刚度测试装置中的变刚度轴设计

在扭转加载刚度测试过程中，伺服电机在位置模式输出3种不同力矩，分别用这3种力矩对试件做加载刚度测试，为了精确传输不同力矩，需要采用能承受不同力矩的轴同时还得保证轴的扭转角大于6°。为了安装、拆卸和调试方便，文章提出了在测试装置采用一根轴，其长度不变，通过改变轴截面直径实现刚度变化，此方法能快速实现3种刚度间的切换，操作简单且无需移动各装配体的位置。实际运用中证明了此方法的可靠性和有效性。

Design Variable Stiffness Shaft in the Test of Stiffness

In the process of testing the torsion stiffness, different torques of three are generated by servo motor, and torsion rigidity test was carried out by the three torques on the specimen respectively. In order to transmit the different torque accurately, it is need the shaft can withstand different torques and guarantee that the torsion of the shaft angle is bigger than 6 degrees simultaneously. The conventional method is to use three different diameters or different lengths to obtain different stiffness of the shaft. In order to ease of installing, removing, and debugging, the paper propsed to install a fixed length shaft and realized variety stiffness by changing shaft cross section. The method can switch quickly between three kinds of stiffnesses obtained with easy operation and without moving the location of every assembly. This method is proved to be in reliability and validity of practical applications.