Research On Fault Characteristic Propagation Mechanism Of Gearbox Transmission System Of Wind Turbine

In order to determine the vibration response characteristics of internal gears in the gear box, which is difficult to be measured by experiment, the dynamic model of multi stage gear transmission system with planetary gears is established, which is based on the mechanism of planetary gear transmission and the gear meshing phase relation.On the basis of this model, which are implanted with the planetary gear missing tooth fault, fixed axis gear crack fault and planetary gear teeth missing-fixed axis gear tooth root crack coupling fault, numerical integral method is used to obtain the corresponding gear vibration response. The vibration response of the gear is analyzed, and the fault characteristics of the gear under certain fault are obtained. The fault characteristics of a single fault and coupling fault in a multi stage transmission system are analyzed and compared with the surface signal of the gear box..It is found that the fault characteristics of the gear with the same fault are different from the surface of the box, and the fault characteristics are changed by the different signal transmission path, which brings some trouble to the fault diagnosis. In view of this problem, based on the analysis of the dynamic path of the box and the analysis of the planetary gear, and the system identification theory, the signal propagation model is established by the finite impulse response sequence, where the simulation results obtained from the above mentioned dynamic model are used as input and the surface vibration of the box is used as the output.By using the least square method (RLS-MN method), the parameters of the signal propagation model are estimated, and the transmission function of multi signal propagation path under different fault conditions is obtained. By analyzing the transfer function, the fault feature propagation mechanism is found, and the fault itself is found to change the signal propagation path.