JPS6030862B2 - Riding cam type pressure generating device for friction continuously variable transmission - Google Patents

Description

[Detailed Description of the Invention] Pressure bale force generation devices that generate pressure force between friction transmission elements in frictionless continuously variable transmissions include those using thrust exerted by springs (spring type), and those using a pair of cams. There is also a type (riding cam type) consisting of a ball that is interposed between two cams and acts as an acid.

In the spring type, a constant pressure force is applied to prevent slippage even when the load torque is maximum, so when the load torque is small, a pressure force greater than the required force is applied to the frictional engagement point. and reduces transmission efficiency. For this reason, it is desirable to provide a cam type that can generate a pressure contact force at the frictional engagement point corresponding to the magnitude of the load torque. There is a problem. That is,
This type of element is an element that must be adjusted to prevent play when assembling the transmission, and shims are used for adjustment. This adjustment is done to ensure that there is no looseness and to obtain a state in which no thrust is generated due to the fertilizing action, so it is not only a troublesome operation that requires a considerable amount of time to be performed by a skilled person. Since this is done statically, the various parts become accustomed to each other after a relatively short period of operation, and once they have become accustomed to each other, the adjustments made during assembly may not necessarily be optimal. The present invention aims to improve the above-mentioned points, and as will be explained in conjunction with the figures below, the present invention utilizes the fact that the screw or cam acts as an irreversible element against the thrust force. A back gap removing device is constructed, and the back gap removing device does not cause a decrease in efficiency of the continuously variable transmission with respect to generation of pressure force.

In FIG. 1, 1 is an electric motor and 2 is its output shaft.

The speed change mechanism is a speed change mechanism that is moved in the axial direction by an input shaft 3, a transmission wheel 4, a conical rotor 5, a stationary orbit ring 6, and an operating handle 7 to change the effective radius of the conical surface of the conical rotor 5. It includes a ring 8, a compression force generator 9, a thrust bearing 10 for transmitting compression force, an output shaft 11, and the like. The pressure force generating device 9 includes a pair of cams 13 and 1 that sandwich a ball 12 that acts as a sliding door.
4, the rear side (the side with the cam surface) of one of the pair of cams 13 and 14 in this device is referred to as the front side.

) is equipped with a special backgap removing device 15, the details of which are shown in FIGS. 2 and 3. Perspective view of Figure 2 and Figure 3
As shown in the exploded view of the figure, the back gap removing device 15 consists of two elements 16 and 17 that are joined together via screws, and a spring 18 interposed between them. The spring 18 has one end 19 thereof engaged in one of a number of slots 21 provided in the flange portion 20' of the element 16, and
The other end 22 is engaged in a hole 24 provided in the flange portion 23 of the element 17 . The threads cut into elements 16 and 17 have a sufficiently small pitch, so that elements 16 and 17
Relative rotation between them is not caused by a thrust force acting in the axial direction. If this property of the screw is referred to as "irreversibility" for simplicity of expression, in the device according to the present invention, it acts on the compressing force generating device including the ball 12 and the pair of cams 13 and 14. A composite body consisting of elements 16 and 17 that engage with each other while utilizing irreversibility is used to receive the reaction force of the thrust force. The composite body of elements 16, 17 does not change its overall length no matter how great the thrust acting on it, but can change its overall length due to the rotational moment exerted by the spring 18. spring 18
Therefore, relative rotation between the elements 16 and 17 occurs when conditions are established that allow the overall length of the composite body made up of the elements 16 and 17 to change. 14) is loose. This play is a type of back gap, and in this respect, what is shown in FIGS. 2 and 3 is a type of back gap removing device. What you need to be careful about with this device is the spring 18.
is not an element provided to apply thrust, but an element provided to apply rotational moment. The back gap removal by this device does not occur intermittently but continuously so that the back gap is always maintained at zero. Spring 18 is element 16
, 17 is relatively small (it does not cause the ball 12 to move up onto the slopes of the cams 13 and 14). The spring 18 can be replaced by a spiral spring, and the elements 16, 17 can be replaced by elements having cam surfaces (slopes) that can be imitated as part of a thread.

FIGS. 4 and 5 illustrate such a case, where elements 16 and 17 are designated by 16a and 17a, and spring 18 is designated by 18a. In addition,
In FIG. 4, the reference numeral 25 indicates a hook which disables the action of the spring 18a until the assembly is completed in order to facilitate assembly, and this hook is later removed. The difference between those shown in Figures 2 and 3 and those shown in Figures 4 and 5 is that the former has a smaller outer diameter and larger axial length, while the latter has a larger outer diameter. is short in axial length and located at a point.

Which of these to adopt depends on the length of the casing.
It is determined by considering the arrangement of the transmission mechanism inside the casing, etc.
The device according to the present invention described above can stably generate pressure force without causing hunting or instability, and can also be easily fitted to a transmission.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of a friction continuously variable transmission having a compression force generating device according to the present invention, and FIGS. 2 and 3 are perspective views showing a back gap removing device in the device shown in FIG. 4 is a longitudinal cross-sectional view showing a modification of the one shown in FIGS. 2 and 3; FIG. 5 is a cross-sectional view taken along line V--V in FIG. 4. DESCRIPTION OF SYMBOLS 1... Electric motor, 2... Output shaft of the motor, 3... Input shaft, 4... Transmission wheel, 5... Conical trochanter, 6... Stationary orbit ring, 7... Operation Handle, 8... Speed change ring, 9... Pressure force generator, 10... Thrust bearing, 1
1... Output shaft, 12... Ball, 13, 14... Cam, 1
5... Back gap removing device, 16, 17... Elements that engage each other via screws, 16a, 17a... Elements that engage each other via cam, 18a... Spring, 19... Spring One end of 20...flange part, 21...slot, 2
2...Other end of the spring, 23...Flange part, 2
4...hole, 25...hook. Murasaki' figure, younger brother 2 figure, grass 3 figure, younger brother 4 - figure hair 5 figure

Claims (1)

[Claims] 1. A pressure force generating device 9 that generates a pressure force between friction transmission elements is interposed between a pair of cams 13 and 14, and a ball 12 that acts as a wedge acts in the axial direction. a pair of elements 16, 17 that engage with each other via screws or cams that prevent rotation between them depending on the thrust force applied;
A device consisting of a spring 18, 18a which exerts a rotational moment between the elements 16, 17 so as to increase the overall length of the composite body consisting of one of the pair of cams 13, 14.
4, and the strength of the springs 18, 18a is selected to such an extent that the wedge action exerted by the ball does not occur depending on the rotational moment exerted by the springs 18, 18a. A cam-type pressure generating device for friction continuously variable transmissions.