摘要
大型星载天线展开机构中常采用齿轮系统来实现桁架结构的同步展开,而卡滞失效是展开机构中同步齿轮副的一种主要失效形式.从齿轮啮合的极限位置出发,给出了同步齿轮副不发生卡滞的条件.在综合考虑齿轮加工误差、装配误差和太空环境温度等因素的基础上,构建了齿轮副防卡滞的可靠性分析模型,得到了用最小齿顶隙表示的齿轮啮合运动功能函数.把齿轮形状和位置的实际尺寸视为随机变量,用二阶矩方法推导出齿轮防卡滞可靠度的计算公式.最后,针对某周边桁架式星载天线的实例进行计算,得到如下结论:1)温度荷载对于同步齿轮系防卡滞可靠性的影响不容忽视;2)如果两齿轮以标准中心距安装,太空环境中的热变形会明显降低齿轮的传动性能;3)适当采用正变位中心距安装齿轮副,并避免星载天线的展开机构在高温下工作,可以提高防卡滞可靠度.
Gears are often used in the deployment mechanism of a large satellite antenna to spread the truss synchronously, and seizure is a main invalidation of a pair of synchronous gears in the deployment mechanism. From the ultimate position of the gearing mesh, the seizure-preventing condition for the gear pair is given in this paper. Then, with gears' mismachining tolerances and fitting allowances and the space temperature considered synthetically, an analytical model of seizure-preventing reliability of the gear pair is presented, and the movement function of the gearing mesh is obtained, which is expressed by the tooth clearance. With the true dimensions of the shape and position of a gear regarded as random variables, the formula of the gear's degree of seizure-preventing reliability is derived by the method of second-order moment. Finally, a real satellite antenna with hoop-truss is calculated and some conclusions are obtained as follows: 1) the effect of thermal loads on the seizure-preventing reliability of synchronous gears deserves not to be ignored; 2) if two gears are fixed at the normal center-to-center distance, the thermal distortion in the space will obviously lower their performance; 3) properly adopting the method to fix the gear pair at the normal-shifted center-to-center distance, and preventing the deployment mechanism from working at high temperature can improve the degree of seizure-preventing reliability. Computational results show that the analytical model of seizure-preventing reliability in this paper is reasonable and efficient.
出处
《西安电子科技大学学报》
EI
CAS
CSCD
北大核心
2005年第3期329-334,共6页
Journal of Xidian University
基金
国家部委预研资助项目(41321070301)
关键词
星载天线
同步齿轮
防卡滞
运动可靠性
Analysis
Gears
Mechanisms
Moving
Reliability
Satellites
Temperature
Thermal load
Trusses
