Geometric Derivation of 6R Linkages with Circular Translation

A mathematical explanation on the circular translation is briefly presented and the planar-hinged parallelogram is introduced as the simplest generator of circular translational motions without using prismatic pairs. Based on the geometric properties of circular translation and spherical translation, a kind of 6R paradoxical linkage with a relative motion of circular translation is derived by a new purely geometric approach. The already published linkage having a link with the translation property is verified and other existing ones are distinguished and compared by the use of the parameterization of linkage architecture too.