Bartelmus Walter. Computer-aided multistage gearbox diagnostic inference by computer simulation

Monografia. — Wrocław: Politechnika Wrocławska, 2002. — 118 s.The monograph is a review of the current possibilities for using mathematical modelling and computer simulation for investigating the dynamic properties of gearbox systems. Computer simulation of dynamic behaviour of gearboxes is a powerful tool for supporting diagnostic inference. The monograph gives evidence that using DPTOCC leads to inference diagnostic information. By means of simplified parametric description of gearing errors given by an error mode presented by symbolic description E(a, e, r) signals which are close to signals measured from real gearboxes are obtained by computer simulation. For gearbox faults detection, many different ways of signal analysis should be done. In the monograph, for fault detection a time trace examination, spectrum, cepstrum and time-frequency spectrogram have been used. It has been shown that using these ways of vibration signal analysis there are possibilities to detect signal faults and distributed faults in gearboxes. A signal fault is caused by a tooth crack/fracture and breakage, a spall in a gearing or in an inner or outer race of a bearing, a spall on a rolling element of a bearing; distributed faults are caused by uneven wear (pitting, scuffing, abrasion, erosion). Using mathematical modelling and computer simulation distributed faults caused by gearing wear are detected by the cepstrum. Computer simulation enables one to infer that the cepstrum not only detects single gearing faults, but also distributed faults. It has been shown that for explicit detection of a tooth fracture and breakage there is a need to use a cepstrum and a time-frequency spectrogram.