Abstract: It was challenge to balance the large turning angle and low stiffness of multiple-cross-springs flexure pivots with straight beams. The multiple-cross-springs flexure pivots with arc curved beam springs was designed to reduce the maximum stress and rotational stiffness. The high rotation accuracy and large stroke were obtained under pure torque driving conditions. The calculation equation of deformation stress of the arc curved beam springs was deduced, and the large deformation mechanicals analysis model of the flexure pivots was established. The accuracy of the theoretical model was verified by the rotation stiffness experiments and the deformation stress simulation calculation. Moreover, the relationship among the driving torque and deformation stress of the flexure pivots and the design variables, radius coefficient, spring curvature and configuration angle was discussed by using the deformation model. Some design schemes to reduce the rotation stiffness and deformation stress concurrently were proposed. The appropriate variable combination for the flexure pivots to obtain zero stiffness characteristics and negative stiffness characteristics were determined. The designed flexure pivots and the rotation characteristics analysis results provide a reference for the design of a new type of large-stroke flexure pivots.

Key words: flexure pivot, arc curved beam spring, large stroke, rotational stiffness, maximum stress

摘要： 针对直梁型多交叉簧片柔性铰链难以兼顾大转角、低刚度的问题，设计了一种多交叉曲梁簧片柔性铰链。采用圆弧曲梁簧片减小变形应力和转动刚度，在纯转矩驱动条件下具有高转动精度和大转角行程。推导了圆弧曲梁簧片的变形应力计算方程，建立了柔性铰链的大变形力学分析模型，并通过转动刚度实验和变形应力仿真计算验证了理论模型的准确性。进一步分析了半径系数、簧片曲率和位形角等设计变量对柔性铰链驱动转矩和变形应力的影响关系，提出了同时减小转动刚度和变形应力的设计方案，确定了使柔性铰链获得零刚度特性和负刚度特性的设计变量组合。所设计的柔性铰链结构及其性能分析结果可为新型大行程柔性铰链的设计提供参考。

关键词: 柔性铰链, 圆弧曲梁簧片, 大行程, 转动刚度, 最大应力