RU2550598C1 - Planetary gear - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: planetary gear contains eccentric shaft (1), two cone satellite gears with external teeth (2), fixed central wheel in form of two cone central wheels with internal teeth (3), output shaft (4), discs (5), (6), (7) rigidly connected with each other, and output shaft by means of braces (8), and rollers (10) free located in holes of the satellite gears and discs. Angles of cones of the central wheel (3) and satellite gear (2) are selected such that during engagement their axes will be parallel. The central wheels are installed in the casing (18) on balls (15) and pressed to the satellite gears by the resilient elements (17). Between the satellites the thrust roller bearing (14) is installed.

EFFECT: simplified design of the planetary gear and increased level of its workability.

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Description

The invention relates to the field of engineering, in particular to high-precision gears, and can be used in robotics, servo systems and other mechanisms.

Known planetary gear containing an eccentric shaft; two satellites; motionless central wheel; disks rigidly connected to each other and with the output shaft, and rollers located freely in the holes of the satellites and disks. Moreover, to exclude gaps in the gears of the wheels and reduce play, the eccentric shaft is prefabricated, containing segments and wedges located on the flats of the shaft and shifting the satellite in the radial direction (US Pat. No. 2493453 of the Russian Federation, IPC F16H1 / 32. Planetary gear / Plekhanov F.I. , Ovsyannikov A.V., Veretennikov N.D., Maksimov A.N. Publ. September 20, 2013, Bull. No. 26) (prototype).

The disadvantage of this design is its complexity and low technology, which is associated with the need to manufacture high-precision parts of complex shape: segments, wedges, adjusting nuts with fixing screws.

The objective of the invention is to simplify the design and increase the level of adaptability of the planetary gear.

The solution to this problem is achieved by the fact that in a planetary gear containing an eccentric shaft; two satellites; motionless central wheel; disks rigidly connected with each other and with the output shaft, and rollers located freely in the holes of the satellites and disks, the satellites and the fixed central wheel are conical with parallel axes, and the fixed central wheel is made up of two central wheels mounted in the housing on the balls and pressed to the satellites by elastic elements, and a thrust roller bearing is installed between the satellites.

Simplification of the design of the planetary gear and increasing the level of its manufacturability in the absence of gaps in the gears of the wheels is achieved using simple to manufacture and standard parts (rods, balls, thrust rolling bearings).

The essence of the invention is illustrated by drawings, where in Fig.1 shows a General view of the planetary gear section, in Fig.2 - view along aa in Fig.1.

The planetary gear includes an eccentric shaft 1; two satellites 2; two central wheels 3; output shaft 4; wheels 5, 6, 7; screeds 8; bushings 9; rollers 10; eccentric shaft bearings 11; satellite bearings 12; bearings of the output shaft 13; persistent rolling bearing 14; balls 15; rods 16; elastic elements 17; case 18, covers 19.

 The central wheels 3 are made conical with internal teeth, the satellites 2 are conical with external teeth, and the angles of the cones of the central wheel 3 and satellite 2 are selected so that when engaged their axes are parallel. The diameter of the rollers 10 is less than the diameter of the holes in the satellites 2 and disks 5, 6, 7 by the distance of the axle distance of the planetary gear. Grooves of a cylindrical shape with a radius equal to the radius of the balls 15 are made in the housing 18 and on the outer surfaces of the central wheels 3. The elastic elements 17 are rubber rings.

The couplers 8 are pressed into the disks 5, 6, 7. The satellites 2 are mounted by bearings 12 on the eccentric shaft 1 and engage with the central wheels 3. The rollers 10 are located in the holes of the satellites 2 and disks 5, 6, 7. The rods 16 are installed in the grooves of the central wheels 3 and the housing 18 with a gap.

         The planetary gear assembly is carried out in the following sequence.

         A disk 6 with axial rolling bearing 14 located therein and tie rods pressed in its holes 8 is axially displaced into the middle part of the eccentric shaft 1. On the eccentric shaft 1, the satellites 2 are mounted with the bearings 12 installed in them, and then the bearings 11. The bushings 9 are mounted on screeds 8. After that, disks 5 and 7 are pressed onto the screeds 8 and simultaneously fit on the bearings of the eccentric shaft 11. In the holes of the satellites 2 and disks 5, 6, 7, the rollers are inserted 10. Moreover, the rollers 10 are selected in diameter so that their manifestation with satellites 2 and disks 5, 6, 7 was gapless. The thus assembled block of satellites is inserted into the housing 18, after which the central wheels 3 are introduced into engagement with the satellites 2. The central wheels 3 are fixed in the housing 18 by balls 15, between which the rods 16 are located freely. After that, its bearings 13 are mounted on the output shaft 4, elastic elements 17 are inserted into the housing 18, the covers 19 are seated simultaneously on the bearings of the output shaft 13 and into the housing 18, pressing the elastic elements 17 against the central wheels 3.

         The planetary gear operates as follows.

   Rotational motion is transmitted from the eccentric shaft 1 through the satellites 2 and the rollers 10 to the disks 5, 6, 7 and the output shaft 4. In this case, the central wheels 3 under the action of the elastic elements 17 are displaced axially on the balls 15, choosing the clearances in the engagement.

  To reduce the backlash in the proposed planetary gear, simple to manufacture and standard parts are used, thereby simplifying the design and increasing the level of its manufacturability.

                         INFORMATION SOURCES

1. Pat. No. 2493453 of the Russian Federation, IPC F16H 1/32. Planetary gear / Plekhanov F.I., Ovsyannikov A.V., Veretennikov N.D., Maksimov A.N. Publ. 09/20/2013, Bull. No. 26 (prototype).

Claims (1)

A planetary gear comprising an eccentric shaft, two satellites, a fixed central wheel, disks rigidly connected to each other and with the output shaft, and rollers located freely in the holes of the satellites and disks, characterized in that the satellites and the fixed central wheel are made conical with parallel axes moreover, the stationary central wheel is made up of two central wheels mounted in the housing on balls and pressed to the satellites by elastic elements, and a thrust rolling bearings.

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