JP2002031206A - Toroidal type continuously variable transmission and continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a low-cost, small-sized and lightweight structure. SOLUTION: Abutting pressure of abutting parts of input side discs 2A', 2B, the inner surfaces 4a, 4a of output side discs 4, 4, and peripheral surfaces 9a, 9a of power rollers 9, 9 is obtained by spring force of a plate spring 52. A loading cam type pressing device is not provided. Since torque passing through a toroidal type continuously variable transmission is not largely fluctuated in a state where the continuously variable transmission is constituted by being combined with a planetary gear mechanism, transmitting efficiency can be sufficiently secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The toroidal type continuously variable transmission and the continuously variable transmission according to the present invention are used, for example, as a transmission incorporated in a pump or a generator installed in a building or a factory. In particular, the present invention is intended to simplify the structure of the toroidal type continuously variable transmission, reduce the size and weight and reduce the cost, and to ensure stable operation regardless of the magnitude of the torque to be transmitted.

[0002]

2. Description of the Related Art As an automatic transmission for an automobile, FIGS.
A toroidal type continuously variable transmission as schematically shown in FIG. This toroidal-type continuously variable transmission supports an input disk 2 concentrically with an input shaft 1 and is disposed concentrically with the input shaft 1 as disclosed in, for example, Japanese Utility Model Application Laid-Open No. 62-71465. An output disk 4 is fixed to an end of the output shaft 3. Inside the casing 5 (see FIGS. 6 to 7 described later) in which the toroidal-type continuously variable transmission is housed, the swinging motion is made about the pivots 6, 6 which are twisted with respect to the input shaft 1 and the output shaft 3. Trunnions 7 and 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 exists in a twisted position that is a direction perpendicular to or 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 allow the displacement shafts 8, 7 to swing. The inclination angles of 8, 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. These 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. Further, a loading device 10 of a loading cam type is provided between the input shaft 1 and the input side disk 2,
The pressing device 10 elastically presses the input-side disk 2 toward the output-side disk 4 and makes the input-side disk 2 freely rotatable.

When the toroidal-type continuously variable transmission configured as described above is used, the pressing device 10 is driven by the rotation of the input shaft 1.
Rotates the input side disk 2 while pressing the input side disk 2 against the plurality of power rollers 9, 9. Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 via the plurality of power rollers 9, 9, and the output shaft 3 fixed to the output side 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 and the peripheral surface 9 of each of the power rollers 9 and 9 described above.
As shown in FIG. 3, each of the displacement shafts 8 and 9a comes into contact with a portion of the inner surface 2a of the input disk 2 near the center and a portion of the inner surface 4a of the output disk 4 near the outer periphery. , 8 are tilted.

On the other hand, in order to increase the speed, the trunnions 7, 7 are swung, and the power rollers 9, 9 are rotated.
As shown in FIG. 4, the peripheral surfaces 9a, 9a of the input side disk 2
Each of the displacement shafts 8 is inclined so as to abut against a portion of the inner side surface 2a near the outer periphery and a portion of the inner side surface 4a of the output side disk 4 near the center, respectively. Each of these displacement axes 8, 8
If the angle of inclination is set between FIG. 3 and FIG. 4, an intermediate speed ratio can be obtained between the input shaft 1 and the output shaft 3.

FIGS. 5 and 6 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. A loading device 1 of a loading cam type is provided between the end of the input shaft 11 and the input disk 2.
0 is provided. On the other hand, an output gear 12 is connected to the output side disk 4 so that the output side 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 a pair of support plates (yoke) 1
In FIGS. 3 and 13, swing and axial directions (front and back directions in FIG. 5, FIG.
(Up and down direction). 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 direction in which the base half and the front half of each of the displacement shafts 8, 8 are eccentric is the same direction (vertical opposite direction in FIG. 6) with respect to the rotation direction 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 disposed.

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, the trunnions 7, 7 can be displaced in the axial direction of the pivots 6, 6 by hydraulic actuators (hydraulic cylinders) 17, 17.

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 side disk 2 via the pressing device 10. The rotation of the input disk 2 is transmitted to the output disk 4 via the pair of power rollers 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 right power roller 9 of FIG. 6 is placed on the lower side of FIG. 6, and the left 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, each of the trunnions 7, 7 is pivoted around the pivots 6, 6 pivotally supported by the support plates 13, 13.
Swing in opposite directions. As a result, as shown in FIGS. 3 and 4 described above, the peripheral surfaces 9a, 9
a and the inner surfaces 2a and 4a change, and the rotational speed ratio between the input shaft 11 and 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.

Further, in order to increase the transmittable torque, two input disks 2A and 2B and two output disks 4 and 4 are provided around the input shaft 11a as shown in FIGS. A so-called double-cavity structure in which two input disks 2A and 2B and two output disks 4 and 4 are arranged in parallel with respect to the power transmission direction is also conventionally known. The structure shown in FIGS. 7 and 8 supports an output gear 12a around an intermediate portion of the input shaft 11a so as to be freely rotatable with respect to the input shaft 11a, and a cylindrical portion provided at the center of the output gear 12a. The output disks 4 are spline-engaged at both ends.
Each of the input side disks 2A and 2B is connected to the input shaft 1
The input shaft 11a is rotatably supported at both ends of the shaft 1a. The input shaft 11a is driven by the drive shaft 18
It is rotationally driven via a loading cam type pressing device 10. In the case of such a double-cavity toroidal-type continuously variable transmission, transmission of power from the input shaft 11a to the output gear 12a is performed between one input-side disk 2A and the output-side disk 4 and the other side. Since power is divided into two systems, that is, between the input side disk 2B and the output side disk 4, large power can be transmitted.

When the toroidal-type continuously variable transmission configured and operating as described above is incorporated into an actual vehicle continuously variable transmission, a power circulation type continuously variable transmission is configured by combining with a planetary gear mechanism. Japanese Patent Application Laid-Open Nos. 1-169169, 1-312266 and 10-196759.
And JP-A-11-63146-7, etc., have been conventionally proposed. That is, the torque applied to the toroidal-type continuously variable transmission during high-speed traveling is transmitted by transmitting the driving force of the engine only at the time of low-speed traveling by the toroidal-type continuously variable transmission, and transmitting the driving force by the planetary gear mechanism at high-speed traveling. Is to be reduced. With this configuration, it is possible to improve the durability of each component of the toroidal-type continuously variable transmission.

FIG. 9 shows Japanese Patent Application Laid-Open No.
1 shows a continuously variable transmission described in 196759. The continuously variable transmission includes an engine 19 as a drive source.
Output end of the crankshaft 20 (right end in FIG. 9)
A start clutch 22 is provided between the input shaft 21 and the input end of the input shaft 21 (the left end in FIG. 9). An output shaft 23 for extracting power based on the rotation of the input shaft 21 is arranged in parallel with the input shaft 21. And this input shaft 21
Around the output shaft 2
A planetary gear mechanism 25 is provided around the periphery of each of the gears 3.

A cam plate 26 which constitutes the loading cam type pressing device 10 incorporated in the toroidal type continuously variable transmission 24 is fixed to an intermediate portion of the input shaft 21 near an output end (rightward in FIG. 9). are doing. The input side disk 2 and the output side disk 4 are arranged around the input shaft 21.
The input shaft 2 is formed by a bearing (not shown) such as a needle bearing.
In contrast to the first, the independent rotation is freely supported.
Then, by the cam plate 26 and the input side disk 2,
The pressing device 10 is configured. Therefore, the input side disk 2 rotates while being pressed toward the output side disk 4 as the input shaft 21 rotates. A plurality of power rollers 9, 9 are sandwiched between the inner surface 2a of the input side disk 2 and the inner side surface 4a of the output side disk 4 to form a toroidal type as shown in FIGS. The continuously variable transmission 24 is configured.

The sun gear 27 constituting the planetary gear mechanism 25 is fixed to the input end of the output shaft 23 (the right end in FIG. 9). Therefore, the output shaft 23 rotates with the rotation of the sun gear 27. This sun gear 27
, A ring gear 28 is supported concentrically with the sun gear 27 and rotatably. A plurality (usually 3 to 4) of planetary gear sets 29, 29 are provided between the inner peripheral surface of the ring gear 28 and the outer peripheral surface of the sun gear 27.
Is provided. In the illustrated example, each of these planetary gear sets 29,
Numeral 29 is a combination of a pair of planetary gears 30a and 30b. Each pair of these planetary gears 30a,
30b meshes with each other, meshes the planetary gear 30a arranged on the outer diameter side with the ring gear 28, and meshes the planetary gear 30b arranged on the inner diameter side with the sun gear 27. The reason that each planetary gear set 29, 29 is constituted by a pair of planetary gears 30a, 30b is to make the rotation directions of the ring gear 28 and the sun gear 27 coincide. Therefore, if it is not necessary to make the rotation directions of the ring gear 28 and the sun gear 27 coincide with each other in relation to other components, a single planetary gear meshes with both the ring gear 28 and the sun gear 27. You may let it. The planetary gear sets 29, 29 as described above
1 is rotatably supported on one side surface (the right side surface in FIG. 9). The carrier 31 is rotatably supported at an intermediate portion of the output shaft 23.

The carrier 31 and the output-side disk 4 are connected by a first power transmission mechanism 32 in a state where torque can be transmitted. In the illustrated example, the first power transmission mechanism 32 is constituted by first and second gears 33 and 34 meshed with each other. Accordingly, with the rotation of the output side disk 4, the carrier 31 moves the first and second gears 3 in the opposite direction to the output side disk 4.
It rotates at a speed corresponding to the number of teeth 3, 34.

On the other hand, the input shaft 21 and the ring gear 2
Reference numeral 8 designates a freely connectable state in which the second power transmission mechanism 35 can transmit torque. In the illustrated example, the second power transmission mechanism 35 is connected to the first and second sprockets 3.
6, 37, and a chain 38 bridged between the two sprockets 36, 37. That is,
The first sprocket 36 is fixed to a portion protruding from the cam plate 26 at the output end (the right end in FIG. 9) of the input shaft 21, and the second sprocket 37 is connected to the transmission shaft 39.
Is fixed to the input side end (the right end in FIG. 9). Accordingly, with the rotation of the input shaft 21, the transmission shaft 39 rotates in the same direction as the input shaft 21 at a speed corresponding to the number of teeth of the first and second sprockets 36 and 37.

Further, the continuously variable transmission has a clutch mechanism constituting mode switching means. In this clutch mechanism, only one of the carrier 31 and the transmission shaft 39 which is a component of the second power transmission mechanism 35 is connected to the ring gear 28. In the case of the structure shown in FIG. 9, the clutch mechanism includes a low speed clutch 40 and a high speed clutch 41. The low-speed clutch 40 is provided between the outer peripheral edge of the carrier 31 and one axial end of the ring gear 28 (the left end in FIG. 9). Such a low-speed clutch 40 prevents the relative displacement between the sun gear 27, the ring gear 28, and the planetary gear sets 29, 29 constituting the planetary gear mechanism 25 when connected, and the sun gear 27 and the ring gear 28 And are integrally joined. The high-speed clutch 41 is provided between the transmission shaft 39 and a center shaft 43 fixed to the ring gear 28 via a support plate 42. When one of the low-speed clutch 40 and the high-speed clutch 41 is connected, the connection of the other clutch is disconnected.

In the example shown in FIG.
And a fixed clutch such as a housing (not shown) of the continuously variable transmission. The reverse clutch 44 is provided to rotate the output shaft 23 in the reverse direction in order to reverse the vehicle. The reverse clutch 44 is in a state where one of the low speed clutch 40 and the high speed clutch 41 is connected.
Connection is lost. When the reverse clutch 44 is connected, the low-speed clutch 40 and the high-speed clutch 41 are both disconnected.

Further, in the illustrated example, the output shaft 23 and the differential gear 45 are connected to third to fifth gears 46 to 46.
The second power transmission mechanism 49 is connected by a third power transmission mechanism 49. Therefore, when the output shaft 23 rotates, the pair of left and right drive shafts 50, 50 rotates via the third power transmission mechanism 49 and the differential gear 45, and the drive wheels of the automobile are rotationally driven.

In the continuously variable transmission configured as described above, first, when the vehicle is running at a low speed, the low speed clutch 40 is connected, and the high speed clutch 41 and the reverse clutch 44 are disconnected. When the starting clutch 22 is connected and the input shaft 21 is rotated in this state, only the toroidal type continuously variable transmission 24 transmits power from the input shaft 21 to the output shaft 23. In such a low-speed running, the operation of changing the gear ratio between the input side and output side disks 2, 4 is different from that of the conventional toroidal type continuously variable transmission shown in FIGS. The same is true. Of course, in this state, the speed ratio between the input shaft 21 and the output shaft 23, that is, the speed ratio of the continuously variable transmission as a whole is proportional to the speed ratio of the toroidal type continuously variable transmission 24. In this state, the torque input to the toroidal type continuously variable transmission 24 is equal to the torque applied to the input shaft 21.

On the other hand, during high-speed running, the high-speed clutch 41 is connected and the low-speed clutch 40 and the reverse clutch 44 are disconnected. In this state, when the starting clutch 22 is connected and the input shaft 21 is rotated, the first and second sprockets constituting the second power transmission mechanism 35 are connected from the input shaft 21 to the output shaft 23. The power is transmitted to the gears 36, 37 and the chain 38 and the planetary gear mechanism 25.

That is, when the input shaft 21 rotates during the high-speed running, the rotation is transmitted to the center shaft 43 via the second power transmission mechanism 35 and the high-speed clutch 41,
The ring gear 28 to which the central shaft 43 is fixed is rotated. Then, the rotation of the ring gear 28 is transmitted to the sun gear 27 via the plurality of planetary gear sets 29, 29, and rotates the output shaft 23 to which the sun gear 27 is fixed. When the ring gear 28 is on the input side, the planetary gear mechanism 25 assumes that each of the planetary gear sets 29, 29 is stopped (does not revolve around the sun gear 27).
The speed is increased at a gear ratio according to the ratio of the number of teeth between the ring gear 28 and the sun gear 27. However, each of the above planetary gear sets 2
The gears 9 and 29 revolve around the sun gear 27, and the gear ratio of the entire continuously variable transmission is determined by each of the planetary gear sets 29 and 29.
It changes according to the orbital speed of 29. Therefore, by changing the speed ratio of the toroidal type continuously variable transmission 24 and changing the revolution speed of each of the planetary gear sets 29, 29, the speed ratio of the entire continuously variable transmission can be adjusted.

That is, each of the planetary gear sets 29 revolves in the same direction as the ring gear 28 during the high-speed running. The lower the revolution speed of each of the planetary gear sets 29, 29, the higher the rotation speed of the output shaft 23 to which the sun gear 27 is fixed. For example, if the revolution speed becomes equal to the rotation speed of the ring gear 28 (both angular velocities), the rotation speed of the ring gear 28 becomes equal to the rotation speed of the output shaft 23.
On the other hand, if the revolution speed is lower than the rotation speed of the ring gear 28, the rotation speed of the output shaft 23 is higher than the rotation speed of the ring gear 28. Conversely, if the revolution speed is higher than the rotation speed of the ring gear 28, the rotation speed of the output shaft 23 is lower than the rotation speed of the ring gear 28.

Accordingly, during the high-speed running, the speed ratio of the entire continuously variable transmission changes to the speed increasing side as the speed ratio of the toroidal type continuously variable transmission 24 changes to the speed decreasing side. In such a state at the time of high-speed running, torque is applied to the toroidal-type continuously variable transmission 24 from the output-side disk 4 instead of the input-side disk 2 (when the torque applied at low speed is plus torque, minus torque is applied). Torque is applied). That is, when the high-speed clutch 41 is connected, the torque transmitted from the engine 19 to the input shaft 21 is applied to the second power transmission mechanism before the pressing device 10 presses the input disk 2. The light is transmitted to the ring gear 28 of the planetary gear mechanism 25 through the reference numeral 35. Therefore, almost no torque is transmitted from the input shaft 21 to the input disk 2 via the pressing device 10.

On the other hand, a part of the torque transmitted to the ring gear 28 of the planetary gear mechanism 25 via the second power transmission mechanism 35 is transmitted from the respective planetary gear sets 29, 29 to the carrier 31 and the first Through the power transmission mechanism 32 to the output side disk 4. As described above, the torque applied from the output side disk 4 to the toroidal type continuously variable transmission 24 changes the transmission ratio of the toroidal type continuously variable transmission 24 to the reduction side in order to change the transmission ratio of the entire continuously variable transmission to the speed increasing side. The smaller the value, the smaller it becomes. As a result, the torque input to the toroidal type continuously variable transmission 24 during high-speed running can be reduced, and the durability of the components of the toroidal type continuously variable transmission 24 can be improved.

Further, when the output shaft 23 is rotated in the reverse direction in order to reverse the vehicle, both the low speed and high speed clutches 40 and 41 are disconnected and the reverse clutch 44 is connected. As a result, the ring gear 28 is fixed, and the respective planetary gear sets 29, 29 revolve around the sun gear 27 while meshing with the ring gear 28 and the sun gear 27. And this sun gear 2
The output shaft 7 to which the sun gear 27 and the sun gear 27 are fixed rotates in a direction opposite to that at the time of the above-described low-speed running and at the time of the above-described high-speed running.

The toroidal-type continuously variable transmission 24 incorporated in the above-described continuously variable transmission is not limited to the single-cavity type shown in FIGS.
To 8 may be used. A continuously variable transmission incorporating a double-cavity toroidal-type continuously variable transmission is described in JP-A-11-63146-7 or the like. For example, FIGS. 10 to 11 show two examples of a continuously variable transmission described in JP-A-11-63147. Among them, the structure shown in FIG. 10 is a double-cavity toroidal type continuously variable transmission 24.
9A, the input shaft 21a is inserted into the center of the toroidal-type continuously variable transmission 2 as in the case of the structure shown in FIG.
The power is divided between the toroidal type continuously variable transmission 24a and the planetary gear mechanism 25 on the side opposite to the input section in the axial direction of 4a. On the other hand, the structure shown in FIG. 11 is such that the transmission shaft 51 is provided beside the toroidal-type continuously variable transmission 24a.
Are arranged in parallel with the toroidal-type continuously variable transmission 24a, and the toroidal-type continuously variable transmission 24a is arranged on the same side as the input portion in the axial direction of the toroidal-type continuously variable transmission 24a.
a and the planetary gear mechanism 25.

In any structure, by combining the toroidal type continuously variable transmissions 24 and 24a and the planetary gear mechanism 25, a power circulating type continuously variable transmission called a power split type is constituted. Further, the power passing through the toroidal type continuously variable transmission 24, 24a during high-speed running can be reduced. Therefore, the toroidal type continuously variable transmission 2
4, 24a can be improved in durability. That is, the ratio of the torque applied to the input side disks 2, 2A, 2B constituting the toroidal-type continuously variable transmission 24, 24a to the torque applied to the toroidal-type continuously variable transmission 24, 24a from the driving source such as the engine. Changes as shown in FIG.

In FIG. 12, the α range located in the left half portion is where the low speed clutch 40 is connected and the high speed clutch 4 is connected.
1 corresponds to the low-speed mode state in which the connection is disconnected, and the β range located in the right half corresponds to the high-speed mode state in which the high-speed clutch 41 is connected and the low-speed clutch 40 is disconnected. As is apparent from FIG. 12, in the low-speed mode, the torque of the driving source passes through the toroidal-type continuously variable transmissions 24 and 24a as it is, but in the high-speed mode,
The torque that passes through the toroidal type continuously variable transmission 24, 24a decreases as the speed ratio of the entire continuously variable transmission changes to the speed increasing state. As is clear from the above description, in the high-speed mode state corresponding to the above-mentioned β range, as the speed ratio of the entire continuously variable transmission changes to the speed-up state,
The speed change state of the toroidal-type continuously variable transmission 24, 24a changes to the reduction side.

Each of the continuously variable transmissions shown in FIGS. 9 to 11 is intended to constitute an automatic transmission for an automobile, and power is transmitted only by the toroidal type continuously variable transmissions 24 and 24a. The range from the low-speed running mode to the high-speed mode in which power transmission is mainly performed by the planetary gear mechanism 25 is used. On the other hand, the drive of auxiliary equipment attached to various engines, pumps and generators installed in buildings, etc. is controlled by an engine or a motor by combining a toroidal type continuously variable transmission with a planetary gear mechanism. It has been considered to be performed via a step transmission.

In the case of a continuously variable transmission used for such an application, a large gear ratio is not required and a rotation direction needs to be changed as compared with a continuously variable transmission used as an automatic transmission for an automobile. Absent. For this reason, it is conceivable that the power is mainly transmitted by the planetary gear mechanism, and the toroidal type continuously variable transmission employs a mechanism used only for changing the speed ratio of the planetary gear mechanism. In this case, the low-speed clutch 40 and the reverse clutch 44 are omitted from the continuously variable transmission shown in FIGS. 9 to 11, and the second power transmission mechanism 35 and the ring gear 28 can always transmit power. Combine with.

[0037]

When implementing a continuously variable transmission for transmitting power mainly through the planetary gear mechanism 25 as described above, a continuously variable transmission that is supposed to be used as an automatic transmission for automobiles is considered. If the configuration of the step transmission is used as it is, the following waste occurs. That is, in the case of an automobile transmission, since the torque to be transmitted fluctuates greatly, the input disks 2, 2A, 2B, the inner surfaces 2a, 4a of the output disk 4, and the peripheral surfaces of the power rollers 9, 9 are formed. In order to make the surface pressure of the contact portion with 9a, 9a an appropriate value regardless of the above fluctuation,
A loading device 10 of a loading cam type was provided. On the other hand, when the continuously variable transmission is incorporated in a drive for driving a pump or a generator, the torque passing through the toroidal-type continuously variable transmission incorporated in the continuously variable transmission does not change much. It is not possible to incorporate the above-described pressing device 10 in which a toroidal type continuously variable transmission used in such a state requires many components and requires precise processing such as a precise cam surface. It is useless.

Further, depending on the pump or generator to be driven, the contact pressure of the contact portion between the surfaces 2a, 4a and 9a becomes unstable, and the transmission efficiency of the continuously variable transmission is not necessarily increased. May not be able to keep good. For this reason,
This will be described with reference to FIG. The loading device 10 of the loading cam type has a thrust (the above-mentioned surfaces 2a,
No axial force for applying a contact pressure to the contact portion between 4a and 9a) is generated. Therefore, in order to prevent slippage from occurring at the contact portion immediately after the start of torque transmission, as shown in FIGS.
The contact pressure is applied to the contact portions of the members a, 4a and 9a.
In the toroidal type continuously variable transmission incorporating the pressing device 10 and the plate spring 52 in this manner, the thrust changes as shown in FIG. 13 according to the change in the torque to be transmitted. In FIG. 13, the relatively flat portion at the center is the above-mentioned disc spring 52.
Of the pressing device 1
0. In addition, the lines are doubled up and down in each part due to hysteresis.

When a pump or a generator is driven to rotate by a continuously variable transmission incorporating a toroidal type continuously variable transmission, the torque passing through the toroidal type continuously variable transmission is
In the case where it is near the switching point between the disc leaf spring 52 and the pressing device 10 surrounded by a chain line 図 in FIG. 13, the contact pressure applied to the contact portion between the surfaces 2a, 4a, and 9a is Becomes unstable. As a result, as described above, the transmission efficiency of the continuously variable transmission cannot always be kept good. The toroidal-type continuously variable transmission and the continuously variable transmission according to the present invention have been invented in view of such circumstances.

[0040]

SUMMARY OF THE INVENTION Among the toroidal-type continuously variable transmission and the continuously variable transmission according to the present invention, the toroidal-type continuously variable transmission according to the first aspect has a concave surface having an arc-shaped cross section. The input side disk and the output side disk which are supported concentrically and rotatably in a state where the inner side surfaces of the input side disk face each other, and a pivot which is twisted with respect to the center axis of the input side disk and the output side disk A plurality of trunnions swinging around the center, a displacement shaft supported at a middle portion of each of the trunnions so as to protrude from the inner surface of each of the trunnions, and A power roller having a circumferential surface that is spherically convex and rotatably supported around each of the displacement axes while being sandwiched between the side disk and the output side disk. In particular, in the toroidal type continuously variable transmission according to the present invention, the contact pressure of the contact portion between the inner surface of the input disk and the output disk and the peripheral surface of each power roller is ensured. The pressing means comprises only a disc spring that presses one of the input-side disk and the output-side disk toward the other disk.

Further, the continuously variable transmission according to claim 2 is
2. A toroidal continuously variable transmission according to claim 1, wherein the input shaft is connected to a drive source and is rotationally driven by the drive source, an output shaft for taking out power based on the rotation of the input shaft, a planetary gear mechanism, and an output shaft. A first power transmission mechanism for transmitting the power input to the input shaft through the toroidal-type continuously variable transmission; and a power transmission mechanism for transmitting the power input to the input shaft through the toroidal-type continuously variable transmission. And a second power transmission mechanism for transmitting without power. The planetary gear mechanism is provided between a sun gear and a ring gear disposed around the sun gear, and includes a planetary gear rotatably supported by a carrier that is rotatably supported concentrically with the sun gear. The sun gear and the ring gear are engaged with each other. The power transmitted through the first power transmission mechanism and the power transmitted through the second power transmission mechanism can be freely transmitted to two members of the sun gear, the ring gear, and the carrier. In addition, the output shaft is connected to the remaining one of the sun gear, the ring gear, and the carrier.

[0042]

The operation of the toroidal-type continuously variable transmission of the present invention configured as described above is the same as that of the conventional toroidal-type continuously variable transmission shown in FIGS. The operation of converting the speed ratio between the input shaft and the output shaft to a continuously variable value by the continuously variable transmission of the present invention incorporating the continuously variable transmission is performed, for example, as shown in FIGS. ,
This is the same as a shift operation in a state in which only a high-speed clutch is connected and other clutches are disconnected in a conventionally known power circulation type continuously variable transmission. In particular, according to the toroidal type continuously variable transmission and the continuously variable transmission of the present invention, it is possible to reduce the size and weight by simplifying the structure of the toroidal type continuously variable transmission and to secure transmission efficiency. That is, in the case of the toroidal-type continuously variable transmission of the present invention, the pressing means for securing the contact pressure of the contact portion between the inner surfaces of both the input and output disks and the peripheral surface of each power roller is provided. Since only the disc spring is used and the loading device of the loading cam type is omitted, the cost can be reduced and the size and weight can be reduced by simplifying the structure. Further, the contact pressure is made substantially constant, so that it is possible to prevent the transmission efficiency from being deteriorated due to the sudden change in the contact pressure.

[0043]

FIG. 1 shows a first embodiment of the present invention.
An example is shown. In this example, the input disks 2A and 2B and the output disks 4 and 4 as shown in FIGS.
Are shown in a case where the present invention is applied to a so-called double-cavity toroidal type continuously variable transmission in which a pair is provided in series with respect to the power transmission direction. still,
The feature of the present invention lies in that the pressing means is constituted only by the plate spring 52 in order to secure transmission efficiency while reducing costs and reducing size and weight. Since the configuration and operation of the other parts are the same as those of the conventional structure shown in FIGS. 7 and 8 described above, the same parts are denoted by the same reference numerals, and duplicated description is omitted or simplified. The following description focuses on the characteristic portions of

A portion of the input disk 2A '(left side in FIG. 1) close to the inner diameter of the outer surface of the input shaft 11a is abutted against a flange 53 formed on the outer peripheral surface of the base end (left end in FIG. 1). ing. The inner peripheral surface of the input side disk 2A 'is spline-engaged with the input shaft 11a near the base end of the input shaft 11a. On the other hand, the inner peripheral surface of the other input-side disk 2B (right side in FIG. 1) is located near the front end of the input shaft 11a (rightward in FIG. On the other hand, only the displacement in the axial direction is supported freely. The disc spring 52 is provided between the loading nut 55 screwed to the tip of the input shaft 11a and the other input-side disc 2B. Therefore, the other input-side disk 2B and the one input-side disk 2A 'rotate synchronously with each other while the elasticity in the direction approaching each other is provided.

For example, when the one input side disk 2A 'is rotationally driven via a drive shaft 56 by a driving source (not shown) in order to drive a pump or the like, the other input side disk 2B also rotates synchronously. The rotation of the two input-side disks 2A 'and 2B is performed by a pair of output-side disks 4, 4 via a plurality of power rollers 9, 9, respectively.
Transmitted to. In this way, these two output disks 4, 4
Is transmitted through an output gear 12a provided at the center of the outer peripheral surface of a sleeve 57 in which both output disks 4, 4 are spline-engaged at both ends thereof.

As described above, each of the input side disks 2A ', 2A'
B, when transmitting power between the output side disks 4 and 4, the inner surfaces 2 of these disks 2A 'and 2B
a, 4a and outer peripheral surfaces 9a, 9 of the power rollers 9, 9, respectively.
The contact pressure of the contact portion with a is secured by the elasticity of the plate spring 52. Therefore, no slippage or the like occurs at these contact portions. The contact pressure applied to each of these contact portions based on the elasticity of the disc spring 52 remains substantially constant irrespective of the torque applied from the drive shaft 56 to the one input side disk 2A '. is there. However, by combining the toroidal type continuously variable transmission of the present invention with a planetary gear mechanism,
When a continuously variable transmission for driving a pump, a generator, or the like is configured, a sufficient transmission efficiency can be obtained even if the contact pressure remains constant. This reason will be described with reference to FIG.

When a continuously variable transmission for driving a pump, a generator and the like is configured by combining a toroidal type continuously variable transmission with a planetary gear mechanism, as described above, FIGS.
1, the low-speed, high-speed, and reverse clutches 40, 41, and 44 are removed, and the planetary gear mechanism is always used for power transmission, and the toroidal-type continuously variable transmission uses the planetary gear mechanism. Used only to change gear ratios. In such a case, the speed ratio of the entire continuously variable transmission changes as shown by the solid line A in FIG. 2, and the speed ratio of the toroidal type continuously variable transmission also changes as shown by the broken line B.
The input torque of the entire continuously variable transmission changes as shown by the solid line C in FIG. 2 and the output torque changes as shown by the broken line D, while passing through the toroidal type continuously variable transmission. The torque to be applied does not change much, as shown by the chain line E in FIG. As is apparent from the chain line E in FIG. 2, a sufficient transmission efficiency can be obtained even when the contact pressure is kept constant.

According to the present invention, as shown in the figure, the contact point between the peripheral surface of each power roller and the inner surface of each disk exists in a state where the contact point is deviated to one side with respect to the center of the tilt point of each power roller. It is preferable to use a half toroidal type continuously variable transmission. The reason for this is that in the case of a half toroidal type continuously variable transmission, the pressing force required during operation is substantially constant. On the other hand, in the case of the full toroidal type continuously variable transmission, the contact point between the peripheral surface of each power roller and the inner surface of each disk is located 180 degrees opposite to the center of the tilt point of each power roller. The required pressing force greatly varies depending on the gear ratio. Therefore, since the pressing means is constituted only by the plate spring, it is not appropriate to carry out the present invention in which the pressing force is substantially constant by using a full toroidal type continuously variable transmission. In other words, the present invention is an effective invention in a half toroidal type continuously variable transmission.

[0049]

Since the present invention is constructed and operates as described above, it can contribute to the realization of a toroidal-type continuously variable transmission and a continuously variable transmission that are small, lightweight, low-cost, and have good transmission efficiency.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of the present invention in a state where only a toroidal type continuously variable transmission is taken out.

FIG. 2 shows the input, output torque and gear ratio of the continuously variable transmission;
The input torque and the transmission of the toroidal type continuously variable transmission incorporated in the continuously variable transmission are related to the speed ratio of the entire continuously variable transmission (the pump rotation speed when the rotation speed of the drive source is constant). FIG.

FIG. 3 is a schematic side view showing a basic structure of the toroidal-type continuously variable transmission in a state of maximum deceleration.

FIG. 4 is a schematic side view similarly showing a state at the time of maximum speed increase.

FIG. 5 is an essential part cross-sectional view showing a first example of a specific structure of the toroidal type continuously variable transmission.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is an essential part cross-sectional view showing a second example of the specific structure of the toroidal-type continuously variable transmission.

FIG. 8 is a sectional view taken along line BB of FIG. 7;

FIG. 9 is a schematic sectional view showing a first example of a continuously variable transmission incorporating a toroidal type continuously variable transmission.

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

FIG. 11 is a schematic sectional view showing the third example.

FIG. 12 is a diagram showing the relationship between the speed ratio of the entire continuously variable transmission (vehicle speed when the engine speed is constant) and the ratio of the torque applied to the input side disk to the engine torque.

FIG. 13 is a diagram showing a relationship between a transmission torque and a cam generating thrust in a toroidal continuously variable transmission incorporating a pressing device and a plate spring.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2, 2A, 2B, 2A 'input side disk 2a inner surface 3 output shaft 4 output side disk 4a inner surface 5 casing 6 pivot 7 trunnion 8 displacement shaft 9 power roller 9a peripheral surface 10 pressing device 11, 11a input shaft 12, 12a output gear 13 support plate (yoke) 14 thrust ball bearing 15 thrust needle bearing 16 outer ring 17 actuator 18 drive shaft 19 engine 20 crankshaft 21, 21a input shaft 22 starting clutch 23 output shaft 24, 24a toroidal type continuously variable transmission Machine 25 planetary gear mechanism 26 cam plate 27 sun gear 28 ring gear 29 planetary gear set 30a, 30b planetary gear 31 carrier 32 first power transmission mechanism 33 first gear 34 second gear 35 second power transmission mechanism 36 First sprocket 37 Second sprocket Ket 38 Chain 39 Transmission shaft 40 Low speed clutch 41 High speed clutch 42 Support plate 43 Center shaft 44 Reverse clutch 45 Differential gear 46 Third gear 47 Fourth gear 48 Fifth gear 49 Third power transmission mechanism 50 Drive shaft 51 Transmission shaft 52 Disc spring 53 Flange 54 Ball spline 55 Loading nut 56 Drive shaft 57 Sleeve

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Imanishi 1-5-50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa F-term in NSK Ltd. (reference) 3J028 EA07 EA25 EB10 EB16 EB25 EB35 EB37 EB50 EB62 EB66 FA06 FB05 FC16 FC23 3J051 AA03 BA03 BB02 BD02 BE09 CA05 CB06 CB07 DA03 EA01 EB01 EC02 ED15 FA02

Claims (2)

[Claims] An input disk and an output disk which are concentrically and rotatably supported in a state in which their inner surfaces each having a concave surface having an arc-shaped cross section are opposed to each other, and said input disk. And a plurality of trunnions swinging about a pivot axis which is twisted with respect to the center axis of the output side disc, and a displacement shaft supported at a middle portion of each of the trunnions in a state of protruding from the inner surface of each of the trunnions. And are arranged on the inner surface side of each of these trunnions and supported rotatably around each of the displacement shafts while being sandwiched between the input side disk and the output side disk. In the toroidal-type continuously variable transmission having the power rollers described above, a contact portion between the inner surfaces of the input-side disk and the output-side disk and the peripheral surfaces of the power rollers. Characterized in that the pressing means for securing the contact pressure of the disk is constituted only by a disc spring for pressing one of the input-side disk and the output-side disk toward the other disk. Type continuously variable transmission. 2. The toroidal according to claim 1, wherein the input shaft is connected to a driving source and is rotationally driven by the driving source, an output shaft for extracting power based on the rotation of the input shaft, a planetary gear mechanism, and the toroidal. Type continuously variable transmission, a first power transmission mechanism for transmitting the power input to the input shaft through the toroidal type continuously variable transmission, and a power input to the input shaft to the toroidal type continuously variable transmission. A second power transmission mechanism that transmits without passing through a transmission, the planetary gear mechanism includes:
A planetary gear, which is provided between a sun gear and a ring gear disposed around the sun gear and is rotatably supported by a carrier that is rotatably supported concentrically with the sun gear,
The sun gear and the ring gear are meshed with each other, and the power transmitted through the first power transmission mechanism and the power transmitted through the second power transmission mechanism are the sun gear and the ring gear. 2 of the above carriers
A continuously variable transmission in which the output shaft is coupled to the remaining one of the sun gear, the ring gear, and the carrier.