Problems of design of a spherical wrist mechanism for a 6R low-payload robotic manipulator

Abstract

A serial robotic manipulator is composed of an arm and a wrist. The latter is responsible for orienting (local motions) of an end-effector and it is composed of at least 3 joints. The paper concerns the designing procedure of a spherical wrist mechanism for a prototype 6R lightweight manipulating robot carried out by the authors. The analysis of the course of the preliminary design procedure indicated that: selection of the kinematic structures of the wrist’s two final rotations mechanisms, choice of appropriate type of mechanical transmissions for application in the wrist mechanism, structural design taking into account application of composite parts, as well as providing appropriate characteristics of driving system are the most complex problems encountered during the design. This motivated the authors to study and discuss the mentioned problems in this paper. The analysis results were the base of choices made by the authors during the final design procedure.