Mobility analysis of a Sarrus Linkage-like 7-R single closed loop mechanism

This paper introduces the mobility analysis of a 1-DOF (Degrees of Freedom) Sarrus Linkage like 7-R single closed loop mechanism. The analysis procedure implements both group theory based criterion and reciprocal screw theory. The analysis shows that such mechanism allows rectilinear motion with full-cycle mobility. Further, unlike the Sarrus Linkage, which is overconstrained, this 7-R linkage is non-overconstrained. This property makes the Sarrus Linkage-like mechanism more robust to manufacturing errors. Simulation has shown that even with large manufacturing errors, such mechanism is still able to realize desired rectilinear motion. One possible application for this mechanism is a durable automotive suspension.