旋转机械轴心轨迹信号的复数小波分析

提出了一种利用复数小波变换分析转子振动轴心轨迹信号的方法,通过分析小波尺度与振动倍频间的关系,使得观察某一尺度上的小波幅值就相当于考察一定频率范围的周期谱图,对典型非线性故障轴心轨迹信号的分析揭示出,摩擦故障时高频振动地时－频域上呈现出非均匀间歇现象,而轴裂纹时的高频振动是均匀间歇地出现,且周期与旋转基频相同,因此该方法可以直观地识别故障的细节性特征,有望形成一种新的、有效地监测诊断技术。

Rotating Machinery Orbit Analysis Using Complex Wavelet Transform

Amethod is introduced for analyzing the axis orbit of a rotor by using the complex wavelettransform of a pair of vibration signals from two 90° positioned transducers atteched tothe rotor.By the analysis of the relationship between scale parameter and vibrationfreguency,it can be seen that an examination of the amplitudes of the wavelet at a certainscale is equivalent to that of the periodogram at a certain range of frequency.Theanalysis of the orbits produced by two typical nonlinear faults,i.e.the friction and thecrack,shows that the orbits contain different features for different faults.The highfrequency components of the orbit due to the friction are unevenly spaced along the timeaxis in the time-frequency domain,whereas those due to the crack are even spaced,and itsperiod is equal to the rotating period of the rotor.It is expected that the methodproposed in the paper can be developed into a new and effective technology for faultmonitoring and diagnosis due to its capability for the identification of detailed faultfeatures.