A spatial four-bar linkage RSPS for ball-bar to test R-pair

Abstract

A novel mechanism model of RSPS is firstly presented in the paper for testing the rotational ac-curacy of an actual R-pair, which is new in the literature. The spatial four-bar linkage RSPS is comprised of a ball-bar with three kinematic pairs S-P-S and an actual R-pair measured. The outputs of RSPS corresponds to the distance between two master balls’ centers, and the assembly errors of the ball-bar instrument are concisely contained in the outputs of RSPS with different parameters. Hence, the rotational errors of an actual R-pair measured are readily identified by the measured data of the ball-bar instrument minus the theoretical outputs of RSPS.