高可靠度滚动轴承的疲劳寿命模型与实验研究

The quasicrystals can bear high load to 25GPa in terms of maximum Hertzian contact stress, and its density is smaller than that of ceramics such as silicon nitride. Thus, the rolling bearings made of quasicrystals are expected to have higher load capacity and friction resistant, and the rolling elements yield less centrifugal force, the rolling bearings of quasicrystals have excellent tribological performance, compared with ceramic rolling bearings. The new bearings made of metallic glass will provide an alternative way to meet the demanding of very high reliability of rolling bearings. The periodic structure of rolling bearings will be analyzed with time series, and the bearing set and its hub will be calculated with finite element method, and thus the design methodology of tribological design for high reliability bearing will be obtained. The mechanics and stress filed of quasicrystals will be examined, and then the fatigue strength rules and evaluation methods based on stress field of quasicrystals will be mastered. The effects of microstructures, defects, such as points, short lines and flakes inside quasicrystals on crack initiation and propagation will be studied, and the fatigue mechanisms will be revealed. The applicability of Weibull distribution for fatigue failure will be examined. The Weibull slope parameter of the new model, which has three parameters for the Weibull distribution of fatigue lives of bearings, will be obtained with calculate geometry. And thus a calculation method of fatigue life for the demand of high reliability of rolling bearings will be presented. Moreover, the effects of micro dents, traction coefficient, and viscosity and so on, on fatigue span will be studied, and then a new contact fatigue model will be proposed. Furthermore, the effects of micro-ehl, micro-squeezing and thermal expansion of partially confined lubricants under mixed lubrication on feature parameters of lubrication and fatigue span of rolling bearings will be studied. The chaotic behaviors of fiction, temperature and film thickness of greases will be studied. The available interferometry device will be modified to be an optical diffraction system, and with which the effects of defects on contact stress of quasicrystrals will be measured. The results of micro lubrication and micro friction will be verified with this system, and the chaotic features and attractors of greases will be investigated, and then the new characterize methods for film thickness, friction and temperature will be presented.

序列分析轴承的周期性结构，整体滚动轴承与轴承座的有限元分析，获取高可靠度轴承的摩擦学设计方法。分析准晶体晶格力学，准晶体体内的应力场计算，获取准晶体应力场的疲劳强度准则、评价方法。分析准晶的微结构，点缺陷、线缺陷和面缺陷在疲劳过程中的裂纹萌生与扩展过程，揭示接触疲劳过程的机理。研究三参数Weibull分布的适用性。用计算几何的方法，确定准晶轴承的Weibull分布斜率。针对高可靠度的要求，提出轴承的疲劳寿命计算方法。分析表面微坑、润滑条件下的摩阻力系数和润滑油粘度等参数对疲劳寿命的影响，提出轴承的接触疲劳模型。研究微观弹流效应、微观挤压润滑、微观热膨胀，探索润滑脂润滑过程的混沌行为。改进已有的光干涉实验台，建立光散射测试系统，测试分析准晶中缺陷对接触应力影响。验证润滑脂润滑过程的混沌行为分析结果，探索润滑脂在轴承润滑过程中的混沌特征、吸引子等，在此基础上提出新的膜厚、摩擦力与温度表征方法。

高铁、风机和航空发动机等要求高可靠性的轴承，“高可靠度滚动轴承的疲劳寿命模型与实验研究项目”在四年期间内，开展了八个方面的研究工作。. （1）针对深沟球、圆柱滚子与角接触球轴承，对滚动轴承的疲劳寿命模型进行了改进，探讨内外圈运动状态对疲劳寿命的影响。考虑游隙和离心力，计算了内外滚道、滚子和轴承整体的疲劳寿命。（2）建立了角接触球轴承的优化模型，进行了遗传算法和免疫算法优化设计。建立温度计算模型，提出了滚子轴承胶合的判断标准。（3）建立了轴承的弹流模型，求解了波纹度、凹坑参数对润滑膜厚度、压力分布和应力场的影响，探讨了流变指数、载荷、卷吸速度对脂润滑弹流特性的影响。（4）提出了分形、小波模拟表征表面。将支承面曲线推广到三维，研究了粗糙峰和空穴曲线；由弹塑性接触模型得到了接触应力分布、实际接触面积分布和应力场。分析了实际接触面积与名义接触面积、表面形貌对接触疲劳强度的影响。建立了接触电阻模型；分析了负载、表面形貌及材料对实际接触面积、接触电阻、平均电流密度以及单个接触点的电流密度分布的影响。（5）建立了结点增长模型，分析了结点增长与其它参数的变化。建立了三维粗糙表面的瞬态边界润滑模型，分析了边界润滑过程中表面形貌变化以及润滑油的泄漏和受困，得到表面压力、表面温升以及边界膜破裂的分布。实验研究了多种添加剂性能，用拉曼光谱分析了摩擦表面，测试摩擦因数的变化。实验分析了边界润滑膜的形成速率，验证了边界润滑的动态模型。（6）研究了多种磨粒的磨粒磨损，分析得到磨损率和摩擦因数与磨粒尺寸、形状、磨粒个数或相关参数之间的关系，并研究了应力分布与表层深度之间的关系。计入了摩擦热效应，研究得到温度分布和热应力分布与表层深度间的关系。（7）用分子动力学模拟方法，分析准晶的塑性变形机制以及材料缺陷的演化，以设计准晶材料滚动轴承涂层。（8）研究成果推广到滚动轴承、滑动轴承和导轨设计，获得10件发明专利。