基于锰铜高阻尼合金弹簧的反作用轮隔振器性能研究

Performances of a reaction wheel vibration isolator with a spring made ofmanganese-copper high damping alloy

为解决反作用轮微振动引起卫星成像质量下降问题,依据反作用轮微振动特性,设计了一种汇聚式六自由度被动隔振系统。隔振系统通过弹簧刚度设计降低系统整体模态频率,结合高阻尼特性的锰铜合金作为隔振元件材料来提高振动能量衰减。首先,采用拉格朗日方程建立隔振系统动力学模型,考虑刚度对隔振性能影响,设计不同结构参数弹簧进行对照,分析弹簧径轴刚度比与系统基频关系,并确定最佳隔振结构参数;其次,利用有限元法分析隔振系统模态及振动传递特性,讨论各自由度下振动抑制性能;最后,搭建Kistler微振动试验平台对隔振前后的反作用轮微振动进行测量,分析与验证隔振器的减振效果。结果表明:隔振系统在六个扰动方向和中高频范围内隔振效果显著,在1000 Hz主频振动处隔振效果超过40 dB;在0~2500 r/min转速内F z方向上最大振动幅值的减振百分比达到92.42%。

In order to solve the problem of satellite imaging quality degradation caused by the micro-vibration of a reaction wheel,a six-DOF passive vibration isolation system was designed according to the micro-vibration characteristics of the reaction wheel.The vibration isolation system reduces the overall modal frequency of the system through spring stiffness design,and the high damping manganese-copper alloy was used as vibration isolation element material to improve vibration energy attenuation.Firstly,the dynamic model of the vibration isolation system was established by Lagrange equation.Considering the influence of stiffness on the vibration isolation performance,different structural parameters of the spring were designed for comparison.The relationship between the stiffness ratio of diameter to axis and the fundamental frequency of the system was analyzed,and the optimal structural parameters for vibration isolation were determined.Then,the finite element method was used to analyze the modal and vibration transfer characteristics of the vibration isolation system,and the vibration suppression performance corresponding to each degree of freedom was discussed.Finally,a Kistler micro-vibration test platform was built to measure the micro-vibration of the reaction wheel before and after vibration isolation,and the vibration reduction effect of the isolator was analyzed and verified.The results show that the vibration isolation effect of the vibration isolation system is significant in six disturbance directions and in the range of middle and high frequency.The vibration isolation effect is more than 40 dB at 1000 Hz main frequency vibration.The vibration reduction percentage of the maximum vibration amplitude in the F z direction from 0-2500 r/min is 92.42%.