Structural Synthesis of Stationary Cam-Modulated Seven-Bar Linkages for Press Driving Mechanisms

In the design stage of a press driving mechanism, the function generation problem must be dealt with for the dimensional synthesis. Planar cam-modulated linkages are possible solutions for exact function generation. The structural synthesis for stationary cam-modulated seven-bar linkages is presented in this paper. By removing a frame-adjacent non-input/output binary link in a planar one degree-of-freedom eight-bar linkage, and subsequently by combining the two incident simple joints on the two links adjacent to the removed link into a cam pair, thirty-one topological structures of stationary cam-modulated seven-bar linkages are synthesized in total. Also, based on the concepts of identifying the critical fixed pivot and critical force transmission path/sub-train of a topological structure, a classifying procedure for evaluating the degree of stability of all synthesized topological structures for force transmission in the toggle configuration is proposed and discussed. The presented results can be helpful in the conceptual design of press driving mechanisms.