空间太阳望远镜调焦机构的设计与分析  

Design and analysis for focusing mechanism of space solar telescope

作　　者：单博闻 辛宏伟[1] 陈长征[1] Shan Bowen;Xin Hongwei;Chen Changzheng(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,长春130033 [2]中国科学院大学,北京100049

出　　处：《仪器仪表学报》2021年第6期1-8,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(11803036)项目资助。

摘　　要：根据某型号空间太阳望远镜的光学系统特性与整机的结构方式,为了达到节约安装空间、保证成像质量的目的,设计了一种焦平面式调焦机构。该调焦机构由蜗轮蜗杆和凸轮滑槽作为传动件,将步进电机的圆周运动转化为焦平面法线方向的直线运动。调焦范围为1.5 mm,外形尺寸为167 mm×64 mm×94 mm,质量为2 kg,在底座背板和凸轮滑槽之间设有两个相邻的自润滑氮化硅压圈,可增加预紧力而不影响凸轮滑槽的转动,一定程度上提高了定位精度,减少了空回误差。详细介绍了调焦机构的设计方案、分辨率和自锁能力,对误差来源和理论定位精度以及有限元模型仿真进行了分析。最后对调焦机构进行了定位精度试验和振动试验,结果表明定位精度优于±4.5μm,一阶模态为349 Hz,与有限元仿真结果基本一致,具有良好的动态刚度,可以有效地避免共振现象的发生。振动试验前后对调焦机构的编码器码值进行记录,经对比可知其自锁性良好。该调焦机构具有体积小,刚度大,精度高的特点,可以很好的满足空间太阳望远镜的工作条件。According to the optical system characteristics and the structure of a space solar telescope,a focal plane focusing mechanism is designed to save the installation space and ensure the imaging quality.By using worm gear and cam chute groove as transmission parts,the circular motion of the stepping motor is transformed into linear motion in the normal direction of the focal plane.The focus range is 1.5 mm,the overall size is 167 mm×64 mm×94 mm and the mass is 2 kg.Two adjacent self-lubricating silicon nitride rings are arranged between the base back plate and the cam chute.It can increase the preloading force without affecting the rotation of the cam chute,improve the positioning accuracy to a certain extent,and reduce the backlash error.After that,the design scheme,resolution and self-locking capability of the focusing mechanism are introduced in detail,and the error sources,theoretical positioning accuracy and finite element model simulation are analyzed.Finally,the positioning accuracy test and vibration test of the focusing mechanism are carried out.The results show that the positioning accuracy is better than±4.5μm and the first-order mode is 349 Hz,which is basically consistent with the finite element simulation results.As a result,it has good dynamic stiffness and can effectively avoid resonance phenomenon.The encoder code values of the focusing mechanism are recorded before and after vibration test,which shows well self-locking performance.The focusing mechanism has the characteristics of small volume,large stiffness and high precision,which can well meet the working conditions of space solar telescope.

关 键 词：空间望远镜 调焦机构 有限元分析 精度分析 振动试验 

分 类 号：TH122[机械工程—机械设计及理论]