Dynamic modelling of Gear system for condition monitoring and diagnostics

Summary. A non-linear lumped parameter model of a gear system is proposed in order to study the modifications in torsional vibration due to faults. The model takes into account the mass distribution, torsional shaft stiffness and variable tooth-meshing stiffness and is validated by comparison with experimental results. Faults localized in one or a few teeth produce dynamic effects that are typically transient and time-localized. Then, the wavelet transform- that produces a time-frequency representations suited for resolving very short-lived high frequency phenomena in the time domain- is applied to both numerical and experimental results for the detection of damaged teeth. The effectiveness of model both in the case of sound and damaged gears is discussed. 1