基于谱峭度的滚动轴承故障包络阶比跟踪分析

通过对旋转机械变速运行工况的齿轮箱振动分析研究，提出一种基于谱峭度的滚动轴承故障包络阶比跟踪分析方法。该方法利用旋转机械运行过程中滚动轴承故障引起的冲击性振动会激起其周围结构共振的原理，应用谱峭度方法自适应地确定优化的共振解调带通滤波中心频率和滤波带宽，进而通过共振解调算法获得包含轴承故障初始阶段振动特征的包络信号，再将变速工况下的非平稳包络信号通过等角度重采样转化为角度域的准平稳信号，进而获得消除了频率模糊的阶比谱，实现对旋转机械变速运行工况下的滚动轴承故障诊断。仿真和测试试验结果验证了本方法的有效性。

Envelope order tracking analysis for rolling element bearing faults based on spectral kurtosis

Through analyzing gearbox vibration signals under varying speed conditions of rotating machinery,a method of envelope order tracking analysis for rolling element bearing faults based on spectral kurtosis was proposed here.It was known that the impact vibration produced by rolling element bearing faults can excite resonances of its surrounding structures.In the proposed method the spectral kurtosis algorithm was used to obtain adaptively both the optimal central frequency and the bandwidth of band-pass filtering for envelope analysis.Then,the envelope signal containing the vibration features in the initial stage of rolling element bearing faults could be gained.Consequently,the envelope signal was resampled with even-angle sampling so that the non-stationary envelope signal in time-domain could be converted into a quasi-stationary one in angle-domain.As a result,the frequency smearing could be eliminated in an order spectrum and the fault diagnosis of rolling element bearing under varying speed conditions of rotating machinery was realized.Simulations and tests verified the feasibility of the proposed method.