Analysis of Spherical Linkages

Abstract

In this chapter we examine spherical linkages. These linkages have the property that every link in the system rotates about the same fixed point. Thus, trajectories of points in each link lie on concentric spheres with this point as the center. Only the revolute joint is compatible with this rotational movement and its axis must pass through the fixed point. We study the spherical RR and 3R open chains and the 4R closed chain and determine their configuration as a function of the joint variables and the dimensions of the links.