为实现(165mm×96mm)矩形扫描反射镜组件的轻量化并保证反射镜面形精度与组件支撑刚度, 提出了一种锥套柔节一体化的背部支撑方法, 实现了重量小于0.5kg的超轻量化碳化硅反射镜组件设计。镜体材料的选择为碳化硅, 支撑结构材料选择了铟钢。通过有限元仿真对扫描反射镜组件进行了仿真分析, 并采用ZYGO干涉仪对实际的反射镜组件进行了检测。实验表明, 在各方向重力的工况和轴系驱动时的扭矩作用下, 扫描反射镜面形误差的均方根值(RMS)最大值为9.705nm, 实际测试结果为10.125nm, 误差为4%, 满足RMS值优于12.6nm的要求; 组件一阶固有频率302.25Hz, 满足刚度要求。研究结果表明, 锥套柔节一体化背部支撑方法合理、有效, 解决了结构超轻量化与结构刚度、光学面形精度难以同时保证的难题。

In order to realize the lightweight of the (165mm×96mm) rectangular scanning mirror assembly and ensure the accuracy of the mirror shape and the support stiffness of the assembly, a back support method with the integration of cone-sleeve and flexible joints was proposed, and the weight of the mirror assembly designed with this method is less than 0.5kg. The mirror body was made of silicon carbide and the supporting structure was made of indium steel. The support stiffness and surface accuracy of the scanning mirror assembly are simulated and analyzed by finite element analysis and verified by actual testing. The results show that the maximum root mean square (RMS) value of the scanning mirror shape error is 9.705nm, the actual test result 10.125nm, the error is 4% and meets the requirement that the RMS value should be less than 12.6nm in the case of gravity in all directions and the torque of the shaft-driven. The first-order natural frequency of the component was 302.25Hz, which met the stiffness requirements. The results show that the proposed method is reasonable and effective, which solves the problem that the ultra-lightweight structure and the structural stiffness and optical surface accuracy are difficult to guarantee at one time.