一种基于变形运动矢量分析法的转子耦合故障机理建模

A Rotor Coupling Fault Mechanism Modeling Based on the Deformation Motion Vector Analysis Method

为完善和丰富目前旋转机械耦合故障所普遍采用的数值解法,提出一种松动—碰摩转子耦合故障的建模方法:变形运动矢量分析法。首先,"变形运动"以故障定义变形,然后利用傅里叶级数建立起故障变形和周期信号的关系;其次,"矢量分析"利用动、静两套坐标系建立起故障变形运动和周期性激励力的关系,并在动坐标系中分析故障运动;第三,利用谐波平衡求出解析解。变形运动分析法是一种全新的解析解法,该解法能够对旋转机械耦合故障的发展走向做出理论并整体的把握,在求解过程中能够从机理上解析耦合故障如何一层一层的被展开和发展,以及故障的结构性存在。假如对解析解做更深入的推理分析,可以对数值解法作为现象提出的混沌、分岔等故障特征得到机理层面的解释,而在故障诊断实践中一直难以解释的分数倍频、和差频率等成分,其实质也只是解析解中的一部分。最后,采用工程实践的方法验证了建模方法的有效和解析解结论的正确。

In view of the special limitation of the numerical method commonly used in the coupling fault of rotating machinery,in order to explain the fault mechanism more deeply and widely,a modeling method of a rotor coupling fault mechanism modeling based on the deformation-motion vector analysis method is proposed.Firstly,"deformation movement"defines deformation by fault,and establishes the relationship between fault deformation and periodic signal by Fourier series;secondly,"vector analysis"analyzes fault movement in dynamic coordinate system,and establishes the relationship between fault deformation motion and periodic excitation force by using dynamic and static coordinate systems;thirdly,analytic solution is obtained by harmonic balance.The deformation motion vector analysis method is a new method of solving the analytic solution,which can make a theoretical and overall grasp of the development trend of the coupling fault of rotating machinery,it can explain mechanically how the coupling fault unfolded layer by layer and the fault structure.If the analytic solution is further rational analysis,the fault characteristics of chaos and bifurcation proposed by numerical solution as a phenomenon can be explained at the mechanism level.The fractional frequency multiplication and sum difference frequency which are difficult to explain in fault diagnosis practice are also part of the solution.Finally,the effectiveness of the modeling method and the correctness of the analytic solution are verified by engineering practice.