混合润滑状态下超高速球轴承微剥落机理及精度早期失效预测

Micro-pitting at the contact surface of super-high-speed ball bearings is one of the main factors that result in the initial precision failure and reliability degradation of the complicated mechanical systems such as aero engines and ultra-high-speed motor spindle. As the lubricating condition and roughness of the contact surfaces are the key factors that may result in micro-pitting and initial precision failure, it is of great importance to consider them in the research of the micro-pitting mechanism. By building the dynamic model of the super-high-speed ball bearings, this project aims to analyze the non-linear dynamic characteristics of the components of the super-high-speed ball bearings; study the rolling-sliding contact behavior of the ball and track of the bearing both macroscopically and microscopically; and find the law of the rolling-sliding contact behavior varying with the working conditions. Then the geometry of contact surface is used to build the microscopic contact model considering the roughness of the contact surfaces. The law of micro-pitting influenced by mixed- lubrication condition and roughness of the contact surfaces is studied in depth. Based on that, the mechanism of micro-pitting is revealed. On the basis of the aforementioned, the project explores the methods for prediction of the precision initial failure and the reliability analysis of the precision. Finally a theoretical method is introduced aiming to analyze the micro-pitting and predict the initial failure of super-high-speed ball bearings based on the mixed-lubrication and roughness of the contact surface, which can provide theoretical support for the optimization design of the super-high-speed ball bearings in aero engines and high-speed machines, etc.

超高速球轴承滚滑接触表面微剥落是航空发动机、超高速电主轴等复杂机械系统精度早期失效、寿命与可靠性降低的最主要因素之一，而接触表面润滑状态与粗糙度则是微剥落形成及精度早期失效的主要条件，研究考虑混合润滑状态与粗糙度的接触表面微剥落形成机理迫在眉睫。本项目力求通过构建超高速球轴承动力学模型，分析其服役工况下零件非线性动力学特性，研究混合润滑状态下球与滚道的宏微观滚滑接触行为，揭示滚滑行为随服役工况的变化规律；然后引入滚滑接触表面形貌，构建考虑粗糙度的滚滑表面微观接触模型，研究混合润滑状态与粗糙度对滚滑接触表面微剥落的影响规律，揭示混合润滑状态下粗糙接触表面微剥落形成机理，在此基础上，研究精度早期失效预测方法，并分析精度可靠性，形成一种能够综合考虑混合润滑状态与粗糙度的超高速球轴承微剥落分析及精度早期失效预测的理论方法，为航空发动机、高速机床等超高速球轴承应用领域中轴承优化设计提供理论支撑。

超高速球轴承滚滑接触表面微剥落是航空发动机、超高速电主轴等复杂机械系统精度早期失效、寿命与可靠性降低的最主要因素之一，而接触表面润滑状态与粗糙度则是微剥落形成及精度早期失效的主要条件，因而研究考虑混合润滑状态与粗糙度的接触表面微剥落形成机理迫在眉睫。本项目首先基于动力学构建超高速球轴承动力学模型，分析服役工况下零件非线性动力学特性的变化规律，并研究了混合润滑状态下超高速球轴承接触表面宏微观滚滑行为，其中宏观层面研究打滑行为，微观层面研究椭圆接触区域内微观滑动行为；然后将滚滑接触表面形貌引入动力学模型，构建考虑粗糙度的轴承滚滑表面微观接触模型，从而研究混合润滑状态与粗糙度对滚滑接触表面微剥落的影响规律，揭示混合润滑状态下粗糙接触表面微剥落形成机理；在此基础上，研究旋转精度随微剥落的演化规律，并探索轴承精度早期失效判据，从而实现预测轴承精度早期失效预测，同时分析旋转精度可靠性；最终形成一种超高速球轴承微剥落分析与精度早期失效预测的理论方法与数值实现手段，从而为航空发动机、高速机床等超高速球轴承应用领域中轴承优化设计提供理论支撑。