JPH06174033A - Toroidal type continuously variable transmission - Google Patents

Abstract

PURPOSE:To obtain the width of change gear ratio larger than that of toroidal change gear mechanisms, as well as to realize a small size in the diameter direction. CONSTITUTION:While a hollow driving shaft 8 whose one end is connected to the second output disk 5 is fitted rotatable to an input shaft 1, it is inserted to the center hole of the second input disk 4, and the other end is connected to a sun gear 9. As a result, the hollow driving shaft 8 can be made in a compact size in the diameter direction. Since the torque of the second output disk 5 is transmitted from the sun gear 9 with a smaller number of teeth to a ring gear 13 with a larger number of teeth through the first pinion 10 and the second pinion 11, and then transmitted to an output shaft 14, the width of the change gear ratio of the whole body of the toroidal CVT is made larger compared to the width of the change gear ratio of the toroidal gear change mechanisms 15 and 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal type continuously variable transmission applied to an automobile or the like, and more particularly to a double cavity type toroidal type continuously variable transmission in which two sets of toroidal transmission mechanisms are coaxially arranged. .

[0002]

2. Description of the Related Art Conventionally, a toroidal type continuously variable transmission is shown in FIG.
As shown in FIG.
Input disk 22 which rotates in the direction and is slidable in the axial direction with respect to the input shaft 21, an output disk 23 which is rotatably provided in the input shaft 21, and rotates in the direction B, And a toroidal transmission mechanism 25 including a power roller 24 and the like arranged between the output disk 23 and the output disk 23. In FIG. 4, the output disk 23
The connection structure from to the output shaft is omitted. The power transmission between the power roller 24 and the disks 22 and 23 depends on the shearing force of oil under high pressure, that is, the traction force (adhesive friction force). To obtain a predetermined traction force,
A very large pressing force is required in the axial direction at the contact point between the power roller 24 and the disks 22 and 23. The pressing force F is applied to the input disk 22 by a pressing means such as a spring, a cam, or a hydraulic device. Further, the reaction force is configured to be received by the thrust bearing 26 arranged between the input shaft 21 and the output disk 23. However, since this toroidal type continuously variable transmission is applied with a very large pressing force F in the axial direction, the thrust bearing 26 that receives the reaction force must be made large, and the rolling resistance of the thrust bearing 26 is large. However, there is a problem that the efficiency of the toroidal type continuously variable transmission decreases as a whole.

As a solution to this problem, a double-cavity toroidal type continuously variable transmission has recently been proposed. As a double cavity type toroidal type continuously variable transmission,
For example, there is one as shown in FIG. That is, this toroidal type continuously variable transmission has a pair of input disks 22, 27.
And output disks 23, 28 arranged to face the respective input disks 22, 27, and input disks 22,
Two sets of toroidal speed change mechanisms 25, 30 having tiltable power rollers 24, 29 for transmitting torque from 27 to the output disks 23, 28 are arranged on the input shaft 21 so as to face each other. Further, a pressing unit that changes the pressure contact force of the power rollers 24 and 29 according to the magnitude of the torque input from the input shaft 21 to the input disks 22 and 27,
It is provided on one toroidal transmission mechanism 25. Furthermore, the pair of output disks 23, 28 are configured such that their back surfaces are connected to each other and can rotate integrally.
An output gear 31 is provided at the connecting portion. In the figure, symbol A indicates the rotation direction of the input shaft 21, and symbol B indicates the rotation direction of the output disk 23.

By the way, when the double-cavity toroidal type continuously variable transmission is used as a transmission for an automobile or the like, the output shaft is usually arranged on the same axis as the input shaft 21. Therefore, for example, as shown in FIG. 6, a parallel shaft 33 having a gear that meshes with the output gear 31 is arranged in parallel with the input shaft 21 and across the toroidal transmission mechanism 30, and the parallel shaft 33 and the output shaft 32 are arranged. And the spur gear mechanism 34 is arranged between them. In the figure, symbol A indicates the rotation direction of the input shaft 21, and symbol B indicates the rotation direction of the output disk 23.

Alternatively, as shown in FIG. 7, a planetary gear mechanism 35 may be arranged between the parallel shaft 33 and the output shaft 32. Instead of providing a gear mechanism such as a spur gear mechanism 34 or a planetary gear mechanism 35, there is one using a chain or the like. In any case, the conventional toroidal type continuously variable transmission needs to be provided with the parallel shaft 33 in parallel with the input shaft 21 so that the torque can be transmitted across the toroidal transmission mechanism 30. For this reason, the conventional toroidal type continuously variable transmission has a problem that the size becomes large in the radial direction and the mountability on the vehicle is impaired. In the figure, symbol A indicates the rotation direction of the input shaft 21, and symbol B indicates the rotation direction of the output disk 23.

As a solution to the above-mentioned problems, Japanese Patent Laid-Open No.
There is a toroidal type continuously variable transmission disclosed in JP-A-2-255655. This toroidal type continuously variable transmission is composed of two sets of toroidal transmission mechanisms 25 and 30, as shown in FIG. One toroidal transmission mechanism 25 is provided on the input shaft 21. The input shaft 21 and the output shaft 32 are arranged coaxially, and the other toroidal transmission mechanism 30 is provided on a hollow drive shaft 36 that is rotatably fitted to the output shaft 32.

Adjacent output disks 23 and 28 are connected to each other and can rotate integrally. Output disk 23
The input disc 22 arranged facing the
Is rotatably supported on the input shaft 21 via a loading cam 37. On the other hand, the input disk 27 arranged to face the output disk 28
Is rotatably supported by the hollow drive shaft 36, and is drivingly connected to the hollow drive shaft 36 via a loading cam 38. A power roller 24 is arranged between a pair of opposing input disks 22 and output disks 23, and a power roller 29 is arranged between the input disks 27 and output disks 28. The power roller 24 receives torque from the input disk 22 to rotate and transmits the rotation to the output disk 23, and the power roller 29 receives torque from the input disk 27 to rotate and rotate. This is transmitted to the output disk 28, and both power rollers 24 and 29 are tilted in conjunction with each other, and a continuously variable transmission ratio can be obtained according to the tilt angle.

The integrated output disks 23, 28 are hollow, and a double pinion type planetary gear mechanism 35 for transmitting the torque of the output disks 23, 28 to the output shaft 32 is built therein. A ring gear 39 is provided on the inner peripheral surface of each of the output disks 23 and 28. The first pinion 40 meshes with the ring gear 39, the second pinion 41 meshes with the first pinion 40, and the second pinion 41 is coaxially integrated with the second pinion 41. The third pinion 42 is rotatably supported by the carrier 43, and the sun gear 44 is meshed with the third pinion 42 to form a double pinion type planetary gear mechanism. The carrier 43 integrally connects the input shaft 21 and the hollow drive shaft 36, and the sun gear 44 is connected to the output shaft 32.

[0009]

However, the toroidal type continuously variable transmission disclosed in Japanese Unexamined Patent Publication No. 62-255655 is miniaturized in the radial direction, but the planetary gear mechanism 35 causes the output disk 23, Since it is built inside 28, the output discs 23 and 28 are connected to the ring gear 39 and the input disc 22 regardless of whether it is a double pinion type or a single pinion type when there is one set of planetary gears. , 27 are connected to the carrier 43, and the output shaft 3
2 is connected to the sun gear 44. In such a configuration,
Since the ring gear 39 always has more teeth than the sun gear 44, the number of teeth of the planetary gear is 25, 30.
The gear ratio width of the entire toroidal type continuously variable transmission must be much smaller than the gear ratio width of (1) (For the calculation formula and calculation result of the gear ratio, refer to the section of the embodiment of the present invention. ). To solve this, use 2 planetary gears.
More than one set is required, the device becomes long in the axial direction, and the structure becomes complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems. Even if the gear ratio width of the toroidal transmission mechanism is small, a large gear ratio width can be obtained for the toroidal type continuously variable transmission as a whole. Therefore, it is to provide a toroidal type continuously variable transmission that is downsized in the radial direction.

[0011]

In order to achieve the above object, the present invention is configured as follows. That is,
The present invention relates to a first input disc that rotates integrally with an input shaft, a first output disc that is arranged so as to face the first input disc and is rotatably supported by the input shaft, and the first output disc. A second output disk having a one-piece structure, the second output disk
A second input disc disposed opposite the output disc,
A tiltable power roller disposed between the first input disc and the first output disc and between the second input disc and the second output disc, respectively;
A hollow drive shaft integrally connected to the output disc and rotatably fitted to the input shaft to rotatably support the second input disc, a sun gear integrally connected to the hollow drive shaft, and the second drive shaft. A carrier that supports a pinion that is integrally connected to the input disk and that meshes with the sun gear;
And a toroidal type continuously variable transmission that has an output shaft that is integrally connected to a ring gear that meshes with the pinion and that is arranged coaxially with the input shaft.

Further, in this toroidal type continuously variable transmission, the pinion is composed of a single pinion that meshes with the sun gear and meshes with the ring gear, or a first pinion that meshes with the sun gear and a mesh with the first pinion. Further, it may be configured by a double pinion including a second pinion that meshes with the ring gear.

[0013]

Since the toroidal type continuously variable transmission according to the present invention is constructed as described above, it operates as follows. That is, in this toroidal type continuously variable transmission, the input shaft is drivingly connected to the first input disk, and the driving shaft is also connected to the second input disk via the carrier.
The torque input to the input shaft is applied to the first input disk and the second input disk.
It is transmitted to the input disc. The torque transmitted to the first input disc and the second input disc is transmitted to the first output disc and the second output disc via the power roller, respectively. Since the second output disk is integrally connected to the hollow drive shaft that is inserted through the center hole of the second input disk, the torque of the second output disk is transmitted to the sun gear that is connected to the hollow drive shaft. The rotational force of the sun gear is transmitted to the ring gear via the pinion and then to the output shaft connected to the ring gear.

In this toroidal type continuously variable transmission, the input shaft and the output shaft are arranged on the same axis, the hollow drive shaft is rotatably fitted to the input shaft, and one end of the hollow drive shaft is connected to the second output disk. Since the hollow drive shaft is inserted into the center hole of the second input disk and the other end of the hollow drive shaft is connected to the sun gear, the hollow drive shaft is conventionally arranged parallel to the input shaft so as to straddle the second input disk. The parallel shaft, which has been used, is no longer necessary, and the transmission itself can be downsized in the radial direction.

Further, the toroidal type continuously variable transmission according to the invention as claimed in claim 1 adopts a double pinion type planetary gear mechanism having a first pinion and a second pinion as a pinion, and the torque has a number of teeth. Since it is configured to be transmitted from a small number of sun gears to a ring gear having a large number of teeth, the gear ratio width of the entire toroidal type continuously variable transmission is larger than the gear ratio width of the toroidal transmission mechanism.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the toroidal type continuously variable transmission according to the present invention will be described below with reference to the drawings.
1 is a half schematic diagram showing an embodiment of a toroidal type continuously variable transmission according to the present invention. This toroidal type continuously variable transmission is a double-cavity toroidal type continuously variable transmission in which two sets of toroidal transmission mechanisms 15 and 16 are coaxially arranged to face each other. The first toroidal transmission mechanism 15 includes a first input disk 2, a first output disk 3 arranged to face the first input disk 2, a first input disk 2 and a first input disk 2.
It is composed of a first power roller 6 which is arranged between the output disc 3 and frictionally engaged with both discs 2 and 3.
Similarly, the second toroidal speed change mechanism 16 also includes a second input disk 4 and a second input disk 4 that is disposed so as to face the second input disk 4.
It is composed of an output disk 5 and a second power roller 7 which is disposed between the second input disk 4 and the second output disk 5 and frictionally engages with both disks 4, 5. Each of the first power roller 6 and the second power roller 7 is rotatable about its own rotation axis and tilts about a tilt axis perpendicular to the rotation axis.

The first input disk 2 is rotatably supported with respect to the input shaft 1, but is drivingly connected to the input shaft 1 via a loading cam (not shown) and can rotate integrally with the input shaft 1. it can. The first output disk 3 facing the first input disk 2 is rotatably supported on the input shaft 1. The first output disc 3 and the rear faces of the second output disc 5 are connected to each other.
5 is integrated. The second input disk 4 arranged so as to face the second output disk 5 is rotatably supported by the hollow drive shaft 8. The hollow drive shaft 8 is fitted into the input shaft 1 and is rotatably supported with respect to the input shaft 1. The hollow drive shaft 8 extends through the center hole of the second input disk 4, and one end of the hollow drive shaft 8 is integrally connected to the second output disk 5. In the figure, reference numeral A indicates the rotation directions of the first input disk 2 and the second input disk 4, and reference numeral B indicates the rotation directions of the first output disk 3 and the second output disk 5.

The toroidal transmission mechanisms 15 and 16 are drivingly connected to the output shaft 14 via a planetary gear mechanism 17.
The output shaft 14 is arranged coaxially with the input shaft 1. The planetary gear mechanism 17 is a double-pinion type planetary gear mechanism, and includes a sun gear 9 integrally connected to the other end of the hollow drive shaft 8 and a first pinion 10 meshing with the sun gear 9.
And the second pinion 1 meshing with the first pinion 10.
1, the first pinion 10 and the second pinion 11 are rotatably supported, and the input shaft 1 and the second input disk 4
And a ring gear 13 that meshes with the second pinion 11 and that is integrally connected to the output shaft 14.

This toroidal type continuously variable transmission is constructed as described above. Next, the operation of this toroidal type continuously variable transmission will be described. When torque is input to the input shaft 1 as the engine operates, the torque is transmitted to the first input disk 2 via the loading cam. At the same time, the torque is transmitted from the input shaft 1 via the carrier 12 to the second input disk 4. When the torque is transmitted to the first input disk 2, the first input disk 2 rotates, the rotation of the power roller 6 causes the rotation of the first input disk 2.
It is transmitted to the output disk 3. Also, the second input disk 4
The torque transmitted to the second output disk 5 is transmitted to the second output disk 5 via the power roller 7. Since the first output disc 3 and the second output disc 5 are integrally connected, they rotate together. During this transmission, when the power rollers 6 and 7 are synchronized and tilted about the tilt axis by the same angle, the friction engagement points between the power rollers 6 and 7 and the input disks 2 and 4 and the output disks 3 and 5 Changes, and continuously variable transmission can be performed.

When the second output disk 5 rotates, the hollow drive shaft 8 connected to the second output disk 5 also rotates. Since the sun gear 9 is provided at the other end of the hollow drive shaft 8, the rotation of the sun gear 9 is transmitted to the planetary gear mechanism 17. In the planetary gear mechanism 17, the torque varies from the sun gear 9 to the first pinion 10, the second pinion 11, and the ring gear 1.
3 to the output shaft 14 from the ring gear 13. In the above embodiment, the double pinion type planetary gear mechanism 17 having the first pinion 10 and the second pinion is adopted as the planetary gear mechanism 17, but a single pinion type planetary gear mechanism is adopted. Good.

Next, regarding the gear ratio, a comparison will be made between the toroidal type continuously variable transmission according to the present invention and the conventional toroidal type continuously variable transmission disclosed in Japanese Patent Laid-Open No. 62-255655. First, the code will be defined as follows. I: Gear ratio of the entire toroidal type continuously variable transmission I _CVT : Gear ratio of the toroidal transmission mechanism Z _S : Number of sun gear teeth Z _R : Number of ring gear teeth The gear ratio I of the toroidal continuously variable transmission according to the present invention is
When the double pinion type planetary gear mechanism 17 is adopted as the planetary gear mechanism, I = −Z _R · I _CVT / (Z _S + Z _S · I _CVT −Z _R · I _CVT ) ───── (1) Can be expressed. Further, when the single pinion type planetary gear mechanism is adopted, the gear ratio I of the toroidal type continuously variable transmission according to the present invention is I = Z _R · I _CVT / (Z _S + Z _S · I _CVT + Z _R · I _CVT ) ───── (2)

On the other hand, the gear ratio I of the conventional toroidal type continuously variable transmission is I = -Z _S I _CVT / (Z _R + Z _R I when the double pinion type planetary gear mechanism is adopted. _CVT- Z _S · I _CVT ) ───── (3) Further, when the single pinion type planetary gear mechanism is adopted, the gear ratio I of the conventional toroidal type continuously variable transmission is I = Z _S · I _CVT / (Z _R + Z _R · I _CVT + Z _S · I _CVT ) ───── (4). Where Z _S <Z _R , Z _S >
Since 0, Z _R > 0 and I _CVT > 0, only equation (1) has a singular point.

The number of teeth Z _S of the sun gear in the planetary gear mechanism
Of 40 and the number of teeth Z _{R of the} ring gear is 105, the gear ratio I _CVT of the toroidal transmission mechanism is 0.385.
When the gear ratio I of the toroidal type continuously variable transmission is calculated using the above equations (1) to (4) for the range of to 2.600, the results of FIGS. 2 and 3 can be obtained. 2 and 3, the vertical axis represents the gear ratio I (T / M ratio) of the toroidal type continuously variable transmission, and the horizontal axis represents the gear ratio I _CVT (CVT ratio) of the toroidal transmission mechanism, which is a double pinion type. This is a comparison between the case where a (D / P) planetary gear mechanism is adopted and the case where a single pinion type (S / P) planetary gear mechanism is adopted. Further, FIG. 3 is an enlarged view of FIG. As is apparent from these figures, the toroidal type continuously variable transmission according to the present invention can obtain a larger gear ratio than the conventional toroidal type continuously variable transmission. In particular,
When a double pinion type (D / P) planetary gear mechanism is adopted, the difference between the two is remarkable.

Looking at the amount of change of the gear ratio, that is, the gear ratio width, when the double pinion type (D / P) planetary gear mechanism is adopted, the toroidal type continuously variable transmission according to the present invention is used. It can be seen that the gear ratio width is considerably larger than the gear ratio width of the conventional toroidal type continuously variable transmission. On the other hand, when the single pinion type (S / P) planetary gear mechanism is adopted, the speed ratio width is small in both cases.
Further, when the double pinion type (D / P) planetary gear mechanism is adopted, the toroidal type continuously variable transmission according to the present invention can continuously shift from normal rotation to reverse rotation.

The toroidal type continuously variable transmission of the above embodiment can be used with the input and output reversed. In that case, as a matter of course, in the above embodiment, the input shaft becomes the output shaft, the input disc becomes the output disc, and the output disc becomes the input disc.

[0026]

Since the toroidal type continuously variable transmission according to the present invention is configured as described above, it has the following effects. That is, in this toroidal type continuously variable transmission, the input shaft and the output shaft are arranged on the same axis, the hollow drive shaft is rotatably fitted to the input shaft, and one end of the hollow drive shaft is connected to the second shaft.
Since the hollow drive shaft is connected to the output disc, the hollow drive shaft is inserted through the center hole of the second input disc, and the other end of the hollow drive shaft is connected to the sun gear, conventionally, the hollow drive shaft is parallel to the input shaft so as to straddle the second input disc. The parallel shafts that have been arranged are unnecessary, and the size can be reduced in the radial direction. Further, since the parallel shaft is not necessary, the number of bearings can be reduced and the mechanical efficiency can be improved.

Further, since the toroidal type continuously variable transmission is constructed so that the torque is transmitted from the sun gear having a small number of teeth to the ring gear having a large number of teeth, the double pinion having the first and second pinions is provided. When the planetary gear mechanism of the type is adopted, this toroidal type continuously variable transmission can obtain a gear ratio width considerably larger than the gear ratio width of the toroidal transmission mechanism.

Further, when the double pinion type planetary gear is adopted, the output shaft can continuously shift from normal rotation to reverse rotation.

[Brief description of drawings]

FIG. 1 is a half schematic diagram showing an embodiment of a toroidal type continuously variable transmission according to the present invention.

FIG. 2 is a graph showing a gear ratio I of a toroidal type continuously variable transmission with respect to a gear ratio I _{CVT of} a toroidal transmission mechanism.

FIG. 3 is an enlarged view of the graph of FIG.

FIG. 4 is a half schematic diagram showing an example of a conventional toroidal type continuously variable transmission.

FIG. 5 is a half schematic diagram showing an example of a conventional double-cavity toroidal type continuously variable transmission.

6 is a half schematic diagram showing an example in which a spur gear mechanism is arranged between a parallel shaft and an output shaft in the toroidal type continuously variable transmission of FIG.

7 is a half schematic diagram showing an example of disposing a planetary gear mechanism between a parallel shaft and an output shaft in the toroidal-type continuously variable transmission of FIG.

FIG. 8 is a half schematic diagram showing another example of a conventional double-cavity toroidal-type continuously variable transmission.

[Explanation of symbols]

 1 Input Shaft 2 1st Input Disc 3 1st Output Disc 4 2nd Input Disc 5 2nd Output Disc 6 1st Power Roller 7 2nd Power Roller 8 Hollow Drive Shaft 9 Sun Gear 10 1st Pinion 11 2nd Pinion 12 Carrier 13 Ring gear 14 Output shaft 15,16 Toroidal speed change mechanism 17 Planetary gear mechanism

Claims (3)

[Claims] 1. A first input disk that rotates integrally with an input shaft, a first output disk that is disposed so as to face the first input disk and is rotatably supported by the input shaft, and the first output disk. A second output disc having an integral structure with the second output disc
A second input disc disposed opposite the output disc,
A tiltable power roller disposed between the first input disc and the first output disc and between the second input disc and the second output disc, respectively;
A hollow drive shaft integrally connected to the output disc and rotatably fitted to the input shaft to rotatably support the second input disc, a sun gear integrally connected to the hollow drive shaft, and the second drive shaft. A carrier that supports a pinion that is integrally connected to the input disk and that meshes with the sun gear;
And a toroidal type continuously variable transmission including an output shaft that is integrally connected to a ring gear that meshes with the pinion and that is arranged coaxially with the input shaft. 2. The toroidal type continuously variable transmission according to claim 1, wherein the pinion comprises a single pinion that meshes with the sun gear and meshes with the ring gear. 3. The toroidal type continuously variable transmission according to claim 1, wherein the pinion comprises a double pinion including a first pinion that meshes with the sun gear and a second pinion that meshes with the first pinion and meshes with the ring gear. Machine.