Development of novel multiple-axis flexure hinges based on hook function curve and a generalized model for multiple-axis flexure hinges

A novel asymmetric multiple-axis hook-function-curve (HFC) flexure hinge (HFCFH) with higher motion precision is proposed. For obtaining high-accuracy compliance and motion precision models of multiple-axis flexure hinges, a brief and generalized analytical model is presented by using the finite beam based matrix modeling (FBMM) method. It can be used to quickly obtain the compliance and precision models by just changing the notch contour functions. The comparative results prove the high accuracy and efficiency of the analytical model. For a much fairer comparison of motion precision between flexure hinges, a new precision model is proposed, in which a non-dimension and more intuitive precision matrix is defined. By using the precision model, the comparison of motion precision between multiple-axis HFCFHs and other multiple-axis flexure hinges indicates that asymmetric flexure hinges have higher motion precision, and multiple-axis HFCFHs also have higher motion precision in asymmetric flexure hinges. Based on the design concept of hybrid flexure hinges, eight types of hybrid multiple-axis flexure hinges with much higher performance are designed, enriching the types of multiple-axis flexure hinges and providing more reference for the selection of hinges in spatial compliant mechanisms.