垂直载荷对交叉簧片柔性铰链准恒定转动刚度的影响分析

The rotational stiffness characteristics of cross-spring pivot are important consideration for designers, but some of these attributes of the pivots subjected to vertical loads have not been revealed. A simple rotational angle model with high order terms of vertical loads is developed to study the influence of vertical loads on Quasi-constant rotational stiffness of cross-spring pivot used in compliant static balance instrument. Then rotational stiffness and vertical stiffness are analyzed to better characterize the influence of vertical loads on rotational stiffness. The study shows that can rotational stiffness be deemed to be quasi-constant only when the value of vertical load and rotational angle both are small. Otherwise, when vertical load is very large, rotational stiffness is quadratic function of vertical load. While when rotational angle is very large, vertical load will be a driving load, and the nonlinear characteristic of rotational stiffness becomes apparent. Finally, these attributes, analyzed by theoretical model, are verified by finite element analysis (FEA) and experiments.