鉴于空间遥感器反射镜组件需要具有高面形精度、高可靠性和高稳定性支撑的性能, 设计了一种应用于天基反射镜的三点背部支撑结构, 该支撑结构包括锥套、柔节和修研垫。对三点背部支撑的支撑原理以及工程实现开展了深入研究。对引起三点背部支撑反射镜组件面形误差变化的误差源进行了归纳总结, 研究了各个误差源引起面形变化的作用机理, 对支撑结构开展相应的设计来缓解各个误差源导致的反射镜的面形精度的变化。首先采用有限元仿真的方法对设计结果开展静、动力学仿真, 然后对加工装配完成的反射镜组件开展了试验测试。测试结果表明, 在工作状态下采用该三点支撑结构的镜组件的面形误差优于λ/60(λ=632.8 nm), 镜体刚体位移小于0.01 mm, 镜体转角小于2″, 质量小于4.5 kg。整个组件具有合理的模态分布, 基频是254 Hz, 大大高于设计要求值120 Hz。镜组件在正弦振动和随机振动下的最大放大倍率为1.73倍, 在正弦振动和随机振动下的最大应力为369 MPa, 远低于选用材料的屈服极限。

In view of the functional requirements of high surface shape error accuracy, high reliability and high stability of mirror support for space remote sensor, a three-point back support structure applied in the mirror support in the field of space was designed, the back support structure included taper sleeve, flexible segment and adjusting pad. The in-depth study was done about support principle and engineering realization of the three-point back support structure. The error source which caused the variation of surface shape error of the three-point back supporting mirror component was summarized, the theory of surface shape variation caused by various error sources was studied, and the corresponding design of the supporting structure was carried out to alleviate the variation of the surface shape error of the mirror caused by various error sources. Firstly, the static and dynamic simulation of the design results were carried out by means of finite element analysis, then the assembled and processed mirror assembly was tested. The results show that the surface shape error of mirror with the three-points support structure is better than λ/60(λ=632.8 nm), the rigid body displacement of mirror is smaller than 0.01 mm, the dip angle is smaller than 2″, the mass of the mirror component is smaller than 4.5 kg. The component has a reasonable distribution of modal, the fundamental frequency is 254 Hz, which is higher than the requirement of 120 Hz. The maximum magnification rate of the mirror assembly under sine vibration and random vibration is 1.73 times, and the maximum stress under sine vibration and random vibration is 369 MPa, far lower than the yield limit of the selected material.