Kinematic Synthesis of Spherical Two-Gear Drives With Prescribed Entire-Motion Characteristics: Displacement Analysis and Dwell Characteristics

Abstract

This paper presents an analytical and computer-aided procedure on the kinematic synthesis of the spherical two-gear drive with prescribed dwell characteristics. The first part gives a displacement analysis which includes an investigation of the general case of spherical five-link, 5R mechanisms and the spherical geared five-link case. Two approaches, one making use of the spherical trigonometric relations and the other involving sequential coordinate transformations by real and orthogonal [3 × 3] matrices, yield identical input-output expressions. The remainder of the paper focuses on the dwell characteristics of the spherical two-gear drive using algebraic methods based on the displacement equation. Dwell criteria for the general m th-order dwell are derived. A specific example which involves a joint consideration of other entire-motion characteristics, such as limit positions and transmission-angle variations, is given to illustrate both the theory as well as the computer-aided synthesis procedure.