【作者】 黄敦新；

【导师】 吴一辉；

【作者基本信息】 中国科学院研究生院（长春光学精密机械与物理研究所） ， 机械制造及其自动化， 2010， 博士

【摘要】 本文从卫星对其姿控飞轮性能更高地要求出发,对影响姿控飞轮轴系性能的关键问题进行研究,以期获得长寿命、高性能和高可靠性的摩擦学系统,进而提高卫星寿命和控制精度。针对飞轮润滑系统采用油润滑时低速性能差、转速范围窄,而固体润滑寿命短、摩擦系数大等问题,提出采用固-液复合润滑技术为轴承提供润滑以改善其在启动和低速状态的性能,并实现其低摩擦、宽转速和精确控制等目标。基于液体润滑理论及固体润滑技术,结合摩擦学和界面化学研究固-液复合润滑的可行性;并从材料学、摩擦学、界面化学及流体力学等学科交叉融合的角度,采用理论分析和实验相结合的研究方法分析固-液复合润滑系统的摩擦磨损性能和机理。首先建立了固-液复合润滑在零速启动、边界润滑、混合润滑及弹流润滑摩擦模型,并对各状态下的减摩机制进行研究;并建立球-盘式摩擦学试验系统,先后完成对磁控溅射MoS2膜和化学气相沉积DLC膜的摩擦和磨损试验,从试验角度研究润滑条件、速度和载荷对其摩擦学特性的影响,进而分析膜层减摩机制和耐磨特性,从而为固-液复合润滑的应用提供理论和实验依据。理论和试验结果表明:固-液复合润滑能有效改善摩擦副润滑性能,在零速启动、边界润滑、混合润滑或弹流润滑等各状态下的摩擦系数均得到有效降低,零速启动和低速时性能的改善可提高飞轮的可靠性和控制精度,而中高速时摩擦的改善要有效降低飞轮功耗,延长卫星寿命。由于MoS2膜的减摩效果优于DLC膜,其在提高飞轮过“零”性能和提高低速控制精度等方面更具有优势,但MoS2膜在有液体润滑剂的条件下耐磨性能磨损寿命明显降低;DLC膜在有液体润滑剂时的磨损寿命反而提高,能更长久发挥固-液复合润滑性能的优势,对降低飞轮电机功耗、延长卫星寿命具有重要意义。为研究润滑剂空间挥发损失及其对轴系润滑寿命的影响,建立了飞轮轴系润滑系统油气分子物理循环模型,并完成模拟真空条件下润滑油的挥发试验;通过理论和试验结果的对比分析,提出降低轴系流导,减少润滑油的挥发损失率,对提高轴系润滑寿命具有重要意义。通过干摩擦条件下的运转试验和对电流特性和摩擦表面形貌的分析,研究润滑不良时氮化硅陶瓷球混合轴承的临界失效特性,对分析飞轮轴系临界性能具有重要意义。更多还原

【Abstract】 To achieve longer life, better performance and higher reliability of the tribological system in demanding increasing more higher requirement of the attitude control flywheel for satellite, and furthermore to improve the life and the control precision of the satellite, the key factors and which influence the performance of the axle of the attitude control flywheel be studied in this paper.Aiming at the problem of the poor performance at low speed, the narrow range of the rotator when the flywheel lubricated with liquid lubricants, and the short lubrication life and poor antifriction while that lubricated with solid lubricant, for improve the performance of the fly wheel when work at start-up and low speed, and realize the low friction, wide speed range and accurate control, the solid lubrication coatings using with liquid lubricants simultaneously is proposed.Based on the theory of liquid lubrication and solid lubrication, and combined with the tribology and the surface and interface chemistry principles, the feasibility of solid lubricating coatings-oil composite lubrication was analyzed, and the performance and mechanism of solid lubrication film used with liquid lubricants was studied with experiment and theoretic based on the knowledge of material mechanics, tribology, surface and interface chemistry and hydrodynamic. First, the tribological modal of solid lubricating coatings-oil composite lubrication were established when the friction couples work at start-up, boundary lubrication, mixed lubrication and hydrodynamic lubrication, and antifriction mechanism of each model was analyzed. Then the tribological experiment were carried out on magnetron sputtered MoS2 coatings and chemical vapor deposited hydrogenated diamond-like carbon (DLC) films against Si3N4 ball using a ball-on-disk tribo-tester under the conditions of room temperature and different lubrication condition, and the influence of lubrication condition, speed and load to the tribology performance of solid coatings was analyze from the results of experiment, at the same time, the antifriction mechanism and antiwear property be studied too based on surface morphology of coatings, investigated by atom force microscope (AFM), and so as to provide theoretical and experimental basis for the applications of solid - liquid composite lubrication in flywheel.The results of theoretical analysis and experiment both showed that: The performance of friction couples be improved greatly when the solid lubrication film used with liquid lubricants simultaneously, the friction of the couple at start-up, boundary lubrication, mix lubrication and hydrodynamic lubrication be improved effectively, the improvement of the tribological performance at start-up and low speed could improve the reliability and control precision of the attitude control flywheel, and the decrease of the friction at high speed could reduce the power and prolong the life the satellite effectively. For the anti-friction performance of MoS2 better than DLC, the effect of MoS2 film to improve the zero-speed reversing and control precision at low speed of the flywheel better than DLC, but the anti-wear performance of MoS2 film be reduced by the liquid lubricants. While the anti-wear performance of DLC film be improved evidently and which could exert the advantage of solid lubricating coatings-oil composite lubrication chronically, and that is important to reduce the motor’s power and increase the life of the flywheel.In order to analyze the loss of lubrication oil vapor in space and the influence of the oil loss to the lubrication life of attitude control Flywheel, the physical mode of the lubrication was established and the transfer of the oil molecule via by the seal gap was studied, and experimental of the selected oil volatilized in a simulant vacuum room, and the way to reduce the flow conductance of the shafting and the loss of oil vapor molecule was given through the comparative study of theoretical and experimental investigation, and then improve the lubrication life of the flywheel effectivly.To investigate the properties of critical failure of the Si3N4 hybrid ceramic ball bearing when the lubrication got worse, the characteristic of currents of driver motor and the wear surface morphology was analyzed after the tribology experiment of the test bearing rotating at the high speed to failure without lubrication was completed, the research would be useful to the critical performance of flywheel.更多还原