arrangement space can be shortened, and the axial dimension of the entire transmission can be further shortened.

Effects of the Invention As is clear from the above explanation, according to the present invention, the input disk and the output disk of the toroidal transmission section have a property of rotating in opposite directions, so if the output disk is connected to the output shaft via the counter shaft, , the output shaft rotates in the opposite direction to the input shaft during forward movement.
Therefore, by meshing the direct-coupled driving gear provided on the input shaft with the direct-coupled driven gear provided on the output shaft, a direct-coupled device can be easily configured, and power can be transmitted through this direct-coupled device during high-speed forward travel. This can significantly improve efficiency.

In addition, a starting clutch and a drive gear are provided behind the output disk, a direct drive gear is provided behind the input disk, and the speed change drive path and the direct drive path are arranged in parallel with the toroidal transmission section in between.
The speed change drive path and the direct connection drive path are not intertwined, and the speed change drive path and the direct connection drive path can be arranged compactly in a limited space.

Furthermore, since the starting clutch is provided in the middle of the power transmission path from the output disk to the output shaft, that is, downstream of the toroidal transmission section, it can be used as a power intermittent clutch during direct drive and forward/reverse switching. Even if the gear ratio has not returned to the lowest gear ratio when the vehicle is stopped, the toroidal gearbox is constantly idling due to the engine power, so it can be easily returned to the lower gear ratio, eliminating the situation where the vehicle cannot restart.

[Brief explanation of the drawing]

The drawing is a developed sectional view of an example of a toroidal continuously variable transmission according to the present invention. 10...Input shaft, 20...Troidal transmission section,
21...Input disk, 22...Output disk,
23...Power roller, 24...Loading cam device, 25b...Direct drive gear, 30...Start clutch, 34...Drive gear, 35...Counter shaft, 40...Output shaft, 41...Forward and backward movement switching mechanism,
50... Differential device, 60... Direct connection clutch, 64... Direct connection driven gear.

Claims (1)

[Claims] 1. An input shaft and an output shaft arranged in parallel, an input/output disk arranged facing each other on the input shaft, and a toroidal transmission section consisting of a plurality of power rollers arranged between the two disks, and an input shaft or an output disk arranged on the input shaft or the output disk. a supported drive gear; a starting clutch that connects and connects the drive gear to the output disk; a counter shaft that transmits power from the drive gear to the output shaft; a loading cam device that applies a corresponding thrust to the input disk; a direct drive gear provided behind the input disk and coupled to the input shaft; and a direct drive gear supported on the output shaft and meshed with the direct drive gear. , a toroidal continuously variable transmission characterized by comprising a directly coupled clutch that connects and connects a directly coupled driven gear to and from an output shaft.