Rotational Transmission Error of K-H-V-Type Planetary Gears With Cycloid Gears : 2nd Report, Effects of Manufacturing and Assembly Errors on Rotational Transmission Error

Abstract

Since the K-H-V-type planetary gears with cycloid gears can be made compact and light, and have a large reduction ratio, high efficiency, and high torsional stiffness, they have been used in industrial robots and machines requiring precise positioning. The rotational transmission error of the K-H-V-type planetary gears with cycloid gears should be as small as possible in order to apply the planetary gears in various fields. In this paper, K-H-V-type planetary gears with cycloid gears were transformed into a two-dimensional model with twenty degrees of freedom, and the effects of machining and assembly errors of elements on the rotational transmission error were determined analytically, and some analytical results obtained were checked experimentally, giving the following results. The major errors affecting the rotational transmission error are the position error of holes for the crank cam in the cycloid gear ; runout and accumulative pitch error of the cycloid gear ; error in the crank cam ; the accumulative pitch error of the internal gear. Directions of position error of the hole, runout and accumulative pitch errors of one cycloid gear should be identified with those of the other cycloid gear respectively, so as to decrease the rotational transmission error.