Performance evaluation of path-generating planar, spherical and spatial four-bar linkages

Abstract

A general method for coupler-curve generation and evaluation, associated with one-degree-of-freedom four-bar linkages is presented in this paper. The linkages under study may be planar, spherical or spatial. As to the latter, the method is applicable to those spatial linkages whose input-output or input-coupler functions are quadratic. An index X is introduced, which not only unifies the analysis regardless of the basic classification of linkages, i.e. Grashof or non-Grashof, but also eliminates the branch problem in the computational procedure. A computer-aided package has been developed to implement the described method on planar, spherical and spatial four-bar linkages. This package has been successfully used in the optimum synthesis of these types of path-generating linkages.