Development of a novel sort of exponent-sine-shaped flexure hinges

Abstract

Various types of flexure hinges have been developed to construct flexural mechanisms, however, all these hinges may have limited moving accuracies, blocking performance improvements of the flexural mechanisms. In this paper, a novel sort of exponent-sine-shaped flexure hinges (ESSFHs) with asymmetric structures is proposed to achieve much higher motion accuracy. To characterize elastic deformation behavior of the ESSFHs, a novel finite beam based matrix modeling (FBMM) method is employed to calculate the compliance matrix and the defined non-dimensional precision factors without executing laborious integration operations. Furthermore, finite element analysis is conducted and compared with the FBMM method, the maximum deviation of the obtained compliances and the precision factors by the two methods is less than 8%, well demonstrating the efficiency of the analytical method. Comparisons of the accuracies of the ESSFHs and certain state-of-the-art flexure hinges verify that the proposed ESSFHs can not only significantly improve the motion accuracy but also decrease the inherent parasitic motions of conventional flexure hinges. Based on the established analytical models, influences of the dimensional parameters on the compliances and the motion accuracy of the ESSFHs are well revealed. Finally, performances of the ESSFH and the efficiency of the analytical model are well investigated by means of experimental tests.