标准镜的高精度柔性支撑镜框的优化设计

Optimized design of high precision flexure-support barrel for reference sphere

为了实现干涉仪标准镜中光学元件的高精度定位,设计了一种柔性支撑镜框,研究了该结构的力学模型、结构参数、定位精度和透镜变形。首先,根据材料力学原理将柔性镜框等效为一个弹簧系统;根据力学方程和几何关系,建立了透镜中心位置与柔性结构的挠度之间的二元方程。然后,分析了安装位置、温度、结构参数对透镜位置以及作用力的影响。最后,应用有限元仿真分析了所设计结构的力学性能,并进行对比验证。结果表明,数值仿真分析的结果与有限元仿真结果基本相同,柔性镜框的柔性结构厚度最优值为1.5 mm。该设计方案完全满足干涉仪标准镜对镜框在定位精度、稳定性方面的要求。

To achieve the positioning optical components of a reference sphere in a interferometer accurately, a flexure barrel was designed. The mechanical model, structure parameter, positioning accuracy and lens deformation of the structure was studied. Firstly, a spring model system was established based on the principle of material mechanics. According to the mechanical equation and geometry relations, a binary equation of the center position of lens and the flexure＇s deformation was given. Then, the effects of assemble position, tem- perature, and structure parameters on the the positions and force of the lens were analyzed. Finally, the me- chanical performance of the designed structure was analyzed by using the FEA method. The results indicate that the results of numerical simulation is coincident with that of finite element simulation well, and the best thickness of the flexure barrel is 1.5 ram, which fully meet the requirements of the reference sphere in the in- terferometer for the positioning accuracy and stability of the lens barrel.