Bearing fault detection of gear-box drive train using active filters

Failures on a rolling bearing in the gearbox drive system can be detected via vibration sensors or accelerometers. Measured signals include rotating harmonics, noises, signals associated with a bearing fault. Characteristic frequencies of a faulty bearing are very close to the higher harmonics of rotor frequency. This causes a big challenge to know if a bearing is in a faulty or healthy condition by using spectral analysis. An effective extraction of fault-related signals from the measured signals is very useful to analyze the characteristic frequencies. It is found that active filters can fast extract the fault-related signals in the time-domain. The bearing diagnostic analysis can be quickly implemented on the extracted signals via Fast Fourier Transform in the frequency domain or energy calculation in the time domain.