推力轴承试验台异常振动故障诊断方法
Fault Diagnosis Method of Abnormal Vibration for Thrust Bearing Test Rig

针对某推力轴承试验台运行过程中的异常振动问题进行了故障诊断研究。首先，基于快速傅里叶变换方法（fast Fourier transformation,简称FFT），对实验台的异常振动信号及其特征进行了捕捉和提取；其次，从激振力、系统刚度、共振等因素对异常振动进行了专家系统故障诊断，结合有限元分析的计算结果表明，转频与试验台的动态特性发生耦合是诱发整个试验台共振的根本原因，基于此原因对试验台出现的3个异常振动特点进行了解释；最后，对试验台局部进行了优化，以避免共振发生，优化后的试验台整体动态特性可以有效避开转动频率，测试结果显示新试验台在运行工况范围内均不会出现较大的振动。
Aiming at the problem of abnormal vibration of one thrust bearing test rig during the operation, the fault diagnosis of the test rig is investigated by applying dynamics and experimental method. First, based on the approach of fast Fourier transform (FFT), the vibration signal and its characteristics of the abnormal vibration are captured and extracted. Second, using the expert system fault diagnosis methods, abnormal vibration of the test rig is analyzed from three aspects: exciting force, system stiffness and resonance. Combined with the finite element calculated results, modal analysis and harmonic response analysis, it shows that the rotating frequencies are coupling with the dynamic properties, which is the vibration source of the resonance for the whole test rig. Based on this reason, three characteristics of the abnormal vibration are well explained. Finally, local optimization of the structure for the test rig is conducted. The dynamic properties of the new structure can usefully avoid the rotating frequencies. During all over the operational working cases, the resonance of the test rig will not occur. Moreover, the test results show that the new structure will not appear big vibration.