Optimization Design Of Main Bearing And Bolt Connection Structure Of Large Wind Turbine

With the development of science,technology and society,energy and ecological issues are gradually paid attention to by the international community,and clean energy is gradually entering the public’s vision.Wind energy is favored by all countries in the world because of its rich resources,low cost and high conversion efficiency.Large wind turbines play an important role in the process of wind energy conversion into electricity.The three row cylindrical roller bearings and the bolt connection structure of the main wind turbine bearing are important parts in the wind turbine.But at present the design of the whole structure,there is not considering load at the same time,the performance constraints,and the problem of space volume at the same time,the design method of the original process is too complicated,but in the actual design,hope to get a conform to the requirements of the various performance and space volume optimal wind main bearing three rows of cylindrical roller bearing and bolt connection structure.In order to solve the above problem,this paper with three rows of cylindrical roller bearing and bolt connection structure to optimize the target volume,geometric size,longevity,stress and strength as constraint conditions,such as basic structure bearing and bolt parameters as optimization variables,using genetic algorithm to design this structure under complex conditions,to get the optimal solution.Specific research contents are as follows:(1)The static model of three rows of cylindrical roller bearings of wind power main bearings was established,and the contact force between the rolling body and the bearing ring was calculated.Based on the Hertz contact theory,the finite element method was used to calculate the contact stress distribution along the different roller generatrix.(2)The complex fatigue load spectrum in the wind turbine was equivalent solved,and a regular and simple load spectrum was obtained.The entire bearing life under this load spectrum was obtained according to the L-P life theory.The calculation method of bearing life under complex operating conditions were obtained,the influence of bearing clearance,roller structure parameters and generatrix shape on bearing performance and its distribution law are analyzed.(3)Based on the calculation criterion of VDI2230 bolt,the static strength and fatigue strength of the bolt were calculated by combining with the model of three-row cylindrical roller bearing and bolt connection structure.(4)The nonlinear spring integral finite element model and the single solid rolling body finite element model are established,and the load distribution and contact stress distribution of the rolling body are obtained.(5)Taking the volume of bearing and bolt as the optimization target and the performance of geometry,stress,life and strength as the constraint conditions,the genetic algorithm was used to solve the optimization model considering the effect of load.Comparing the results before and after,while meeting the performance requirements,the volume of the bearing is reduced by 18.6%,and the volume of the bolt is reduced by 27.14%,which provides a method for optimizing the design of large wind power main bearing and bolt connection structure with both performance and cost.The research work in this paper provides a feasible method for the optimal design of large wind power main bearing and bolted connection structure,and lays a foundation for the realization of low cost and high performance design of large wind power main bearing in various application conditions.