JPS601502B2 - Planetary friction transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a planetary friction transmission that uses rolling friction of rollers instead of meshing gears to increase and decrease speed.

Conventionally, this type of planetary friction transmission has mostly been a combination of a barrel-shaped loaf and a drum-shaped roller, and the sun roller, which is divided into two parts, is pressed against each other in the direction of the ball to generate the pressing force of the roller. There is.

This pressing force needs to be large enough to prevent slippage from occurring with respect to the transmitted torque. If the transmission torque is greater than this, for example, excessive torque at startup, slippage may occur and damage to the roller may occur. However, it is extremely disadvantageous to always apply a pressing force that does not cause slippage even in the case of excessive torque at startup or rated torque, since this reduces efficiency and the life of the roller. Therefore, depending on the magnitude of the transmitted torque, it is important to always apply the minimum necessary pressing force that does not cause slippage.
This is very disadvantageous as it reduces efficiency and roller life. Therefore, a function is required to generate a pressing force of at least 4.0 times as much as necessary to prevent slippage, depending on the magnitude of the transmitted torque. FIGS. 1 and 2 show a planetary friction transmission that satisfies the above requirements, and is deep in the center with respect to the direction of the pitch circle provided on the back surfaces of the sun loaves a, a' and on the grooved plates b, b'. A plurality of grooves c, c' that become continuously shallower as they approach both ends, and the depth becomes zero at both ends.
and ball d, due to the deviation of the grooved plates b, b' and the sun loaf a, a' caused by the input torque,
Using the movement of the ball d in the shallow direction of the grooves c and c', it pushes the sun loaf a and a' towards the enemy, and the wedge action of the planetary roller e and the sun loaf a and a' pushes the o-ra. It generates force. However, although the planetary friction transmission configured as described above can obtain a roller pressing force depending on the transmitted torque, it has the following problems. [1- Since the shape of the roller is barrel-shaped or drum-shaped, the diameter of the roller changes in the axial direction of the roller, which inevitably causes slippage as it approaches the end of the roller.

■ The contact surface of each roller becomes a point contact, increasing Hertzian stress, which limits transmission capacity. {3' As the generation of slip increases heat generation on each roller surface, the transmission efficiency decreases and the life of the rollers is shortened. [
4} Because each roller has a special shape, advanced technology is required to manufacture the rollers.

In view of the above points, the present invention forms a sun roller, a plurality of planetary rollers, and an inner ring constituting a planetary mechanism so as to be in parallel contact with each other, so that slippage does not occur in the inner ring depending on the magnitude of the transmitted torque. To provide a planetary friction transmission capable of generating a roller pressing force in the radial direction.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, "1 is a cylindrical sun roller formed integrally with the input shaft 2, and the sun roller 1 is pivotally supported by a gear case 3 via the input shaft 2. 4 is a cylindrical sun roller formed integrally with the input shaft 2. A plurality of cylindrical planetary rollers arranged between inner rings to be described later and in parallel contact with the roller,
This planetary loaf 4 is rotatably supported by a planetary roller shaft 7 via a carrier 6 connected to an output shaft 5 disposed on the same axis as the input shaft 2.

8 is an inner ring provided between the gear case 3 and the planetary roller 4, and the inner ring 8 is divided into a first inner ring 9 that contacts the planetary roller 4 in parallel and a second inner ring 101 that is fixed to the gear case 3. ing.

The respective opposing surfaces of the first inner ring 9 and the second inner ring 10 constituting the IJ ring 8 are formed in a tapered shape, and the tapered opposing surfaces are provided with a spiral groove 9a in the rightward direction. ,1
0a is provided.

Reference numeral 11 indicates a plurality of balls interposed in the spiral grooves 9a and 10a of the first inner ring 9 and the second inner ring 10.

In addition, when the spiral grooves 9a and 10a are provided on the opposing surfaces of the first inner ring 9 and the second inner ring 10, the direction of deflection of the spiral grooves 9a and 10a is determined by considering the rotational direction of the input shaft 2. Determined by

That is, when the spiral grooves 9a, 10a are in the rightward direction, the input shaft 2 is rotated clockwise (in the direction of the arrow in the figure).

In the planetary friction transmission configured as described above, when the sun roller 1 is rotated by the input shaft 2, the planetary roller 4 rotates and revolves due to the rolling friction resistance between the sun roller 1 and the first inner ring 9. The revolution of the roller 4 is transmitted from the planetary roller 7 to the output shaft 5 via the carrier 6.

The sun roller 1, the planetary roller 4, and the inner IJ ring 8
The first inner ring 9, which constitutes a part of the inner ring 9, is formed so as to be in parallel contact with each other, so that the contact surface of each roller becomes a surface ferrule, and the Hertzian stress is lowered, so that the transmission capacity can be increased.

Next, a method for generating a radial roller pressing force on the first inner ring 9 of the inner ring 8 will be explained.

First, when the input shaft 2 is rotated clockwise, the rotation from the input ball 2 is transmitted to the planetary roller 4 via the sun roller 1.

At this time, due to the rotation of the planetary roller 4, the first inner ring 9 constituting the inner ring 8 is moved in the rightward swing direction (as shown by the arrow direction) depending on the magnitude of the transmitted torque. For this reason, the first inner ring 9 and the second inner ring 10
A radial roller pressing force is generated due to the sinking action of the roller.
The roller pressing force generated on the first inner ring 9 is applied to the planetary roller 4 and the sun roller 1, and their mutual pressing force generates a traction force to transmit power from the input shaft 2 to the output shaft 5. It will be done. Since a roller pressing force is applied to each roller in parallel contact in accordance with the magnitude of the transmitted torque, there is no slippage between the rollers, and the life of the rollers can be extended. The present invention provides a planetary friction transmission in which a sun roller, a plurality of planetary rollers, and an inner ring constituting a planetary mechanism are formed so as to be in parallel contact with each other. and a second inner ring fixed to the gear case, and the first
Each of the contacting surfaces of the inner ring and the second inner ring is formed into a tapered shape, each of the tapered contacting surfaces is provided with a spiral groove, and a plurality of balls are interposed in the spiral groove, Since the roller pressing force in the radial direction is generated according to the magnitude of the transmitted torque by the rubbing action between the first inner ring and the second inner ring, the transmission capacity can be increased, and
This has the advantage that the roller can be manufactured easily and the life of the roller can be extended.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a conventional planetary friction transmission, Fig. 2 is an enlarged view of the main part of the subordinate roller pressing force generation mechanism, and Fig. 3 is a longitudinal cross-sectional view of the planetary friction transmission of the present invention. It is. DESCRIPTION OF SYMBOLS 1... Sun roller, 3... Gear case, 4... Planetary roller, 8... Inner ring, 9... First inner ring, 10... Second inner ring, 9a, 10a... Spiral groove , 11...
Pole. Traditional/Figure 2 Leopard 3

Claims (1)

[Claims] 1. In a planetary friction transmission in which a sun roller, a plurality of planetary rollers, and an inner ring forming a planetary mechanism are formed in parallel contact, the inner ring is fixed to a first inner ring that contacts the planetary roller and a gear case. the first inner ring and the second inner ring each have a tapered contact surface, and each of the tapered contact surfaces is provided with a spiral groove. A plurality of balls are provided in the spiral groove, and the torsional action of the first inner ring and the second inner ring generates a radial force according to the magnitude of the transmitted torque. A planetary friction transmission.