Mobility analysis of spatial 4- and 5-link mechanisms of the RS class

Abstract

When a spatial mechanism has many links, the mobility analysis and the input-output relation are very difficult to obtain due to the high degree of the underlying polynomial. For spatial RS-class mechanisms such as RSSR, RRSS, and RRSRR mechanisms, the quadratic input-output relation and the associated mobility condition are developed in this paper. The method is based on the geometric interpretation of the distance function for spatial mechanisms. The method can be applied to mechanisms which have a symmetric relation between two conjugate configurations. Especially, for the spatial 5-link RRSRR mechanism, a maximum of 12 limit positions of the crank are obtained by the proposed method. (C) 1996 Elsevier Science Ltd.