变速非平稳条件下滚动轴承故障特征提取方法研究

旋转机械设备启停、电压波动及载荷变化等因素使滚动轴承通常是在变速非平稳条件下运行,利用传统共振解调方法获得的谱图将变得模糊,无法识别故障特征.根据该条件下滚动轴承损伤点冲击引起的固有谐振信号频率不变的特点,利用连续小波分析方法提取固有谐振信号,通过瞬时频率估计、阶比跟踪手段进行阶比谱分析,提出滚动轴承故障特征阶比系数的概念和计算方法.将故障特征阶比系数与阶比谱进行比较,可以很好地识别滚动轴承损伤类故障.

Study on the method of bearing characteristic defect frequency at a varying rotating speed

Rolling element bearings often rotate at varying rotating speed because of the load change or in the run-ups and run-downs processes.To solve this problem,proposes a new scheme which is based on wavelet,time-frequency analysis and order analysis techniques.For realizing order tracking without the employment of hardware such as tachometer and keyphasor,the instantaneous frequency estimation method is used for accessing the resampling time serials.By comparing defect characteristic order spectrum of frequency with its defect characteristic coefficient,localized defect can be identified.