JP3428050B2 - Toroidal type continuously variable transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The toroidal type continuously variable transmission according to the present invention is for a four-wheel drive vehicle (full-time 4WD vehicle) or a front engine front-wheel drive vehicle (FF) that constantly transmits driving force to four wheels. It can be used as a transmission with a differential function for cars.

[0002]

2. Description of the Related Art As a transmission for an automobile, use of a toroidal type continuously variable transmission as schematically shown in FIGS. This toroidal type continuously variable transmission supports an input side disk 2 concentrically with an input shaft 1 supported by a bearing 19a for a transmission case (not shown), and also an output supported by a bearing 19b for the transmission case. The output side disk 4 is fixed to the end of the shaft 3. On the inner surface of the transmission case accommodating the toroidal type continuously variable transmission, or on a support bracket provided in the transmission case, a pivot shaft in a twisted position with respect to the input shaft 1 and the output shaft 3 is provided. Trunnions 5, 5 are provided that swing around the center.

Each trunnion 5, 5 is made of a metal material having sufficient rigidity, and has the pivots on the outer surfaces of both ends. Further, around the displacement shafts 6, 6 provided at the center of each trunnion 5, power rollers 7,
7 is rotatably supported. The power rollers 7, 7 are sandwiched between the input side and output side disks 2, 4.

On the axially opposite side surfaces of both the input side and output side disks 2 and 4, the surfaces facing each other have an arcuate input side concave surface 2a whose cross section is centered on a point on the axis, and an output side. The concave surface 4a is formed. Then, the peripheral surfaces 7a, 7a of the respective power rollers 7, 7 formed on the convex surface of the rotating arc surface shape.
Is in contact with the input side concave surface 2a and the output side concave surface 4a.

A loading cam type pressurizing device 8 is provided between the input shaft 1 and the input side disc 2, and the pressurizing device 8 presses the input side disc 2 toward the output side disc 4. ing. The pressurizing device 8 includes an input shaft 1
The cam plate 9 rotates together with the cam plate 9 and a plurality of (for example, four) rollers 11 and 11 held by a holder 10. On one side surface (the right side surface in FIGS. 5 to 6) of the cam plate 9, a cam surface 12 which is a concavo-convex surface extending in the circumferential direction is formed and is slidable in the axial direction with respect to the input shaft 1.
A similar cam surface 13 is also formed on the outer side surface (the left side surface in FIGS. 5 to 6) of the input side disk 2 which is rotatably supported in the rotation direction. And the plurality of rollers 1
1 and 11 are rotatable about an axis in the radial direction with respect to the center of the input shaft 1.

When the cam plate 9 rotates in accordance with the rotation of the input shaft 1 and a rotational phase difference is generated with respect to the input side disk 2, a plurality of rollers 11, 11 are moved to the cam surface 12 and the cam surface 13. The cam plate 9 and the input side disk 2 are ridden from each other by getting on. The cam plate 9 is fixed to the input shaft 1 supported by the bearing 19a with respect to the transmission case and cannot move in the axial direction. Therefore, the input side disk 2 is pushed toward the power rollers 7, 7, 7, 7 are pushed toward the output side disk 4. On the other hand, output side disk 4
Cannot be moved in the axial direction because it is supported together with the output shaft 3 by the bearing 19b with respect to the transmission case. Therefore, the power rollers 7, 7 are pressed between the input side disk 2 and the output side disk 4. Due to this pressing, the peripheral surfaces 7a, 7a of the power rollers 7, 7 and the input-side and output-side concave surfaces 2
A pressing force is generated between the output side disk 4a and 4a, and the rotation of the input side disk 2 is transmitted to the output side disk 4 through the power rollers 7 and 7 without slipping, and the output fixed to the output side disk 4 is output. The shaft 3 rotates.

When the rotational speeds of the input shaft 1 and the output shaft 3 are changed, and when deceleration is first performed between the input shaft 1 and the output shaft 3, as shown in FIG. 5, each trunnion is centered on the pivot shaft. 5 and 5 are swung, and the peripheral surface 7 of each power roller 7, 7
a and 7a are in contact with the central portion of the input side concave surface 2a and the outer peripheral portion of the output side concave surface 4a, respectively.
The displacement axes 6, 6 are tilted. On the contrary, when increasing the speed, the trunnions 5 and 5 are swung as shown in FIG. 6 so that the peripheral surfaces 7a and 7a of the power rollers 7 and 7 become the outer peripheral portion of the input side concave surface 2a. , The displacement shafts 6, 6 are inclined so as to abut the center portion of the output side concave surface 4a. By setting the inclination angles of the displacement shafts 6, 6 in the middle between FIG. 5 and FIG. 6, an intermediate gear ratio can be obtained between the input shaft 1 and the output shaft 3.

In the case of the above structure, as shown in FIG.
Axial thrust Fa pushing the input side disk 2 by the cam plate 9
₁ is applied as a vertical force Fn expanded by the wedge action in the vertical direction of the input side concave surface 2a and the peripheral surface 7a. In addition, the same vertical force Fn is applied to the peripheral surface 7a and the output concave surface 4a in the vertical direction.
Is added. Then, this vertical force Fn becomes an axial force Fa ₂ reduced by the inverse action of the wedge, and pushes out the output side disk 4 in the axial direction. These axial forces Fa ₁ and Fa ₂ are applied to the bearings 19a and 19b as thrust loads.

In order to transmit the rotation between the peripheral surfaces 7a, 7a and the input-side and output-side concave surfaces 2a, 4a without causing a large slip due to the cutting line force generated by the torque,
It is necessary that a vertical force that is sufficiently larger than the cutting line force be applied between the input-side and output-side concave surfaces 2a, 4a.
The vertical force changes depending on the torque to be transmitted and the gear ratio, but in the above structure, the vertical force generated by the action of the cam plate 9 and the wedge action automatically changes to a desired degree to a desired degree. There is a characteristic to do.

However, in all the shift states including the states shown in FIGS. 5 and 6, a vertical force Fn which is sufficiently larger than the cutting line force is required, and therefore the thrust load Fa ₁ of the bearings 19a and 19b is required. And Fa ₂ must also be large. Therefore, the bearings 19a and 19b are required to have durability to withstand this large thrust load. In order to ensure this durability, it is unavoidable that the bearings 19a and 19b become large in size, and the large bearings 19a and 19b and the large thrust load cause large friction loss of the bearings 19a and 19b. , The transmission efficiency of the transmission is reduced.

In particular, when performing the deceleration shown in FIG. 5, the vertical force Fn between the input side concave surface 2a and the peripheral surface 7a is greatly expanded by the axial force Fa ₁ by the cam plate 9 due to the wedge action. This vertical force Fn is almost the same as the output side disk 4
The axial force Fa ₂ is applied to the bearing 19b. Therefore, the bearing 19b receives the expanded axial force F.
It becomes possible to rotate while supporting the a _2, frictional loss at the bearing 19b is particularly increased, the transmission efficiency of the transmission is reduced.

In order to improve the transmission efficiency of the toroidal type continuously variable transmission configured and operating as described above and further increase the power that can be transmitted by this toroidal type continuously variable transmission, as shown in FIGS. Arranging a pair of toroidal type continuously variable transmissions in parallel (in tandem) with respect to the direction of power transmission is disclosed in Japanese Utility Model Laid-Open No. 63-60751 or Japanese Patent Laid-Open No. 2-1.
It has been conventionally proposed as disclosed in Japanese Patent No. 63549.

FIG. 8 is a diagram showing the actual construction of Shokai 63-60751.
The structure described in the publication is shown. Bearings 19c, 1
The rotational force applied to the input shaft 1 supported by the transmission case by 9c is transmitted from the two input side disks 2 and 2 supported around the input shaft 1 through the power rollers 7 and 2 to It is transmitted to the individual output disks 4, 4. The output disks 4, 4 are rotatably supported around the input shaft 1.

The rotational force of the two output side disks 4 and 4 is transmitted to one disk-shaped cam plate 14 via a plurality of rollers 11 and 11, respectively. Furthermore, this cam plate 14
The rotational force transmitted to the gears 15 and 15 meshed with the teeth formed on the outer peripheral edge of the cam plate 14, the transmission shafts 16 and 16 whose one end is fixedly coupled to the gears 15 and 15, and the transmission shafts 1 and 2.
It is transmitted to the output shaft 3 connected and fixed to the central portion of the gear 18 through the gears 17 and 17 fixed to the other ends of the gears 6 and 16 and one gear 18 meshed with the both gears 17 and 17. It

As described above, when two input disks 2 and 2 and two output disks 4 and 4 are combined in parallel with each other, the forces applied in the axial direction of the disks 2 and 4 cancel each other. The disks 2 and 4 are arranged so that Therefore, the bearing 1 that supports the input side disks 2 and 2
Thrust loads are not applied to 9c and 19c, and the bearings supporting the output side disks 4 and 4 can be omitted. Therefore, the friction loss of the bearings supporting the input side and output side disks 2 and 4 is almost eliminated. The power transmission efficiency between the input shaft 1 and the output shaft 3 can be improved.

[0016]

[Description of Invention of Prior Application] By the way, the conventional toroidal type continuously variable transmission shown in FIG. 8 which is constructed and operates as described above is rotationally driven by an engine 20 as shown in FIG. 9 (A). The rotational force of the one input shaft 1 is transmitted to the two toroidal speed change parts 21, 21 provided in parallel with each other,
The outputs of these two toroidal speed change parts 21, 21 are taken out by one output shaft 3.

Therefore, when such a toroidal type continuously variable transmission is used as a transmission for a four-wheel drive vehicle, the driving force once collected on one output shaft 3 is used again for the front wheels and the rear wheels. Must be distributed over the two drive shafts.
As described above, collecting and distributing the rotational driving force repeatedly is not preferable because not only the mechanism becomes complicated and the weight increases, but also the power loss due to friction increases.

Therefore, as shown in FIG. 9 (B), the outputs of the two toroidal transmissions 21, 21 are taken out separately by the engine 20 by the two output shafts 3a, 3b, and one output shaft 3a is taken out. It is conceivable that the front wheel is driven by and the rear wheel is driven by the other output shaft 3b. As a toroidal type continuously variable transmission considered from such a viewpoint,
Japanese Patent Application No. 3-348458 discloses an invention as shown in FIGS. Prior to explaining the problems to be solved by the present invention, the invention according to this prior application will be described first.

One input shaft 22 is supported by the transmission case 38 by bearings 44, 44. This input shaft 22
A pair of input side disks 23a and 23b are provided at both ends of the periphery of the input shaft 22 via a pair of pressurizing devices 8 and 8 which are not rotatable relative to the input shaft 22, respectively. It is rotatably installed. The input-side discs 23a and 23b are axially one-sided faces that face each other and are input-side concave faces 24a and 24b having an arc-shaped cross section.

On the other hand, around the middle portion of the input shaft 22,
A pair of output shafts 25a, 2 each formed in a tubular shape
5b are supported by the ball bearings 39, 39 relative to the transmission case 38 so as to freely rotate with respect to the input shaft 22 and relative to each other. The output disks 26a and 26b are fixed to the outer ends of the output shafts 25a and 25b, respectively. The input side concave surface 24 is formed on one side in the axial direction of each output side disk 26a, 26b.
The surfaces facing a and 24b are the input-side concave surfaces 24a and 2b.
Similar to 4b, the output side concave surfaces 27a, 27 having an arc-shaped cross section
b.

Around the input shaft 22, a portion between one input side disk 23a and one output side disk 26a is
A plurality of trunnions 28a, 28a, which swing about a pivot shaft in a twisted position with respect to the input shaft 22, are provided in the portion between the other input side disk 23b and the output side disk 26b. A plurality of trunnions 28b, 28b swinging about a pivot in a twisted position
Are provided respectively.

Displacement shafts 29a fixed to the surfaces of the trunnions 28a, 28b facing the input shaft 22,
29b includes power rollers 30a and 30b,
It is rotatably supported. Each power roller 30a, 3
The peripheral surfaces of 0b are the input concave surfaces 24a and 24b, respectively.
In addition, the convex surface is a circular arc surface having a sectional curvature slightly smaller than that of the output-side concave surfaces 27a and 27b. The power rollers 30a and 30b are connected to the input side disks 23a and 23b and the output side disks 26a and 26b.
The output side disks 26a and 26b are sandwiched between them and the output side disks 26a and 26b are rotated as the input side disks 23a and 23b are rotated.

Further, gears 31a and 31b fixed to the outer peripheral surfaces of the intermediate portions of the output shafts 25a and 25b and gears 33a and 33 fixed to the pair of transmission shafts 32a and 32b, respectively.
By engaging b with each other, an output means for independently extracting the rotational movements of the pair of output side disks 26a, 26b is configured.

The rotational movement of one transmission shaft 32a of the pair of transmission shafts 32a and 32b is taken out of the transmission case 38 as it is, and the front wheels (or the rear wheels) are driven through a differential gear. And the other transmission shaft 3
The rotational motion of 2b is transmitted to the take-out shaft 37 via the gears 34, 35, 36, taken out of the transmission case 38 by the take-out shaft 37, and is passed through another differential gear to the rear wheel (or front wheel). Used to drive.

In the toroidal type continuously variable transmission of the prior invention constructed as described above, the input shaft 22 and one transmission shaft 32 are provided.
The gear ratio between the two gears is one of the trunnions 28a, 28a.
By displacing the power rollers 30a, 30a supported by the power rollers 30a, 30b, the gear ratio between the input shaft 22 and the other transmission shaft 32b is the same as that of the power rollers 30b, 30b supported by the other trunnions 28b, 28b. By displacing, each can be converted.

The one fixed to the one input shaft 22
The rotary motion transmitted from the pair of input side disks 23a, 23b to the pair of output side disks 26a, 26b is taken out independently of each other, and the front wheel is driven by the rotational force taken out from one output side disk 26a to the transmission shaft 32a. Is configured to drive the rear wheels by the rotational force extracted from the other output side disk 26b to the transmission shaft 32b,
Can drive four-wheel drive vehicles.

As described above, when the four-wheel drive vehicle is driven, the inclination angles of the displacement shafts 29a, 29a provided on the one trunnion 28a, 28a and the other trunnion 2 are set.
The front wheels and the rear wheels can be driven at different rotational speeds by controlling the inclination angles of the displacement shafts 29b, 29b provided on 8b, 28b to be different. Therefore, when the front wheel or rear wheel slips on a bad road and loses the driving force of the wheel, the front wheel and the rear wheel are moved at different speeds in the same direction as described above in the direction of decreasing the rotational speed of the slipping wheel. By controlling to rotate with, the driving force as a four-wheel drive vehicle can be increased.

When the vehicle changes its course, the rotation speed of the wheels on the inner peripheral side in the rotation direction becomes smaller than the rotation speed of the wheels on the outer peripheral side in the rotation direction, and compared with the rotation speed of the front wheels. The rotation speed of the rear wheels decreases. The differential gear absorbs the speed difference between the outer wheel and the inner wheel, but in order to absorb the speed difference between the front wheels and the rear wheels, the conventional four-wheel drive vehicle uses the center differential in addition to the transmission. It had a built-in differential gear or viscous fluid coupling. On the other hand, when the toroidal type continuously variable transmission of the previous invention is used, the rotational speed difference can be absorbed only by the transmission.

[0029]

In the toroidal type continuously variable transmission of the present invention, the transmission efficiency is further improved by improving the toroidal type continuously variable transmission of the prior invention constructed as described above. It is a thing.

As described above, in order to improve the power transmission efficiency of a so-called double cavity type toroidal type continuously variable transmission in which two input side disks 2 and 2 and two output side disks 4 and 4 are provided. It is necessary to offset the forces applied to the input-side disks 2 and 2 in the axial direction and to offset the forces applied to the output-side disks 4 and 4 in the axial direction.

Since both input side disks 2 and 2 rotate at the same speed, both input side disks 2 and 2 can be easily supported by supporting both input side disks 2 and 2 on a single input shaft 1 and 22. The force applied in the axial direction of 2 can be offset. Also, as shown in FIG.
In the case of the conventional structure shown in FIG. 2, both output side disks 4 and 4 rotate at the same speed, so that the back surfaces of the output side disks 4 and 4 (surfaces opposite to the output side concave surfaces 4a and 4a) are butted against each other. Thus, it is possible to easily cancel the force applied in the axial direction of the both output side disks 4, 4.

However, in the case of the toroidal type continuously variable transmission according to the previous invention shown in FIGS. 10 to 11, the rotational speeds of the output side disks 26a and 26b may differ from each other. It is not possible to simply butt the back surfaces of 26b together. Therefore, in the prior invention, angular type ball bearings 39, 39 are provided between the back surfaces of the both output side disks 26a, 26b to allow relative rotation between the both output side disks 26a, 26b. In addition, axial forces in opposite directions, which are applied from both output side disks 26a and 26b, are supported by the transmission case 38 via angular type ball bearings 39 and 39.

In the case of such a structure, both output side disks 2
The axial forces of 6a and 26b are not cancelled, but are applied to the angular type ball bearings 39 and 39. As a result, the ball bearings 39, 39 rotate while receiving a large thrust load Fa ₂ as in the case of the structure shown in FIG. 5, resulting in a large friction loss. Therefore, as in the case of the structure shown in FIG. 5, when the transmission is in the deceleration position,
The friction loss in the ball bearings 39, 39 is particularly increased, and the transmission efficiency of the transmission is significantly reduced. Such ball bearing 39,
In order to prevent the reduction of the transmission efficiency due to the friction loss of 39, it is necessary to reduce either the thrust load Fa ₂ or the rotation speed of the ball bearings 39, 39.

The toroidal type continuously variable transmission of the present invention was invented in view of the above-mentioned circumstances.

[0035]

A toroidal type continuously variable transmission according to the present invention includes a transmission case and a rotation in the transmission case.
One input shaft that is freely supported and one axial surface of each input shaft are concave input sides having an arcuate cross section, and with the input concave surfaces facing each other, a space is provided around the input shaft. 1 which is installed so as not to rotate with respect to this input shaft
A pair of input side disks and one axial side surface are output side concave surfaces having an arcuate cross section, the output side concave surface and the input side concave surface are opposed to each other, and rotation with respect to the input shaft and between Relative rotation is allowed, and each of them is provided around the input shaft in a portion between the pair of input disks.
With the angular type ball bearing to the transmission case,
A pair of output-side disks that are supported to rotate independently of each other, and a thrust bearing that is exclusively provided to receive a thrust load between the axial one surfaces of the pair of output-side disks; A plurality of trunnions that swing around a pivot that is in a twisted position with respect to the input shaft and a convex surface with a rotating arc surface on the peripheral surface, and are rotatably supported by the displacement shaft supported by the trunnions, and each input is supported. A plurality of power rollers sandwiched between the output side and output side disks, and an output means for extracting the rotational force of the pair of output side disks independently of each other.

[0036]

With the toroidal continuously variable transmission of the present invention constructed as described above, the rotational force input from one input shaft is divided into two systems and taken out. If the rotational speeds of the two systems are different from each other. The action of making it work is the same as that of the toroidal type continuously variable transmission according to the above-mentioned invention.

In particular, in the case of the toroidal type continuously variable transmission of the present invention, the forces acting in the axial directions of the two output disks are opposite to each other, and the thrust loads are applied between the two output disks.
It is applied from the reverse direction to the thrust bearing that is specially provided to receive it . This thrust bearing, which is specially provided to receive the thrust load, has sufficient rigidity against the force in the axial direction, so the power to be transmitted becomes large and the force applied in the axial direction of each output side disk is increased. Even if it grows up, it can fully support this power. And 2 in normal state
Since the output side disks rotate at almost the same rotation speed,
The thrust bearing practically hardly rotates and friction loss is small. Therefore, a reduction in transmission efficiency of the transmission is prevented. Also, under normal running conditions, the output side
The thrust bearing bears most of the axial thrust of
Therefore, the thrust load applied to the angular type ball bearing is extremely small.
It is small and the power loss in this ball bearing is also small. Therefore,
The power loss of the last bearing and angular type ball bearing is
Angular in the structure according to the prior invention shown in FIG.
It is significantly smaller than the power loss of a ball bearing of the type. Furthermore,
As mentioned above, under normal running conditions, angular type balls
The thrust load applied to the bearing is extremely small, so
It is sufficient to use a small-sized ball-type ball bearing.
Moreover, this angular type ball shaft is part of the transmission case.
There is no need to increase the rigidity of the part that supports the bridge.
It As a result, the toroidal type continuously variable transmission is small and light.
Can be quantified.

[0038]

FIG. 1 shows a first embodiment of the present invention , which corresponds to claims 1, 2, and 5 . The feature of the present invention is that
The structure is that of a portion that supports the force applied in the axial direction of each of the output side disks 26a, 26b (see FIG. 11) while allowing the relative rotation of both output side disks 26a, 26b .
The configuration and operation of the other parts are the same as the invention according to the previous invention described above, and therefore, the illustration and the overlapping description will be omitted, and the characteristic part of the present invention will be described below.

Gears 31a and 31b are provided on the back surfaces (side surfaces opposite to the output concave surfaces 27a and 27b) of the two output disks 26a and 26b, respectively.
26b are concentrically connected and fixed to each output side disk 26a,
These gears 31a and 31b are adapted to rotate together with the rotation of 26b.

The gears 31a and 31b are provided with angular type ball bearings 39 and 39, respectively, to form the transmission case 3.
Inside 8 is freely supported independent rotation . Further, a thrust ball bearing 40 is sandwiched between the end faces of the gears 31a and 31b. Clear from the figure
As you can see, this thrust ball bearing 40 supports radial loads.
There is no function to make it, and it is specially made to receive the thrust load.
It was the one.

During operation of the toroidal type continuously variable transmission, the respective gears 31a and 31b are actuated by the pressurizing device 8 (FIG. 11), and the input side disks 23a and 23b, the power rollers 30a and 30b, Output side disks 26a, 26b
An axial force (axial force) is applied via (see FIG. 11). This axial force is in the left direction in the right gear 31a and in the right direction in the left gear 31b in FIG.

Therefore, the axial force applied to each gear 31a, 31b becomes a force for holding the thrust ball bearing 40 as it is. The thrust ball bearing 40 is designed to receive a thrust load, and has sufficient rigidity against a force applied in the axial direction . For this reason, the power transmitted by the toroidal type continuously variable transmission increases, and each output side disk 26
Even if the force applied from a and 26b in the axial direction of the gears 31a and 31b increases, this force can be sufficiently supported. Moreover, it is possible to prevent the gears 31a and 31b from rotating independently of each other.

Further, the thrust ball bearing 40 according to claim 5
As described above, when the input torque is not applied, the load is hardly received, and most of the axial thrust of the output side disks 26a and 26b by the preload spring of the pressurizing device 8 is the angular type ball bearings 39 and 39. This ball bearing 3
The initial gaps of 9 and 39 are set.

With this structure, as shown in FIG. 2, when the input torque is extremely small, the axial thrust (a in FIG. 2) of the output side disks 26a and 26b by the preload spring is equal to each gear 31a. , 31b and the transmission case 38 are supported as thrust loads of the angular type ball bearings 39, 39, and almost no load is applied to the thrust ball bearing 40.

If the input torque increases and the axial thrust of the output side disks 26a, 26b (the straight line B in FIG. 2) by the pressure device 8 increases, the axial rigidity of the angular type ball bearings 39, 39 is low. The thrust load of the ball bearings 39, 39 (straight line C in FIG. 2) does not increase so much, and most of the increased axial thrust is the thrust load of the thrust ball bearing 40 having high axial rigidity (straight line D in FIG. 2). When loaded, the two output disks 26a and 26b are pressed against each other via the thrust ball bearing 40.

In a normal running state, the two output side disks 26a and 26b rotate at substantially the same rotational speed, so that the thrust ball bearing 40 does not substantially rotate, and the thrust ball bearing 40 does not rotate. Even if a large thrust load is applied to the thrust ball bearing 40, there is almost no power loss consumed in the thrust ball bearing 40. Further, since the thrust ball bearing 40 bears most of the axial thrust of the output side disks 26a, 26b, the thrust load applied to the angular type ball bearings 39, 39 is extremely small, and the power of the ball bearings 39, 39 is small. The loss is also small. Therefore, the thrust ball bearing 40 and the angular type ball bearing 3
The power loss of 9, 39 is significantly smaller than the power loss of the angular type ball bearings 39, 39 in the structure shown in FIG. 11, and the transmission efficiency is almost the same as that of the structure shown in FIG. To be improved. In particular, in the structure shown in FIG. 11, it is possible to prevent the transmission efficiency from significantly lowering at the deceleration position of the transmission.

For example, when a large torque is applied to the thrust ball bearing 40 such as a wheel idling on sandy sand, a large thrust load is applied to the thrust ball bearing 40, and the differential function operates to operate the two output side disks 26a and 26b. The frequency of occurrence of a large difference in rotation speed is rare, and the total number of rotations of the thrust ball bearing 40 during the lifetime of the transmission is small. Therefore, the life of the thrust ball bearing 40 needs to be considered so much. There is no. Therefore, the thrust ball bearing 40 may be of a relatively small size.

Further, the thrust load of the angular type ball bearings 39, 39 is much smaller than the thrust load in the structure shown in FIG. 11 in a normal running state, and one of the front and rear wheels slips and the other wheel slides. That is, the output side disks 26a, 2
A large thrust load acts only when torque is applied only to 6b, but the frequency thereof is rare, and the life of the ball bearings 39, 39 is significantly extended. Therefore, the angular type ball bearings 39, 39 can be made smaller than the structure shown in FIG. 11, the power loss can be reduced, and the weight of the ball bearings 39, 39 can be reduced.

These effects are similarly obtained when used as a front and rear wheel differential or as a left and right wheel differential.

Next, FIG. 3 corresponds to claims 1, 2, 3 , and 5.
7 shows a corresponding second embodiment of the present invention. In the above-described first embodiment, the thrust ball bearing 40 for supporting the axial force applied to both gears 31a, 31b is independent of the ball bearings 39, 39 for supporting each gear 31a, 31b in the transmission case 38. In contrast to this, in the case of the present embodiment, the inner rings forming both ball bearings 39, 39 are extended inward in the diametrical direction to form the bearing rings of the thrust ball bearing 42. That is, it has a rotating ring 41 in which the inner ring of the angular type ball bearings 39, 39 and the race ring of the thrust ball bearing 40 are integrally formed.
The outer ring spacer 43 is arranged between the outer rings of the individual angular bearings 39, 39. The rotating wheel 41 includes a gear 31a,
The inner surface and the side surface of the rotating wheel 41 are in contact with 31b.

Because of the above-described structure, in the present embodiment, the initial clearances of the bearings 39, 39 are set to the gears 31a, 31b.
Except for the fitting of the rotary wheel 41 with the rotary wheel 41, it is determined substantially only by the dimensions of the bearings 39, 39 and the outer ring spacer 43. Therefore, in addition to the effects of the first embodiment described above, the assembly of the transmission is significantly facilitated.

Next, FIG. 4 corresponds to claims 1 to 5,
3 shows a third embodiment of the present invention. In this embodiment, the outer ring spacer 43 between the two angular type ball bearings 39, 39 in the above-described second embodiment is omitted, and the two ball bearings 39, 39 constituting the two ball bearings 39, 39 are omitted. The outer ring is integrated. At the center of the outer peripheral surface of the outer ring, there is provided a retaining ring 45 that functions as a locking means in the axial direction. In this embodiment, the bearing clearance cannot be adjusted by the outer ring spacer, but the bearing 3
Since the initial clearance of 9, 39 can be determined almost only by the internal dimensions of the bearings 39, 39, the axial length of the outer ring can be shortened.
In addition to the effects of the first embodiment, the bearings 39, 39 can be made even smaller and lighter.

Further, in this embodiment, since the retaining ring 45 functioning as the locking means is provided integrally with the outer ring, the outer ring is prevented from being eccentric when the transmission is assembled, and the assembly work is prevented. Contribute to ease. The locking means may be a projection or the like provided on the outer peripheral surface of the outer ring, in addition to the retaining ring 45.

[0054]

The toroidal type continuously variable transmission of the present invention is constructed and operates as described above, and therefore, like the previous invention,
It is possible to smoothly drive a full-time 4WD vehicle or an FF vehicle without using a complicated and heavy device such as a center differential or a differential gear, and to reduce power loss. Therefore, high-performance full-time 4WD vehicles, FF vehicles, etc. can be provided at low cost.

Further, in the toroidal type continuously variable transmission of the present invention, there is almost no power loss due to the thrust bearing,
Further, since the power loss in the bearing supporting the output side disk during normal traveling is small, the transmission efficiency in normal traveling can be improved to almost the same level as in the case of the dual cavity type having no differential function. Moreover, it is possible to use small ball bearings.
In addition to the above, the output side device
There is no need to increase the rigidity of the part that supports the disc.
By doing so, it becomes possible to reduce the size and weight.

Further, the inner ring of the bearing supporting the output side disc and the bearing ring of the thrust ball bearing are integrated (in the case of the second embodiment of the present invention) or the bearing supporting the output side disc. By integrating the two outer races (in the case of the third embodiment of the present invention), the size of the transmission can be made smaller as compared with the case where a bearing for supporting the output side disc and a thrust bearing are used in combination. And weight reduction, and the assembling work becomes easy.

Further, according to the toroidal type continuously variable transmission of the present invention, high transmission efficiency can be maintained even when the power to be transmitted becomes large.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention, corresponding to part A in FIG.

FIG. 2 is a diagram showing the relationship between the input torque, the axial thrust of the output disk, and the thrust load of the bearing.

FIG. 3 is a view similar to FIG. 1, showing a second embodiment of the present invention.

FIG. 4 is a view similar to FIG. 1 showing the third embodiment.

FIG. 5 is a side view showing the basic structure of the toroidal-type continuously variable transmission in a state of maximum deceleration.

FIG. 6 is a side view showing the same state at the time of maximum acceleration.

FIG. 7 is a diagram showing the axial thrust of the output side disk and the thrust load of the bearing.

FIG. 8 is a sectional view showing a conventional structure.

FIG. 9 is a schematic diagram showing two examples of a state in which a toroidal type continuously variable transmission is incorporated in a 4WD vehicle.

FIG. 10 is a schematic cross-sectional view showing the prior invention.

FIG. 11 is a sectional view showing a specific structure of the same.

[Explanation of symbols]

1 input axis 2 Input side disk 2a Input concave surface 3, 3a, 3b output shaft 4 Output side disc 4a Output concave 5 trunnion 6 Displacement axis 7 power rollers 7a peripheral surface 8 Pressurizing device 9 cam plate 10 cage 11 Laura 12 Cam surface 13 Cam surface 14 Cam plate 15 gears 16 transmission shaft 17 gears 18 gears 19a, 19b, 19c bearings 20 engine 21 Toroidal transmission 22 Input axis 23a, 23b Input side disk 24a, 24b concave on the input side 25a, 25b Output shaft 26a, 26b Output side disc 27a, 27b Output concave 28a, 28b trunnion 29a, 29b Displacement axis 30a, 30b Power roller 31a, 31b gears 32a, 32b transmission shaft 33a, 33b gears 34 gears 35 gears 36 gears 37 Take-out shaft 38 transmission case 39 ball bearings 40 thrust ball bearing 41 rotating wheels 42 thrust ball bearing 43 Outer ring spacer 44 bearing 45 retaining ring

Front page continued (58) Fields surveyed (Int.Cl. ⁷ , DB name) F16H 13/00-15/56 F16H 57/00-57/12 F16C 19/00-19/56 F16C 33/30-33 / 66

Claims (5)

(57) [Claims] 1. A transmission case, and a case inside the transmission case.
One input shaft that is rotatably supported, and one axial surface of each of the input shafts is an input side concave surface having an arcuate cross section, and with the input side concave surfaces facing each other, there is a space around the input shaft. And a pair of input side discs that are non-rotatably provided with respect to the input shaft , and one side in each axial direction is an output side concave surface having an arcuate section, and the output side concave surface and the input side concave surface are Facing each other and free to rotate with respect to the input shaft as well as relative rotation between each other, in a portion between the pair of input side disks around the input shaft ,
Each is mounted on the transmission case by an angular ball bearing.
On the other hand, a pair of output side discs that are independently supported to rotate independently of each other, and a thrust bearing that is exclusively provided to receive a thrust load between the one axial side faces of the pair of output side discs. , A plurality of trunnions swinging about a pivot in a twisted position with respect to the input shaft, and a circumferential surface having a convex surface of a rotating arc surface, and rotatably supported by a displacement shaft supported by the trunnions, A toroidal type continuously variable transmission including a plurality of power rollers sandwiched between both input side and output side disks and output means for independently extracting the rotational force of the pair of output side disks. . 2. A thrust ball bearing provided on a rear surface of a pair of output disks, concentric with the output disks, and between gears rotatably supported together with the output disks. The toroidal type continuously variable transmission according to claim 1. 3. The toroidal type continuously variable transmission according to claim 2, wherein the inner rings forming the pair of angular type ball bearings are extended inward in the diametrical direction to form thrust ring bearing races. 4. The toroidal type continuously variable transmission according to claim 3, wherein two outer rings forming a pair of angular type ball bearings are integrated. 5. When the input torque is not applied, most of the axial thrust of the output side disk by the preload spring of the pressurizing device is applied to the pair of angular type ball bearings, and the thrust ball bearing receives almost no load. The toroidal type continuously variable transmission according to any one of claims 2 to 4, wherein an initial clearance of each of these ball bearings is set so as not to be received.