Research On Time-frequency Fault Feature For Multiple Impact Source Vibration Signals Of Reciprocating Compressors

Reciprocating compressor is complicated in structure, incentive, vibration source tomultiple source impact signal is given priority to, show strong nonstationarity andnon-gaussian and nonlinear and complicated characteristics, adopts the traditional vibrationsignal analysis method can not be extracted reciprocating compressor fault information, nowhas become the bottleneck of reciprocating compressor fault diagnosis problem. Vibrationsignal of time-frequency analysis as the equipment fault feature extraction of advanced means,in rotating machinery fault diagnosis process plays a very important role. However, with faultdiagnosis field to reciprocating machinery and equipment is outspread, the traditionaltime-frequency fault feature extraction method challenges. For reciprocating compressorcomplex vibration signals, with short time Fourier transform, Wigner-Ville distribution,wavelet transform and HHT transform as the basis of time-frequency analysis method, it isdifficult to identify fault useful information, time-frequency distribution become verycomplicated, many frequency component a lack of clear physical meaning. Aiming at thereciprocating compressor multi-source impact vibration characteristics, combining moderntime-frequency analysis method, the advantages and disadvantages of in-depth developmentbased on local frequency reciprocating compressor fault time-frequency characteristicsresearch.First, by wavelet transform, HHT and other modern time-frequency processing method foramplitude modulation, frequency modulation and frequency modulation amplitudemodulation and the simulation signal on the time-frequency characteristic analysis, andapplied to fault diagnosis of reciprocating compressor, although have some effect, but thereare still resolution is low, the boundary effect interference problem, which is difficult to meetthe practical application.Then, according to the global frequency and instantaneous frequency two extreme sexconcept limitations, this paper puts forward more applicability of local frequency new concept,giving multiple source impact vibration signal with definite physical meaning of frequencycontent, from this definition, through with adaptive peak decomposition method combines,further and HHT time-frequency analysis method, and the results show that the contrast,based on the local frequency of time-frequency analysis method is more effective than revealsthe source impact vibration signal characteristics, for reciprocating compressor fault diagnosisprovides a new means.Finally, the reciprocating compressor basic working principle, main components of thekinematics and dynamics analysis, and points out that the reciprocating compressor test signalof strong nonstationarity, according to the simulation results, will be based on the localfrequency of time-frequency analysis method is applied to fault diagnosis of reciprocatingcompressor has more significant effect, further verified the method for large reciprocating compressor fault diagnosis to provide more rich the failure characteristics of information,improve the reciprocating compressor fault characteristics of the accuracy and robustness.