Tripod bearing device and a method of torsion compensation

摘要

A tripod bearing device featuring a stationary frame and a carrier moveable relative to it, which are connected together via three braces that are adjustable in their lengths. Each brace is coupled to the frame and to the carrier via a joint each with two rotational degrees of freedom. Moreover, a torsion drive is assigned to each brace for twisting the carrier-end joint of the relevant brace relative to the frame-end joint of this brace about its longitudinal axis. Consequently, a constructively simple parallel structure with three machining axes can be realized which, with its high dynamic stiffness, enables an accurate positioning of the carrier. Furthermore, a method for torsion compensation in the braces is given.