Vibration Analysis Of1.5MW Wind Turbine Gearbox

A Gearbox is one of the key components of a large double-fed wind turbine. Due to compact structure, complex loads and high speed ratio the gearbox has high failure rate in actual operation. This article takes typical wind turbines of1500kW as an object to study the dynamical characteristics by means of simulation and real measured vibration signals. Two types of most commonly used gearboxes, two-stages planetary gear plus one-stage parallel shaft gear and one-stage planetary gear plus two-stage parallel shaft gear are researched, in order to provide the technical support for the optimization design, reasonable operation and fault diagnosis. The main research contents and results are summarized as follows:(1) the dynamic characteristic of two kinds of gearboxes are analyzed by means of the modeling software Pro/E and dynamic software ADAMS. The axial angular acceleration levels of each stage, pinion meshing force in the time domain and frequency domain features are reached synchronously. Simulation results is credible compared to theoretical calculation, the value is very close. The dynamic loads of two-stage planetary gear plus one-stage parallel shaft gear is smaller than that of one-stage planetary gear plus two-stage parallel shaft gear.(2) Time domain and frequency domain characteristics of gearbox vibrations were analyzed using measured vibration signals sampled under operating conditions. By comparing the waveform and spectrum of measured vibration signals with the simulation results it can be seen that there are certain comparability between them.(3) The influence of operating conditions on wind turbine gearbox vibration was discussed. It shows that certain frequency components in vibration signals are equals to the structural natural frequencies under certain rotating speed that excited a strong resonance phenomenon and causes the stronger gearbox vibration.