Fault diagnosis of rolling element bearings based on ensemble empirical mode decomposition

Periodic impulses in vibration signals and its repeating frequency are the key indicators for diagnosing the localized damage of rolling element bearings. Traditional envelope spectrum is effective in fault diagnosis of rolling element bearings, but it needs optimization of filter parameters which is complicated. A new method based on ensemble empirical mode decomposition (EEMD) and envelope spectral analysis is proposed to extract the characteristic frequency of bearing element fault. The signal is firstly decomposed into mono-components by means of EEMD, then the obtained first intrinsic mode function is analyzed by means of envelope spectrum to identify the repeating frequency of fault induced periodic impulses and thereby to diagnose bearing faults. Its effectiveness in extracting the characteristic frequency of bearing faults, and especially its performance in identifying the symptoms of weak faults, are validated by the experimental signal analyses of seeded fault experiments.