Research And Development On Gearbox Fault Diagnosis System Based On Vibration Signals

Gear box is widely applied in the modern industry as an important transmission, it is an equipment part of frepuent fault with complex structures. The failure, such as broken tooth, pitting corrosion, gear surface abrasion and axis bending often occurs to gear box especially in severe condition. But the running states of gear box will affect the whole machine’s functions directly. Therefore, the fault diagnosis technology of gear box is of great significance. Vibration signal analysis is one of the most validity and applicability method. This thesis developed a gear box fault diagnosis system based on vibration signal analysis.Firstly, the fault vibration property, failure forms, failure cause and modulation phenomenon are analyzed. Secondly, the principle of time domain parameters, autocorrelation, zoom spectrum, Hilbert demodulation and cepstrum analysis are explained in details. The advantages and disadvantage of these methods are analyzed respectively. This paper points out that the autocorrelation analysis can reduce the noise effectively. Zoom spectrum analysis can identify fine structure in the spectrum. Hilbert demodulation can extract information from a modulated carrier wave, but it has limitations in dealing with sum signals. Cepstrum can discriminate periodic component from sidebands and simplify sidebands into a single spectrum line. Moreover, it can be weekly influenced by the transmission path. Then a gearbox fault diagnosis method which integrates autocorrelation and spectrum analysis is presented. Thirdly, the gear pitting corrosion and broken tooth fault dianosis experiment are conducted. The result shows that the improved method proposed in this thesis is effective for the diagnosis of the gear pitting corrosion and broken tooth fault. Finally the software for the gear box fault diagnosis system based on vibration signal is designed via Visual C++, which can extract the fault characteristics and diagnose the fault of the gear box effectively.