Research On Dynamic Response Of Local Defects In Planetary Gear System Of Wind Power Gearbox

As the energy crisis and environmental pollution problems become more and more serious,how to better develop and utilize renewable resources like wind energy has become a hot issue that is generally concerned by countries around the world.As one of the main forms of wind energy development,wind power generation plays an important role in adjusting the industrial structure.In order to achieve the sustainable development of the wind power industry,higher requirements are placed on the field of safety,reliability and economy of wind turbines and main components.As the core device of wind turbine power transmission,the wind power gearbox directly affects the safe operation of wind turbines during the workin g process.Therefore,it has great engineering value to investigate the evolution law of local defects in wind power gearboxes.This subject mainly conducts research from the following aspects:(1)It systematically reveals the generation mechanism of the gear train vibration signal during gear meshing,the cause of the formation of local defects and the modulation effect of different types of gear defects on the gear meshing vibration signal,as well as the formation mechanism of the gear fault vibration signal.Simulation signal analysis provides a theoretical basis for the following parts.(2)Analyze the structure and transmission principle of the wind power gearbox,using UG NX 12.0 and ADAMS software to establish a virtual prototype model of the first-level planetary gear system of the wind power gearbox,and determining the three-dimensional modeling method of different types of local defects.According to the needs of actual working conditions,the components are flexibly processed on the basis of the virtual prototype model,and the rigid-flexible coupling model of the first-level planetary gear train is established.By comparing the theoretically calculated rotation speeds of the sun and planet gears with the simulation results,the validity of the model is verified,and the model basis is provided for the dynamic simulation in the subsequent chapters.(3)To explore the influence of local defects on the contact stiffness of gears,this paper calculate the contact stiffness coefficient of gears with different degrees of local defects according to Hertz contact theory,and reset the contact stiffness coefficient of the faulty gear through ADAMS software to establish the planetary gear system rigidity with local defects Flexible coupling model.Through the establishment of local defect models of different sizes to simulate the evolution process of local defects,and complete the dynamic simulation.Collect ing the displacement of the sun wheel axis with different degrees of local defects and mak e the axis trajectory.Exploring the influence of the local defects on the sun wheel center of mass according to the offset of the axis position.(4)The acceleration time-frequency signals in the post-processing results of the simulation of healthy gears and planetary gear trains with d ifferent types and sizes of fault gears are analyzed respectively to explore the effects of the sun gear's partial tooth breakage and the width of spalling defects on the gear dynamic response.The method of spline interpolation and polynomial fitting is u sed to study the change trend of the acceleration amplitude that can reflect the fault characteristics in the time domain and the frequency domain with the defect size and the corresponding functional relationship,which provides a theoretical reference fo r the gearbox fault diagnosis.