Title: Kinematic Analysis of RSCR Spatial Four-Link Mechanisms.
Abstract: The formulas for displacement and velocity analyses are derived for a spatial four-link mechanism with two revolute pairs, a spherical pair and a cylindrical pair. Then, a procedure for determining instantaneous screw axes is presented and their behaviors in the neighborhood of limit positions are clarified. The condition for limit positions of the driving-link motion is obtained on the basis of force transmission from the coupler link to the driven link and the determinant composed of the coefficients of simultaneous equation for velocity analysis. The conditional function is investigated geometrically and a quantity is proposed in order to evaluate motion and force transmission characteristics.