Kinematic synthesis of planar four-bar mechanisms for multi-phase motion generation with tolerances

This article presents a new technique for synthesizing planar four-bar mechanisms to achieve phases of both precise rigid body positions and rigid body positions with tolerances. This method is an extension of the adjustable RRSS motion generation synthesis methods developed by the authors. (Russell, K., Sodhi R. S. (2001). Kinematic synthesis of adjustable RRSS mechanisms for multi-phase motion generation. Journal of Mechanism and Machine Theory 36:939-952; Russell K., Sodhi R. S. (2002). Kinematic synthesis of adjustable RRSS mechanisms for multi-phase motion generation with tolerances. Journal of Mechanism and Machine Theory 37:279-294.) By incorporating rigid body point tolerances in the rigid body displacement matrices and calculating mechanism fixed and moving pivot solution loci for the prescribed rigid body positions under the tolerance limits, circle and center point regions were calculated. The circle and center points for the crank and follower link solutions for the planar four-bar mechanism were selected from these regions. In this article, two-phase moving pivot adjustment problems with constant crank and follower lengths are considered.