RU2017037C1 - Gear-friction transmission - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: when shaft rotates inner race 2 sets in rotation intermediate cylindric bushings 6,7, which in turn rotate rolling bodies 4,5, through gear engaging. Cylindric grooves are provided on outer surface of race 2. The grooves are provided with rings 8 made of self-lubricating material which prevent shifting of bushings 6,7 and rolling bodies 4,5 along the axis of the shaft. EFFECT: enhanced reliability. 2 cl, 2 dwg

Description

 The invention relates to reducing mechanisms and can be used in drive mechanisms of reciprocating machines and in friction planetary gearboxes, for example, in gas refrigeration machines.

 Known friction planetary gearbox containing a shaft, an inner and an outer race, the rolling bodies located between them and the intermediate hollow cylindrical bushings [1].

 A disadvantage of the known gearbox is its low bearing capacity, since the load is small, which the frictional connection of the inner cage with the intermediate bushings is capable of transmitting. Slipping in the friction joint reduces the accuracy of the gear ratio.

 The closest in technical essence to the claimed transmission is the drive mechanism of a predominantly piston gas refrigeration machine [2] selected as a prototype, comprising a shaft, inner and outer cages, rolling elements between them and intermediate hollow cylindrical bushings.

 The disadvantages of this design are low bearing capacity, inaccuracy of gear ratio.

 To separate (separate) the bushings and prevent them from shifting along the axis of the mechanism, protrusions are made on the working surfaces of the inner race and rolling elements, and grooves are made on the outer race. The implementation of the protrusions and grooves on the working surfaces complicates the design, leading to a decrease in the accuracy of manufacturing of the working surfaces, bearing capacity and accuracy of the gear ratio due to slippage.

 The connection of the inner cage with the intermediate bushings can transmit 1.5-2 times less load than the friction joints of the rolling elements with the bushings and the outer cage, which is due to the design of the drive (geometric ratios of the radii of curvature of the mating surfaces).

 The purpose of the invention is to increase the bearing capacity and accuracy of the gear ratio of the transmission. This goal is achieved by the fact that in the known drive mechanism comprising a shaft, two cages are mounted coaxially on it, two hollow cylindrical bushings and rolling bodies in series, interacting with the inner surface of the outer cage and the outer surface of the cylindrical bushings, are installed with an interference fit and on the inner surfaces of the cylindrical bushings and the outer surface of the inner race are teeth designed to interact with each other.

 On the outer surface of the inner race grooves are made in which rings of self-lubricating material are installed. In this case, the absence of stress concentrators increases the strength of the hollow cylindrical bushings, and the bearing capacity of the transmission increases.

 In FIG. 1 shows a gear-friction gear, a transverse section; in FIG. 2 is a section AA in FIG. 1.

 The gear-friction gear contains an inner race 2 mounted on the shaft 1, an outer race 3, rolling elements 4 and 5, and intermediate hollow cylindrical bushings 6 and 7. On the inner cavities of the bushes 6 and 7 and the outer surface of the race 2, teeth are made. On the outer surface of the inner race 2 grooves are made in which rings 8 of self-lubricating material are installed.

 Gear-friction gear operates as follows.

 When the shaft 1 is rotated, the inner race 2 through the gear engages the intermediate cylindrical bushings 6 and 7, which rotate the rolling bodies 4 and 5. Rolling bodies 4 and 5 can be made with different diameters of the outer surfaces and, rolling on the inner surface of the race 3, can set it in motion, which is transmitted by a piston mechanism. Rolling bodies 4 and 5 can be made with the same diameters of the outer surfaces and connected via bearings to the carrier and the output shaft. In this case, the gear-friction gear performs the function of a planetary gear. The rings 8 of self-lubricating material in the process of separating the sleeves 6 and 7 and prevent the movement of the sleeves 6 and 7 and the rolling elements 4 and 5 along the axis of the shaft 1. The implementation of the rings 8 of self-lubricating material allows to reduce heat emission during friction of the sleeves on the ring, to eliminate seizing. The teeth on the bushings 6 and 7 and the yoke 2 increase the bearing capacity of the sleeve-yoke connection and the transmission as a whole.

Claims (2)

 1. DENTAL-FRICTIONAL TRANSMISSION, comprising a shaft, two cages mounted on it coaxially, two hollow cylindrical bushings and rolling bodies installed between them, interacting with the inner surface of the outer race and the outer surface of the cylindrical bushings, characterized in that, in order to increase the bearing abilities and accuracy, the rolling bodies are tightened, and on the inner surfaces of the cylindrical bushings and the outer surface of the inner race teeth are made for interaction Twi with each other.  2. The transmission according to claim 1, characterized in that the grooves are made on the outer surface of the inner race, and the transmission is equipped with rings of self-lubricating material placed in the corresponding grooves.

Images