高速动载角接触滚动轴承打滑机理研究

The roller skidding is the main factor affecting the stability of angular contact bearings. With the increasing trends of high speed, heavy load in modern rotating machinery, the roller skidding would greatly increase the temperature of bearing structure and lubrication oil, and then cause the accelerated wear (skidding damage). The skidding damage problem of high speed angular contact bearings has become an international problem besetting the bearing industry. Three means, including theoretical analysis, numerical simulation and experimental test, are utilized to study the dynamic characteristics of high speed angular contact bearings under variable load condition. Considering the structural properties, micro-friction/lubrication and multi-source dynamic excitations, the dynamic model with multiple degrees of freedom for the rollers and retainer is established. After dynamic analysis of high speed dual rotor system, the time-variable load applied on the rolling bearing is obtained. Then, by solving the nonlinear time-varying differential equations, three-dimensional skidding behaviors of the roller are analyzed in detail. Effects of non-steady load conditions of rotor systems (static/dynamic eccentricities, stator/rotor rub impact, time-variable axial loads, fluctuate rotational speed, etc.) on the skidding mechanism are discussed, respectively. A high-speed rolling bearing skidding test system is built, and the three-dimensional motion characteristics of rolling body are tested in real time. Test results are utilized to verify and correct theoretical prediction results. A novel prediction method and analysis program for dynamic skidding mechanism of high-speed angular contact bearing are finally presented. The research results are expected to provide a theoretical basis for the design and monitoring of high-reliability and long-life rolling bearings.

滚动体打滑是影响角接触滚动轴承运行平稳性的主要因素。在高转速、大变载工况下，一旦出现打滑，使得轴承及润滑油温度剧增，磨损加剧，出现滑蹭损伤。高速角接触滚动轴承的滑蹭损伤问题已成为困扰高端轴承工业界的国际性难题。本项目拟综合运用理论分析、数值仿真和实验测试三种手段，研究高速动载角接触滚动轴承的动力学特性。综合考虑角接触滚动轴承的结构特征、微观摩擦以及多源激振等因素，建立滚动体-保持架多自由度动力学模型；根据双转子系统动力学分析所得到的轴承时变动载荷，求解表征打滑动力学特性的非线性时变微分方程组，分析滚动体三维空间打滑运动规律，并探讨转子系统非稳态载荷工况对打滑机理的影响规律；搭建高速滚动轴承打滑测试系统，实时测试滚动体三维运动特性，修正理论预测结果，并最终形成高速动载角接触轴承打滑预测方法与分析程序。研究成果有望为高可靠长寿命滚动轴承的设计、监控提供理论依据。

针对高速动载角接触滚动轴承的打滑机理，开展了较为系统深入的研究：首先，提出了一种具有5层结构的运动-赫兹接触-热-弹-流模型，分析高速动载滚动轴承过打滑行为；开展了7307AC轴承在不同运行速度、轴向载荷和两种润滑条件下的试验研究，以验证机理模型的准确性；考虑保持架柔性和三维保持架的涡动运动以及保持架不稳定引起的打滑波动，开发了先进的轴承动力学模型，从恒载变转速、恒速变轴向载荷和恒速变复合载荷三个方面分析了运行条件对保持架动态特性和打滑行为的影响；进而，提出了高精度、自供电的摩擦电轴承打滑传感器以及超高速混合陶瓷摩擦电滚动轴承，通过3000万循环的耐久性测试和16000 rpm的超高转速测试，表明了所提出的摩擦电滚动轴承的优越性；提出了一种含预弯曲膜的盘式摩擦发电机和基于浪形保持架的摩擦电轴承，并将其应用于旋转机械故障诊断研究；建立考虑电极间距非线性变化的机电耦合模型，解析求解了多种形式摩擦发电机的动态输出特性；在此基础上，开展了摩擦发电技术在机械滚动轴承、风能收集领域的应用尝试，分别提出了具有自供能、自感知功能的摩擦电滚动球轴承和颤振双旗帜型纳米摩擦发电机；基于磁等效电路对有缺陷的异步电动机滚动轴承进行了定子电流建模，有效识别了定子电流谱中的故障特征频率；最后，开展了随机风速分布模型及其在风资源评估中的应用研究，提出了一种用于中国大陆地区的风速概率分布核密度估计模型，构造了四种带宽选择器；基于beta边界核和最优带宽算法，提出了适用于中国风资源评估的风矢量联合概率密度分布的非参数copula模型，对中国进行了风电功率密度和风电机组功率输出的估计。上述成果已发表论文27篇，其中SCI收录论文26篇，EI收录论文1篇。项目研究成果有望为高可靠长寿命滚动轴承的设计、监控提供理论依据。