【作者】 朱丙奇；

【导师】 陈志刚；

【作者基本信息】 哈尔滨工业大学 ， 机械工程， 2011， 硕士

【摘要】 齿轮传动机构是空间机械结构的关键部件,属于故障多发件,故障多为润滑失效,其失效比例占总故障的60%。由于真空环境中缺少传导热的有效介质,导致齿轮运转过程中齿面因摩擦、冲击产生的热量不易散失,齿轮较高的温升,导致齿面油膜损伤和润滑失效。齿轮系统一旦出现故障将直接威胁到传动机构甚至整个航天器系统的安全。因此有必要对齿轮系统进行故障诊断和寿命预测。齿轮的润滑失效形式主要与摩擦有关,因此,本文从摩擦角度出发,研究摩擦与振动的关系,通过振动信号的变化判断齿轮的使用寿命。开展齿轮寿命周期过程中摩擦与振动信息耦合、故障监测和诊断、寿命评价等的研究,建立轮齿摩擦副摩擦系数与故障诊断、寿命评价间的联系,将对空间齿轮系统摩擦磨损机理和振动故障研究具有重要的意义,也将对空间齿轮系统状态监测和寿命预测具有重要的应用价值。本文从弹流润滑理论着手,分析了摩擦系数同油膜比厚的变化关系,指出摩擦系数可以作为油膜厚度评定的指标。考虑齿轮摩擦和振动的相关性,将摩擦系数引入到齿轮系统的动力学方程中,建立了两自由度的齿轮啮合动力学方程,分区段讨论了变摩擦系数对齿轮径向力的影响。利用ABAQUS对该齿轮机构在不同摩擦系数下进行了动力学分析,通过对提取的运动学参量(角速度)和动力学参量(角加速度、摩擦力、径向力)的时域和频域特征分析,提出振动信号的均方幅值RMS指标可以有效识别摩擦系数的变化,具有相对较好的灵敏性,并给出了径向力的均方幅值RMS和频率幅值随摩擦系数变化的函数关系。搭建振动测试试验平台,分别对干摩擦和脂润滑条件下齿轮径向力进行RMS和频谱分析。与仿真结果比较,数据吻合,满足分析要求,证明了采用RMS指标建立振动与摩擦系数间关系的可行性。提出了采用振动信号RMS指标作为真空条件下齿轮运行寿命的评价指标,依据齿轮运行的时间—RMS曲线,可以初步预测齿轮的寿命。更多还原

【Abstract】 Gear transmission agencies are important parts of airspace structures, there areabout 60 percents of faults happened in gears. In vacuum, the energy which caused byfriction or impact couldn’t loss, lacking of effective heat conduction medium. With thetemperature increasing in gear tooth surfaces, oil film of teeth will be damanged orlubrication failure. Once faults happened in gear system, Which will affect thetransmission agencies, what’s worse, will threat the whole airspace system. Lubricationfailure or wear usually is taken as the criteria standand to evaluate the life. So it isnecessary to do some researches in the relationships between wear and vibration, faultsmonitoring and diagnosis, evaluation about life. Friction is the main factor which causethe lubrication failure. To build the relationships between gear friction and faultsdiagnosis, it is great for researching in the theory of friction and wear, vibrationcharacters, as well as very useful to promote the application of faults monitoring andevaluation life in gear system.In this article, we can get some information between friction coeficient from EHLtheory. Under the analysis the empirical formulation, we can get the relationship betweenfriction coefficient and the thickness of oil film. Friction coefficient is an good indicatorto infer the thicken of oil film. Consider of the correlation between the friction andvibration, adding friction coefficient into the dynamic equation. To establish the twodegrees of freedom dynamic equations of gear meshing, and analysis the changes ofradial force under varying friction coefficients. Dynamics simulation and analysis useABAQUS under different friction coefficients. By extracting the kinematicsparameters(angular velocity) and mechanical dynamical parameters (angularacceleration,friction,the radial force) from this gear system and analysis them in timedomain and frequency domain , get that the amplitude RMS and frequency amplitude caneffectively indentify the friction coefficient.To build the vibration test platform on dry friction and grease lubricationconditions, and analysis the RMS and frequency of signal from vibration test, frequencyamplitude is fluctuating by accidental factors from interior or exterior, and RMS is wellagreement with the simulation results.Analysis RMS in the vibration signal which fromthe vacuum whole life test of gear box, get gear running time-RMS curve, which isagreement with the wear-time curve. Propose the method in predition and evaluationgearing life, and development of life evaluation criteria.更多还原