小卫星姿控动量轮陶瓷球混合轴承性能分析与试验

小卫星的技术发展对星上姿控系统的主要部件一动量轮的主要技术指标提出了严格的要求。为了满足动量轮对轴承的使用要求，本研究开发了Si3N4陶瓷球混合轴承。基于滚动轴承分析理论和摩擦学知识，对其接触应力、旋滚比、轴向刚度、润滑、额定静载荷等指标进行了优化设计和分析。结果显示：与原全钢轴承比较，优化后混合轴承消除了原全钢轴承存在的控制类型“阶跃”问题，在精度寿命指标上具有明显的优势。摩擦力矩测量结果及分析表明该轴承的功耗指标优于原全钢轴承。力学模拟、温度循环试验后动量轮电机电流升高小于5％，表明该轴承具有良好的抗振动冲击能力和温度适应能力。在动量轮连续二年的运转试验中，电机的功耗始终较小而且稳定，进一步证明陶瓷球混合轴承具有良好的抗粘着磨损能力。

Performance Analysis and Experiments of Hybrid Bearing for Micro-Satellite Attitude Control Momentum Wheel

The technical development in small satellite has demanded strict requirements for the main parts of attitude control system-momentum wheel,which is supported by a pair of precision angular contact ball bearings.For purposes of meeting these application conditions,the Si3N4 ceramic hybrid ball bearings were developed in this study.With the rolling-element bearing's analysis theory and tribological knowledge,its dynamic indexes,such as contact pressure,spin/roll ratio,axial stiffness,lubrication and rating static load have been optimized and analyzed.The results demonstrated that the current hybrid bearing has solved the "jump" problem of control type which existed in the previous one,and has an obvious advantage in precision lifetime.The frictional torque experiment and its analyzing result showed that the hybrid bearing is superior to the original one in power dispersion.The mechanical simulation and temperature cycling experiment proved that the hybrid bearings have the good ability to resist impact,vibration and environmental temperature variation with less 5% higher in its electric current comparing with the primary value.The long term lifetime experiment which lasted for 2 years while keeping up a stable,lower electric current of momentum motor has further verified that the ceramic hybrid bearings have a better ability on its anti-adhesive wear performance.