关键传动件故障动态特征演化机理与变尺度解调方法研究

The early faults in key transmission components cannot be accurately identified. This occurs because the propagation mechanisms of the spatial tooth root crack, tooth surface spalling and rotor crack are not completely investigated, and the demodulation method for the multi-frequency modulation signals of the faults cause by their propagations is not successfully resolved. To overcome this problem, the elastic-plastic propagation mechanism at the edges of the tooth surface spalling and the corresponding vibration characteristics is studied. A new method for calculating the nonlinear contact force at the edge of the tooth surface spalling caused by elastic-plastic-elastic contact is presented. A new dynamic modeling method for the tooth surface spalling is also developed. The effects of the propagation mechanisms of the tooth root crack and rotor breathing crack on the vibration characteristics of the transmission system is analyzed. A new dynamic modeling method for the tooth root crack propagation and gear-rotor-bearing system considering the tooth root crack propagation, bearing deflection and rotor crack is proposed. In addition, a new method for multi-scale demodulation and faults characteristics extraction is presented. The coupling relationship between the vibration characteristics and faults propagations is obtained. The central frequencies traversal search principle and the corresponding bandwidth selection principle for the propagation characteristic signals of the compound faults considering time-varying velocities and loads. This study can be useful for development in the propagation mechanism of the cracks and spalling. It can also help improve the accuracy of the signal characteristics extraction and identify method for the faults in the key transmission components due to the fault propagation.

关键传动件早期故障不能准确识别的根本原因是齿根空间曲面裂纹、齿面剥落及传动轴裂纹故障的演变机理及其振动特征的演变规律尚未解明，同时多频率调制的故障演变信号特征提取未能很好解决。本项目针对这些问题，研究齿面剥落故障边缘接触变化及其振动特征演变，提出剥落故障边缘"弹性-塑性-弹性接触"非线性接触力的计算方法，探索轮齿剥落故障的振动特征演变规律；研究传动轴"呼吸式"裂纹与轮齿齿根裂纹扩展的振动特征演变规律，提出轮齿齿根裂纹扩展动力学建模方法和耦合轮齿齿根空间曲面裂纹扩展、轴承偏转变形及传动轴裂纹扩展的齿轮-传动轴-轴承动力学建模方法；研究非线性振动信号的变尺度解调方法及故障特征提取方法，构建故障形貌演变与振动特征演化之间的映射关系，提出多频率调制的故障演变中心频率搜索规则及多带宽选择规则。本项目研究对提高早期故障的诊断的成功率和准确性，保障人员和重要装备的安全，具有重要的理论和工程价值。

针对齿根空间曲面裂纹、齿面剥落及传动轴裂纹故障的演变机理及其振动特征、多频率调制的故障信号演变及特征提取问题，提出了齿面剥落故障边缘弹性-塑性-弹性接触的强非线性接触力计算方法及剥落故障演变齿轮动力学建模方法；提出了轮齿齿根裂纹扩展、耦合轮齿齿根空间曲面裂纹扩展、轴承偏转变形及传动轴“呼吸式”裂纹扩展的齿轮-轴-轴承动力学建模方法，获得了裂纹扩展及其振动特征演变规律；构建了故障演变与振动特征演化之间的耦合关系，提出了多频率调制的故障演变中心频率遍历搜索规则及其带宽选择规则。 本项目揭示可故障动态演化机理，创新了变尺度复合解调方法，共计发表SCI论文16篇，EI/国际论文9篇，CSCD 2篇，发明专利4项。