高速滚动轴承多因素耦合动态润滑膜热失稳研究

With the development of high-speed machinery such as aircraft engine, etc., problems due to thermal generation in bearings become more and more severe. Under the condition of high speed and high temperature, not only failure of elastohydrodynamic lubrication (EHL) and surface damage occur frequently, but also the lubricating property deviates from the classical EHL theory. At present, study on the temperature field of rolling bearings has yet not combined with the thermal instability of EHL film, and an investigation on the thermal instability of oil film has not been carried out systematically; whereas most research on EHL of bearings assumed that the boundary temperature of the bearing assembly was the same as that of the lubricating film, and problems of the thermal instability of dynamic film coupled with multi-factors in high-speed rolling bearings have not been considered. This proposal is proposed by means of experiment and numerical simulation, including: 1) To develop a measuring system for the temperature field of bearings; 2) To set up a model of thermal analysis for bearings; 3) To build a thermal instability model of dynamic film incorporating multi-factors; 4) To overall consider effects of the rheological property of the lubricant, surface micro-characteristic, the supply of the lubricant, and dynamic behaviour, etc. on the thermal instability of the film; 5) To present a relationship between the film rupture and the temperature, to determine the critical temperature for film rupture, and to provide criteria for thermal instability of the film. Upon success of this project, realistic temperature field of bearings will combined with thermal instability of film for the first time, useful data will be provided for failure analysis in high-speed rolling bearings, and improve their lubricating performance.

随着航空发动机等高速机械的发展，滚动轴承因发热产生的问题愈来愈严重。在高速高温条件下不仅弹流润滑膜失效和表面损伤多发，且其润滑行为偏离经典弹流润滑理论。目前对轴承温度场的研究尚未与弹流润滑膜的热失稳相联系，油膜热失稳的研究尚未系统展开，而轴承热弹流润滑的研究多假定轴承组件与润滑膜的边界温度相同，而未考虑多因素耦合条件下高速滚动轴承动态油膜的热失稳问题。 本研究拟通过实验手段和数值模拟，1) 研制滚动轴承温度测量系统；2) 建立滚动轴承热分析模型；3) 建立多因素耦合的动态润滑膜热失稳模型；4) 综合考虑润滑剂流变特性、表面微观特性、润滑剂供给和动态特性等因素对油膜热失稳的影响；5) 给出表面润滑膜破裂和组件温度的关系，确定油膜破坏的临界温度，为油膜的热失稳提供判据。本项目首次将滚动轴承温度场与动态油膜的热失稳研究相结合，可为高速滚动轴承的失效分析提供基础数据，提高其润滑性能。

采用理论分析和试验研究相结合的方法，研究了高速滚动轴承的温度场及动态油膜的热失稳机理及影响因素，获得了一批理论和试验成果。建立了滚动轴承温度动态测量系统，研究了内圈温度测试方法，进行了滚动轴承的测温和润滑脂性能试验。建立了滚动轴承温度场的理论分析模型，研究了轴承组件热量产生和传递规律。成功推导出反映接触固体运动状态的普遍Reynolds方程。推导了一个具有两参数的新剪稀流变模型。提出了一种求解Eyring剪稀流变模型等效粘度的新方法。研制了自旋弹流油膜光干涉试验台，建立了考虑表面粗糙度、冲击振动、流变效应的多因素耦合的滚动轴承动态油膜热失稳模型，给出了热失稳影响因素及热失稳临界温度。研究了润滑剂的供给及分布对滚动轴承润滑状态的影响。结果表明，轴承温升随轴向预紧力的增加先增后减再增。角接触球轴承的热生成与转速、载荷、离心力和自旋有关。求解Eyring剪稀流变模型等效粘度的新方法高效、简便、适用范围广。在轴承运转中产生的高温和热剪稀引起的较小膜厚会导致热失稳的危险。粗糙度波长和接触固体尺度等参数与摩擦系数相关联。润滑剂油品和分布会影响滚动轴承的成膜特性和温度场。.在标注了本项目资助的成果中包括SCI英文期刊论文7篇、EI期刊论文5篇，中文期刊论文17篇，实用新型专利1项，在国际会议上宣读论文4篇。到目前为止本项目组已经顺利完成申请书中几乎全部预定目标。围绕本项目，培养博士研究生1名，硕士研究生10名。获山东省优秀博士学位论文1篇，教育部自然科学二等奖1项 (公示中)。