Research On The Fatigue Life Of The Bearing Of The Wind Turbine Gearbox

Wind energy has been more and more popular because of its advantages such asclean, renewable ability, large storage, and wide distribution. At the present time, newkinds of energy are being searched all around the world, which offers a good chanceto wind energy industry. The key problem for the wind turbine is to reduce failure rateduring designing and operating. Operation efficiency and generating capacity arelargely influenced by failure, which increases the cost for maintenance and replacingparts. Reliability has become one of main standards for wind turbines.The failure of the gearbox leads to the highest rates of halt among the parts inwind turbines. It is difficult to forecast fatigue life of bearings accurately in thecondition of the complex loads outside, which is one of the important factors to affectfailure of the gearbox. In order to fulfill the requirement of operating life, bearings inlarge wind turbine domestic gearboxes have to rely on import, which increasesproduction cost. So there will be great significances for the research on stress and thefatigue life of wind turbine gearbox bearings for the wind energy industry. High speedand largely variational loads lead to the indetermination for the cylindrical rollerbearings located on the high speed shaft in the gearbox. In the paper, dynamicssimulation and the analysis of fatigue life will be carried on for the bearings in thelocation.The analysis methods for fatigue life of bearings are divided into experimentalmethod and finite element analysis. The first one is more credible, however, spendingmore time and cost. Finite element analysis is used in numerical simulation to forecastthe fatigue life of bearings. Though statics or accurate dynamics simulation is widelyused in the second method, dynamics research on the whole transmission systemthrough multi-body dynamics software is less used.Combining with the actual situation of wind energy development in our country,researching on the basic life, simulation on the variational loads and forecasting thefatigue life for bearings are carried out in the paper, aiming at the key technology forthe2MW wind turbine gearbox. The main parts in the bearing are analyzed underthree kinds of conditions in ADAMS, from which dynamic load data is obtained.Stress and strain for the roller and cage in different time are showed in ANSYS. The fatigue life of the cylindrical roller bearing of wind turbine gearbox is forecasted innSoft.By using theory analysis, dynamics simulation and the fatigue life analysis, themethods for strength and fatigue life of the cylindrical roller bearing in wind turbinegearbox are discussed, which provide a certain theory reference to the design,optimization and improvement for bearings in the wind turbine gearbox.