Type synthesis and principal freedom analysis of parallel flexure mechanisms based on screw theory

With the development of precision engineering, flexure mechanisms are more and more applied in many fields. The increasing of application requirements call for development of a variety of flexure mechanisms, especially high performance ones. Under the direction of screw theory, a graphic configuration synthesis method based on the complementary rule of freedom and constraint is proposed to synthesize parallel flexure mechanisms. This method is visual and has a definite physical meaning. The synthesis chart of 2R1T and 3R parallel flexure mechanisms is presented as an illustration. In order to verify the characteristic of freedom, a principal freedom analysis method aiming at the practical flexible constraint is also proposed. The analysis of a 2R1T parallel flexure mechanism is implemented, and the influence of structure parameters on the mechanism characteristic compliance is given through the analysis.