This paper presents the static analysis of general spherical nR simple open or closed kinematic chains with joint friction. The internal loading on each link is found to consist of a bending moment and a torsional moment. The goal of this analysis is to determine these moments which are then used in designing the link.
The moment and force balance equations for each link yields a linear system of equations which define the internal moments of the mechanism and the output torque on the driven crank for a given input torque. A Coulomb model of joint friction is used to determine the friction torque along the axis of a joint. The joint friction model requires an iterative solution.
The purpose of this algorithm is to provide a means of computing the complete internal and external loading on the members of spherical chains while including frictional effects in order to facilitate the design of a functional spherical mechanisms.