JP2002005258A - Continuously variable transmission - Google Patents

Abstract

(57) [Problem] To reduce the size and weight of a toroidal type continuously variable transmission 24c incorporated in a power circulation type continuously variable transmission,
The durability of the plate spring 56a for applying the preload is ensured. SOLUTION: A loading device 10 of a loading cam type is provided with:
On the side opposite to the input section, the above-mentioned disc leaf spring 56a is
Each is provided. Further, a stopper mechanism is provided to prevent the disc spring 56a from being completely compressed when the pressing device 10 is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A continuously variable transmission according to the present invention
Used as an automatic transmission for automobiles. In particular, the present invention
It is intended to ensure the durability of a plate spring for applying a preload while reducing the size and weight.

[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 a casing 5 (see FIGS. 7 and 8 described later) in which the toroidal type continuously variable transmission is housed, swinging about pivots 6, 6 which are twisted with respect to the input shaft 1 and the output shaft 3. Trunnions 7, 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 1 is driven by the rotation of the input shaft 1.
0 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 to oscillate, and the peripheral surface 9a of each power roller 9, 9;
9a is the inner surface 2a of the input side disk 2 as shown in FIG.
Are displaced in such a manner that the respective displacement shafts 8 and 8 are in contact with the portion near the center and the portion near the outer periphery of the inner surface 4a of the output side disk 4, respectively.

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

FIGS. 6 and 7 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, swinging and axial directions (front and back directions in FIG. 6, 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 direction in FIG. 7) 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 the opposite directions, for example, the power roller 9 on the right side of FIG. 7 is on the lower side of the figure, the power roller 9 on the left side of FIG. Displace each. As a result, the direction of the tangential force acting on the contact portions between the peripheral surfaces 9a, 9a of the power rollers 9, 9 and the inner surfaces 2a, 4a of the input disk 2 and the output disk 4 changes. I do. Then, with the change in the direction of the force, the trunnions 7, 7 swing in opposite directions about the pivots 6, 6 pivotally supported by the support plates 13, 13, respectively. As a result, as shown in FIGS. 4 and 5 described above, the contact positions between the peripheral surfaces 9a, 9a of the power rollers 9, 9 and the inner surfaces 2a, 4a change, and the input shaft 11 The rotation speed ratio with the output gear 12 changes.

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

Further, in order to increase the torque that can be transmitted, as shown in FIGS. 8 and 9, two input disks 2A and 2B and two output disks 4 and 4 are provided around the input shaft 11a. 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. 8 and 9 supports an output gear 12a around an intermediate portion of the input shaft 11a so as to be 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. 10 shows Japanese Patent Application Laid-Open No.
1 shows a continuously variable transmission described in JP-A-196759. This continuously variable transmission includes an engine 1 as a drive source.
The start clutch 22 is provided between the output end of the crankshaft 20 (the right end in FIG. 10) and the input end of the input shaft 21 (the left end in FIG. 10). Also, the input shaft 2
An output shaft 23 for extracting power based on one rotation is arranged in parallel with the input shaft 21. A toroidal type continuously variable transmission 24 is provided around the input shaft 21, and a planetary gear mechanism 25 is provided around the output shaft 23.

The cam plate 26 which constitutes the pressing device 10 of the loading cam type of the toroidal type continuously variable transmission 24 includes:
An intermediate portion of the input shaft 21 is fixed to a portion closer to the output side end (rightward in FIG. 10). The input side disk 2 and the output side disk 4 are supported around the input shaft 21 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 21. The cam plate 26 and the input disk 2 constitute the pressing device 10. Therefore, the input side disk 2 rotates while being pressed toward the output side disk 4 as the input shaft 21 rotates. Further, a plurality of power rollers 9, 9 are sandwiched between the inner surface 2a of the input disk 2 and the inner surface 4a of the output disk 4,
The toroidal-type continuously variable transmission 2 as shown in FIGS.
4.

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. 10). Therefore, the output shaft 23 rotates with the rotation of the sun gear 27. This sun gear 2
7, 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 (the right side in FIG. 10). 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. The first power transmission mechanism 3 constituting a first power transmission path described in the claims.
2 is constituted by first and second gears 33 and 34 meshed with each other. Therefore, the carrier 31 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 33 and 34 with the rotation of the output side disk 4.

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. The second power transmission mechanism 35, which constitutes the second power transmission path described in the claims, extends between the first and second sprockets 36 and 37 and between the two sprockets 36 and 37. And a chain 38. 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. 10) of the input shaft 21, and the second sprocket 37 is connected to the input side of the transmission shaft 39. It is fixed to the end (the right end in FIG. 10). Therefore, the transmission shaft 39 is rotated by the rotation of the input shaft 21 so that the input shaft 2
1, the first and second sprockets 36, 3
7 rotates at a speed corresponding to the number of teeth.

Further, the continuously variable transmission includes a clutch mechanism constituting a mode switching means described in the claims. 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.
0 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. 10). 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.

Further, in the example of 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. The operation of changing the speed ratio between the input-side and output-side disks 2 and 4 during such low-speed running 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 before the loading cam device 10 presses the input side disk 2. Mechanism 35
Through the ring gear 28 of the planetary gear mechanism 25. Therefore, almost no torque is transmitted from the input shaft 21 to the input disk 2 via the loading cam 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.

FIG. 11 shows the speed ratio (icvt) of the toroidal type continuously variable transmission 24 when the speed ratio (itotal) of the continuously variable transmission as shown in FIG. 10 is continuously changed. , The input torque (T _in ) input to the toroidal type continuously variable transmission 24 and the output shaft 23 of the continuously variable transmission.
The figure shows an example of a state in which the output torque (T _s ) taken out of the motor changes. Each of these gear ratios (itotal) (icv
t) and the relationship between the torques (T _in ) and (T _s ) include the shift width of the toroidal-type continuously variable transmission 24, the structure and the gear ratio of the planetary gear mechanism 25, the reduction ratio of the second power transmission mechanism 35, and the like. It changes according to. As a condition for obtaining each line shown in FIG. 11, the speed change width of the toroidal-type continuously variable transmission 24 is set to approximately four times (0.5 to 2.0), and the planetary gear mechanism 25 includes one pair of planets. The planetary gear sets 29, 29 composed of the gears 30a, 30b were provided, and the reduction ratio of the second power transmission mechanism 35 was set to about 2. The switching between the low speed clutch 40 and the high speed clutch 41 is performed when the speed ratio (itotal) of the continuously variable transmission is 1 as a whole.

FIG. 1 shows the result of a trial calculation under the above conditions.
1, the vertical axis indicates the gear ratio (icvt) of the toroidal-type continuously variable transmission 24, the input torque (T _in ) of the toroidal-type continuously variable transmission 24, or the output torque (T _s ) of the continuously variable transmission.
And the torque (T _e ) transmitted from the engine 19 to the input shaft 21 (FIG. 10) (T _in / T _e ) (T _s / T _e ).
T _e ), and the horizontal axis represents the speed ratio (itotal) of the entire continuously variable transmission. The value indicating the gear ratio (icvt) of the toroidal type continuously variable transmission 24 is negative because the rotation direction of the output disk 4 (FIG. 10) incorporated in the toroidal type continuously variable transmission 24 corresponds to the rotation of the input shaft 21. This is because it is opposite to the direction. The solid line a indicates the speed ratio (icvt) of the toroidal-type continuously variable transmission 24, and the broken line b indicates
The ratio between the torque (T _e) which is transmitted to the input shaft 21 from the output torque (T _s) and the engine 19 (T _s / T
_e ), the chain line c indicates the input torque (T _in ) and the torque (T _in ) transmitted from the engine 19 to the input shaft 21.
_e ) and (T _in / T _e ). As is clear from the description of FIG. 11 as described above, FIG.
The torque applied to the toroidal type continuously variable transmission 24 during high-speed running can be reduced.
Under the conditions obtained in FIG. 11, the input torque (T _in ) is
At the maximum, the torque (T _e ) transmitted from the engine 19 to the input shaft 21 can be reduced to about 14%.

The toroidal type continuously variable transmission 24 incorporated in the continuously variable transmission as described above is not limited to the single cavity type shown in FIGS. A double cavity type as shown may be used.
A continuously variable transmission incorporating a toroidal type continuously variable transmission of a double cavity type is disclosed in Japanese Patent Application Laid-Open No. H11-63146-7.
No., etc. For example, FIGS.
2 shows two examples of a continuously variable transmission described in JP-A-11-63147. The structure shown in FIG. 12 is a double-cavity toroidal type continuously variable transmission 24.
10, the input shaft 21a is inserted into the center of the toroidal-type continuously variable transmission 24a on the opposite side to the input portion in the axial direction of the toroidal-type continuously variable transmission 24a. The power is divided into a transmission 24a and a planetary gear mechanism 25. On the other hand, the structure shown in FIG. 13 has a transmission shaft 51 on the side of 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.

When the structures shown in FIGS. 12 and 13 are compared, as shown in FIG. 12, the toroidal type continuously variable transmission 2
The structure in which the input shaft 21a is inserted through the center of 4a is smaller and lighter than the structure in which the transmission shaft 51 is provided on the side of the toroidal-type continuously variable transmission 24a as shown in FIG. Easy to plan. On the other hand, when the structure shown in FIG. 12 is employed as it is, the magnitude of the power passing through the input shaft 21a increases as described in Japanese Patent Application Laid-Open No. 7-198014. In order to reduce the power passing through the input shaft 21a in the structure shown in FIG. 12, the pressing device 10 incorporated in the toroidal type continuously variable transmission is input in the axial direction of the toroidal type continuously variable transmission 24a. It is preferable to provide it on the side opposite to the part.

With respect to the axial direction, a toroidal type continuously variable transmission which has a structure in which a pressing device is provided on the side opposite to the input portion and which can be used to constitute the above-described power-circulating type continuously variable transmission is described in Germany. What is described in patent publication DE19775425A1 is known. The toroidal type continuously variable transmission 24b described in this German patent publication is configured as shown in FIG. This toroidal type continuously variable transmission 2
The input shaft 11b constituting the 4b is connected at its base end (left end in FIG. 14) to a drive shaft of a drive source (not shown) such as an engine via a connection bracket 52. Further, a cam plate 53 for constituting the loading cam type pressing device 10 is supported via a ball spline 54 at a portion of the input shaft 11b closer to the front end of the input shaft 11b (rightward in FIG. 14). Further, the rear surface of the cam plate 53 (the right surface in FIG. 14).
A plate spring 56 is provided between the input shaft 11b and a locking flange 55 formed near the tip of the input shaft 11b.
0 is preloaded.

Further, around the intermediate portion of the input shaft 11b,
A cylindrical input side sleeve 57 is arranged concentrically with the input shaft 11b and freely rotates relative to the input shaft 11b. The input side disk 2A is connected to the base end (the left end in FIG. 14) of the input side sleeve 57 via the ball spline 58, and another input side disk 2B is connected to the front end (the right end in FIG. 14) of the spline 59. Through each support. A rolling bearing 60, such as an angular ball bearing, capable of supporting a radial load and a thrust load is provided between the input disk 2A on the base end side and the connection bracket 52. In addition, a rolling bearing 61 such as a needle bearing that can support only a radial load is provided between the input disk 2B on the distal end side and the outer peripheral surface of the intermediate portion of the input shaft 11b.

Further, the outer side surface (the right side surface in FIG. 14) of the input side disk 2B on the front end side and the front surface (FIG. 1) of the cam plate 53.
4 (left surface of FIG. 4), cam surfaces 62 and 63, which are uneven surfaces extending in the circumferential direction, are formed. A plurality of rollers 64, 64 are provided between the two cam surfaces 62, 63.
To constitute the pressing device 10. Accordingly, with the rotation of the input shaft 11b, the pair of input-side disks 2A and 2B rotate synchronously with each other around the input shaft 11b while being applied with a force in a direction approaching each other.

Further, an output side sleeve 65 is provided around an intermediate portion of the input side sleeve 57, and the input side sleeve 57 is provided.
Concentrically with the input side sleeve 57. The base halves of the pair of output disks 4 and 4 are spline-engaged with both ends of the output sleeve 65. The inner peripheral surfaces of the first half of each of the output side disks 4 and 4 and the input side sleeve 57.
Rolling bearings 66, 66, such as needle bearings, which can support only a radial load, are provided between the outer peripheral surfaces of the intermediate portions. Therefore, the pair of output-side disks 4 and 4 are disposed around the input shaft 11 b and the input-side sleeve 57.
The input shaft 11b and the input side sleeve 57 are supported so that they can be rotated and displaced in the axial direction in synchronization with each other. Further, the output side sleeve 65 is attached to a support wall 67 provided inside the housing by a four-point contact type ball bearing or the like.
A rolling bearing 68 capable of supporting a radial load and a thrust load supports only rotation. Further, an output gear 12b is fixedly provided at a middle part of the outer peripheral surface of the output side sleeve 65 and on a side part of the support wall 67.

Between the inner surfaces 4a, 4b of the output disks 4, 4 installed as described above and the inner surfaces 2a, 2a of the input disks 2A, 2B installed as described above. Has a plurality of power rollers 9, 9 (see FIG. 9), each of which is capable of adjusting the inclination angle thereof. When the input shaft 11b rotates, the rotation of the input disks 2A and 2B is transmitted to the output disks 4 and 4 via the power rollers 9 and 9 and the rotational force is extracted from the output gear 12b. . When the rotation of the input shaft 11b is transmitted to the output gear 12b in this manner, the input disks 2A, 2B are transmitted to the output disks 4, 4 based on the thrust force generated by the pressing device 10. Pressed towards. In this state, the plate spring 56 for applying the preload is crushed or the constituent members are elastically deformed, whereby the constituent members are relatively displaced in the axial direction. Based on the existence of each of the ball splines 54 and 58 and the rolling bearings 61 and 66 which do not support the thrust load, it is smoothly permitted.

As described above, the rotation of the input shaft 11b is transmitted to the output gear 12b, and at the same time, the rotation of the input shaft 11b is controlled by the tip of the input shaft 11b (right end in FIG. 14).
In addition, it can be taken out through a take-out bracket 69 arranged concentrically with the input shaft 11b. The take-out bracket 69 is supported by a rolling bearing 70 at the tip end of the input shaft 11b, and has driven-side protruding pieces 71, 71 formed on its outer peripheral edge, and a drive formed on the back surface of the cam plate 53. The side projections 72 are engaged with each other. Therefore, the rotation of the input shaft 11b can be taken out via the take-out bracket 69 without going through the toroidal type continuously variable transmission 24b.

Such a toroidal type continuously variable transmission 24b
Is incorporated in the power circulation type continuously variable transmission shown in FIG. 12 described above, the torque applied to the toroidal type continuously variable transmission 24b during high-speed traveling is reduced, and the configuration of the toroidal type continuously variable transmission 24b is configured. The durability of each member can be improved. Further, as shown in FIG. 12, the power transmitted by the input shaft 11b can be made smaller than that of the structure in which the pressing device 10 is arranged on the input side, and the diameter of the input shaft 11b can be reduced.

[0043]

In the case of the conventional structure shown in FIG. 14, it is difficult not only to secure the durability of the disc leaf spring 56 for applying a preload, but also it is troublesome to process parts and the cost is increased. Moreover, it is difficult to achieve both a reduction in axial dimension and a reduction in weight. The reason is as follows.

First, the reason why it is difficult to ensure the durability of the disc spring 56 is that the disc spring 5
6 is completely crushed. That is, when the toroidal type continuously variable transmission 24b is not operated, the elasticity of the disc spring 56 is such that the inner surfaces 2a, 4a of the input-side and output-side disks 2A, 2B, 4 and the peripheral surfaces of the power rollers 9, 9 are disengaged. Surface 9a, 9a
Is relatively small enough to apply a preload to the contact portion with the toroidal type continuously variable transmission 24.
The thrust force generated by the pressing device 10 at the time of the operation of b is for preventing the respective contact portions from slipping,
Quite large. For this reason, the amount of deflection of the plate spring 56 repeatedly changes between an initial set value and a maximum value as the toroidal-type continuously variable transmission 24b operates and stops. This state is a severe use condition for the plate spring 56, and it is difficult to ensure sufficient durability.

The reason why the machining of parts is troublesome and the cost is increased is that the cam plate 53 constituting the pressing device 10 is connected to the input shaft 1.
This is because 1b is supported via the ball spline 54. The cam plate 53 and the input shaft 11b need to be configured to rotate synchronously. In the case of the conventional structure shown in FIG.
Therefore, it is necessary to smooth the axial displacement of the cam plate 53, and the ball spline 54 is provided. The processing of the ball spline is troublesome as compared with a general spline, and the cost increases accordingly.

Further, the reason why it is difficult to achieve both a reduction in the axial dimension and a reduction in weight is as follows. First, in order to reduce the axial dimension of the toroidal type continuously variable transmission 24b, as shown in the right part of FIG.
A concave portion 73 is provided in a portion near the inner diameter of the outer surface of the
It is necessary to make the portion near the inner diameter of 3 go into the concave portion 73. On the other hand, the axial length of the inner peripheral surface of the input side disk 2B needs to be secured to a certain degree or more because of the provision of the spline engagement portion with the rolling bearing 61 and the input side sleeve 57. is there. For this reason, in the case of the conventional structure shown in FIG. 14, the decrease in the axial length of the inner peripheral surface due to the provision of the concave portion 73 is compensated for by extending the inner diameter portion on the inner side surface 2a side. I have. However, this extended portion shown by the oblique lattice in FIG. 14 is provided only for coupling the input side disk 2B and the input side sleeve 57, and does not contribute to power transmission or the like. The existence of such a portion causes the weight of the toroidal type continuously variable transmission 24b to increase. The continuously variable transmission according to the present invention has been invented in order to eliminate any of these disadvantages.

[0047]

A continuously variable transmission according to the present invention is connected to a drive source and has an input shaft that is rotationally driven by the drive source, similarly to the above-described conventionally known continuously variable transmission. An output shaft for extracting power based on the rotation of the input shaft, a planetary gear mechanism, a toroidal-type continuously variable transmission, and transmitting the power input to the input shaft via the toroidal-type continuously variable transmission. And a second power transmission path for transmitting the power input to the input shaft without passing through the toroidal-type continuously variable transmission.

The planetary gear mechanism is provided between a sun gear and a ring gear disposed around the sun gear, and is rotatably supported by a carrier concentrically and rotatably supported by the sun gear. A planetary gear is meshed with the sun gear and the ring gear. Further, the power transmitted through the first power transmission path and the power transmitted through the second power transmission path 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. Further, there is provided mode switching means for switching a state in which the power input to the input shaft is sent to the planetary gear mechanism through the first power transmission path and the second power transmission path. The mode switching means includes a first mode in which power is transmitted only through at least the first power transmission path, and a power transmission in both the first power transmission path and the second power transmission path. The mode is switched to the second mode for transmitting. Further, the toroidal-type continuously variable transmission has an input-side disk and an output-side disk which are concentrically and rotatably supported with each other in a state where the inner surfaces, each of which is a concave surface having an arc-shaped cross section, face each other. And a plurality of trunnions swinging about a pivot axis which is twisted with respect to the center axis of the input side disk and the output side disk, and a state in which the trunnions project from the inner surface of each trunnion to an intermediate portion of each trunnion. The displacement shafts supported by, and disposed on the inner surface side of each of the trunnions and sandwiched between the input side disk and the output side disk, rotatably supported around the respective displacement axes, A power roller having a spherical convex surface on a peripheral surface thereof; and a pressing device for rotating the input-side disk while pressing the input-side disk toward the output side with the rotation of the input shaft. A plate plate which presses the input side disk and the output side disk in a direction approaching each other when the pressing device is not operated to apply a preload to a contact portion between an inner surface of both disks and a peripheral surface of each of the power rollers. And a spring.

In particular, in the continuously variable transmission according to the present invention,
The pressing device is provided at an axial end of the toroidal continuously variable transmission at an end opposite to a member that transmits power to the toroidal continuously variable transmission. Further, the plate spring is provided at an end of the toroidal-type continuously variable transmission that is opposite to the pressing device in both axial ends.
Further, a stopper mechanism is provided for preventing the plate spring from being completely compressed when the plate spring is compressed by the operation of the pressing device.

[0050]

According to the continuously variable transmission of the present invention configured as described above, the structure can be made small and lightweight even if the second power transmission path for bypassing the toroidal type continuously variable transmission is provided. The durability of the plate spring for applying the preload is easily ensured, and furthermore, the processing of parts is easy and the cost can be reduced. Further, it is easy to achieve both the axial dimension and the weight reduction.

[0051]

1 and 2 show a first embodiment of the present invention. A feature of the continuously variable transmission according to the present invention is that the arrangement of the components of the toroidal continuously variable transmission 24c constituting the power circulation type continuously variable transmission is devised so that the toroidal continuously variable transmission 24c is improved. And the durability of the plate spring 56a for applying the preload is ensured. With respect to the structure and operation of the other parts, the structure and operation of the entire continuously variable transmission are the same as those of the conventional structure shown in FIG.
Since the basic structure and operation of c are the same as those of the conventional structure shown in FIG. 14 described above, the description of the equivalent parts will be omitted or simplified, and the following description will focus on the characteristic parts of the present invention. I do.

A cam plate 53a for forming the loading cam type pressing device 10 is provided on a portion of the input shaft 11c of the toroidal type continuously variable transmission 24c near the front end (to the right in FIG. 1) of the input shaft 11c. Support through. The spline 74 is a simple spline unlike the ball spline 54 having the conventional structure shown in FIG. Then, a portion of the cam plate 53a on the rear side (the right side in FIG. 1) near the inner diameter is directly abutted with a locking flange 55a formed on a portion near the tip of the input shaft 11c. Thus, the cam plate 53a is connected to the input shaft 1
1c support part (not ball spline)
By simply using the spline 74, the processing of this portion can be facilitated and the cost can be reduced.

A concave portion 73 similar to the conventional structure shown in FIG. 14 is formed on the outer side surface (the right side surface in FIG. 1) of the input side disk 2B 'constituting the pressing device 10 together with the cam plate 53a. Not formed. For this reason, the outer surface of the input side disk 2B 'is simply a flat surface except for the cam surface 62 formed in the outer diameter half. Such an input side disk 2B 'has an inner side surface (the left side surface in FIG. 1) of its inner peripheral surface.
The side half is spline-engaged with the end of the input side sleeve 57, and the outer side half of the inner peripheral surface thereof and the input shaft 1.
A rolling bearing 61 is provided between the outer peripheral surface of the intermediate portion 1c. The installation portion of the rolling bearing 61 is connected to the cam plate 53a.
The input side disk 2
The overall axial dimension of B 'is shorter than the input side disk 2B incorporated in the conventional structure shown in FIG.
That is, there is no extended portion as shown by the oblique lattice in FIG. 14 at the inner side end portion on the inner diameter side of the input side disk 2B 'incorporated in this example. Therefore, as compared with the conventional structure shown in FIG. 14 described above, the axial size of the input side disk 2B 'is shortened, and the weight of the toroidal type continuously variable transmission 24c including the input side disk 2B' is reduced. Can be achieved.

The input side disk 2 supported at the base end of the input side sleeve 57 via a ball spline 58.
An annular support recess 75 is formed in the inner half of the outer surface of A ′ (the left side in FIGS. 1 and 2), and the support recess 75 has the first half of the outer ring element 76 (the right half in FIGS. 1 and 2). ) Is slidably fitted in the axial direction (the left-right direction in FIGS. 1 and 2) without play. The outer ring element 76 is used to support a radial load and a thrust load on the connection bracket 52 in which the input side disk 2A 'is fixed to the base end (the left end in FIG. 1) of the input shaft 11c. Rolling bearing 60
This is for constituting a.

In such an outer ring element 76, an angular outer ring track 77 is formed at a portion near the tip of the inner peripheral surface, and an outward flange-shaped locking flange 78 is formed at the base end of the outer peripheral surface. . A disc spring 56a for applying a preload is compressed by a predetermined amount (an amount necessary for applying the preload) between the locking flange 78 and the radially intermediate portion of the outer surface of the input side disk 2A '. It is provided in a state where it is set. In the state where the disc spring 56a is provided in this manner, a first gap 79 is provided between the distal end surface of the outer ring element 76 and the support recess 75, and a second gap 79 is provided in the inner diameter side portion of the disc spring 56a. Are formed respectively.

When a large thrust force is applied to the input side disk 2A 'with the operation of the pressing device 10, the disc spring 56a is elastically compressed, and the first and second gaps 79 and 80 are closed. Although the axial dimension is reduced, even in this case, the plate spring 56a is not completely compressed, in other words, the second gap 80 is not eliminated. For this reason, the axial dimension L ₇₉ of the first gap 79 is smaller than the second gap L ₈₀ (L ₇₉ <
L ₈₀ ), and the inner surface of the support recess 75 and the outer ring element 76
The second gap 80 is made to exist even in a state in which the front end surface is in contact. That is, in the case of the present embodiment, a stopper mechanism for preventing the disc spring 56a from being completely compressed is constituted by the back surface of the support concave portion 75 and the distal end surface of the outer ring element 76.

By preventing the plate spring 56a from being completely compressed in this way, the stress applied to the plate spring 56a is reduced, and the design for securing the durability of the plate spring 56a is facilitated. become. In the illustrated example, the space for installing the disc spring 56a is wider than the space for installing the disc spring 56 in the conventional structure shown in FIG. The degree of freedom in selection is increased, and from this aspect also, the design for ensuring the durability of the disc spring 56a is facilitated. Further, when a large thrust force is applied to the input-side disk 2A 'in accordance with the operation of the pressing device 10, the distal end surface of the outer ring element 76 and the inner surface of the support recess 75 come into contact with each other. The element 76 is in a state of backing up the input side disk 2A '. Therefore, regardless of the thrust load applied to the input side disk 2A 'from the power rollers 9, 9 (see, for example, FIG. 9), it is possible to suppress an increase in stress inside the input side disk 2A'.

FIG. 3 shows a second embodiment of the present invention.
An example is shown. In the case of this example, a step portion 81 is formed on the outer peripheral surface of the intermediate portion of the outer ring element 76a so as to connect the small diameter portion on the input side disk 2A 'side and the large diameter portion on the locking flange 78 side.
A stopper mechanism for preventing the disc spring 56a from being completely compressed by regulating a gap 82 between the step 81 and the radially intermediate portion of the outer surface of the input side disk 2A '. I have. The structure and operation of the other parts are the same as in the case of the first example described above.

[0059]

Since the present invention is constructed and operates as described above, it can contribute to the realization of a continuously variable transmission that is small and lightweight and has excellent durability.

[Brief description of the drawings]

FIG. 1 is a half cutaway view of a toroidal type continuously variable transmission incorporated in a continuously variable transmission, showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a part A of FIG.

FIG. 3 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention;

FIG. 4 is a schematic side view showing a basic structure of the toroidal-type continuously variable transmission in a state of maximum deceleration.

FIG. 5 is a schematic side view similarly showing a state at the time of maximum speed increase.

FIG. 6 is an essential part cross-sectional view showing a first example of a specific structure of the toroidal type continuously variable transmission.

FIG. 7 is a sectional view taken along line BB of FIG. 6;

FIG. 8 is an essential part cross-sectional view showing a second example of the specific structure of the toroidal-type continuously variable transmission.

FIG. 9 is a sectional view taken along the line CC of FIG. 8;

FIG. 10 is a schematic cross-sectional view showing a first example of a continuously variable transmission incorporating a toroidal-type continuously variable transmission.

FIG. 11 is a diagram showing a relationship between a speed ratio of the entire continuously variable transmission, a speed ratio of only the toroidal type continuously variable transmission, and a torque ratio of each part.

FIG. 12 is a schematic sectional view showing a second example of a continuously variable transmission incorporating a toroidal type continuously variable transmission.

FIG. 13 is a schematic sectional view showing the third example.

FIG. 14 is a diagram illustrating a third example of the specific structure of the toroidal-type continuously variable transmission.
The principal part sectional view showing an example.

[Explanation of symbols]

Reference Signs List 1 input shaft 2, 2A, 2B, 2A ', 2B' 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, 11b, 11c Input shaft 12, 12a, 12b Output gear 13 Support plate 14 Thrust ball bearing 15 Thrust needle bearing 16 Outer ring 17 Actuator 18 Drive shaft 19 Engine 20 Crank shaft 21, 21a Input shaft 22 Start clutch 23 Output shaft 24, 24a, 24b, 24c Toroidal-type continuously variable transmission 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 6 First sprocket 37 Second sprocket 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 Connecting bracket 53, 53a Cam plate 54 Ball spline 55, 55a Locking flange 56, 56a Disc spring 57 Input side sleeve 58 Ball spline 59 Spline 60, 60a Rolling bearing 61 Rolling bearing 62 Cam surface 63 Cam surface 64 Roller 65 Output side sleeve 66 Rolling bearing 67 Support wall portion 68 Rolling bearing 69 Take-out bracket 70 Rolling bearing 71 Driven side protrusion 72 Drive side protrusion 73 Recess 74 Spline 75 Support Parts 76,76a outer element 77 outer raceway 78 holding flange 79 first gap 80 second gap 81 step portion 82 gap

Continued on front page F-term (reference) 3J051 AA03 AA08 BA03 BB02 BD01 BD02 BE09 CB06 EA01 EA10 EB01 ED15 FA02 3J059 AA04 AB11 AE04 AE05 BA23 BB03 DA14 GA12 3J101 AA02 AA42 AA54 AA62 BA11 BA57 BA63 FA60 GA

Claims (1)

[Claims] An input shaft connected to a drive source and rotationally driven by the drive source, an output shaft for extracting power based on the rotation of the input shaft, a planetary gear mechanism, a toroidal-type continuously variable transmission, and the like. A first power transmission path for transmitting the power input to the input shaft through the toroidal type continuously variable transmission, and the power input to the input shaft without passing through the toroidal type continuously variable transmission. A second power transmission path for transmission, wherein the planetary gear mechanism is provided between a sun gear and a ring gear disposed around the sun gear, and is rotatably supported concentrically with the sun gear. A planetary gear rotatably supported by a carrier is meshed with the sun gear and the ring gear, and is transmitted through the first power transmission path and transmitted through the second power transmission path. The power can be transmitted to two members of the sun gear, the ring gear, and the carrier, and the power is transmitted to the remaining one of the sun gear, the ring gear, and the carrier. And a mode switching means for switching a state in which power input to the input shaft is transmitted to the planetary gear mechanism through the first power transmission path and the second power transmission path. The mode switching means includes a first mode in which power is transmitted only through at least the first power transmission path, and a power transmission in both the first power transmission path and the second power transmission path. The toroidal-type continuously variable transmission,
An input disk and an output disk which are concentrically and rotatably supported with each other in a state where the inner surfaces which are concave surfaces having an arc-shaped cross section are opposed to each other, and an input disk and an output disk which are rotatably supported. A plurality of trunnions swinging about a pivot axis which is twisted with respect to the central axis, a displacement shaft supported at a middle portion of each of the trunnions so as to protrude from an inner surface of each of the trunnions, and In the state where it is arranged on the inner side of and is sandwiched between the input side disk and the output side disk,
A power roller, which is rotatably supported around each of the displacement axes, has a spherical convex surface on its periphery, and rotates while pressing the input-side disk toward the output side with the rotation of the input shaft. A pressing device to be driven, and a contact portion between the inner surface of each of these disks and the peripheral surface of each of the power rollers by pressing the input side disk and the output side disk toward each other when the pressing device is not operated. A disc spring that applies a preload to the toroidal-type continuously variable transmission, wherein the pressing device transmits power to the toroidal-type continuously variable transmission at axially opposite ends of the toroidal-type continuously variable transmission. At the end opposite to the transmitting member, the disc spring is provided at the end of the toroidal-type continuously variable transmission at the end opposite to the pressing device, and Above with the operation of the pressing device When the plate spring is compressed, continuously variable transmission, characterized in that the disc plate spring is provided with a stopper mechanism for so as not fully compressed.