航空发动机主轴轴承局部故障激励机理与特征提取方法研究

项目名称： 航空发动机主轴轴承局部故障激励机理与特征提取方法研究

项目编号： No.51505486

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 机械、仪表工业

项目作者： 明安波

作者单位： 中国人民解放军火箭军工程大学

项目金额： 21万元

中文摘要： 现代航空发动机普遍采用双转子多点支承方案，通过主轴轴承实现飞行动力的传递。随着发动机转子的工作温度和运行转速不断提升，转子热弯曲、不平衡等产生的振动对主轴轴承的状态监测与故障诊断的干扰越来越突出。鉴于此，本项目从表征轴承故障的非规则形貌出发，构建转子轴承动力学模型，探讨点蚀、疲劳剥落和滑蹭损伤等局部故障的激励机理，揭示轴承故障对转子系统动力学特性的影响规律。在此基础上，探索多分量信号的包络分析理论，提出基于单通道信号的转子、轴承故障振动成分分离方法；掌握复杂变速工况下轴承故障特征增强与提取过程中相关参数的优化选择规律，提出具有较好自适应性的主轴轴承故障特征提取方法，实现具有转子热弯曲、不平衡等振动干扰环境下主轴轴承早期微弱故障的诊断，为航空发动机主轴轴承的状态监测与故障诊断提供理论支撑和技术支持。研究成果对于提高我国航空发动机的测试水平和运行可靠性具有重要的理论和实用价值。

中文关键词： 航空发动机；主轴轴承；局部故障；激励机理；特征提取

英文摘要： Widely used in the modern aero-engine to transform the flight power, the main bearings are key components at several support points in the dual-rotor. The rotor vibrations produced by the thermal bending, unbalance, eccentricity, etc. are disturbing more and more prominently the condition monitoring and fault diagnosis of the main bearings, since the operation temperature and running speed of the dual-rotor are gradually increasing more and more higher. In this instance, starting at the point of the description of the localized fault with un-uniform shape, a rotor-bearing system dynamic model is proposed at first in this project in order to discuss the excitation mechanism of the localized faults such as the pitting, fatigue spalling and slip rub damage and reveal the effect law of these bearing faults on the dynamic characteristic of the rotor system. Then, the envelope analysis theory suitable for the multi-component signal is further improved and a signal decomposition method which can obtain the vibrations produced by rotor and bearing fault from only one single channel is proposed. Finally, by mastering the determination law of corresponding parameters, a feature enhancement and extraction method is proposed to adaptively solve the main bearing fault diagnosis in a complex environment involving even varying speed and interferences produced by the rotor thermal bending or unbalance. The research in this project will provide theoretical basis and technical support for the condition monitoring and fault diagnosis of the main bearing in aero-engine. The research results have significant theoretical and practical merit for enhancing the test level and operation stability of aero-engines in our country.

英文关键词： Aero-engine;Main bearing;Localized fault;Excitation mechanism;Feature extraction