Simulation Of Bearing Wear And Dynamic Characteristics Of Compound Clearance Transmission System Of Wind Turbine

Due to the rapid development of the global economy,oil,coal and other non renewable resources have been gradually depleted,wind energy as renewable resources can meet China's energy needs at a certain extent and the wind turbine attracts more and more attention.The cost of wind turbines is becoming more expensive in the aspect of transport and check maintaining because of the biger single-machine capacity,taller tower and more obvious flexible features,so the wind turbine gearbox must be operated for a long time without trouble.Bearings have more frequently faults in the gear box transmission system as the key parts,and their structural characteristics affect the dynamic characteristics of the gear box transmission system seriously.So it is very important to study the dynamic behavior of the wind turbine drive system under the flexible support.This apper studied the dynamic characteristics of the wind turbine transmission system under the flexible support with the condition of compound clearance.The main research methods and conclusions in this paper as follows:At first,considering the factors of bearing stiffness and damping,the mathematical model of the transmission system of wind turbine is established by using method of flexible multi-body dynamics theory.In this paper,the mechanism and calculation method of the internal and external excitation of the gear box are analyzed,and the equation are reduced to a unified matrix form.Secondly,the kinematics model of the bearing and the numerical simulation model of bearing wear are established.Considering the oil film thickness,contact half width parameter is optimized,and then the wear quantity of wind turbine shaft bearing is calculated.It is found that the outer ring of bearing is the most serious.Finally,considering the backlash and bearing clearance parameters,A mathematical model of gear box transmission system of wind turbine under compound clearance is established.Simulink system module is used to calculate the vibration displacement of each part of the transmission system,then the dynamic response of each component,the vibration displacement difference of the medium speed gear and bearing of the transmission system with or without clearance are compared.It is found that the vibration amplitude of the gear is larger than the vibration amplitude of the bearing in the same direction,each part has its own natural vibration frequency and the amplitude of vibration without clearance is less than that of the gap.The research results have certain reference value for the design of wind turbine transmission system.