Synthesis and Analysis of Spherical-Cylindrical (SC) Link in the McPherson Strut Suspension Mechanism

Abstract

This paper introduces the equations for the synthesis and analysis of the spherical-cylindrical (SC) link and its use for the McPherson suspension in automobiles. In this particular SC link, the cylindrical joint axis passes through the spherical joint and this type of SC link has yet to be investigated. The equations developed are applied to the design of a spatial mechanism—a McPherson suspension. This is modeled as a multiloop spatial rigid body guidance mechanism—an RSCS-SS, with a single degree of freedom for the guidance of the wheel assembly. Then the design equations for RS, SS, and newly developed SC links are applied to synthesize an RSCS-SS for up to three prescribed positions for the rigid body guidance. The mechanism is also analyzed for the two major motions of rigid body guidance problems: the wheel jounce/rebound and the steering, using the displacement matrix method. The displacement matrix method consists of two main components: matrices such as displacement, velocity, and acceleration matrices, and the constraint equations. Thus a McPherson suspension which is kinematically synthesized is also analyzed for the displacement, velocity, and acceleration during the entire range of guidance motion.