Abstract:

Marine reciprocating air compressor has many excitation sources and complex structure, poor working environment, the characteristics of complex signal transmission path. These factors affect the signal analysis and fault source to determine. In order to extract the characteristic frequency, using the conventional method and the forced denoising, the default threshold denoising and the given soft threshold denoising method to deal with the vibration signal of the air compressor, By comparing the advantages and disadvantages of the four methods and the applicable conditions, it is found that the default threshold method retains the characteristic signal well and the noise reduction effect is good, so the default threshold denoising method is used to analyze the time and frequency domain of the vibration signal of the air compressor. Through the time domain analysis, it can be found 0.5 × rpm impact interval is obvious, by frequency domain analysis it can be found 1 × rpm frequency and with the emergence of 2 × rpm. The maintenance program can be presented according to the vibration mechanism of the air compressor and the historical maintenance record. The results show that the amplitude of the vibration and the frequency of the main frequency are significantly reduced, the maintenance effect is well.

摘要：

船用往复式空压机激励源众多、结构复杂、工作环境恶劣、信号传播路径复杂等因素都影响信号的分析与故障源的确定。为提取特征频率,运用常规方法和基于小波变换的强制去噪、默认阈值去噪和给定软阈值去噪方法对空压机振动信号进行处理，通过比较这四种方法的优劣和适用条件，发现默认阈值法能很好地保留特征信号并且去噪效果良好，所以选取默认阈值去噪法对空压机振动信号的时域和频域进行分析。时域分析发现0.5×r/min冲击间隔明显，频域分析发现1×r/min频率突出且伴随出现2×r/min的情况，根据该空压机的振动机理和历史维修记录针对性地提出检修方案。对检修后的空压机进行二次诊断，结果表明整机振动烈度和主要频率处的幅值显著降低，检修效果良好。

关键词: 振动与波, 往复式空压机, 故障诊断, 小波变换, 时域分析, 频域分析。