Dynamic Modeling And Analysis Of Gear Transmission System For 5MW Wind Turbine

The high failure rate of the large wind turbine gear transmission system is one of the main reasons that case the wind turbine downtime. The wind turbine gear box is usually three helical gear system with planetary gear train, its large transmission ratio,high dynamic load growth system. But under the wind load of the wind turbine impeller not only produce the torque load, but also produce thrust, moment,non-torque loads and so on, this loads transfer to the gear transmission system will cause vibration and dynamic load increases through the spindle, bearings and other components and premature gear failure. Therefore, it is the basic research content of the high reliability design to study the dynamic characteristics inherent characteristics of the gear transmission system and the response characteristics of the system under non-torque loads. This paper takes a 5 MW wind power gear transmission system as the analysis object, the research content mainly includes the following two aspects:(1) Developing the parameter calculation of 5MW wind power gear transmission system, included in the gear transmission system components of the three translation and three rotation degrees of freedom, detailed analysis of the gear side along the meshing line elastic deformation, considering the generalized coordinates on each component's stress. The mathematical model of gear system is established by using the theorem of moment of momentum. To carry out modal analysis is used to obtain the gear transmission system of wind power of each order natural frequency and vibration type. The results show that there is more order natural frequency of high-speed gear meshing frequency resonance range, the gear meshed excitation force will cause vibration system violently, and then carry out the high grade gear contact finite element analysis, getting the gear tooth bending stress distribution(2) Considering the flexibility of the two stages planet carrier ? three stages transmission shaft and the support stiffness of the planet wheel bearing, calculating the meshing stiffness and damping parameters of gear meshing pairs, ADAMS software was used to build the rigid flexible coupling dynamic model, then study the effect of non-torque loads on the dynamic response of gear transmission system. By comparing with the dynamic response of the system under a single torque load,analysis results show that non-torque loads will caused the low-speed gear vibration displacement and dynamic meshing force increased significantly, and the flexible body is conducive to the smooth transmission. Analysis of the load sharing characteristics of planetary gear train, the influence of gear meshing stiffness parameters on the load sharing performance is discussed, indicated that reduce the gear meshing stiffness will increase the load sharing characteristics of planetary gear train.