Dynamic And Fatigue Analysis Of Wind Power Gear Box

With the rapid development of modern industrialization,the gear transmission system is widely used in various industries with the advantages of contact velocity ratio,big transmission power and long service life.Gear transmission process,however,is more complex,the contact between gear pair is a higher pair,and the fatigue life of gear system will be greatly affected by the action of dynamic load.As higher requirements for the performance of gear transmission,it is very important to analyze gear contact stress,the dynamic characteristics of gear system,and the fatigue life of gear system,which will improve the gear bearing capacity and prolong fatigue life of gear system.To the megawatt wind power gearbox transmission system,the gear contact model is simplified according to the Hertz contact theory.The load for transient dynamics analysis is provided through dynamics analysis of rigid-flexible coupled gear system,and the fatigue life of gear system is studied under random load spectrum.The main work in this paper is as follows:(1).The megawatt wind power gear contact model is simplified according to Hertz contact theory.The contact stress analysis of two kinds of contact model is used to verify the rationality and accuracy of the simplified contact model,it also provides basic evidence for experimental analysis of gear contact.(2).The kinematics simulation of wind power growth gearbox system is carried out for verifying the accuracy of this model.The first stage planetary with rigid-flexible couple is established in order to get more realistic time-varying load torque in sun wheel.(3).The first stage planetary is carried on the transient dynamics simulation when the time-varying load torque is as dynamic incentive,and the random load on the dangerous point of tooth surface and tooth root is obtained during the gear meshing process.Rain flow count method is used to construct the load of dangerous points into a serious of various amplitude load spectrum.(4).Nominal stress method and AWB fatigue module are used to analyze the fatigue life of low level sun gear which report as tooth surface contacting fatigue life and tooth root bending fatigue life,respectively.Finally,the gear root fillet is optimized to meet the design bending fatigue life of tooth root.