The Stress Analysis And Fatigue Evaluation Of Fan Main Shaft Bearing Structure Based On FMEA

Today,the proposal of the goal of carbon neutrality makes wind power generation of great significance.Many wind farms are built in remote areas with harsh environment.The bearing parts of the main shaft bearings of wind turbines are prone to various failures and reduce their life after bearing complex alternating loads for a long time.For the above considerations,the fault mode and impact analysis method applied in the system reliability is applied to the fault analysis of the main shaft bearing of the fan,and the fault mode with the highest hazard is obtained by comparing two different hazard analysis methods;Then,based on the main failure modes determined by FMEA analysis,the structural stress and fatigue life of the main shaft bearing under different structural parameters are studied to explore the deep causes of the main failure and provide reference for the prevention and improvement of the failure.The main research contents include:Conduct structural and functional analysis on the main shaft bearing of the fan and its drive system,identify the common fault modes of the main shaft bearing of the fan,and conduct failure mode impact analysis(FMEA)on the wind turbine.In order to determine the main failure of the main shaft bearing,this thesis uses qualitative and quantitative hazard analysis methods to compare and analyze the failure modes,and the last two methods get consistent results: that is,fatigue damage is the main reason for the failure of the fan bearing.The research on structural stress and fatigue life is carried out for fatigue damage,which is the most dangerous fault.Firstly,3D solid modeling is carried out for the main bearing of the fan.On the basis of setting the contact and boundary conditions,combined with the central load data of the blade hub provided by the enterprise and the finite element software,the static stress analysis of the structure under the limit load is carried out to determine the load characteristics and stress distribution of the main bearing of the fan,and to identify the areas prone to dangerous load and deformation,This process can further explain the cause of bearing failure in the FMEA analysis table.Considering that not all rollers are loaded in bearing stress analysis,based on this phenomenon,the stress distribution difference of inner raceway of bearing under limit load is explored on the basis of changing working clearance of bearing,and then representative operating conditions are selected according to the operating table of wind turbine unit for load spectrum generation,combining with S-N curve,the fatigue life of bearing before and after clearance improvement is evaluated by means of fatigue analysis software.To verify the feasibility of improvement measures and provide new ideas for fault compensation in FMEA analysis table.