JP2836305B2 - Friction wheel type continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction wheel type continuously variable transmission.

[0002]

2. Description of the Related Art A conventional friction wheel type continuously variable transmission is disclosed in Japanese Patent Application Laid-Open No. 62-297564. The friction wheel type continuously variable transmission shown here has a four-shaft configuration, a starting device on a first central axis, a continuously variable transmission mechanism on a second central axis, a reduction gear on a third central axis, Differential devices are respectively disposed on the fourth central axis, and a forward / reverse switching mechanism and an overdrive gear mechanism are provided between the first central axis and the third central axis. The input shaft rotation of the first central axis is transmitted by the toroidal drive gear to the toroidal input gear on the second central axis that meshes therewith. The toroidal input gear is formed integrally with the input side of the loading cam. The continuously variable transmission mechanism has an input disk, an output disk, and a pair of friction rollers (power rollers) arranged to make frictional contact with both disks, and is opposite to a friction roller contact surface of the input disk. The loading cam is arranged on the back side of the camera. The rotation of the toroidal input gear is directly input to the loading cam and transmitted to the input disk.

[0003]

However, in the above-described conventional friction wheel type continuously variable transmission, the structure is only shown as a skeleton diagram, and the support structure of the toroidal input gear is not clear. The loading cam and the continuously variable transmission mechanism that are formed integrally with the input gear
If an axial thrust other than that of the loading cam mechanism is applied, the input / output disk will change position,
In this case, it becomes an obstacle in performing accurate shift control. In other words, when the toroidal input gear is pushed by some axial force and the loading cam mechanism is pushed, the contact pressure of the friction roller changes from an appropriate value, which may adversely affect the speed ratio control accuracy. Come. An object of the present invention is to solve such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention comprises a friction roller arranged in frictional contact with both disks in an input disk, an output disk, and a toroidal groove formed by the disks. A loading cam mechanism that applies a pressing force according to the input torque between the two disks that is configured to be movable in the axial direction in the sandwiching direction,
, A second shaft input gear is provided on a second central axis where the continuously variable transmission mechanism is disposed, and the second shaft input gear is provided with a second central axis. The first shaft output gear and the second shaft input gear are meshed with a first shaft output gear provided on a first center axis parallel to the second shaft, and the second shaft is formed by a helical gear. The input gear is axially and radially supported by a casing via a bearing, and the second shaft input gear and the loading cam mechanism are coupled to each other so as to transmit a rotational force or move relatively in the axial direction. Further, the loading cam mechanism is characterized in that the input disk is supported via a bearing so as not to move to the second shaft input gear side.

[0005]

The second shaft input gear is supported on the casing in the axial and radial directions via bearings, so that the loading cam coupled with the second shaft input gear can be rotated without applying an axial force. Only force can be transmitted. Thereby, the movement of the continuously variable transmission mechanism in the axial direction can be prevented.

[0006]

FIG. 1 shows a frame diagram of a friction wheel type continuously variable transmission.
Torque converter 12 to which engine torque is input
Has a pump impeller 12a, a turbine runner 12b, a stator 12c, and a lock-up clutch 12d. The turbine shaft 10 that rotates integrally with the turbine runner 12b is connected to a forward / reverse switching mechanism 14. The turbine shaft 10 is disposed around a first center axis 11 that is concentric with the crankshaft of the engine. The forward / reverse switching mechanism 14 includes a planetary gear mechanism 16, a forward clutch 3
2 and a reverse brake 34. The planetary gear mechanism 16 includes a sun gear 22, a pinion carrier 28 having two pinion gears 24 and 26, and an internal gear 30. Pinion gears 24 and 26 of the same diameter are engaged with each other, and
Meshes with the internal gear 30, and the pinion gear 26 meshes with the sun gear 22. Sun gear 22
Are always connected so as to rotate integrally with the turbine shaft 10. The pinion carrier 28 can be connected to the turbine shaft 10 by a forward clutch 32. The internal gear 30 can be fixed to a casing 36 by a reverse brake 34. The second center axis 4 is connected to the first shaft output gear 38 connected to the pinion carrier 28.
Power is transmitted to the first side. The first center axis 11 has a torque converter 1 from the right in the figure (from the engine arrangement side).
2, the first shaft output gear 38, the planetary gear mechanism 16, the forward clutch 32, and the reverse brake 34 are arranged in this order. The first shaft output gear 38 meshes with a second shaft input gear 42 that is coupled to one end of an input shaft 40 disposed about a second central axis 41 so as to rotate integrally therewith. First shaft output gear 38 and second shaft input gear 4
2 is constituted by a gear. On the second central axis 41, a cam flange 62, a cam roller 64, a first continuously variable transmission mechanism 44, and a second continuously variable transmission mechanism 46, which will be described later, are arranged adjacent to the second shaft input gear 42 in parallel. I have. The first continuously variable transmission mechanism 44 and the second continuously variable transmission mechanism 46 are connected by an output shaft 71 that rotates integrally therewith. A second shaft output gear 72 connected to the output shaft 71 so as to rotate integrally therewith is disposed between the first continuously variable transmission mechanism 44 and the second continuously variable transmission mechanism 46. The second shaft output gear 72 meshes with a third shaft input gear 76 that is integrally and rotatably coupled to one end of an idler shaft 74 disposed parallel to the input shaft 40. Third central axis 7
At the other end of the idler shaft 74 arranged around the center 5,
A third shaft output gear 78 that rotates integrally therewith is provided. The third shaft output gear 78, which is a final drive pinion, meshes with a fourth shaft input gear 82, which is a final gear provided on a fourth central axis 80. A differential gear 84 is provided integrally with the fourth shaft input gear 82, and power is transmitted to wheels (not shown) via the differential gear 84.

FIG. 2 shows a specific structure of the member on the second central axis. The second shaft input gear 42 is axially and radially supported by the casing 36 via a ball bearing 90.
The inner race of the ball bearing 90 is fixed by a nut 94, and the outer race is fixed to the casing 36 by a plate 96 and a bolt 98. The end of the input shaft 40 on the torque converter 12 side is supported by the second shaft input gear 42 via the needle bearing 100, and the other end is supported by the side cover 104 via the roller bearing 102. The side cover 104 is, as shown in FIG.
Covers the entire left opening. On the second central axis 41, the first continuously variable transmission mechanism 44 and the second continuously variable transmission mechanism 46 are arranged in parallel as described above. First continuously variable transmission mechanism 4
4 is a first input disk 48 and a first output disk 50
And a pair of first friction rollers 5 for transmitting a rotational force between the two.
And 2. The contact surfaces of the first input disk 48 and the first output disk 50 with the first friction roller 52 are toroid surfaces. By changing the contact state of the first friction roller 52 with the first input disk 48 and the first output disk 50, the rotation speed ratio between the first input disk 48 and the first output disk 50 can be continuously changed. The second continuously variable transmission mechanism 46 has a second input disk 54 and a second output disk 5 similar to the first continuously variable transmission mechanism 44.
6 and a pair of second friction rollers 58. However, the arrangement of the second input disk 54 and the second output disk 56 is opposite to that of the first continuously variable transmission mechanism 44. That is, the first output disk 50 and the second output disk 56 are arranged so as to be adjacent to each other. First input disk 4
8 is supported on the outer periphery of the input shaft 40 via a ball spline 60. A cam flange 62 is arranged on the back side of the first input disk 48. The cam flange 62 is axially supported on the input shaft 40 by a thrust bearing 99. Cam flange 62 and first input disk 48
The cam rollers 64 are provided on the cam surfaces facing each other. The cam surface and the cam roller 64 are connected to the first input disk 4.
8 and the cam flange 62 are shaped so as to generate a force for pressing the first input disk 48 toward the first output disk 50 when the cam flange 62 and the cam flange 62 rotate relatively. Cam flange 62, first
The input cam 48 and the cam roller 64 constitute a loading cam mechanism 66. The second input disk 54 of the second continuously variable transmission mechanism 46 is also connected to the input shaft 40 via a ball spline 68. The second input disk 54 is a loading nut 2 screwed into the input shaft 40.
06 receives a force directed toward the second output disk 56 by a disc spring 70 receiving a compressive force. Loading nut 2
06 and the disc spring 70 constitute a pressing force preload mechanism. Second
The shaft input gear 42 is disposed adjacent to the cam flange 62 as described above. A meshing tooth 106 is formed on the side of the second shaft input gear 42 facing the cam flange 62, while a meshing tooth 108 is formed on the cam flange 62 on the side facing the second shaft input gear. Meshing teeth 10
Nos. 6 and 108 are formed by alternately forming peaks and valleys in the radial direction, and can engage with each other to transmit a rotational force. However, no axial force is generated by the engagement of the engagement teeth 106 and 108. A rotation transmitting mechanism 200 for transmitting the rotational force of the second shaft input gear 42 to the cam flange 62 is formed by the meshing teeth 106 and 108. The first output disk 50 of the first continuously variable transmission mechanism 44 and the second output disk 5 of the second continuously variable transmission mechanism 46
6 is an output shaft 71 rotatably supported on the input shaft 40
It is provided so that it may rotate integrally. A second shaft output gear 72 is provided between the first output disk 50 and the second output disk 56 so as to rotate integrally with the output shaft 71. The second shaft output gear 72 is mounted on the angular bearing 20.
2 and rotatably supported by the casing 36 via the gear housing 204.

Next, the operation will be described. The torque of the engine is input to the torque converter 12 and output from the turbine runner 12b to the turbine shaft 10. A sun gear 22 that rotates integrally with the turbine shaft 10 is connected to the turbine shaft 10, and the power of the turbine shaft 10 is transmitted to the sun gear 22. During forward movement, the pinion carrier 28 is connected to the turbine shaft 10 by the forward clutch 32,
The power of the turbine shaft 10 is transmitted directly to the pinion carrier 28. The rotation of the pinion carrier 28 is in the same direction as the rotation of the engine, and this rotation is transmitted to the first shaft output gear 38. In reverse, the internal gear 30 of the planetary gear mechanism 16 is fixed to the casing 36 by the reverse brake 34. Thus, the rotation of the pinion carrier 28 is in the opposite direction to the rotation of the engine, and this rotation is transmitted to the first output gear 38. The rotation of the first shaft output gear 38 meshes with the rotation of the second shaft input gear 4.
It is conveyed to 2. The rotation of the second shaft input gear 42 is transmitted to the cam flange 62 by the rotation transmission mechanism 200.
When rotation is input to the cam flange 62, a force for pressing the first input disk 48 in the direction of the first output disk 50 is generated by the loading cam mechanism 66. Input shaft 40
Via the second input disk 54 and the second output disk 5
The pressing force acts between 6. The output of the first continuously variable transmission mechanism 44 and the second continuously variable transmission mechanism 46 is output to the second
It is transmitted to the shaft output gear 72. Second shaft output gear 72
Is transmitted to the idler shaft 74 by a third shaft input gear 76 meshing therewith. The rotation of the idler shaft 74 is transmitted by the third shaft output gear 78 to the fourth shaft input gear 82 meshing therewith. The rotation of the fourth shaft input gear 82 is transmitted to the wheels via a differential device 84 integrated therewith.

At the time of power transmission as described above, an axial force acts on the second shaft input gear 42 which is a helical gear.
This axial force is supported by ball bearings 90. Therefore, no axial force acts on the cam flange 62 from the second shaft input gear 42. On the other hand, the cam flange 62
, A reaction force from the cam roller 64 acts on the second shaft input gear 4 from the cam flange 62 because the reaction force is supported by the input shaft 40 via the thrust bearing 99.
No axial force acts on 2. Therefore, an axial force other than that of the loading cam mechanism does not act on the continuously variable transmission mechanisms 44 and 46, and accurate shift control can be performed.

Next, the operation of assembling the continuously variable transmission mechanism will be described. The second input disk 54 of the second continuously variable transmission mechanism 46
Is installed from the opposite side of the torque converter 12 or inserted from the space for the control valve arrangement opened on the upper surface. After assembling the second input disk 54, the ball spline 68, the disc spring 70, the loading nut 206
Insert and assemble in order. In order to insert each member as described above, the casing 36 to which the side cover 104 is attached
Is larger than the size in which the pressing force preload mechanism 208 can be inserted.

[0011]

As described above, according to the present invention, the second shaft input gear is supported on the casing via the bearings in the axial and radial directions through the bearing, so that the second cam is connected to the loading cam connected thereto. Only rotational force can be transmitted. This prevents an axial force other than that applied by the loading cam from acting on the input / output disk of the continuously variable transmission mechanism, and can always maintain the contact pressure of the friction roller appropriately. Further, by making the opening of the casing on the side of the second center axis where the second shaft input gear is not provided larger than the outer diameters of the loading nut and the disc spring, the assembling work thereof is facilitated. Can be.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a friction wheel type continuously variable transmission according to the present invention.

FIG. 2 is a diagram showing members on a second central axis in detail.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st shaft 12 Torque converter 14 Forward / reverse switching device 36 Casing 38 1st shaft output gear 41 2nd shaft 44 1st continuously variable transmission mechanism 42 2nd shaft input gear 46 2nd continuously variable transmission mechanism 48 1st input Disk 50 First output disk 52 First friction roller 54 Second input disk 56 Second output disk 58 Second friction roller 66 Loading cam 75 Third shaft 76 Third shaft input gear 80 Fourth shaft 84 Differential gear 90 Ball Bearing (Bearing) 208 Pressing force preload mechanism

Claims (2)

(57) [Claims] 1. A input disk, an output disk, and a friction roller which is positioned in frictional contact with the discs in a toroidal shape only within each formed by two discs, friction
It is configured to be axially movable in the direction to sandwich the rubbing roller.
And a loading cam mechanism for applying a pressing force between the two disks in accordance with the input torque, wherein the second shaft is disposed on a second central axis on which the continuously variable transmission mechanism is disposed. An input gear is provided, and the second shaft input gear meshes with a first shaft output gear provided on a first center axis parallel to the second center axis, and the first shaft output gear and The second shaft input gear is constituted by a helical gear,
The shaft input gear is axially and radially supported by a casing via a bearing, and the second shaft input gear and the loading cam mechanism are coupled to each other so as to transmit rotational force but relatively move in the axial direction. And the loading cam mechanism is
The bearing so that the disc does not move to the second shaft input gear side.
A friction wheel-type continuously variable transmission characterized by being supported via a friction wheel. 2. An end of the second center axis opposite to the side on which the second shaft input gear is disposed is covered by a side cover fixed to an opening of a casing. The second to receive the reaction force of the loading cam mechanism
Loadin that presses this from outside the output disk of the shaft
The friction wheel type continuously variable transmission according to claim 1, which has a size that allows passage of a gnut and a disc spring .