Kinetic-Geometric Three-Position Synthesis of a Balanced 4R Four-Bar Linkage

This paper proposes a synthesis method in which dynamic requirements are the starting point for deriving the corresponding geometric properties of the linkage for a certain task, which is different from common geometric synthesis methods which do not consider dynamic aspects. By means of a 4R four-bar linkage, first the link lengths are derived for specific requirements on the mass properties and force balance. Subsequently the locations of the base pivots and the coupler pivots are derived for three desired task poses. Here it is interesting that the link lengths are given, while in finite-position synthesis they are usually obtained as the outcome.