变速器设计外文翻译.doc

第 PAGE 7 页 共 7 页 Dynamic Modeling of Vehicle Gearbox for Early Detection of Localized Tooth Defect Nagwa Abd-elhalim, Nabil Hammed, Magdy Abdel-hady, Shawki Abouel-Seoud and Eid S. Mohamed Helwan University ABSTRACT Dynamic modeling of the gear vibration is a useful tool to study the vibration response of a geared system under various gear parameters and operating conditions. An improved understanding of vibration signal is required for early detection of incipient gear failure to achieve high reliability. However, the aim of this work is to make use of a 6-degree-of-freedom gear dynamic model including localized tooth defect for early detection of gear failure. The model consists of a gear pair, two shafts, two inertias representing load and prime mover and bearings. The model incorporates the effects of time-varying mesh stiffness and damping, backlash, excitation due to gear errors and modifications. The results indicate that the simulated signal shows that as the defect size increases the amplitude of the acceleration signal increases. The crest factor and kurtosis values of the simulated signal increase as the fault increases. Though the crest factor and kurtosis values give similar trends, kurtosis is a better indicator as compared to crest factor. KEYWORDS：Vibration acceleration, system modeling, Crest Factor, Kurtosis value, defect size, gear meshing, pinion, gear NOMENCLATURE ，，， Drive motor, pinion, gear, and load mass moment of inertia replacement decision in a suitable time. ， Masses of pinion and gear. Driving motor torque. Load torque. ， Friction torque. ， Viscous damping coefficient of pinion and gear bearing. Gear mesh damping. Gear mesh stiffness. ， Pinion and gear shaft stiffness. The variance square.