Research On Gear Crack Of Wind Turbine Based On Thermal Analysis

The speed increase gear transmission system is the core component of the wind turbine,Once there is a failure in speed increase gear,the whole wind turbine will shut down.The gear fault occupies the main part of the gear transmission system fault,and the partial fault is the most important cause of the gear fault,including cracks,broken tooth and so on,moreover,the crack is the most difficult to identify and the most prone to happen type.Therefore,in order to avoid the production accidents of broken tooth caused by the gear crack,the research on the realated characters of gear cracks is needfulThe object of research is 1.5MW wind turbine high-speed involute gear pair because of the high speed and heavy load of high-speed class gear,the research on the influence of temperature on gear have great sense.The research on gear crack characteristics is done in this paper based on thermal analysis The main contents are as follows:The three-dimensional models are established of no-crack involute gear pair and crack involute gear pair respectively in the ANSYS environment.The cold mode analysis of two kinds of gear is done on the basis of static analysis.The research on contact characteristics and the time-varying meshing stiffness of two kinds of gear are done the influence on gear of crack is analyzed by comparing two kinds of results.The correlative discipline of the influence on gear by crack is obtained through changing the parameter of crack.Considering the influence of temperature on gear crack,the research on hot mode gear crack statics characteristics is done based on thermal analysis.Comparing with the results of cold mode analysis,the stress,strain and meshing stiffness all changed because of thermal deformation.the result indicates that the influence of hot mode gear crack on contact characteristics shows more sensibility,The analysis results more conform with the actual situation.On the basis of static analysis,the spur gear dynamics model is established by Lumped Parameter Method(LPM),considering temperature variation,the hot mode time-varying meshing stiffness calculated by finite element analysis is applied to dynamics model,the dynamic response of gear under different crack depth and different working environment is obtained by the program in MATLAB.The research on gear crack dynamic performance based on thermal analysis is done.The theoretical basis is provided for gear high-speed and stable operation by theanalysis of crack gear correlative characteristics working in normal environment,which full of profound meaning for understanding the reason why gear products vibration noise and the research on gear fault diagnosis.