MOBILITY OF STEPHENSON SIX-BAR CHAINS―PART Ⅰ: CIRCUIT AND CIRCUIT DEFECT

摘要

Circuit defect is a fundamental and difficult problem in the process of linkage synthesis. In this paper, a Stephenson six-bar chain can be regarded as combination of a four-bar chain and a dyad. Base on the distance of two common joints shared by the four-bar chain and the dyad, the principle is elucidated and the model is established for circuit identification of Stephenson six-bar chains. The criteria and procedures to automatically identify the circuit and circuit defect of Stephenson six-bar chains are developed. The results provide theoretical basis and technical method for computer aided dimensional scheme selection of Stephenson six-bar mechanisms synthesis. In addition, the model for circuit identification can be directly used to solve the motion order defect that is often encountered in Stephenson six-bar mechanisms synthesis.