RU2323378C2 - Drive with intermediate roller links - Google Patents

Abstract

FIELD: precision engineering; precision drives.

SUBSTANCE: invention relates to gear drives used to transmit rotation and it can be used in drives reducing and increasing speed of output shaft of high-precision machines and mechanism. Proposed drive with intermediate roller links has coaxial high-speed shaft 1 and slow-speed shaft 2. Eccentric 3 displaced relative to central axis through value "e" is made on high-speed shaft 1. Antifriction bearing 4 being in mechanical contact with intermediate links 6 is installed on eccentric. Intermediate roller links are placed in holder 7 secured on outer race of bearing 4. intermediate roller links 6 are simultaneously in contact with inner shaped profile of central wheel 8, outer race of bearing 4 and shaped profile of cam 9 rigidly secured on slow-speed shaft 2.

EFFECT: improved reliability of drive by preventing getting of holder under intermediate link.

1 dwg

Description

The invention relates to precision engineering, in particular to gears for communicating rotational motion, and can be used in drives that lower and increase the output shaft speed of high-precision machines and mechanisms.

A known transmission with intermediate links containing freely rotating roller drive elements, including a pair of conjugated epicyclic and hypocyclic surfaces located on the drive and driven drives, with a large number of rolling bodies located between the surfaces and transmitting torque from the drive wheel to the driven. The rolling bodies are made in the form of cylindrical rollers, which, rotating, transmit torque, while remaining in continuous contact with the opposite trochoidal surface. The hypotrochoidal and epitrochoidal surfaces have many cams, and the number of hypotrochoidal cams is two more than the number of epitrochoidal cams. The number of rollers is one greater than the number of epitrochoidal cams (US Patent No. 4,584,904, IPC: F16H 1/28).

The disadvantage of this device is the misaligned movement of the output link of a single-stage transmission, which is why additional wheels with epitrochoidal and hyprochoidal profiles are introduced, as well as dynamic balancers to eliminate a significant imbalance. This increases the axial size and mass of the mechanism.

As a prototype selected coaxial gear with intermediate roller links containing coaxial high-speed and low-speed shafts. At the same time, an eccentric is made on the high-speed shaft, offset by an amount e from the central axis. The transmission also contains a fixed central wheel with an internal shaped profile, a cage with radial grooves in which roller intermediate links are placed, the number of which differs from the protrusions of the central wheel profile. On the eccentric of the high-speed shaft, a rolling bearing is installed, which is in kinematic contact with the roller intermediate links, which also come in contact with the shaped profile made on the outer surface of the cam. The cam is rigidly fixed to a low-speed shaft (patent RU No. 2247882, IPC: F16H 1/32, BI No. 7, 2005).

The transfer works as follows.

During operation, a high-speed shaft with an eccentric rotates with the operating frequency of the electric motor. Thanks to the eccentric, which creates an oncoming wave, the roller intermediate links fall into the wedge between the profile of the central wheel and the outer ring of the bearing mounted on the eccentric of the high-speed shaft. Roller intermediate links located in the cage, trying to get out of the wedge, run around the profile of the fixed central wheel and, while in contact with the profile of the cam, force it to rotate. The cam transmits rotational motion to a low-speed shaft by means of a rigid connection with it.

The disadvantage of this device is the lack of a rigid connection between the cage and the eccentric of the high-speed shaft, which is why during transmission of significant loads it is possible to jam the transmission from falling into the cage under the roller intermediate link.

The task is to increase the reliability of the transmission by eliminating the possibility of the clip falling under the intermediate link.

This problem is solved thanks to the transmission with intermediate roller links, containing coaxial high-speed and low-speed shafts. At the same time, an eccentric is made on the high-speed shaft, offset by an amount e from the central axis. The fixed central wheel with an internal shaped profile kinematically interacts with intermediate roller links located in the radial grooves of the cage, the number of which differs from the protrusions of the central wheel profile. The rolling bearing is mounted on the cam of the high-speed shaft and is in kinematic contact with the intermediate roller links. A cam with a shaped profile formed on the outer surface is rigidly fixed to the low-speed shaft and is in contact with the intermediate roller links. A cage is fixed on the outer ring of the bearing mounted on the eccentric, in the grooves of which intermediate roller links are located.

With this arrangement, it is possible to provide a fixed position of the cage opposite the center of the intermediate roller link and to exclude the possibility of jamming of the gear due to falling of the cage under the intermediate link.

The drawing shows a transmission with intermediate roller links, a longitudinal section.

The transmission with intermediate roller links contains coaxial high-speed 1 and low-speed 2 shafts, and high-speed shaft 1 is made with an eccentric 3 offset from the central axis of the gear by an amount of e. A rolling bearing 4 mounted on the eccentric 3 of high-speed shaft 1, a balancer 5 mounted on the high-speed shaft 1, roller intermediate links 6, placed in a cage 7, which is mounted on the outer ring of the bearing 4, the central profile wheel 8, cam 9, rigidly connected to the low-speed shaft 2 mounted on Orach 11 in the housing 10. In addition, if the number of projections of the profile of the cam 9 is equal to Z, then the number of roller intermediates equals 6 Z + 1, and the number of the profile projections of the center wheel 8 is equal to Z + 2.

The transfer works as follows.

In the process, a high-speed shaft 1 with an eccentric 3 rotates with the operating frequency of the electric motor. Due to the eccentric 3, which creates an oncoming wave, the roller intermediate links 6 fall into the wedge between the profile of the central wheel 8 and the outer ring of the bearing 4 mounted on the eccentric 3 of the high-speed shaft 1. The roller intermediate links 6 located in the cage 7 mounted on the bearing 4, aiming exit the wedge, run on the profile of the fixed central wheel 8 and, while in contact with the profile of the cam 9, through the jumpers of the cage 7 make it rotate. Cam 9 transmits rotational motion to low-speed shaft 2 by means of a rigid connection with it.

Claims (1)

Coaxial gear with intermediate roller links, containing coaxial high-speed and low-speed shafts, wherein the high-speed shaft is made with an eccentric offset by an amount e from the central axis, a fixed central wheel with an internal shaped profile, a cage with radial grooves in which the roller intermediate links are located, number which differs from the protrusions of the central wheel profile, a rolling bearing mounted on the cam of the high-speed shaft and in kinematic contact with the roller with intermediate links, a cam with a shaped profile made on the outer surface, rigidly fixed to a low-speed shaft, characterized in that a cage with intermediate roller links is fixed on the outer ring of the bearing mounted on an eccentric.