Detection of Gear Fault Based on Amplitude Demodulation of Rotary Speed

Aiming at the features of the engaging vibration´s direct effects on the rotary speed of axis, this paper puts forward the faults diagnosis method of gearbox using amplitude demodulation technology to analyze the signals of rotary speed. First, the signals of rotary speed of gearbox are synchronously sampled in time domain; Next, the signals of torsional vibration are worked out using the signals of rotary speed, and the signals are averaged in time domain to decrease the noise and increase the power signal-to-noise ratio; Last, the averaged signals in time domain are analized with amplitude demodulation and according to the function graph of the amplitude demodulation, the features of the gear fault are picked up. With the analysis of the fault experimental signals of partially abraded gears, partially abraded faults are effectively diagnosed with this method.