JP2001165264A - Toroidal type continuously variable transmission - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To realize a structure which can regulate the contact pressure of a traction portion to an optimum value, and can easily assemble and secure a yield. SOLUTION: By a hydraulic loading device 47,
Inner surface 2a, 4a of each disk 34, 35, 37, 38
And a traction portion, which is a contact portion between the power rollers 36 and 39 and the peripheral surfaces 9a and 9a, is secured. The loading device 47, together with the second input side disk 37,
A loading disk unit 48 is assembled around the inner diameter side cylinder cylinder 49. Then, the loading disc unit 48 is connected to the rear half 11 b of the input shaft 11.
To the rear end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the structure of a toroidal-type continuously variable transmission used as a transmission unit of an automatic transmission for an automobile, and realizes a structure that facilitates assembly work.

[0002]

2. Description of the Related Art The use of a toroidal type continuously variable transmission as schematically shown in FIGS. This toroidal type continuously variable transmission supports an input disk 2 concentrically with an input shaft 1 as disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 62-71465.
An output disk 4 is attached to the end of the output shaft 3 concentrically
Is fixed. Inside a casing 5 containing a toroidal-type continuously variable transmission (see FIG. 8 to be described later), a trunnion 7 swinging about pivots 6, 6 which are twisted with respect to the input shaft 1 and the output shaft 3. , 7 are provided.

Each of the trunnions 7, 7 is provided with a pair of pivots 6, 6 on the outer surfaces of both ends thereof, concentric with each other and with each of the trunnions 7, 7.
The central axis of each of these pivots 6, 6 is
Does not intersect with the center axis of each of these discs 2,
4 lies in a torsional position that is substantially perpendicular to the direction of the central axis. The trunnions 7, 7 support the base half of the displacement shafts 8, 8 at the center thereof, and swing the trunnions 7, 7 about the pivots 6, 6 to thereby displace the displacement shafts 8, 7. , 8 can be freely adjusted. Power rollers 9, 9 are rotatably supported around the first half of the displacement shafts 8, 8 supported by the trunnions 7, 7, respectively. The power rollers 9, 9 are sandwiched between the inner surfaces 2a, 4a of the input and output disks 2, 4, respectively.

The inner surfaces 2a and 4a of the input and output disks 2 and 4 facing each other are obtained by rotating a circular arc centered on the pivot 6 or a curve close to such circular arc. It has an arc-shaped concave surface. Then, the peripheral surfaces 9a, 9a of the power rollers 9, 9 formed on the spherical convex surfaces are brought into contact with the inner side surfaces 2a, 4a. In addition, a loading cam device 10 is provided between the input shaft 1 and the input disk 2, and the loading cam device 10 is used to load the input disk 2.
, While being elastically pressed toward the output-side disk 4, can be rotationally driven.

When the toroidal-type continuously variable transmission configured as described above is used, the loading cam device 10 causes the input side disk 2 to move to the plurality of power rollers 9 with the rotation of the input shaft 1. Rotate while pressing. And
The rotation of the input disk 2 is transmitted to the output disk 4 via the plurality of power rollers 9, and the output shaft 3 fixed to the output disk 4 rotates.

When the rotational speed between the input shaft 1 and the output shaft 3 is changed, and when deceleration is first performed between the input shaft 1 and the output shaft 3, each of the trunnions 7, 7 to oscillate, and the peripheral surface 9a of each power roller 9, 9;
9a is an inner side surface 2a of the input side disk 2 as shown in FIG.
And the displacement shafts 8 so as to abut against the portion near the center of the output disk 4 and the portion near the outer periphery of the inner surface 4a of the output side disk 4, respectively.
8 is tilted.

On the contrary, when increasing the speed, the trunnions 7, 7 are swung so that the peripheral surfaces 9a, 9a of the power rollers 9, 9, as shown in FIG. A portion of the inner surface 2a near the outer periphery and the inner surface 4 of the output disk 4
Each of the displacement shafts 8, 8 is inclined so as to abut on the portion near the center of a. If the inclination angle of each of the displacement shafts 8, 8 is set between those in FIGS. 5 and 6, an intermediate speed ratio can be obtained between the input shaft 1 and the output shaft 3.

FIGS. 7 and 8 show Japanese Utility Model Application No. 63-6929.
3 shows a more specific toroidal-type continuously variable transmission described in Microfilm No. 3 (Japanese Utility Model Laid-Open No. 1-173552). Input disk 2 and output disk 4
Are rotatably supported around the input shaft 11 having a tubular shape. Further, a loading cam device 10 is provided between the end of the input shaft 11 and the input side disk 2. On the other hand, the output side disk 4 has the output gear 1
2 so that the output disk 4 and the output gear 12 rotate synchronously.

Axles 6, 6 provided concentrically at both ends of a pair of trunnions 7, 7 are attached to a pair of support plates 13, 13, respectively.
Swing and axial direction (front and back in FIG. 7, left and right in FIG. 8)
It is supported so as to be freely displaceable. A base half of the displacement shafts 8, 8 is supported at an intermediate portion between the trunnions 7, 7. Each of these displacement shafts 8 and 8 makes the base half and the first half eccentric to each other. The base half of the trunnions 7 is rotatably supported in the middle of the trunnions 7, and the power rollers 9 are rotatably supported in the first half thereof.

The pair of displacement shafts 8, 8 are provided at positions opposite to the input shaft 11 by 180 degrees. or,
The directions in which the base half and the front half of each of the displacement shafts 8, 8 are eccentric are the same (the left and right opposite directions in FIG. 8) with respect to the rotation directions of the input side and output side disks 2, 4. .
Further, the eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 11 is provided. Accordingly, the power rollers 9 are supported so as to be slightly displaceable in the direction in which the input shaft 11 is provided.

A thrust ball bearing is provided between the outer surface of each of the power rollers 9 and 9 and the inner surface of the intermediate portion of each of the trunnions 7 and 7 in order from the outer surface of each of the power rollers 9 and 9. 14, 14 and thrust needle bearings 15, 1
5 are provided. Of these, thrust ball bearings 14, 1
4 allows the rotation of the power rollers 9 while supporting the load in the thrust direction applied to the power rollers 9. Further, each of the thrust needle bearings 15,
Reference numeral 15 denotes the first half of each of the displacement shafts 8 and 8 and the outer ring 16 while supporting the thrust load applied from the respective power rollers 9 and 9 to the outer rings 16 and 16 constituting the respective thrust ball bearings 14 and 14. , 16 are allowed to swing about the base half of each of the displacement shafts 8, 8. Further, each of the trunnions 7, 7 is provided with a hydraulic actuator 17, 1,
7, the pivots 6, 6 can be displaced in the axial direction.

In the case of the toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 11 is transmitted to the input disk 2 via the loading cam device 10. And
The rotation of the input disk 2 is transmitted to the output disk 4 via a pair of power rollers 9, 9, and the rotation of the output disk 4 is extracted from the output gear 12.

When changing the rotational speed ratio between the input shaft 11 and the output gear 12, the above-mentioned actuators 17, 1
7, the pair of trunnions 7, 7 are respectively arranged in opposite directions, for example, the lower power roller 9 of FIG. 8 is on the right side of the figure, the upper power roller 9 of FIG. Displace each. As a result, the direction of the tangential force acting on the contact portions between the peripheral surfaces 9a, 9a of the power rollers 9, 9 and the inner surfaces 2a, 4a of the input disk 2 and the output disk 4 changes. I do. Then, with the change in the direction of the force, the trunnions 7, 7 swing in opposite directions about the pivots 6, 6 pivotally supported by the support plates 13, 13, respectively. As a result, as shown in FIGS. 5 and 6 described above, the contact positions between the peripheral surfaces 9a and 9a of the power rollers 9 and the inner surfaces 2a and 4a change, and the input shaft 11 The rotation speed ratio with the output gear 12 changes.

During power transmission by the toroidal type continuously variable transmission, the power rollers 9 are displaced in the axial direction of the input shaft 11 based on the elastic deformation of the components. Then, the respective displacement shafts 8 supporting the respective power rollers 9 slightly rotate about the respective base halves. As a result of this rotation, each of the thrust ball bearings 14, 1
4 and the outer surfaces of the outer races 16, 16 and the respective trunnions 7, 7
Relatively displaces with the inner surface. Since the thrust needle bearings 15, 15 exist between the outer surface and the inner surface, the force required for the relative displacement is small.

In the case of the toroidal type continuously variable transmission constructed and operated as described above, the input shaft 11 and the output gear 12 are used.
Is transmitted by two power rollers 9, 9. Therefore, the peripheral surface 9 of each power roller 9
a, 9a and the inner surface 2 of both the input and output disks 2, 4
a and 4a, the force per unit area transmitted becomes large, and the power that can be transmitted is limited. In view of such circumstances, it has been conventionally considered to increase the number of power rollers 9 in order to increase the power that can be transmitted by the toroidal-type continuously variable transmission.

As a first example of a structure for increasing the number of power rollers 9 for such a purpose, three power rollers 9 are provided between a pair of input side disks 2 and output side disks 4.
It is conventionally known to dispose a power supply 9 and transmit power by using these three power rollers 9 and 9 as described in, for example, Japanese Patent Application Laid-Open No. 3-74667. In the case of the structure described in this publication, as shown in FIG.
At three positions at equal intervals in the circumferential direction of the fixed frame 18,
Each pivotally supports an intermediate portion of the support pieces 19, 19 bent at 120 degrees. Then, the adjacent support pieces 19,
The trunnions 7, 7 are supported between each other 19 so as to swing and displace in the axial direction.

Each of the trunnions 7, 7 can be displaced in the axial direction of a pivot 6 provided concentrically at both ends thereof by hydraulic actuators 17, 17, respectively. The respective hydraulic cylinders 20, 20 constituting the respective actuators 17, 17 are controlled via a control valve 21.
It communicates with the discharge port of the pump 22, which is a hydraulic pressure source. The control valve 21 includes a sleeve 23 and a spool 24, each of which is displaceable in the axial direction (the left-right direction in FIG. 9).

When the inclination angle of the power rollers 9, 9 pivotally supported by the displacement shafts 8, 8 is changed to the respective trunnions 7, 7, the sleeve 23 is moved in the axial direction by the control motor 25 (FIG. 9). Left and right directions). As a result, the pressure oil discharged from the pump 22 is sent to each of the hydraulic cylinders 20, 20 through a hydraulic pipe. The drive pistons 26, 26 fitted to the hydraulic cylinders 20, 20 for displacing the trunnions 7, 7 in the axial direction of the pivot shaft are provided on the input side disk 2 and the output side disk 4 (see FIG. (See 5 to 7). In addition, each drive piston 2
With the displacement of the hydraulic cylinders 6, 26,
The hydraulic oil pushed out from the oil tank is returned to the oil reservoir 27 through a hydraulic pipe (not shown) also including the control valve 21.

On the other hand, the displacement of the drive piston 26 accompanying the feeding of the pressure oil is transmitted to the spool 24 via a cam 28 and a link 29, and displaces the spool 24 in the axial direction. As a result, with the drive piston 26 displaced by a predetermined amount, the flow path of the control valve 21 is closed, and the supply and discharge of pressure oil to and from the hydraulic cylinders 20 and 20 are stopped. Therefore, the amount of displacement of each of the trunnions 7, 7 in the axial direction only depends on the amount of displacement of the sleeve 23 by the control motor 25.

Japanese Unexamined Patent Publication No. 4-69439 discloses a second structure having a structure for increasing the number of power rollers 9 in order to increase the power that can be transmitted by a toroidal type continuously variable transmission.
As an example, a structure in which two pairs of an input side disk and an output side disk are provided is described. In the structure of the second example, as shown in FIG. 10, the input shaft 11 is provided inside the casing 5a.
Is freely rotatable only. This input shaft 11
A front half portion 11a coupled to an output shaft of the clutch and the like, and a rear half portion 1 capable of slightly rotating with respect to the front half portion 11a;
1b. The front half 11a functions as an output shaft of a starting clutch, such as a torque converter, provided at the front of the toroidal-type continuously variable transmission. The second half 1
1b functions as an input shaft of the toroidal type continuously variable transmission. A pair of input side disks 2 and 2 are provided at both ends in the axial direction (left and right direction in FIG. 10) of the rear half 11b.
Are supported via ball splines 30, 30 with the respective inner surfaces 2a, 2a facing each other.

At both ends of a sleeve 31 rotatably supported around an intermediate portion of the rear half 11b, a pair of output side disks 4, 4 are provided with inner side surfaces 4a, 4a and the input side disks 2, 4, respectively. 2 are supported in a state where the inner side surfaces 2a and 2a face each other. Also, a plurality of power rollers 9, 9 rotatably supported by a plurality of trunnions via a displacement shaft.
Is sandwiched between the inner surfaces 2a, 4a.
An output shaft 32 is provided inside the casing 5a on a side opposite to the front half 11a, and a rear half 1 of the input shaft 11 is provided.
It is rotatably supported concentrically with 1b and independently of the rear half 11b. The rotation of the two output-side disks 4 is freely transmitted to the output shaft 32.

[0022]

In the case of the conventional structure as described above, the inner surface 2 of each of the input side and output side disks 2 and 4 is used.
In order to secure the contact pressure of each traction portion, which is the contact portion between the power rollers 9 and 9 and the peripheral surfaces 9a and 9a of each of the power rollers 9 and 9a, a mechanical pressing is performed according to the torque applied to the input shaft 1. A loading cam device 10 that generates pressure was used.
Therefore, the contact pressure of each traction portion cannot be finely adjusted. On the other hand, in order to ensure both the transmission efficiency of the toroidal type continuously variable transmission and the durability of the components, it is necessary to take into account the driving conditions of the vehicle, such as the difference between acceleration and deceleration. It is preferable that the contact pressure of each traction portion can be finely adjusted. In order to make the contact pressure freely adjustable from such a viewpoint, a piston is fitted in a cylinder as a loading device for applying the contact pressure, and pressure oil is fed into the cylinder. Press the input disk toward the output disk,
It is conceivable to use a hydraulic type.

However, when incorporating a hydraulic loading device into a toroidal-type continuously variable transmission, it is necessary to take different considerations from the mechanical loading cam device 10. In order to generate a large thrust force, it is necessary to make a certain degree of fitting between a piston and a cylinder constituting a hydraulic loading device for feeding high-pressure oil into the cylinder. Therefore, the work of fitting the piston into the cylinder needs to be performed with a strong force using a light press or the like. It is difficult to perform such fitting work around the input shaft 11, and even if it can be performed, the work efficiency is poor, the assembly cost is increased, or other components are damaged, and the yield is deteriorated. There is a possibility. In view of such circumstances, the toroidal type continuously variable transmission of the present invention has been invented to improve the mass productivity of a toroidal type continuously variable transmission incorporating a hydraulic loading device.

[0024]

A toroidal-type continuously variable transmission according to the present invention is provided with an input shaft and a non-rotatable around the input shaft, similarly to the above-mentioned conventional toroidal-type continuously variable transmission. An input side disk whose one axial direction has an arc-shaped input side concave surface, and an output side concave surface whose one axial direction has an arc-shaped cross section, the output side concave surface and the input side concave surface facing each other. In the state, the output side disk which is rotatably supported with respect to the input shaft, and a portion between the output side disk and the input side disk, which exists at a position twisted with respect to the central axis of each of these disks, Four or more even number of pivots, a plurality of trunnions swinging about these respective pivots, displacement axes protruding from the inner surface of each of the trunnions, and rotatably supported around these respective displacement axes Enter the above in the state A plurality of power rollers sandwiched between the inner surface of the disk and the inner surface of the output disk, each of which has a spherical convex surface on its periphery, and a direction in which the input disk and the output disk are brought closer to each other. And a loading device that presses the sheet.

In particular, in the toroidal type continuously variable transmission according to the present invention, the loading device is constituted by fitting a piston into a cylinder, and by sending pressure oil into the cylinder, the loading device is connected to the input side disk. A hydraulic loading device for pressing any one of the output-side disks toward the other disk is provided. The loading device and one of the discs pressed by the loading device are combined in a non-separable unit, and the unit and the input shaft are formed separately and can be combined later. And

[0026]

According to the toroidal type continuously variable transmission of the present invention constructed as described above, it is possible to assemble the hydraulic loading device before assembling it with another member such as the input shaft. Assembly can be done easily and without damaging other parts.

[0027]

1 to 4 show an example of an embodiment of the present invention. In the example shown in the figure, the toroidal type continuously variable transmission 33 of the present invention is used as a transmission unit of an automatic transmission for a four-wheel drive vehicle incorporating an engine that generates a large torque for a passenger vehicle. Is shown. Therefore, three first power rollers 36, 36 are provided between the first input disk 34 and the first output disk 35 constituting the toroidal type continuously variable transmission 33.
To the second input disk 37 and the second output disk 38
And three second power rollers 39 are provided between them, and power is transmitted by a total of six power rollers 36 and 39.

The foremost part in the power transmission direction includes:
A torque converter 40, which is a starting clutch, is provided, and an output portion of the torque converter 40 incorporates a front half 11a of the input shaft 11 constituting the toroidal-type continuously variable transmission 33. The front half 11 a is rotationally driven by the torque converter 40 with the rotation of a traveling engine (not shown). The rear half 11b of the input shaft 11 is supported on the rear end of the front half 11a via a pair of radial needle bearings 41a and 41b so as to be concentric and relatively rotatable.

The first half 11a and the second half 11b
A forward / reverse switching unit 42 for switching between forward and backward is provided in series with respect to the power transmission direction. The forward / reverse switching unit 42, which is a planetary gear mechanism, includes a forward clutch 43 and a reverse clutch 44, each of which is a wet multi-plate clutch. Such a forward / reverse switching unit 42 connects the forward clutch 43 and disconnects the reverse clutch 44 during forward travel. In this state, the first half 11a and the second half 1
1b, and the latter half 11b rotates together with the first input disk 34 in the same direction and at the same speed as the former half 11a. On the other hand, at the time of reverse, the reverse clutch 44 is engaged, and the forward clutch 43 is disconnected. In this state, the latter half 11b is
It rotates in the opposite direction at a lower speed than a. Since the structure and operation of the forward / reverse switching unit using the planetary gear mechanism have been conventionally known and are not related to the gist of the present invention,
Detailed description is omitted.

With respect to the power transmission direction, an input portion connected to the output portion of the forward / reverse switching unit 42, a front wheel drive shaft 45 and a rear wheel drive shaft are provided behind the forward / reverse switching unit 42 as described above. The toroidal-type continuously variable transmission 33 is provided to continuously change the gear ratio between the output unit and the output unit connected to the toroidal transmission 46. The toroidal type continuously variable transmission 33 is provided around the rear half 11b. For this reason, the first and second input-side disks 34, 37 are opposed to each other in the vicinity of both front and rear ends of the rear half portion 11b, with the inner surfaces 2a, 2a each having a concave surface having an arc-shaped cross section facing each other. In this state, they are supported concentrically and rotatably in synchronization with each other. Among them, the first input side disk 34 provided on the front side (left side in FIG. 1) is connected to the rear half portion 11 via the carrier 71 constituting the forward / reverse switching unit 42.
The spline is engaged with the middle front portion of b.
On the other hand, the second input side disk 37 provided on the rear side (the right side in FIG. 1) is supported at the rear end of the rear half 11b via the ball spline 30. And, by the hydraulic loading device 47 which is the main point of the present invention,
The second input-side disc 37 faces the first input-side disc 34 and can be freely pressed.

In the case of the present invention, a loading disk unit 48 in which the second input side disk 37 and the loading device 47 are non-separably combined with each other is used. Such a loading disc unit 48
It is assembled around the inner cylinder cylinder 49. The inner diameter side cylinder cylinder 49 is formed in a two-stage cylindrical shape in which a small diameter portion 50 and a large diameter portion 51 are connected by a step portion 52. The ball spline 30 is provided between the outer peripheral surface of the small diameter portion 50 and the inner peripheral surface of the second input side disk 37. That is, the second input side disk 37 is supported around the small diameter portion 50 so as to be freely displaceable only in the axial direction.

On the other hand, the base end (the left end in FIG. 1) of the outer diameter cylinder cylinder 53 is fixedly connected to the outer peripheral edge of the outer surface of the second input disk 37. The inner peripheral surface of the outer diameter side cylinder cylinder 53 is provided with a small diameter portion 5 on the base half side (left side in FIG. 1).
4 and the large diameter portion 55 on the first half side (right side in FIG. 1)
To form a stepped cylindrical surface. And
The inner peripheral edge of the ring-shaped end plate 58 is locked to a flange 57 formed on the outer peripheral surface of the large diameter portion 51 on the inner diameter side cylinder cylinder 49 side. Oil tightness between the inner and outer peripheral edges of the end plate 58 and the peripheral surfaces of the large-diameter portions 51 and 55 is maintained by an O-ring. A first piston 59 is oil-tightly fitted between the peripheral surfaces of the two large-diameter portions 51 and 55 and closer to the second input disk 37 than the end plate 58. . Further, a second piston 60 is oil-tightly fitted between the small diameter portions 50 and 54. In the illustrated example, a short cylindrical portion formed on the inner peripheral edge of the second piston 60 is oil-tightly fitted on the inner peripheral surface of the second input-side disk 37.

Thus, in the case shown in the drawing, the loading device 47 causes the first and second pistons 59 and 60 to transmit a force in series with each other in the axial direction in order to generate a large pressing force with a small diameter. They are provided in parallel with each other in the direction. That is, when the pressing force is generated, the pressure oil is introduced into the pair of hydraulic chambers 61a and 61b. Then, the second input-side disk 37 is pressed toward the first input-side disk 34 via the outer-diameter-side cylinder cylinder 53 with the introduction of the hydraulic pressure to the one (rightward in FIG. 1) hydraulic chamber 61 a. Is done.
At the same time, the second input-side disc 37 is pressed directly against the first input-side disc 34 with the introduction of the hydraulic pressure into the other (leftward in FIG. 1) hydraulic chamber 61b. The force accompanying the introduction of the pressure oil into the two hydraulic chambers 61a and 61b is applied to the second input-side disk 37 in a state where they are added. Therefore, the loading device 47 generates a large pressing force with a small diameter. A preload spring 62 such as a disc spring is provided in the other hydraulic chamber 61b so that the two hydraulic chambers 61a and 61
1b, the surface pressure of the contact portion between the inner surfaces 2a, 4a of the discs 34, 35, 37, 38 and the peripheral surfaces 9a, 9a of the power rollers 36, 39 is maintained. , So that the minimum can be secured.

At the time of assembling the toroidal type continuously variable transmission, the loading disk unit 4 configured and operated as described above is used.
Numeral 8 is fixed to the rear end of the rear half 11b and is rotatable together with the rear half 11b. For this reason, in the illustrated example, the small diameter portion 50 of the inner diameter side cylinder cylinder 49 is spline-engaged with the rear end of the rear half portion 11b, and protrudes from the small diameter portion 50 at the rear end of the rear half portion 11b. A holding nut 63 is screwed into the portion. The coupling structure between the small diameter portion 50 and the rear half portion 11b is not limited to the illustrated example, but may be a combination of a spline engagement and a cotter, a combination of a screw engagement and a lock nut, and a combination of loosening prevention such as caulking,
Various structures conventionally used for coupling the rod-shaped member and the cylindrical member, such as a key engagement and a nut, can be adopted.

In any case, the loading disk unit 48 is assembled before being fixed to the rear end of the rear half 11b, and its function is confirmed. Therefore, both the inner and outer diameter cylinder cylinders 49, 5
3 between the end plate 58 and the first and second pistons 5.
The work of assembling the components 9 and 60 can be easily performed without being disturbed by other members such as the rear half portion 11b. Further, other parts such as the rear half portion 11b are not damaged during the assembling work. In the function checking operation, the second input side disk 37 is pressed while the hydraulic pressure is introduced into both of the hydraulic chambers 61a and 61b to determine whether the dimensions and the positional relationship of the components are as designed. It is checked whether the applied force is as designed. Then, only when all of them are as designed (within the allowable range), the loading disk unit 48 is connected and fixed to the rear end of the rear half 11b. Therefore, the toroidal type continuously variable transmission 33
After assembling, the operation of the loading disc unit 48 is found to be inferior, so that it is not necessary to disassemble and reassemble many parts.

A support cylinder 64 is provided concentrically with the rear half 11b around the middle of the rear half 11b. Both ends of the support cylinder 64 are fixedly supported by inner diameter side ends of stays 66, 66 having outer diameter ends supported and fixed to support rings 65, 65 described later. A radial needle bearing 67 and a radial needle bearing 67 are provided between the outer peripheral surface of the intermediate portion of the rear half 11b and the inner peripheral surfaces of both ends of the support cylinder 64, respectively.
A rear portion 11b is provided inside the support cylinder 64 so as to be freely rotatable and displaceable in the axial direction.

On the other hand, around the support cylinder 64, the first and second output side disks 35, 38 are rotatably and axially displaceable by radial needle bearings 68, 68, respectively. I support it. A thrust needle bearing 69 is provided between the end faces of the first and second output disks 35 and 38 facing each other to reduce the thrust load applied between the output disks 35 and 38. While being supported, the relative rotation between these two output side disks 35 and 38 can be made freely.

A first output gear 70 is fixed to the outer surface of the first output disk 34, and the first output gear 7
0 and the front wheel drive shaft 45 are connected via a front wheel driven gear 73, and the first output side disk 34 allows the front wheel drive shaft 45 to rotate freely. Further, the rotation of the front wheel drive shaft 45 can be transmitted to a front wheel (not shown) via a front wheel differential gear 74.

On the other hand, a second output gear 75 is fixed to the outer surface of the second output disk 38, and the second output gear 75 and the rear wheel drive shaft 46 are connected to a rear wheel driven gear 76.
The second output side disk 38 allows the rear wheel drive shaft 46 to be rotatably driven. In addition, the rotation of the rear wheel drive shaft 46 can be transmitted to a rear wheel (not shown) via a rear gear (not shown). The center axis of the front wheel drive shaft 45 and the center axis of the rear wheel drive shaft 46 do not coincide with each other. The arrangement of the drive shafts 45 and 46 can be optimally selected in consideration of space efficiency.

The three first power rollers 36, 36 are provided between the inner surface 2a of the first input side disk 34 and the inner surface 4a of the first output side disk 35, The three second power rollers 39 are interposed between the inner surface 2a of the side disk 37 and the inner surface 4a of the second output side disk 38, respectively. These first,
The second power rollers 36 and 39 are rotatably supported on the inner surfaces of the first and second trunnions 77 and 78, respectively. These first and second trunnions 77 and 78 do not intersect with the central axes of the discs 34, 35, 37 and 38 provided concentrically at both ends thereof. The first and second pivots 79 (the second pivots are not shown) which are present at the twist positions substantially perpendicular to the direction of the central axes of 35, 37, and 38 swing. The first and second trunnions 77, 7
Numeral 8 is supported at both ends of first and second swing frames 80, 81 by radial needle bearings 82, 82 so as to be freely swingable.

The first and second swing frames 8
The intermediate portions 0 and 81 are supported on the support rings 65 and 65 so as to be freely swingable about support shafts 83 and 83 parallel to the central axes of the discs 34, 35, 37 and 38, respectively. . Further, the first and second swing frames 80, 81
A hydraulic cylinder 84a provided between both ends of the swing frames 80, 81 and the support rings 65, 65,
84b makes it possible to swing freely. A control valve 21a for controlling the supply and discharge of the pressure oil to and from the hydraulic cylinders 84a and 84b is supported by the support rings 65 and 65. When the swing frames 80 and 81 swing by the supply and discharge of the pressure oil to and from the hydraulic cylinders 84a and 84b, the swing frames 80 and 81 are provided on the outer surfaces of the trunnions 77 and 78 supported by the swing frames 80 and 81. The cam surface 85 displaces the spool 24a of the control valve 21a via a plunger 86 attached to the control valve 21a, and the control valve 21a
a is switched.

The control valve 21 together with the spool 24a
The sleeve 23a constituting a is displaced to a predetermined position by the control motor 25a so that a desired gear ratio can be achieved during gear shifting. The control valve 21a and the control motor 25a are provided with a first cavity 87 including the first input disk 34 and the first output disk 35.
One on the side, one on the second cavity 88 side including the second input side disk 37 and the second output side disk 38, and two in the toroidal type continuously variable transmission 33 as a whole. Then, the control motor 25a on the first cavity 87 side
The control valve 21a on the first cavity 87 side is controlled by the control motor 25a on the second cavity 88 side to control the control valve 21a on the second cavity 88 side based on a command signal from a controller (not shown) incorporating a microcomputer. Are controlled in synchronism with each other (in a straight running state) or independently of each other (in a turning state).

At the time of shifting, each of the swing frames 80, 8
Of the hydraulic cylinders 84a, 84b provided two pairs for each (four for each oscillating frame, for a total of 24 toroidal-type continuously variable transmission units), each of the oscillating frames 80, 81 One hydraulic cylinder 84a (84b) provided at one end in the length direction is extended and the other hydraulic cylinder 84b (84a) is contracted to swing each of the rocking frames 80 and 81 by a predetermined amount in a predetermined direction. Displace. That is, the swing frames 80 and 81 are respectively supported by the support shafts 83 and 8 bridged between a pair of support rings 65 and 65 disposed in parallel with each other at intervals.
3 supports a swingable displacement. The hydraulic cylinders 84a and 84b are respectively connected to the support rings 65 and 65, respectively.
Are provided at positions corresponding to both ends of each of the swing frames 80 and 81. And each of the above hydraulic cylinders 8
The pistons 89a and 89b fitted to the 4a and 84b are engaged with rods 90a and 90b fixed to both ends of the swing frames 80 and 81, respectively.

With this configuration, at the time of gear shifting, the hydraulic oil is supplied to and discharged from the hydraulic cylinders 84a and 84b based on
The first and second swing frames 80 and 81 swing and displace in a predetermined direction by a predetermined amount. As a result, the first and second trunnions 77 and 78 supported by the swing frames 80 and 81 are displaced substantially in the axial direction of the first and second pivots 79 (actually, the respective support shafts 79 and 78 are moved). Circular motion about the axes 83, 83). Then, similarly to the case of the conventional structure shown in FIGS.
9 and the above-mentioned disks 34, 35, 3
The direction of the tangential force acting on the contact portions between the inner surfaces 2a and 4a of the first and second inner surfaces 7 and 38 changes. The first and second trunnions 77 and 78 are changed according to the change in the direction of the force.
Swings in opposite directions about the first and second pivots 79 pivotally supported by the first and second swing frames 80 and 81, respectively, as shown in FIGS. In addition, the contact position between the peripheral surfaces 9a, 9a of the first and second power rollers 36, 39 and the inner surfaces 2a, 4a is changed, and the first and second input side disks 34, 37 are changed. And the rotational speed ratio between the first and second output disks 35 and 38 changes.

In the illustrated example, the displacement shafts 8a, 8a for supporting the first and second power rollers 36, 39 with respect to the first and second trunnions 77, 78 are provided on the base half. The part and the front half part are not particularly eccentric, and a linear shape is used. Instead, the distal end of each of the displacement shafts 8a, 8a is connected to the outer ring 16 forming the thrust ball bearings 14a, 14a.
a, 16a are fitted at positions off the center.
Further, the first and second power rollers 36 and 39 are formed in a round bowl shape having no through hole, and the thrust ball bearings 14 and 39 are formed.
By making the contact angles a and 14a (angular contacts), a radial load as well as the thrust load applied to the thrust ball bearings 14a and 14a can be supported. Even with such a structure, the first and second power rollers 36, 39 can be supported rotatably at predetermined positions and slightly displaceable in the axial direction of the disks 34, 35, 37, 38. . The structure of the portion supporting the first and second power rollers 36 and 39 is not the gist of the present invention. The structure of this portion is not limited to the illustrated example, and may be configured in the same manner as the conventional structure shown in FIGS.

During operation of an automatic transmission for a four-wheel drive vehicle incorporating the toroidal type continuously variable transmission 33 of the present invention constructed as described above, the input shaft 11 and the rear half 11b are rotated in synchronization with each other. Of the first and second input side disks 34, 37, the front wheel is driven by the power transmitted from the first input side disk 34 to the first output side disk 35 via the first power rollers 36, 36. Drive shaft 4
5 is driven to rotate. The rear wheel drive shaft 46 is driven to rotate by the power transmitted from the second input disk 37 to the second output disk 38 via the second power rollers 39.

The first and second input side disks 34, 3
7 and the first and second output-side disks 35 and 38 to ensure transmission efficiency.
The contact pressure between the inner surfaces 2a, 4a of 5, 37, 38 and the peripheral surfaces 9a, 9a of the first and second power rollers 36, 39 constitutes the hydraulic loading device 47. It can be easily adjusted by changing the hydraulic pressure introduced into each of the hydraulic chambers 61a and 61b. In the case of a transmission for a full-time 4WD vehicle, the torque to be distributed to the front wheels and the torque to be distributed to the rear wheels may differ depending on running conditions. In the case of the toroidal type continuously variable transmission 33, Since the pressure is adjusted by the hydraulic loading device 47,
Optimal surface pressure can be applied according to conditions.

When the vehicle is running straight, the front wheel drive shaft 4 is adjusted to match the rotation speed of the front wheels with the rotation speed of the rear wheels.
In order to match the rotation speed of the rear wheel drive shaft 46 with the rotation speed of the rear wheel drive shaft 46, the rotation speed of the rear wheel drive shaft 46 is centered on the support shafts 83, 83 based on the supply and discharge of pressure oil to and from the hydraulic cylinders 84a, 84b. The swing angles of the first and second swing frames 80 and 81, and the first and second swing shafts 79 supported by the swing frames 80 and 81, about the first and second pivots 79, respectively. The inclination angles of the trunnions 77 and 78 are matched. Then, the speed ratio between the first input side disk 34 and the first output side disk 35 and the second input side disk 3
7 and the speed ratio between the second output side disc 38 and the second output side disc 38.

On the other hand, when the vehicle is in a turning state, the rear wheel drive shaft 45 has a lower rotational speed than the front wheel drive shaft 45 so as to make the rear wheel rotational speed slower than the front wheel rotational speed. When decreasing the rotation speed of the shaft 46, the inclination angles of the first trunnions 77 and 77 and the inclination angles of the second trunnions 78 are made different. Specifically, the speed reduction ratio between the second input side disk 37 and the second output side disk 38 is smaller than the speed reduction ratio between the first input side disk 34 and the first output side disk 35. Increase ratio. As a result, even if the center differential is not provided, the operation of the vehicle can be stably performed without causing excessive slippage between the front and rear wheels and the road surface.

It should be noted that the example shown in the figure is for the case where the toroidal type continuously variable transmission of the present invention is used as a transmission unit for an automatic transmission for a four-wheel drive vehicle incorporating a large-sized and large-torque engine. I explained it. However, the toroidal type continuously variable transmission of the present invention is not limited to four-wheel drive vehicles,
It can also be used as a transmission unit for an automatic transmission for a general two-wheel drive vehicle. In this case, a pair of output-side disks are freely coupled to rotate in synchronism with each other, and output is taken out from these two output-side disks to one output shaft. Further, when used as a transmission unit for an automatic transmission for a small car that does not generate too much torque, the input side disk and the output side can be used as in the conventional structure shown in FIGS. A so-called single-cavity toroidal-type continuously variable transmission in which one side disk and one side disk are provided can also be configured. In this case, the loading device can be combined with the output disk.

[0051]

Since the present invention is constructed and operates as described above, it is possible to adjust the contact pressure of the traction portion to an optimum value, and to realize a structure which is easy to assemble and secures a yield, and has a high yield. It can contribute to the realization of a toroidal type continuously variable transmission with high performance.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an example of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along the line BB in FIG.

FIG. 4 is a cross-sectional view showing a portion substantially the same as FIG. 3 cut along a plane including a central axis of a first pivot provided at both ends of the first trunnion;

FIG. 5 is a side view showing a basic configuration of a conventionally known toroidal type continuously variable transmission in a state of maximum deceleration.

FIG. 6 is a side view showing a state at the time of maximum speed increase.

FIG. 7 is a sectional view showing an example of a conventional specific structure.

FIG. 8 is a sectional view taken along the line CC in FIG. 7;

FIG. 9 is a main part front view showing a first example of a conventionally known structure for increasing the transmittable power in a partially cut state.

FIG. 10 is a partial sectional view showing the second example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input shaft 2 Input side disk 2a Inner surface 3 Output shaft 4 Output side disk 4a Inner surface 5, 5a Casing 6 Axis 7 Trunnion 8, 8a Displacement axis 9 Power roller 9a Peripheral surface 10 Loading cam device 11 Input shaft 11a Front half 11b Rear half part 12 Output gear 13 Support plate 14, 14a Thrust ball bearing 15 Thrust needle bearing 16, 16a Outer ring 17 Actuator 18 Frame 19 Support piece 20 Hydraulic cylinder 21, 21a Control valve 22 Pump 23, 23a Sleeve 24, 24a Spool 25, 25a Control motor 26 Drive piston 27 Oil reservoir 28 Cam 29 Link 30 Ball spline 31 Sleeve 32 Output shaft 33 Toroidal type continuously variable transmission 34 First input side disk 35 First output side disk 36 First power roller 37 Dual input disk 38 Second output disk 39 Second power roller 40 Torque converter 41a, 41b Radial needle bearing 42 Forward / reverse switching unit 43 Forward clutch 44 Reverse clutch 45 Front wheel drive shaft 46 Rear wheel drive shaft 47 Loading Device 48 Loading disk unit 49 Inner diameter side cylinder tube 50 Small diameter portion 51 Large diameter portion 52 Step portion 53 Outside diameter side cylinder tube 54 Small diameter portion 55 Large diameter portion 56 Step portion 57 Collar portion 58 End plate 59 First piston 60 Second piston 61a, 61b Hydraulic chamber 62 Preload spring 63 Holding nut 64 Support cylinder 65 Support ring 66 Stay 67 Radial needle bearing 68 Radial needle bearing 69 Thrust needle bearing 70 First output gear 71 Carrier 73 Front wheel driven gear 74 Front wheel differential Tooth gear 75 Second output gear 76 Rear wheel driven gear 77 First trunnion 78 Second trunnion 79 First pivot 80 First swing frame 81 Second swing frame 82 Radial needle bearing 83 Support shaft 84a, 84b Hydraulic cylinder 85 Cam Surface 86 Plunger 87 First cavity 88 Second cavity 89a, 89b Piston 90a, 90b Rod

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takashi Machida 1-5-50 Kumeinuma Shinmei, Fujisawa-shi, Kanagawa Nippon Seiko Co., Ltd. (72) Inventor Hiroshi Kato 1-150 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Inside NSK Ltd. Lars Hoffmann, Germany Day 04600 Altenburg Neuer Beck 16 (72) Inventor Peter Tenberge, Germany Day 09123 Chemnitz Dross Ring 14 (72) Inventor Homogenizer Emanjome Federal Republic of Germany, Day 40878 Ratti Ngen Ziegler-Strasse 24 (72) inventor Ierugu Mekeru Federal Republic of Germany, Day 09122 Kemuni' Tsu Burano Grants Bahnhofstrasse 22 F-term (reference) 3J051 AA03 BA03 BB01 BD01 BE09 CA05 CB06 DA05 ED04 FA02

Claims (1)

[Claims] 1. An input shaft, an input disk provided non-rotatably around the input shaft, and having one axial surface having an arc-shaped concave concave input surface, and one axial surface having a circular cross section. An output disk having an arc-shaped output side concave surface, with the output side concave surface facing the input side concave surface and rotatably supported with respect to the input shaft, the output disk and the input disk In the middle portion, four or more even number of pivots, which are twisted with respect to the center axis of each of the discs, a plurality of trunnions swinging about these respective pivots, and Displacement shafts protruding from the side surfaces, and the respective peripheral surfaces sandwiched between the inner surface of the input-side disk and the inner surface of the output-side disk while being rotatably supported around these respective displacement shafts. Multiple with spherical convex surface Power roller, and a toroidal-type continuously variable transmission including a loading device that presses the input-side disk and the output-side disk in directions approaching each other. A hydraulic loading device that presses any one of the input-side disk and the output-side disk toward the other disk by sending pressure oil into the cylinder, This loading device and one of the discs pressed by the loading device are combined in a non-separable unit, and this unit and the input shaft are formed separately so that they can be combined later. A toroidal type continuously variable transmission characterized by the following: