空间机械制冷机微振动研究

Investigation of Micro-vibration of Space Cryocoolers

机械制冷机广泛应用于空间红外遥感器中,由于其中存在运动部件,因此工作过程中不可避免地会产生振动,是卫星在轨状态下影响光学遥感器成像品质的重要振动源之一。文章对空间机械制冷机的微振动问题进行了研究,建立了线性驱动对称布置压缩机以及斯特林膨胀机的力学简化模型;分析了2个对置活塞的质量、阻尼、刚度偏差与压缩机整体的振动输出之间的关系,仿真分析结果表明,压缩机整体的振动输出对阻尼的偏差最为敏感;对3种常用制冷机微振动测量方法进行了介绍,对比了3种方法的优缺点,指出扰振力的测试方法对于空间遥感器领域较为适用。

The mechanical cryocooler is widely used in space remote sensing engineering. Due to the present of moving parts, vibration output is usual accompaniment. It is one of the most important vibration sources that have impact on the image quality of remote sensors. Therefore, this paper investigates the mi- cro-vibration of cryocoolers. The simplified dynamical models of dual-pistol linear compressor and expander are established. The theoretical relationships between the mass, damp, stiffness deviations of dual-pistol and vibration output are derived, respectively. The simulation shows that the vibration output is more sensitive to damp deviation than other two. In addition, three micro-vibration measurement techniques applicable to cryo- coolers are reviewed. The advantages and disadvantages of each technique are analyzed. It indicates that the vibration outout force measurement technique is more suitable for the space remote sensors.