Dynamic Characteristic Analysis And Optimization Design Of The Gear Transmission System For Wind-Turbine Based On FEM

Increasing speed gear-box is one of the most important components of wind-turbine, its performance has a crucial impact on the whole system. Because of its special environment for varying load condition, high operating conditions(with the continuously improve of the power of single wind-turbine ,the operating environment is higher and higher) and other adverse factors, it made special demands for the design, manufacture, installation of the gear transmission system, and the research of its dynamic characters is now a hot topic around the world. However, the vibration and noise of the wind-turbine that design and manufacture in domestic is more serious than the products abroad. Therefore, the research on the vibration and noise of gear transmission is one of the most urgent issues to be resolvedThe thesis subject is supported by National Natural Science Foundation and National Supporting Plan Project. Regarding gear transmission system of wind-driven generator 1.5MW as object, and considering the internal excitation and the external excitation due to wind speed change on Wind farm, the dynamic characteristics of the gear-box system are completely investigated by finite element method. The analytical results will provide a theory basis for optimizing the dynamic performances or decreasing the vibration and noise of the transmission system of wind-turbine.Concrete research work is as follows:①Large-scale integrated FEM dynamic model of gear system including gears, shafts and gearbox is established. The dynamic coupled characteristics of gearbox are perfectly described by the model.②The vibration and noise of gear system are investigated perfectly. The internal excitations of gearing are simulated by finite element method and error-equivalent method. The external excitation that caused by wind speed changes are also investigated. It is the bases of the vibration response calculation of gearbox.③FEM modal analysis of the system is completed by I-DEAS software. The first 10 band of natural characteristics of the gear system are calculated. The results show that there will be no resonance during operating.④Fully consider the internal excitation and the external excitation. The vibration responses of gearbox are calculated by Vibration mode superposition. The vibration response results in time domain are regular, and the Vibration intensity of the gear-box is 0.6026, the system is in good condition when operating. Meet the requirements of the use of wind-turbine.⑤The structure noise of the system is calculated according to the vibration acceleration in time domain by Fourier-transform. The results show that the peak of structure noise is in the mesh frequency multiplier.⑥The dynamical optimization of gear transmission system is presented to minimize the value of vibration acceleration under the constraints of dynamical stress and displacement. The level of vibration and displacement of the gear transmission system is reduced after optimization, and the results of the optimum design of the gear transmission system are analyzed at last.