A generalized analytical compliance model for cartwheel flexure hinges

Normal cartwheel flexure hinge (NCFH) typically consists of two flexible springs crossing at their mid points. These have been used in compliant mechanism applications owing to the large motion range of such hinges. In this paper, a novel generalized cartwheel flexure hinge (GCFH) is proposed by modifying spring number and varying the angle between two springs on the basis of the NCFH. A 6 degrees of freedom (6-DOF) compliance model of the GCFH was derived. Validity of this model was demonstrated using finite element analysis simulation and experimental results on a GCFH with 3 pairs of springs and 70 degrees angle. According to the model, influence of distribution and shape parameters of GCFH on performance was analyzed. Characteristics such as compliance, off-axis/axis compliance ratio, motion precision, and capacity of rotation were determined. Results show that the GCFH can achieve improved performance compared to NCFH with optimized GCFH parameters. (C) 2015 AIP Publishing LLC.