JPH0660669B2 - Toroidal type continuously variable transmission - Google Patents

Description

The present invention relates to a toroidal type continuously variable transmission, and more particularly to the structure of its transmission system.

(Prior Art) A toroidal type transmission unit, which is a main component of a toroidal type continuously variable transmission, has an input cone disk driven by an input member, and is coaxially arranged with respect to the input cone disk.
An output cone disc that drives the output member, a cone roller that frictionally engages the opposing cone surfaces of these discs to transmit power between the two discs, and a thrust roller that generates a thrust according to the transmission torque to drive the cone rollers to both discs. It is configured with a loading cam that secures the above-mentioned frictional engagement by sandwiching the pressure therebetween.

In this configuration, the power that has reached the input cone disc from the input member is transmitted to the output cone disc through the rotation of the cone roller and can be taken out from the output member. During the transmission, the loading cam generates a thrust according to the transmission torque, and the thrust causes the cone roller to be pinched between the input cone disc and the output cone disc to enable the above transmission. In gear shifting, continuously variable gear shifting is possible by swinging and rotating the cone roller about a swing axis line orthogonal to the rotation axis line to change the frictional engagement points for both cone disks.

By the way, when the required torque capacity of a toroidal type continuously variable transmission is too large to be satisfied by one toroidal type transmission unit, a plurality of sets of the toroidal type transmission units are arranged coaxially and issued in, for example, December 1975 in the United States. Magazine "Automotive Engineering" (Automotive Enginee
ring) No. 83, page 36 to page 39.

In this most common double-cavity toroidal type continuously variable transmission, the input cone discs of both transmission units are placed next to each other and coaxially arranged back to back, and the output cone discs have a corresponding input cone disc and toroid surface. Arrange coaxially so as to face each other. Then, a common input member for rotationally driving these input cone discs is interposed, and a rotating cam is interposed between the input member and both input cone discs.

(Problems to be Solved by the Invention) However, in the conventional configuration represented by the above-mentioned documents, each toroidal type transmission unit drives the input cone disc independently through each loading cam. Therefore, even if the input member for driving is common, it is unavoidable that relative rotation occurs between the input cone disks during torque fluctuation.

This relative rotation tries to reach the output cone disc through the cone roller, but the output cone discs are drive-coupled to a common output member, so that they cannot rotate relative to each other. Therefore, the toroidal type transmission units are interlocked with each other, and one transmission unit acts so as to prevent torque transmission of another transmission unit, and the torque capacity of the transmission cannot be calculated.

In addition, the relative rotation between the input cone discs generates a component force that swings each cone roller in an arbitrary direction, which makes it impossible to synchronize the swing control between the cone rollers, which is the cause. There is also a concern that the shift control may be disabled.

On the other hand, a toroidal type continuously variable transmission having a layout as described in JP-B-57-18057 has also been proposed.

Also in the double cavity type toroidal type continuously variable transmission described in this document, the input cone discs of both transmission units are arranged side by side and back to back coaxially, and the output cone discs are arranged so that the corresponding input cone discs and the toroid surface face each other. It is arranged coaxially. By the way, in the conventional toroidal type continuously variable transmission,
Both input cone discs are integrally connected to each other, and one output cone disc is integrally connected to the output shaft,
The other output cone disk is drivingly connected to the output shaft through hydraulic means that functions similarly to the rotating cam, so that the rotating cam is shared by both transmission units.

However, in this case, if the rotating cam is arranged on the output cone disk side (output side) in order to share the rotating cam with both transmission units, the following problems occur.

That is, the loading cam on the output side is decelerated by the toroidal transmission unit, and the increased transmission torque is applied by this, so that the transmission torque applied to the loading cam becomes large, resulting in a large size and durability. Will be at a disadvantage.

Here, both transmission units perform not only deceleration but also acceleration, but the deceleration frequency is much higher than the acceleration frequency, and the case where it is used for an automobile transmission is explained as an example, the acceleration ratio is The gear ratio is at most about 0.8, which is not far from the gear ratio of 1.0, while the reduction ratio reaches about 3.5. Therefore, the durability disadvantage due to the heavy load on the loading cam is serious.

The present invention ensures that relative rotation never occurs between the input cone discs of both transmission units and between the output cone discs, and the rotation cam can be shared between both transmission units. In order to solve the problems of the interlock and the inability to control the shift, and also the problems of increasing the size and durability of the common rotating cam, the common loading cam is used as an input cone disk. It is an object of the present invention to provide a toroidal type continuously variable transmission in which the positional relationship between the input cone disc and the output cone disc of both transmission units is reversed so that they can be arranged on the input side.

(Means for Solving the Problem) For this purpose, the present invention provides a power transmission between an input cone disc and an output cone disc which are coaxially arranged, and frictionally engaging opposite cone faces of these cone discs. The two toroidal type transmission units consisting of a cone roller for performing the above are coaxially provided, and thrust is generated in accordance with the transmission torque to clamp each cone roller between the corresponding input cone disc and output cone disc to cause the friction. In a toroidal type continuously variable transmission provided with a loading cam that ensures engagement, the input cone disks of both toroidal transmission units are coaxially arranged so that the cone surfaces face each other, and between these input cone disks. Drive coupled so that relative displacement in the axial direction is possible The output cone disks of the toroidal transmission units are arranged back-to-back coaxially between the input cone disks, and the output cone disks and the output members between the output cone disks are integrally coupled together. The loading cam is interposed between one of the axially displaceable input cone discs and an input member that drives the one input cone disc, and the thrust generated by the loading cam corresponds to each input cone disc. It is configured so that it can be biased toward the output cone disc.

(Operation) The power input to the input cone disc of each toroidal type transmission unit reaches the output cone disc via the cone roller for each unit and is taken out from the output member. During this transmission, the loading cam generates thrust according to the transmission torque and biases the input cone disc toward the corresponding output cone disc for each unit to ensure the frictional engagement between the cone roller and both cone discs. The above-mentioned power transmission is possible.

By the way, since the input cone disks and the output cone disks of the toroidal transmission units are drivingly coupled to each other, the input cone disks as well as the output cone disks of the transmission unit cannot rotate relative to each other. For this reason, and because of the configuration in which both the transmission units share the rotating cam, the predetermined speed is performed without the synchronization state of the cone roller of each transmission unit being lost even when the torque changes. Therefore, the interlock between the transmission units does not occur, and the torque capacity of the transmission can be increased corresponding to the number of transmission units as calculated.

In addition, since there is no relative rotation between the input cone discs and between the output cone discs, it is possible to prevent unintentional swinging rotation of each cone roller based on this relative rotation.
It is possible to eliminate the fear that the swinging (shifting) control cannot be synchronized between the cone rollers or that the shift control cannot be performed due to this.

When the input cone discs and the output cone discs are drive-coupled to each other for the above-mentioned effect, the 雛 also enables relative displacement of the input cone discs in the axial direction, and the input member and one input driven by the input member. Since the loading cam is interposed between the cone disc and the cone disc, the cone cams of both transmission units are equally clamped between the corresponding input cone disc and output cone disc, and the above power transmission is performed. Is not hindered, and the following operational effects can be obtained.

That is, since the loading cam is arranged on the input side in relation to the input cone disc due to the above arrangement, the torque before deceleration is loaded, the load torque is small, and the size and durability of the loading cam are reduced. It is possible to improve the sex. Note that the toroidal transmission unit may perform not only deceleration but also speed-up action, but the deceleration frequency is much higher than the speed-up frequency, and the reduction ratio is 1.0 when the speed ratio is higher than the speed-up ratio. The effect is very useful in practice, since the difference from is much larger.

Further, due to the configuration in which the both output cone disks and the output member between them are integrally connected, even if the axial dimension of the output member cannot be made too large, it is possible to avoid the situation where the output member tilts. , It is very useful for power transmission.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

FIG. 1 shows an embodiment of the present invention, in which 1 is an input shaft, 2 is an output gear as an output member, and 3 and 4 are toroidal transmission units. A drive shaft 5 is coaxially connected to the input shaft 1, and a drive plate 6 and a thrust plate 7 as input members are integrally connected to both ends of the drive shaft 5. The toroidal transmission units 3 and 4 are provided on the drive shaft 5 between the drive plate 6 and the thrust plate 7 and arranged coaxially with each other.

For this purpose, a hollow coupling shaft 8 is rotatably supported on the drive shaft 5. The toroidal type transmission units 3 and 4 respectively include input cone discs 9 and 10, output cone discs 11 and 12 coaxially opposed to the input cone discs 9 and 10, and opposite cone faces 9a of the cone discs 9 and 11 and 10 and 12, respectively. 11a and 10a, 12a and cone rollers 13 and 14 frictionally engaged with each other. The input cone disc 9 is fixed to the end of the hollow coupling shaft 8 near the thrust plate 7, and the input cone disc 10 is connected to the drive plate 6. Is spline-fitted to the end portion of the hollow coupling shaft 8 close to, and drivingly coupled so as to be slidable in the axial direction.

Output cone disks 11 and 12 are hollow output shaft 1
6 and are drivingly coupled to each other so as not to be axially displaceable,
The output cone disc 1 is further provided on the hollow output shaft 16.
It is arranged between 1 and 12 and the output gear 2 is bound. The hollow output shaft 16 is rotatably supported on the hollow coupling shaft 8.

The cone rollers 13 and 14 have rotational axes 13a and 14a, respectively.
In addition to making it possible to rotate around the cone disks 9 and 11 and 10 and 12 to transfer power, the swing axis 13 orthogonal to the rotation axes 13a and 14a.
By pivoting around b and 14b, the frictional engagement points with the cone surfaces 9a, 11a and 10a, 12a are changed so that continuously variable transmission can be performed.

A thrust metal 17 is inserted between the thrust plate 7 and the input cone disc 9, and a loading cam 18 is inserted between the drive plate 6 and the input cone disc 10. The loading cam 18 transmits power from the drive plate 6 to the input cone disc 10, and at the same time, generates thrust according to the transmission torque during the power transmission to urge the drive plate 6 and the input cone disc 10 in the separating direction. I shall.

The operation of the above embodiment will be described below.

The power from the input shaft 1 reaches the drive shaft 5, which rotates together with the drive plate 6 and the thrust plate 7. After that, power is applied from the drive plate 6 to the loading cam 1.
8 to reach the input cone disc 10, and also to the input cone disc 9 via the spline 15 and the hollow coupling shaft 8 to integrally rotate the input cone discs 9 and 10. Power from the input cone discs 9 and 10 is transmitted to the output cone discs 11 and 12 via the cone rollers 13 and 14, and then can be taken out from the output gear 2 via the hollow output shaft 16.

During this power transmission, the cone rollers 13 and 14 are synchronously pivoted about the axes 13b and 14b by the same angle, so that the cone rollers 14 are rotated.
The frictional engagement point with and the frictional engagement point with the cone discs 10 and 12 are changed, and the toroidal transmission units 3 and 4 can be continuously stepped in the same direction at the same time, so that the transmission can be continuously stepped. is there.

Further, during the above-described power transmission, the loading cam 18 generates thrust for urging the drive plate 6 and the input cone disk 10 in the separating direction. Drive plate 6
Thrust to the input cone disc 9 via the drive shaft 5, the thrust plate 7 and the thrust metal 17, and the input cone disc 9 and the input cone disc 10 can be displaced relative to each other in the axial direction by the spline 15. The cone disks 9 and 10 can be brought close to each other. Therefore, the cone rollers 13 and 14 are attached to the cone disks 9 and 11 respectively.
The pressure is equally clamped between 10 and 12 and frictionally engages with these cone disks, and the thrust increases in accordance with the transmission torque, so that the power transmission can be reliably performed.

By the way, by disposing the loading cam 18 between the input member 6 and the input cone disc 10,
Since the transmission torque applied to the loading cam 18 is the transmission torque before being decelerated by the toroidal type transmission unit 4, the transmission torque is not so large and is advantageous in durability, so that the loading cam 18 can be downsized. .

It should be noted that when the unit 4 performs the speed increasing action, it has an adverse effect, but the speed increasing frequency is much lower than the decelerating frequency, and the speed increasing ratio does not deviate from the gear ratio 1.0 as much as the speed reducing ratio. The above-mentioned effects are possible with almost no problem.

In addition, the output gear 2 is connected to the output cone disc 11,
Even if the output gear 2 cannot be made large in shaft size, it is not tilted with respect to the drive shaft 5 by being integrated with 12, and it is very useful for power transmission.

(Effects of the Invention) Thus, the toroidal type continuously variable transmission of the present invention is as described above.
Between the input cone disks 9 and 10 of each toroidal transmission unit and the output cone disks 11 and 1
Since the two drive couplings are mutually performed, relative rotation between the input cone discs and between the output cone discs is never produced, and because the rotating cams are shared by both transmission units, the cone roller 1 of each transmission unit is
The synchronous state of 3 and 14 is not broken even when the torque changes. Therefore, the interlock between the transmission units 3 and 4 does not occur, and the torque capacity of the transmission can be increased in proportion to the number of transmission units.

Further, since there is no relative rotation between the input cone discs 9 and 10 and between the output cone discs 11 and 12, it is possible to prevent the free rotation of the cone rollers 13 and 14 based on this relative rotation, and to prevent the cone rollers from mutually rotating. It is possible to eliminate the concept that the swing control becomes out of synchronization between the two, or gear shift control becomes impossible due to this.

Further, since the input cone discs 9 and 10 can be displaced relative to each other in the axial direction and one of the input cone discs is rotationally driven by the input member 6 via the loading cam 18, the thrust generated while the loading cam 18 is transmitting. Thus, the cone rollers 13 and 14 can be equally clamped between the corresponding cone discs 9 and 11 and between the cone discs 10 and 12, and the input cone discs 9 and 10 and the output cone disc 11, When the 12 are drive-coupled to each other, the 雛 can always cause the same transmission operation in both the transmission units 3 and 4, and at the same time, the following operational effects can be obtained.

That is, since the loading cam is arranged on the input side in relation to the input cone disc, a small torque before deceleration is applied, its durability is improved, and size reduction can be achieved. .

In addition, the output member 2 is connected to both output cone disks 1
Since the output members are integrally connected to the first and the second members, the output member is not inclined, and the reduction of the transmission performance can be avoided.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the toroidal type continuously variable transmission of the present invention. 1 ... Input shaft 2 ... Output gear (output member) 3, 4 ... Toroidal type transmission unit 5 ... Drive shaft 6 ... Drive plate (input member) 7 ... Thrust plate 8 ... Hollow coupling shaft 9, 10 …… Input cone disc 11,12 …… Output cone disc 13,14 …… Cone roller 15 …… Spline 16 …… Hollow output shaft 17 …… Thrust metal 18 …… Loading cam

Claims (1)

[Claims] 1. A toroidal transmission unit comprising an input cone disc and an output cone disc which are coaxially arranged, and a cone disc which frictionally engages with opposing cone surfaces of these cone discs to transmit power between the both cone discs. A toroidal unit having two sets of coaxial shafts, which is provided with a loading cam for ensuring the frictional engagement by generating thrust according to the transmission torque and pinching each cone roller between the corresponding input cone disc and output cone disc. In the continuously variable transmission, the input cone disks of both toroidal transmission units are coaxially arranged so that the cone surfaces face each other, and the input cone disks are drive-coupled so as to be relatively displaceable in the axial direction. Same between cone discs In addition, the output cone disks of the toroidal transmission units are arranged back to back, and the output cone disks and the output members between the output cone disks are integrally coupled to each other, and the axial relative displacement is possible. The loading cam is interposed between one of the input cone discs and an input member that drives the one input cone disc, and the thrust generated by the loading cam directs each input cone disc to the corresponding output cone disc. A toroidal-type continuously variable transmission characterized by being configured to be able to be urged.