JPH11280867A - Continously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the durability by reducing a load applied to a component of a toroidal continuously variable transmission. SOLUTION: During low speed running, a low speed clutch 57 is engaged while a high speed clutch 58 and a backward clutch 61 are disengaged. During high speed running, the high speed clutch 58 is engaged while the low speed clutch 57 and the backward clutch 61 are disengaged. During high speed running a torque is applied to an output side disc 4 of a toroidal type continuously variable transmission. This torque becomes smaller as the gear ratio is displaced toward the high speed side as a whole. Correspondingly, a load applied to a component of the toroidal continuously variable transmission 34 is reduced. Further, the coupling conditions among components are contrived so as to reduce the number of components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a continuously variable transmission incorporating a toroidal type continuously variable transmission, which is used as, for example, a transmission for an automobile. This realizes a structure that can ensure the durability of the member.

[0002]

2. Description of the Related Art FIGS.
The use of a toroidal-type continuously variable transmission, such as the one shown in FIG. This toroidal type continuously variable transmission supports an input disk 2 concentrically with an input shaft 1 and an output shaft disposed concentrically with the input shaft 1 as disclosed in, for example, Japanese Utility Model Application Laid-Open No. 71465/1987. The output disk 4 is fixed to the end of the output disk 3. Inside the casing containing the toroidal-type continuously variable transmission, trunnions 6, 6 that swing about pivots 5, 5 that are twisted with respect to the input shaft 1 and the output shaft 3, are provided.

That is, the pivots 5, 5 are provided concentrically on the outer surfaces of both ends of the trunnions 6, 6 at right angles to the axial directions of the input shaft 1 and the output shaft 3, respectively. The trunnions 6, 6 are supported at their central ends by the base ends of the displacement shafts 7, 7, and by swinging the trunnions 6, 6 around the pivots 5, 5, the respective displacement shafts 7, 6 are pivoted. The inclination angle of 7 can be freely adjusted. Power rollers 8, 8 are rotatably supported around displacement shafts 7, 7 supported by the trunnions 6, 6, respectively. These power rollers 8, 8 are sandwiched between the input and output disks 2, 4. Inner surfaces 2a, 4a of these input and output disks 2, 4 facing each other
Have a concave surface obtained by rotating an arc around the pivot 5 about the central axis of the disk. Then, the peripheral surfaces 8a, 8a of the respective power rollers 8, 8, which are formed in a spherical convex surface, are attached to the inner surfaces 2a, 4a.
a.

[0004] A loading device 9 of a loading cam type is provided between the input shaft 1 and the input disk 2, and the input disk 2 is connected to the output disk 4 by the pressing device 9.
To be elastically pressable. This pressing device 9
Is a cam plate 10 that rotates together with the input shaft 1 and a retainer 11
(For example, four) rollers 12 held by
12. On one side surface (left side surface in FIGS. 7 and 8) of the cam plate 10, a cam surface 13 which is an uneven surface extending in a circumferential direction is formed, and an outer surface of the input disk 2 (FIG. 7).
The same cam surface 14 is also formed on the right side surfaces of No. 8 to No. 8). The plurality of rollers 12, 12 are rotatably supported around a radial axis with respect to the center of the input shaft 1.

When the cam plate 10 rotates with the rotation of the input shaft 1 when using the toroidal type continuously variable transmission configured as described above, a plurality of rollers 12, 12
Is pressed against the cam surface 14 formed on the outer surface of the input disk 2. As a result, at the same time that the input disk 2 is pressed by the plurality of power rollers 8, 8, the input disk 2 is pressed based on the pressing of the pair of cam surfaces 13, 14 and the plurality of rollers 12, 12. The disk 2 rotates.
Then, the rotation of the input disk 2 is transmitted to the output disk 4 via the plurality of power rollers 8, 8, and the output shaft 3 fixed to the output disk 4 rotates.

When changing the rotation speed ratio (reduction ratio) between the input shaft 1 and the output shaft 3, first, the input shaft 1 and the output shaft 3 are changed.
When deceleration is performed between the power rollers 8 and 5, the trunnions 6 and 6 are swung about the pivots 5 and
As shown in FIG. 7, the peripheral surfaces 8a of the input disk 2
Each of the displacement shafts 7 is inclined so as to abut against the center portion of the inner surface 2a of the output disk 4 and the portion near the outer periphery of the inner surface 4a of the output disk 4, respectively. Conversely, when increasing the speed, the trunnions 6, 6 are swung so that the peripheral surfaces 8a, 8a of the power rollers 8, 8, as shown in FIG. So as to abut against the deflected portion and the deflected portion of the inner surface 4a of the output disk 4 respectively.
Each displacement shaft 7, 7 is inclined. If the inclination angle of each of the displacement shafts 7, 7 is set between those in FIGS. 7 and 8, the input shaft 1 and the output shaft 3
And an intermediate reduction ratio can be obtained.

FIGS. 9 to 10 show Japanese Utility Model Application No. 63-6929.
3 shows an example of a more specific toroidal-type continuously variable transmission described in the microfilm of No. 3 (Japanese Utility Model Laid-Open No. 1-173552). The input disk 2 and the output disk 4 are rotatably supported around a circular input shaft 15 via needle bearings 16 and 16, respectively.
Further, the cam plate 10 is spline-engaged with the outer peripheral surface of the end portion (the left end portion in FIG. 9) of the input shaft 15, and is prevented from moving away from the input disk 2 by the flange portion 17. The cam plate 10 and the rollers 12, 12 constitute a pressing device 9 for rotating the input disk 2 while pressing the input disk 2 toward the output disk 4 based on the rotation of the input shaft 15. An output gear 18 is connected to the output disk 4 by keys 19, 19, so that the output disk 4 and the output gear 18 rotate synchronously.

Both ends of the pair of trunnions 6, 6 are supported on a pair of support plates 20, 20 so as to be swingable and displaceable in the axial direction (front and back directions in FIG. 9, and left and right directions in FIG. 10). I have. The displacement shafts 7, 7 are supported in circular holes 21, 21 formed in the middle portions of the trunnions 6, 6, respectively. Each of the displacement shafts 7 has a support shaft 22, 22 and a pivot shaft 23, 23 which are parallel and eccentric to each other. Each of the support shaft portions 22, 22 is provided inside the above-mentioned circular hole 21, 21 with a radial needle bearing 24,
It is rotatably supported via 24. Further, the power rollers 8, 8 are rotatably supported around the pivot shafts 23, 23 via other radial needle bearings 25, 25.

The pair of displacement shafts 7, 7 are provided at positions opposite to the input shaft 15 by 180 degrees. or,
The directions in which the respective pivot shaft portions 23, 23 of these displacement shafts 7, 7 are eccentric with respect to the respective support shaft portions 22, 22 are determined by the input,
With respect to the rotation direction of both output discs 2 and 4, the same direction (FIG. 10)
In opposite directions). The eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 15 is provided.
Therefore, each of the power rollers 8 is connected to the input shaft 15.
Are supported so as to be slightly displaceable in the disposing direction. As a result, the power rollers 8, 8 move in the axial direction of the input shaft 15 (see FIG. 9) due to the elastic deformation of these components based on the large load applied to the components in the state of transmission of the rotational force. Even in the case of displacement in the left-right direction (the front-back direction in FIG. 10), this displacement can be absorbed without applying excessive force to each of the above components.

Further, between the outer surface of each of the power rollers 8, 8 and the inner surface of the intermediate portion of each of the trunnions 6, 6, a thrust ball bearing 26, 26 and thrust needle bearings 27, 27 are provided. The thrust ball bearings 26 support rotation of the power rollers 8 while supporting the load applied to the power rollers 8 in the thrust direction. In addition, each of the above thrust needle bearings 2
7, 27 support the thrust load applied from the power rollers 8, 8 to the outer rings 28, 28 constituting the thrust ball bearings 26, 26, respectively, while supporting the pivot shaft portions 23, 2,
3 and the outer races 28, 28 support the support shafts 22, 22.
Swing around the center.

Further, drive rods 29, 29 are provided at one end (the left end in FIG. 10) of each of the trunnions 6, 6, respectively.
And drive pistons 30, 30 are fixedly mounted on the outer peripheral surfaces of the intermediate portions of these drive rods 29, 29. And
These drive pistons 30, 30 are oil-tightly fitted in drive cylinders 31, 31, respectively.

During operation of the toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 15 is transmitted to the input disk 2 via the pressing device 9. Then, the rotation of the input disk 2 is transmitted to the output disk 4 via the pair of power rollers 8, and the rotation of the output disk 4 is
It is taken out from the output gear 18. When changing the rotational speed ratio between the input shaft 15 and the output gear 18, the pair of drive pistons 30, 30 are displaced in opposite directions.
With the displacement of each of the driving pistons 30, 30,
The pair of trunnions 6 are displaced in opposite directions, for example, the lower power roller 8 in FIG. 10 is displaced to the right in FIG. 10 and the upper power roller 8 in FIG. 10 is displaced to the left in FIG. . As a result, the direction of the tangential force acting on the contact portions between the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a, 4a of the input disk 2 and the output disk 4 changes. Then, with the change in the direction of the force, the trunnions 6 swing in opposite directions about the pivots 5 pivotally supported by the support plates 20. As a result, as shown in FIGS. 7 and 8 described above, the peripheral surfaces 8a and 8a of the power rollers 8 and the inner surfaces 2 and
a, 4a, and the rotation speed ratio between the input shaft 15 and the output gear 18 changes.

The input shaft 15 and the output gear 1 are
When transmitting the rotational force to the power rollers 8, the power rollers 8, 8 are displaced in the axial direction of the input shaft 15 based on the elastic deformation of the constituent members. Each of the displacement shafts 7 that pivotally support 8 rotates slightly about each of the support shaft portions 22. As a result of this rotation, the outer ring 2 of each of the thrust ball bearings 26, 26
The outer surfaces of the trunnions 6, 6 and the inner surfaces of the trunnions 6, 6 are relatively displaced. Since the thrust needle bearings 27 exist between the outer surface and the inner surface, the force required for the relative displacement is small. Therefore, the force for changing the inclination angle of each of the displacement shafts 7 can be small as described above.

When the toroidal-type continuously variable transmission constructed and operated as described above is incorporated in an actual continuously variable transmission for an automobile, it is known to construct a continuously variable transmission in combination with a planetary gear mechanism. No. 169169, 1-282
As described in Japanese Patent Publication No. 266, it has been conventionally proposed. FIG. 11 schematically shows the basic configuration of such a conventionally proposed continuously variable transmission. A drive shaft 33 (crankshaft) of an engine 32, which is a drive source, is coupled to the input shaft 15 (see FIGS. 9 to 10) of a toroidal-type continuously variable transmission 34 having a configuration as shown in FIGS. ing. An output shaft 36 for driving the drive wheels via a differential gear 35 (see FIGS. 1, 3 to 6 showing an embodiment of the present invention and FIG. 12 described later) is a sun gear constituting a planetary gear mechanism 37. The gear 38 (see FIGS. 1, 3 to 6, and 12) is connected and fixed to rotate with the sun gear 38.

The output disk 4 of the toroidal type continuously variable transmission 34 (see FIGS. 1, 3 to 6, 7 to 9, and 12) and a part of the planetary gear mechanism 37 are connected to a first power source. The transmission mechanism 38 is connected to enable transmission of the rotational force. Also, the drive shaft 33 and the input shaft 15 and other components of the planetary gear mechanism 37 are connected to the second power transmission mechanism 3.
9 enables the connection of the rotational force to be possible. Further, the drive shaft 33, the input shaft 15 and the output shaft 3
6 can be freely switched between three types of modes: a high-speed running mode, a low-speed running mode, and a reverse mode.
Switching means. Then, the ratio β / α of the reduction ratio α of the first power transmission mechanism 38 and the reduction ratio β of the second power transmission mechanism 39 is reduced by the deceleration of the toroidal type continuously variable transmission 34 at the time of maximum speed increase. the ratio is substantially equal to the i _H (reduction ratio between the input shaft 1 and the output shaft 3 in a state shown in FIG. 7).

The continuously variable transmission as shown in FIG.
In a low-speed running mode, the drive shaft 33, the input shaft 15, and the output shaft 36 are called a power split type.
Of the toroidal type continuously variable transmission 34
To communicate through. In high-speed driving mode, on the other hand,
Power is transmitted through the planetary gear mechanism 37, and a part of the power is circulated from the planetary gear mechanism 37 to the toroidal type continuously variable transmission 34. That is, during low-speed running, the driving force of the engine 32 is transmitted to the toroidal-type continuously variable transmission 3.
4, and the driving force is transmitted by the planetary gear mechanism 37 during high-speed running, thereby reducing the torque applied to the toroidal-type continuously variable transmission 34 during high-speed running. With this configuration, the durability of each component of the toroidal type continuously variable transmission 34 can be improved, and at the same time, the transmission efficiency of the entire continuously variable transmission can be improved.

The continuously variable transmission called a power split type as described above can reduce the torque transmitted through the toroidal type continuously variable transmission during high-speed running, thereby improving the durability and the transmission efficiency. On the other hand, the structure becomes complicated, and it is difficult to reduce the size and weight. For example, as disclosed in
In the case of the invention described in Japanese Patent Application Publication No. 169169, two sets of planetary gear mechanisms are provided, and the output disk of the toroidal type continuously variable transmission and the sun gear of each planetary gear mechanism are connected to the drive shaft and the second stage. The ring gear of the planetary gear mechanism is connected to the carrier in the same manner as the output shaft. For this reason, it is inevitable that the structure becomes complicated and large, and the weight increases.

On the other hand, Japanese Patent Application Laid-Open No. 9-89072 discloses a continuously variable transmission in which a toroidal type continuously variable transmission and one planetary gear mechanism are combined.
However, the continuously variable transmission described in this publication transmits driving force via a planetary gear mechanism and a toroidal type continuously variable transmission during low-speed traveling, and transmits the driving force during high-speed traveling to the toroidal type continuously variable transmission. So called geared
This is called a neutral type. In such a geared / neutral type continuously variable transmission, a large torque is applied to the toroidal type continuously variable transmission from the time of starting to the time of traveling at low speed. For this reason, it is difficult to achieve both miniaturization and ensuring the durability of the components of the toroidal-type continuously variable transmission, and it is also difficult to ensure transmission efficiency.

[0019]

DESCRIPTION OF THE PRESENT INVENTION In view of the above-described circumstances, the present inventors have previously described a stepless type of power split type structure which can be constituted by one planetary gear mechanism as shown in FIG. The transmission was invented (Japanese Patent Application No. 9-302569). First, the continuously variable transmission according to the present invention will be described. An input side end of the input shaft 40 (the left end in FIG. 12);
A starting clutch 4 is provided between an output end (right end in FIG. 12) of a crankshaft 42 of an engine 41 as a drive shaft.
3 is provided in series with the crankshaft 42 and the input shaft 40. Therefore, the crankshaft 42 and the input shaft 40 are arranged concentrically with each other. On the other hand, an output shaft 44 for extracting power based on the rotation of the input shaft 40 is arranged in parallel with the input shaft 40. A toroidal type continuously variable transmission 34 is provided around the input shaft 40, and a planetary gear mechanism 37 is provided around the output shaft 44.

The cam plate 10 constituting the toroidal-type continuously variable transmission 34 is fixed to an intermediate portion of the input shaft 40 near an output end (rightward in FIG. 1). The input side disk 2 and the output side disk 4 are supported around the input shaft 40 by a bearing (not shown) such as a needle bearing so as to freely rotate independently of each other with respect to the input shaft 40. Then, one side of the cam plate 10 (left side in FIG. 1)
The rollers 12, 12 are sandwiched between a cam surface 13 formed on the outer surface of the input shaft 2 and a cam surface 13 formed on the outer surface of the input shaft 2 to constitute the pressing device 9. Therefore, the input side disk 2 rotates while being pressed toward the output side disk 4 with the rotation of the input shaft 40.

A plurality (usually two to three) of power rollers 8, 8 are sandwiched between the inner surface 2a of the input disk 2 and the inner surface 4a of the output disk 4. The peripheral surfaces 8a, 8a of the rollers 8, 8 and the inner surfaces 2
a, 4a. Each of these power rollers 8 and 8 includes trunnions 6 and 6 and displacement shafts 7 and 7 (FIGS.
See 10. It is omitted in FIGS. ) So that it is rotatably supported. The toroidal-type continuously variable transmission 34 is, similarly to a conventionally widely known toroidal-type continuously variable transmission, displaced by swinging the trunnions 6 and 6 to support the power rollers 8 and 8. Axis 7, 7
By changing the inclination angle, the reduction ratio between the input-side disk 2 and the output-side disk 4 (including a value less than 1 at which the speed increases) is changed.

The sun gear 45 constituting the planetary gear mechanism 37 is fixed to the input end of the output shaft 44 (the right end in FIG. 1). Therefore, the output shaft 44 rotates with the rotation of the sun gear 45. This sun gear 45
, A ring gear 46 is supported concentrically with the sun gear 45 and rotatably. And, between the inner peripheral surface of the ring gear 46 and the outer peripheral surface of the sun gear 45, a plurality (usually 3 to 4) of planetary gear sets 47, 47 are provided.
Is provided. Each of these planetary gear sets 47, 47 is formed by combining a pair of planetary gears 48a, 48b. The pair of planetary gears 48a and 48b mesh with each other and are arranged on the outer diameter side.
Is meshed with the ring gear 46, and the planetary gear 48b arranged on the inner diameter side is meshed with the sun gear 45. The reason that each of the planetary gear sets 47, 47 is constituted by a pair of planetary gears 48a, 48b is to make the rotation directions of the ring gear 46 and the sun gear 45 coincide.

The above-mentioned planetary gear sets 47, 47 are provided on one side (the right side in FIG. 1) of the carrier 49, on the output shaft 44.
Are rotatably supported by pivots 50a and 50b parallel to the shaft. The carrier 49 is rotatably supported at an intermediate portion of the output shaft 44 by a bearing (not shown) such as a needle bearing.

Further, the carrier 49 and the output side disk 4 are connected by a first power transmission mechanism 38 so as to be capable of transmitting a rotational force. The first power transmission mechanism 38 includes first and second gears 51 and 52 meshed with each other.
It consists of. That is, the first gear 51 is fixed to the outer surface (the left side surface in FIG. 12) of the output-side disk 4 concentrically with the output-side disk 4, and the second gear 52 is connected to one side of the carrier 49 ( A carrier 49 is fixed concentrically to the left side of FIG. 1). Therefore, the carrier 49 rotates in a direction opposite to the output side disk 4 at a speed corresponding to the number of teeth of the first and second gears 51 and 52 with the rotation of the output side disk 4.

On the other hand, the input shaft 40 and the ring gear 4
Reference numeral 6 designates a freely connectable state in which the second power transmission mechanism 39 can transmit torque. The second power transmission mechanism 39 includes first and second sprockets 53 and 54,
A chain 55 is provided between the two sprockets 53 and 54. That is, the first sprocket 53 is fixed to a portion protruding from the cam plate 10 at the output end (the right end in FIG. 12) of the input shaft 40, and the second sprocket 54 is connected to the input side of the transmission shaft 56. It is fixed to the end (the right end in FIG. 12). This transmission shaft 56
Are arranged concentrically with the output shaft 44 and rotatably supported by a bearing (not shown) such as a rolling bearing. Therefore, with the rotation of the input shaft 40, the transmission shaft 56 rotates in the same direction as the input shaft 40 at a speed according to the number of teeth of the first and second sprockets 53 and 54.

Further, the continuously variable transmission according to the invention has a clutch mechanism. This clutch mechanism includes the transmission shaft 5, which is a component of the carrier 49 and the second power transmission mechanism 39.
6 is connected to the ring gear 46. In the case of the illustrated example, the clutch mechanism includes a low-speed clutch 57 and a high-speed clutch 58. The low-speed clutch 57 is provided between the outer peripheral edge of the carrier 49 and one axial end of the ring gear 46 (the left end in FIG. 12). Such a low speed clutch 57
Prevents the sun gear 45, the ring gear 46 and the planetary gear sets 47, 47 constituting the planetary gear mechanism 37 from being displaced relative to each other.
6 are integrally connected. Also, the high-speed clutch 58
It is provided between the transmission shaft 56 and a center shaft 60 fixed to the ring gear 46 via a support plate 59. The low-speed clutch 57 and the high-speed clutch 58 constitute a control circuit (hydraulic, electric) such that when one of the clutches is connected, the other clutch is disconnected. .

Further, between the ring gear 46 and a fixed portion such as a housing (not shown) of the continuously variable transmission,
A reverse clutch 61 is provided. The reverse clutch 61 is provided to rotate the output shaft 44 in the reverse direction in order to reverse the vehicle. The reverse clutch 61 includes the low speed clutch 57 and the high speed clutch 58.
In a state where either one is connected, the connection is disconnected. When the reverse clutch 61 is connected, the low-speed clutch 57 and the high-speed clutch 58 are both disconnected. That is, the starting clutch 4
When any one of the remaining three clutches 57, 58, and 61 except for the third clutch is connected, the connection of the remaining two clutches is disconnected.

Further, the output shaft 44 and the differential gear 35 are connected by a third power transmission mechanism 65 constituted by third to fifth gears 62 to 64. Therefore,
When the output shaft 44 rotates, a pair of left and right drive shafts 66, 66 rotate via the third power transmission mechanism 65 and the differential gear 35, and rotationally drive the drive wheels of the automobile.

The operation of the continuously variable transmission according to the present invention configured as described above is as follows. First, during low-speed running, the low-speed clutch 57 is connected, and the high-speed clutch 58 and the reverse clutch 61 are disconnected. In this state, when the starting clutch 43 is connected and the input shaft 40 is rotated, the toroidal type continuously variable transmission 34 is rotated.
Only the power is transmitted from the input shaft 40 to the output shaft 44. That is, with the connection of the low-speed clutch 57, the ring gear 46 and the carrier 49 are integrally connected, and the respective gears 45, 46, 48 constituting the planetary gear mechanism 37 are formed.
The relative rotation between a and 48b becomes impossible. Further, when the connection between the high-speed clutch 58 and the reverse clutch 61 is disconnected, the ring gear 46 becomes rotatable regardless of the rotation speed of the transmission shaft 56.

Therefore, when the input shaft 40 is rotated in this state, the rotation is transmitted to the input disk 2 via the pressing device 9 and further transmitted to the output disk 4 via the plurality of power rollers 8. Convey. Further, the rotation of the output side disk 4 is transmitted to the carrier 49 and the ring gear 46 via the first and second gears 51 and 52 constituting the first power transmission mechanism 38. As described above, in this state, the gears 45, 46, 48a,
Since the relative rotation between the shafts 8b is disabled, the output shaft 44 rotates at the same speed as the carrier 49 and the ring gear 46.

The operation itself when changing the reduction ratio between the input side and output side disks 2 and 4 during such low speed running is the same as the conventional toroidal type continuously variable transmission shown in FIGS. It is the same as the case of the machine. Of course, in this state, the reduction ratio between the input shaft 40 and the output shaft 44, that is, the reduction ratio of the continuously variable transmission as a whole is proportional to the reduction ratio of the toroidal type continuously variable transmission 34. In this state, the torque input to the toroidal continuously variable transmission 34 is equal to the torque applied to the input shaft 40. During low-speed traveling, the first and second sprockets 53 and 54 and the chain 55 that constitute the second power transmission mechanism 39 are
It just spins idle.

On the other hand, during high-speed running, the high-speed clutch 58 is connected, and the low-speed clutch 57 and the reverse clutch 61 are disconnected. In this state, when the starting clutch 43 is connected and the input shaft 40 is rotated, the first and second sprockets constituting the second power transmission mechanism 39 are connected from the input shaft 40 to the output shaft 44. The power is transmitted to the gears 53, 54 and the chain 55 and the planetary gear mechanism 58.

That is, when the input shaft 40 rotates during the high-speed running, the rotation is transmitted to the center shaft 60 via the second power transmission mechanism 39 and the high-speed clutch 58,
The ring gear 46 to which the central shaft 60 is fixed is rotated. Then, the rotation of the ring gear 46 is transmitted to the sun gear 45 via the plurality of planetary gear sets 47, 47, and rotates the output shaft 44 to which the sun gear 45 is fixed. When the ring gear 46 is on the input side, the planetary gear mechanism 37 assumes that each of the planetary gear sets 47, 47 is stopped (does not revolve around the sun gear 45).
The speed is increased at a reduction ratio (less than 1) according to the ratio of the number of teeth of the ring gear 46 and the number of teeth of the sun gear 45. However, the planetary gear sets 47 revolve around the sun gear 45, and the reduction ratio of the entire continuously variable transmission changes according to the revolving speed of the planetary gear sets 47. Therefore, by changing the reduction ratio of the toroidal type continuously variable transmission 34 and changing the revolution speed of the planetary gear sets 47, 47,
The speed reduction ratio of the entire continuously variable transmission can be adjusted.

That is, in the illustrated example, the planetary gear sets 47 revolve in the same direction as the ring gear 46 during the high-speed running. Each of these planetary gear sets 47, 4
The lower the revolution speed of 7 is, the higher the rotation speed of the output shaft 44 to which the sun gear 45 is fixed is. For example, if the revolution speed and the rotation speed of the ring gear 46 (both angular speeds) are the same, the rotation speed of the ring gear 46 and the output shaft 44 will be the same. On the other hand, if the revolution speed is lower than the rotation speed of the ring gear 46, the rotation speed of the output shaft 44 is higher than the rotation speed of the ring gear 46. Conversely, if the revolution speed is higher than the rotation speed of the ring gear 46, the output shaft 4 is higher than the rotation speed of the ring gear 46.
The rotation speed of 4 becomes slow.

Therefore, during the above-mentioned high-speed running, as the reduction ratio of the toroidal type continuously variable transmission 34 is changed (increased) to the reduction side, the reduction ratio of the entire continuously variable transmission changes to the speed increasing side (deceleration). The ratio value becomes smaller). In such a state at the time of high-speed running, the toroidal type continuously variable transmission 34
The torque is applied not from the input side disk 2 but from the output side disk 4 (a negative torque is applied when the torque applied at a low speed is a positive torque). That is, when the high-speed clutch 58 is connected, the torque transmitted from the engine 41 to the input shaft 40 is transmitted to the second power transmission device before the pressing device 10 presses the input disk 2. 39 through the planetary gear mechanism 3
7 is transmitted to the ring gear 46. Therefore, the input shaft 40
The torque transmitted from the side to the input side disk 2 via the pressing device 10 is almost eliminated.

On the other hand, part of the torque transmitted to the ring gear 46 of the planetary gear mechanism 37 via the second power transmission device 39 is transmitted from the planetary gear sets 47, 47 to the carrier 49 and the first Through the power transmission mechanism 38 to the output side disk 4. Thus, the torque applied from the output side disk 4 to the toroidal type continuously variable transmission 34 changes the value of the reduction ratio of the toroidal type continuously variable transmission 34 in order to change the reduction ratio of the entire continuously variable transmission to the speed increasing side. The larger, the smaller. As a result, the torque input to the toroidal type continuously variable transmission 34 during high-speed traveling can be reduced, and the durability of the components of the toroidal type continuously variable transmission 34 can be improved.

Further, in the structure shown in FIG. 12, when the output shaft 44 is rotated in the reverse direction so that the vehicle moves backward,
The clutches 57 and 58 for low speed and high speed are disconnected, and the clutch 61 for retreat is connected. As a result, the ring gear 46 is fixed, and the respective planetary gear sets 47 revolve around the sun gear 45 while meshing with the ring gear 46 and the sun gear 45. As a result, the sun gear 45 and the sun gear 4
The output shaft 44 to which 5 is fixed rotates in the opposite direction to the above-described high-speed running and the low-speed running described above.

[0038]

The continuously variable transmission according to the prior invention as described above has a simpler structure and a smaller size than the continuously variable transmission described in JP-A-1-169169.
The weight can be reduced. However, in order to realize a smaller and lighter continuously variable transmission for a small vehicle or to realize a more efficient continuously variable transmission, further improvement is desired. That is, in the case of the above-described continuously variable transmission according to the invention, the sun gear 45 and the ring gear 46 constituting the planetary gear mechanism 37 are rotated between the two gears 45 and 46 in order to make the rotation directions coincide with each other. And planetary gear sets 47, 4 each formed by combining two planetary gears 48a, 48b.
7 are provided. Therefore, these planetary gears 48a, 48
The number b is required to be twice the minimum number of planetary gears required to configure the planetary gear mechanism, and it is difficult to reduce the size and weight of the continuously variable transmission by that much. Further, as the number of meshing portions of the gears increases, the power loss based on the friction loss or the like generated at the meshing portion increases, and it becomes difficult to improve the transmission efficiency of the continuously variable transmission as a whole. In view of such circumstances, the present invention has been made to realize a practical structure that can reduce the torque transmitted through a toroidal-type continuously variable transmission during high-speed running, and that can be configured to be small and lightweight. .

[0039]

SUMMARY OF THE INVENTION Among the continuously variable transmissions according to the present invention, the continuously variable transmission described in claim 1 is conventionally known, for example, as described in Japanese Patent Application Laid-Open No. 1-169169. Similarly to the continuously variable transmission, the input shaft connected to the drive source and the output shaft connected to the part to be driven, and the inclination angles of the plurality of power rollers sandwiched between the input disk and the output disk are changed. A toroidal type continuously variable transmission that changes the reduction ratio between the input disk and the output disk, a planetary gear mechanism including a carrier that rotatably supports a sun gear, a ring gear, and a planetary gear. Connecting the continuously variable transmission and the planetary gear mechanism 1
A pair of power transmission mechanisms, and switching means capable of switching a speed change state between the input shaft and the output shaft to at least two types of a high-speed traveling mode and a low-speed traveling mode;
In the low-speed running mode, all the power between the input shaft and the output shaft is transmitted through the toroidal-type continuously variable transmission.In the high-speed running mode, the power is transmitted by the planetary gear mechanism, and a part of the power is transmitted. The fluid is circulated through the planetary gear mechanism to the toroidal-type continuously variable transmission.

In particular, in the continuously variable transmission according to the first aspect, the rotational force is transmitted from the output disk to the planetary gear mechanism during the low-speed running mode, and the high-speed transmission is performed. The sun gear is a member coupled to an end of the first power transmission mechanism for circulating power from the planetary gear mechanism to the output disk in the traveling mode. In the planetary gear mechanism, a member coupled to an end of a second power transmission mechanism that transmits a rotational force from the input shaft to the planetary gear mechanism in a high-speed running mode is the carrier. Further, the output shaft and the ring gear are connected.

Further, the continuously variable transmission according to claim 2 is
An input shaft that is rotationally driven by the drive shaft, an output shaft for extracting power based on the rotation of the input shaft, a toroidal-type continuously variable transmission, and a planetary gear mechanism are provided. The toroidal-type continuously variable transmission rotates based on the rotation of the input shaft by changing the inclination angles of a plurality of power rollers sandwiched between an input disk and an output disk concentrically arranged. It is for changing the reduction ratio between the input disk and the output disk. In addition, the planetary gear mechanism includes a sun gear, a ring gear disposed around the sun gear and coupled to the output shaft, and a sun gear and a ring gear respectively provided by a plurality of pivots arranged concentrically. And a carrier provided with a plurality of pivots for rotatably supporting each of the meshing planetary gears.
Then, the sun gear and the output disk are connected in a state where torque can be transmitted by the first power transmission mechanism, and the input shaft and the carrier are transmitted by the second power transmission mechanism to transmit torque. Can be freely connected in a possible state. Further, there is provided switching means capable of switching the state of shifting between the input shaft and the output shaft to three types of modes: a high-speed running mode, a low-speed running mode, and a reverse mode. Further, the ratio β / α of the reduction ratio α of the first power transmission mechanism and the reduction ratio β of the second power transmission mechanism is set to a reduction ratio i _H at the time of maximum speed increase of the toroidal-type continuously variable transmission. And almost the same.
The reason for restricting the reduction ratios α and β in this manner is to prevent or reduce the discontinuity of the reduction ratio of the entire continuously variable transmission when switching between the low-speed traveling mode and the high-speed traveling mode. It is.

[0042]

The operation of the continuously variable transmission according to the present invention configured as described above is as follows. First, during low-speed running, all power between the input shaft and the output shaft is transmitted through the toroidal-type continuously variable transmission. For this purpose, for example, any one of the sun gear, the ring gear, and the carrier constituting the planetary gear mechanism is connected to each other, and the sun gear, the ring gear, and the carrier are integrally formed around the sun gear. Rotate. In this state, only the toroidal type continuously variable transmission transmits power from the input shaft to the output shaft. The operation of converting the reduction ratio between the input and output disks during low-speed running is the same as that of the conventional toroidal-type continuously variable transmission shown in FIGS. Of course, in this state, the reduction ratio between the input shaft and the output shaft, that is, the reduction ratio of the continuously variable transmission as a whole is proportional to the reduction ratio of the toroidal-type continuously variable transmission. In this state, the torque input to the toroidal type continuously variable transmission is equal to the torque applied to the input shaft.

On the other hand, during high-speed running, power is transmitted by the planetary gear mechanism and a part of the power is circulated to the toroidal-type continuously variable transmission via the planetary gear mechanism. In this state, torque is transmitted to the output disk of the toroidal-type continuously variable transmission from the sun gear constituting the planetary gear mechanism. In this state, the reduction ratio of the entire continuously variable transmission changes in accordance with the revolution speed of the planetary gear. Therefore, by changing the reduction ratio of the toroidal type continuously variable transmission and changing the revolution speed of the planetary gear, the reduction ratio of the entire continuously variable transmission can be adjusted. That is, in this state, as the reduction ratio of the toroidal type continuously variable transmission changes to the reduction side, the value of the reduction ratio of the entire continuously variable transmission decreases (changes to the speed increasing side). In such a state at the time of high-speed running, the value of the reduction ratio of the toroidal type continuously variable transmission is increased in order to reduce the value of the reduction ratio of the entire continuously variable transmission (change the transmission ratio to the speed increasing side). The speed (change to the deceleration side) decreases the torque input to the toroidal-type continuously variable transmission. As a result, the torque input to the toroidal-type continuously variable transmission during high-speed traveling can be reduced, and the durability and transmission efficiency of the components of the toroidal-type continuously variable transmission can be improved.

The operation described above is the same as that of the above-described continuously variable transmission according to the invention. In particular, in the case of the continuously variable transmission of the present invention, the planetary gear mechanism is connected by coupling the sun gear to the end of the first power transmission mechanism and the carrier to the end of the second power transmission mechanism. , The rotation directions of the sun gear and the ring gear can be reversed. Because of this,
One planetary gear can be meshed with both the sun gear and the ring gear, so that the size and weight of the continuously variable transmission and the transmission efficiency can be improved.

[0045]

FIG. 1 shows a first embodiment of the present invention. The continuously variable transmission according to the present invention is connected to a crankshaft 42 of an engine 41 as a drive source and is rotationally driven by the engine 41, similarly to the continuously variable transmission according to the preceding invention shown in FIG. Input shaft 4
0 is provided. A starting clutch 43 such as a torque converter or an electromagnetic clutch is provided between the input end of the input shaft 40 (the left end in FIG. 1) and the output end of the crankshaft 42 (the right end in FIG. 1). , These crankshafts 42
And the input shaft 40 in series. Accordingly, in the case of the illustrated example, the crankshaft 42 and the input shaft 4
0 are arranged concentrically with each other. On the other hand, a tubular output shaft 44 for taking out power based on the rotation of the input shaft 40 is arranged in parallel to the input shaft 40 and rotatably independent of the input shaft 40. A toroidal type continuously variable transmission 34 is provided around the input shaft 40, and a planetary gear mechanism 37 is provided around the output shaft 44 (to the right in FIG. 1).

The cam plate 10 constituting the toroidal type continuously variable transmission 34 is fixed to an intermediate portion of the input shaft 40. Further, the input disk 2 and the output disk 4 are supported around the input shaft 40 by a bearing (not shown) such as a needle bearing so as to freely rotate independently of each other with respect to the input shaft 40. Then, rollers 12 are sandwiched between a cam surface 13 formed on one surface (the right surface in FIG. 1) of the cam plate 10 and a cam surface 14 formed on the outer surface of the input disk 2 to constitute the pressing device 9. doing. Accordingly, the input disk 2 rotates while being pressed toward the output disk 4 with the rotation of the input shaft 40.

A plurality (usually 2) between the inner surface 2a of the input disk 2 and the inner surface 4a of the output disk 4
-3) of the power rollers 8, 8 and the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a,
4a. These power rollers 8, 8
Are rotatably supported by trunnions 6, 6 and displacement shafts 7, 7 (see FIGS. 7 to 10; omitted in FIG. 1). The toroidal type continuously variable transmission 34 oscillates the trunnions 6, 6 in the same manner as a conventionally widely known toroidal type continuously variable transmission, and the power rollers 8, 8,
The reduction ratio between the input disk 2 and the output disk 4 is changed by changing the angle of inclination of the displacement shafts 7 supporting the.

The ring gear 46 constituting the planetary gear mechanism 37 is fixed to the input end of the output shaft 44 (the right end in FIG. 1). Therefore, the output shaft 44 rotates with the rotation of the ring gear 46. A sun gear 45 is provided inside the ring gear 46, and the ring gear 46
It is supported concentrically and rotatably. And, between the inner peripheral surface of the ring gear 46 and the outer peripheral surface of the sun gear 45, a plurality (usually 3 to 4) of planetary gears 48, 4
8 are provided. These planetary gears 48 mesh with the ring gear 46 and the sun gear 45, respectively.

Each of the planetary gears 48, 48 as described above is provided with a pivot 50, which is provided on a carrier 49 and is parallel to the output shaft 44.
By 50, it is rotatably supported. The first transmission shaft 67 having one end (the right end in FIG. 1) coupled to the center of the carrier 49 is provided with a bearing (not shown) such as a needle bearing while the output shaft 44 is loosely inserted. It is rotatably supported. That is, the output shaft 44 is rotatably supported inside a housing (not shown) by a bearing (not shown), and the first transmission shaft 67 is connected to the output shaft 4.
4 is inserted inside. And this first transmission shaft 6
7 is rotatably supported inside the housing or the output shaft 44 by a bearing (not shown).

The sun gear 45 and the output disk 4 are connected by a first power transmission mechanism 38a in a state where torque can be transmitted. The first power transmission mechanism 38a includes a first gear 51 fixed concentrically with the output disk 4 and a second transmission shaft 68 fixed at one end (the left end in FIG. 1) of the sun gear 45. A second gear 52 fixed to the other end of the first and second gears 51, 52
And an idle gear 69 provided therebetween. Therefore, the sun gear 45 rotates with the rotation of the output disk 4 in the same direction as the output disk 4 at a speed according to the ratio of the number of teeth of the first and second gears 51 and 52.

On the other hand, the input shaft 40 and the carrier 49
Means that the second power transmission mechanism 39a can be freely connected to a state in which torque can be transmitted. The second power transmission mechanism 39a includes a driving gear 70 and a driven gear 71 that mesh with each other. That is, the drive gear 70 is fixed to the start clutch 43 (leftward in FIG. 1) at the intermediate portion of the input shaft 40, and the driven gear 71 is
The first transmission shaft 67 is fixed to the other end (the left end in FIG. 1). In the illustrated example, the number of teeth of the driving gear 70 and the number of teeth of the driven gear 71 are equal to each other. Therefore, the first transmission shaft 67 rotates at the same speed as the input shaft 40 in a direction opposite to the input shaft 40 as the input shaft 40 rotates.

Further, the continuously variable transmission according to the present invention includes a clutch mechanism. This clutch mechanism connects only one of the first and second transmission shafts 67 and 68 to the carrier 49. In the case of this example, this clutch mechanism is provided between the first transmission shaft 67 and the low-speed clutch 57 provided between the second transmission shaft 68 and the carrier 49. A high-speed clutch 58 is provided in series with the transmission shaft 67. When connected, the low-speed clutch 57 is connected to the sun gear 45, the ring gear 46, and the planetary gears 48, 4 constituting the planetary gear mechanism 37.
8, and the sun gear 45 and the ring gear 46 are integrally connected. The low-speed clutch 57 and the high-speed clutch 58 constitute a control circuit (hydraulic, electric) such that when one of the clutches is connected, the other clutch is disconnected. .

In the illustrated example, the carrier 49 and
A reverse clutch 61 is provided between a fixed portion such as a housing (not shown) of the continuously variable transmission. The reverse clutch 61 is provided to rotate the output shaft 44 in the reverse direction in order to reverse the vehicle. The reverse clutch 61 is disconnected when one of the low-speed clutch 57 and the high-speed clutch 58 is connected. When the reverse clutch 61 is connected, the low speed clutch 57 and the high speed clutch 5 are connected.
8 is disconnected. That is, the remaining three clutches 57, 58, 61, excluding the starting clutch 43,
When any one of the clutches is connected, the connection of the remaining two clutches is disconnected.

Further, in the illustrated example, the output shaft 44 and the differential gear 35 are connected to the third and fourth gears 62,
The connection is made by a third power transmission mechanism 65a constituted by 63. Therefore, when the output shaft 44 rotates, the third power transmission mechanism 65a and the differential gear 3
The pair of left and right drive shafts 66, 66 rotates via the drive wheel 5 to rotationally drive the drive wheels of the vehicle.

The operation of the continuously variable transmission according to this embodiment configured as described above is as follows. First, during low-speed running, the low-speed clutch 57 is connected, and the high-speed clutch 58 and the reverse clutch 61 are disconnected. When the starting clutch 43 is connected and the input shaft 40 is rotated in this state, only the toroidal type continuously variable transmission 34 transmits power from the input shaft 40 to the output shaft 44. That is,
With the connection of the low-speed clutch 57, the sun gear 45
, The carrier 49 and the ring gear 46 are integrally connected, and the respective gears 45, 4
Relative rotation between 6, 48 becomes impossible. In addition, the connection between the high-speed clutch 58 and the reverse clutch 61 is disconnected, so that the carrier 49 becomes independent of the rotation speed of the driven gear 71 fixed to the other end of the first transmission shaft 67. It becomes rotatable.

Therefore, when the input shaft 40 is rotated in this state, the rotation is transmitted to the input disk 2 via the pressing device 9 and further transmitted to the output disk 4 via the plurality of power rollers 8. Furthermore, this output disk 4
Rotation of the first power transmission mechanism 38a,
The power is transmitted to the sun gear 45 and the carrier 49 via the second gears 51 and 52 and the idle gear 69. As described above, in this state, the gears 45, 4
Since the relative rotation between the gears 6 and 48 is disabled, the output shaft 44 fixedly connected to the ring gear 46 rotates at the same speed as the sun gear 45 and the carrier 49.

The operation itself when changing the reduction ratio between the input side and output side disks 2 and 4 during such low speed traveling is the same as the conventional toroidal type continuously variable transmission shown in FIGS. It is the same as the case of the machine. Of course, in this state, the reduction ratio between the input shaft 40 and the output shaft 44, that is, the reduction ratio of the continuously variable transmission as a whole is proportional to the reduction ratio of the toroidal type continuously variable transmission 34. In this state, the torque input to the toroidal continuously variable transmission 34 is equal to the torque applied to the input shaft 40. During low-speed running, the drive gear 70 and the driven gear 71 constituting the second power transmission mechanism 39a only idle.

On the other hand, during high-speed running, the high-speed clutch 58 is connected, and the low-speed clutch 57 and the reverse clutch 61 are disconnected. When the input shaft 40 is rotated in this state, the drive gear 70 and the driven gear 71 and the planetary gear mechanism 37 that constitute the second power transmission mechanism 39a are connected to the output shaft 44 from the input shaft 40. Transmit power.

That is, when the input shaft 40 rotates during the high-speed running, the rotation is caused by the rotation of the second power transmission mechanism 39a.
In addition, the power is transmitted to the carrier 49 via the high-speed clutch 58, and the carrier 49 is rotated. Then, the rotation of the carrier 49 is transmitted to the ring gear 46 via the plurality of planetary gears 48, 48, and rotates the output shaft 44 to which the ring gear 46 is fixed. When the carrier 49 is on the input side, the planetary gear mechanism 37, assuming that the sun gear 45 is stopped (does not rotate inside the ring gear 46), the ring gear 46 and the sun gear 4
Power is transmitted between the carrier 49 and the ring gear 46 at a gear ratio of 5 and a reduction ratio (a value less than 1) according to the rotation speed of the carrier 49. However, the sun gear 45 rotates inside the ring gear 46, and the reduction ratio of the entire continuously variable transmission changes in accordance with the rotation speed of the sun gear 45. Therefore, if the rotational speed of the sun gear 45 is changed by changing the reduction ratio of the toroidal type continuously variable transmission 34, the reduction ratio of the entire continuously variable transmission can be adjusted.

That is, in the illustrated example, the sun gear 45 rotates in the same direction as the carrier 49 during the high-speed running. Further, the ratio of the number of teeth between the ring gear 46 and the sun gear 45 is regulated to a value at which the speed can be increased between the carrier 49 and the ring gear 46. And the sun gear 45
The rotational speed of the output shaft 44 to which the ring gear 46 is fixed increases as the rotational speed of the output shaft 44 decreases. For example,
The toroidal type continuously variable transmission 34 is set to the maximum speed increasing state,
If the rotation speed of the sun gear 45 and the rotation speed of the carrier 49 (both angular speeds) become the same, the rotation speed of the carrier 49 and the output shaft 44 becomes the same. On the contrary,
If the rotation speed of the sun gear 45 is lower than the rotation speed of the carrier 49, the rotation speed of the output shaft 44 is higher than the rotation speed of the carrier 49.

Therefore, during the high-speed running, as the reduction ratio of the toroidal type continuously variable transmission 34 is increased (changed to the reduction side), the reduction ratio of the entire continuously variable transmission changes to the speed increase side. In such a state at the time of high-speed running, torque is applied to the toroidal type continuously variable transmission 34 from the output disk 4 instead of from the input disk 2 (a negative torque when the torque applied at low speed is a positive torque). Is added). That is, when the high-speed clutch 58 is connected, the torque transmitted from the engine 41 to the input shaft 40 indicates that the pressing device 10
Is transmitted to the carrier 49 of the planetary gear mechanism 37 via the second power transmission mechanism 39a before the pressure is pressed. Therefore, almost no torque is transmitted from the input shaft 40 to the input disk 2 via the pressing device 10.

On the other hand, a part of the torque transmitted to the carrier 49 of the planetary gear mechanism 37 via the second power transmission mechanism 39a is transmitted from the planetary gears 48, 48 to the sun gear 45 and the first gear. The power is transmitted to the output disk 4 via the power transmission mechanism 38a. As described above, the torque applied from the output disk 4 to the toroidal type continuously variable transmission 34 reduces the speed reduction ratio of the toroidal type continuously variable transmission 34 in order to reduce the reduction ratio of the entire continuously variable transmission (change to the speed increasing side). The larger the ratio, the smaller. As a result, the torque input to the toroidal type continuously variable transmission 34 during high-speed running is reduced,
The durability of the components of the toroidal type continuously variable transmission 34 can be improved.

Further, in the structure shown in FIG. 1, when the output shaft 44 is rotated in the reverse direction in order to move the vehicle backward, the connection of the low-speed and high-speed clutches 57 and 58 is cut off and the reverse movement is performed. Connection clutch 61 is connected. As a result,
The carrier 49 is fixed, and the planet gears 48, 4
8 can only rotate and cannot revolve. As a result, with the rotation of the sun gear 45, which is rotationally driven via the toroidal-type continuously variable transmission 34, the ring gear 46 and the output shaft 44 connected and fixed to the ring gear 46 are driven during the above-described high-speed running and It rotates in the direction opposite to that at the time of low-speed running described above.

FIG. 2 shows the structure of the above-described first example. In the case where the reduction ratio (horizontal axis) of the continuously variable transmission is continuously changed, the reduction ratio of the toroidal type continuously variable transmission 34 is changed. An example of a state where the torque passing through the toroidal type continuously variable transmission (right vertical axis) and the torque passing through the toroidal type continuously variable transmission 34 (right vertical axis) changes. The relationship between these reduction ratios and torque changes according to the reduction width of the toroidal type continuously variable transmission 34, the gear ratio of the planetary gear mechanism 37, the reduction ratio of the second power transmission mechanism 39a, and the like. In practicing the present invention, these values and structure are determined by design. The conditions for obtaining the lines shown in FIG. 2 are as follows: the width of the reduction ratio of the toroidal type continuously variable transmission 34 is approximately four times (2.0 to 0.5), and the planetary gear mechanism 37
(The number of teeth of the sun gear 45 / the number of teeth of the ring gear 46) is 0.5, the reduction ratio of the first power transmission mechanism 38a is 2, and the reduction ratio of the second power transmission mechanism 39a is 1. Calculated as Switching between the low speed clutch 57 and the high speed clutch 58 is performed when the reduction ratio of the continuously variable transmission is 1 (the reduction ratio of the toroidal type continuously variable transmission is 0.5).
).

In FIG. 2 showing a case where a continuously variable transmission as shown in FIG. 1 is designed under such conditions, a solid line a indicates the reduction ratio of the toroidal type continuously variable transmission 34, and a broken line b indicates Of the torque transmitted from the engine 41 to the input shaft 40,
The ratio of the magnitude of the torque passing through the toroidal type continuously variable transmission 34 is shown. As is apparent from FIG. 2, according to the continuously variable transmission of the present invention, the reduction ratio of the entire continuously variable transmission is set to 4 to 0.73, and the reduction ratio of the entire continuously variable transmission is the most. In the small (0.73) state, the magnitude of the torque passing through the toroidal type continuously variable transmission 34 can be suppressed to about 9% of the torque transmitted from the engine 41 to the input shaft 40. In this way, by reducing the torque passing through the toroidal type continuously variable transmission 34 including the planetary gear mechanism 37 and having a large power loss (transmission efficiency is about 90%) as compared with the gear type power transmission mechanism, Thus, the transmission efficiency of the entire continuously variable transmission can be sufficiently increased (to approximately 99% in calculation).

When an actual continuously variable transmission is constructed, the low speed clutch 57 and the high speed clutch 58 are always switched when the reduction ratio of the entire continuously variable transmission is 1. When the vehicle is traveling at a speed reduction ratio of about 1, the clutches 56 and 57 are frequently switched. Such a situation not only gives the driver a sense of discomfort, but also adversely affects the durability of the clutches 56 and 57. Therefore, when an actual continuously variable transmission is configured, a so-called hysteresis is provided in which the timing of switching the clutches 56 and 57 is changed depending on whether the reduction ratio is high or low.

FIG. 3 shows a second embodiment of the present invention.
An example is shown. In the case of this example, the crankshaft 4
2 and the input shaft 40 are directly connected (the starting clutch 43 shown in FIG. 1 is omitted), and the low speed clutch 57 also has a function as a starting clutch. For this reason, in the case of the present embodiment, a clutch capable of causing a slip at a low speed, such as a wet multi-plate clutch or a clutch with a torque converter, is used as the low-speed clutch 57. Other configurations and operations are the same as those in the first example described above, including the realizable reduction ratio and the reduction ratio of the torque passing through the toroidal-type continuously variable transmission 34 during high-speed traveling.

FIG. 4 shows a third embodiment of the present invention.
An example is shown. In the case of this example, the arrangement of the toroidal type continuously variable transmission 34, the planetary gear mechanism 37, and the first and second power transmission mechanisms 38a and 39a with respect to the engine 41 is reversed (FIG. 1, 3 left and right). . Also, clutch 5 for low speed
7 is fixed to a ring gear 46 via a first transmission shaft 67 to which a sun gear 45 is fixed and a ring gear 46 via an output shaft 44.
2 is provided. Other configurations and operations are realized by the reduction ratio that can be realized and the toroidal-type continuously variable transmission 3 during high-speed traveling.
4 including the reduction ratio of the torque passing through
This is the same as in the example. The low-speed clutch 57 includes three types of gears 45, 4
As long as the relative displacement of 6, 48 can be prevented, it may be attached to a portion other than the portions in the illustrated examples.

Next, FIG. 5 shows a fourth embodiment of the present invention.
An example is shown. In the case of this example, the crankshaft 4
2 and the input shaft 40 are directly connected (the starting clutch 43 shown in FIG. 4 is omitted), and the low-speed clutch 57 also has a function as a starting clutch. Other configurations and operations are the same as those of the third example described above, including the realizable reduction ratio and the reduction ratio of the torque passing through the toroidal-type continuously variable transmission 34 during high-speed traveling.

Next, FIG. 6 shows a fifth embodiment of the present invention.
An example is shown. In the case of this example, a so-called double-cavity type continuously variable transmission 34a in which two input disks 2, 2 and two output disks 4, 4 are provided in parallel with each other in the power transmission direction. I'm using By using such a double-cavity toroidal-type continuously variable transmission 34a, the torque that can pass through the toroidal-type continuously variable transmission 34a is increased, and a larger output than in the first to fourth examples is obtained. It is possible to realize a continuously variable transmission for an automobile including the engine 41 having the above-described configuration. The configuration and operation other than the structure of the toroidal type continuously variable transmission 34a are the same as those of the first example described above, including the realizable reduction ratio and the reduction ratio of the torque passing through the toroidal type continuously variable transmission 34a during high-speed traveling. Is the same as

[0071]

Since the present invention is constructed and operates as described above, it is relatively simple, compact, lightweight, and can be manufactured at low cost. The load applied to the components of the step transmission can be reduced to improve durability and improve transmission efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first example of an embodiment of the present invention.

FIG. 2 is a diagram showing a reduction ratio of a toroidal type continuously variable transmission, a reduction ratio of the entire continuously variable transmission, and a relationship between an input torque and a torque passing through the toroidal type continuously variable transmission.

FIG. 3 is a schematic configuration diagram showing a second example of the embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a third example.

FIG. 5 is a schematic configuration diagram showing a fourth example.

FIG. 6 is a schematic configuration diagram showing a fifth example.

FIG. 7 is a partially cut-away side view showing a basic structure of a conventionally known toroidal-type continuously variable transmission in a state of maximum deceleration.

FIG. 8 is a partially cut-away side view similarly showing a state at the time of maximum speed increase.

FIG. 9 is a partial cross-sectional view showing an example of a specific structure of a conventionally known toroidal-type continuously variable transmission.

FIG. 10 is a sectional view taken along line AA of FIG. 9;

FIG. 11 is a block diagram showing a basic configuration of a continuously variable transmission to which the present invention is applied.

FIG. 12 is a schematic diagram showing an example of the prior invention.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 input disk 2a inner surface 3 output shaft 4 output disk 4a inner surface 5 pivot 6 trunnion 7 displacement shaft 8 power roller 8a peripheral surface 9 pressing device 10 cam plate 11 retainer 12 roller 13 cam surface 14 cam surface 15 input Shaft 16 Needle bearing 17 Flange part 18 Output gear 19 Key 20 Support plate 21 Circular hole 22 Support shaft part 23 Pivot shaft part 24 Radial needle bearing 25 Radial needle bearing 26 Thrust ball bearing 27 Thrust needle bearing 28 Outer ring 29 Drive rod 30 Drive Piston 31 Drive cylinder 32 Engine 33 Drive shaft 34, 34a Toroidal-type continuously variable transmission 35 Differential gear 36 Output shaft 37 Planetary gear mechanism 38, 38a First power transmission mechanism 39, 39a Second power transmission mechanism 40 Input shaft 41 Engine 42 Link shaft 43 starting clutch 44 output shaft 45 sun gear 46 ring gear 47 planetary gear set 48, 48a, 48b planetary gear 49 carrier 50, 50a, 50b pivot 51 first gear 52 second gear 53 first sprocket 54 first Second sprocket 55 Chain 56 Transmission shaft 57 Low speed clutch 58 High speed clutch 59 Support plate 60 Center shaft 61 Reverse clutch 62 Third gear 63 Fourth gear 64 Fifth gear 65, 65a Third power transmission mechanism 66 drive shaft 67 first transmission shaft 68 second transmission shaft 69 idle gear 70 drive gear 71 driven gear

Claims (2)

[Claims] An input shaft connected to a drive source and an output shaft connected to a portion to be driven, and a plurality of power rollers sandwiched between an input disk and an output disk are changed in inclination angle by changing the inclination angle. A toroidal-type continuously variable transmission that changes the reduction ratio between an input disk and an output disk; a planetary gear mechanism that includes a carrier that rotatably supports a sun gear, a ring gear, and a planetary gear; and a toroidal-type continuously variable transmission And a pair of power transmission mechanisms for connecting the motor and the planetary gear mechanism, and a changeover state in which the speed change state between the input shaft and the output shaft can be switched between at least two modes of a high-speed running mode and a low-speed running mode. Means for transmitting all power between the input shaft and the output shaft through the toroidal-type continuously variable transmission in the low-speed traveling mode, and transmitting the power in the high-speed traveling mode to the planetary gear unit. In the continuously variable transmission that transmits a part of the power to the toroidal-type continuously variable transmission through the planetary gear mechanism while transmitting the power through the planetary gear mechanism, the output of the planetary gear mechanism during the low-speed traveling mode is reduced. A member coupled to an end of a first power transmission mechanism for transmitting torque from the disk to the planetary gear mechanism and circulating power from the planetary gear mechanism to the output disk during the high-speed running mode is provided. The sun gear, a member coupled to an end of a second power transmission mechanism that transmits a rotational force from the input shaft to the planetary gear mechanism during the high-speed running mode is the carrier, the output shaft and A continuously variable transmission, wherein the ring gear is coupled to the ring gear. 2. An input shaft rotatably driven by a drive shaft,
An output shaft for extracting power based on the rotation of the input shaft, a toroidal-type continuously variable transmission, and a planetary gear mechanism.The toroidal-type continuously variable transmission has an input disk and an output disk that are concentrically arranged with each other. By changing the inclination angle of the plurality of power rollers sandwiched between the input gear and the output disk, the reduction ratio between the input disk and the output disk rotating based on the rotation of the input shaft is changed. The mechanism includes a sun gear, a ring gear disposed around the sun gear and coupled to the output shaft, and one each meshing with the sun gear and the ring gear by a plurality of pivots arranged on concentric circles. And a carrier provided with a plurality of pivots for rotatably supporting each of the planetary gears. The sun gear and the output disk are connected by a first power transmission mechanism. While being connected to a state where transmission of rotational force is possible, the input shaft and the carrier are freely connectable to a state where transmission of rotational force is possible by a second power transmission mechanism. Switching means for switching the speed change state between three modes of a high-speed traveling mode, a low-speed traveling mode, and a reverse mode, and a reduction ratio α of the first power transmission mechanism and the second power transmission mechanism. A continuously variable transmission in which the ratio β / α to the reduction ratio β of the toroidal type continuously variable transmission is substantially the same as the reduction ratio i _H at the time of maximum speed increase of the toroidal type continuously variable transmission.