The Lubrication Performance Research And Analysis Of A Diesel Engine Crankshaft Main Bearing

Energy saving and environmental protection are important research topics in the development of diesel engine.The implementation of the "National VI" motor vehicle pollutant emission standards puts forward higher requirements for energy saving and consumption reduction of diesel engines.The crankshaft has complex forces and poor working conditions during work.If the crankshaft bearing is poorly lubricated,it will directly increase the fuel consumption of the diesel engine.Therefore,this paper studies the problem of diesel engine crankshaft bearing lubrication,and proposes a lubrication performance optimization scheme based on the actual operating conditions of the locomotive and the results of simulation analysis,so that the diesel engine can meet the requirements of energy saving and environmental protection.This occupies an important position in the continuous optimization and development of diesel engines.The subject combines the bearing lubrication problem of a 16-cylinder diesel engine.Based on the AVL＿Excite software,the multi-body dynamics simulation analysis is carried out,considering multiple influence lubrication factors,combined with the orthogonal experiment method and the range method,to output a reasonable lubrication optimization plan for the crankshaft bearing of the diesel engine.Firstly,complete the construction of the multi-body dynamics model.1)The crankshaft bearing model is built by UG software.The complex structure which has little influence on the crankshaft strength is processed to ensure the mesh quality and calculation accuracy;2)Import the simplified crankshaft bearing model into Hyper Mesh software for meshing,and complete the steps of adding materials,setting constraints,and establishing main nodes;3)Import the Ansys software for crankshaft modal analysis to ensure consistent crankshaft characteristics before and after the main node is established;4)Import the crankshaft bearing file into the AVL＿Excite software,perform the steps of modal reduction,define parameters,and set boundary conditions to complete the construction of the crankshaft bearing multi-body dynamics model.Then,carry out the numerical simulation result analysis.The initial parameters of the multi-body dynamic model are set by using the important data of oil hole,oil tank,oil supply pressure and cylinder pressure curve provided by the manufacturer.After verifying the accuracy of the model,the numerical calculation of lubrication friction was carried out.The lubrication wear of crankshaft bearing is determined by observing the simulation results such as the calculated axis trajectory,minimum oil film thickness,maximum oil film pressure and pressure nephogram.Compared with the actual working condition of diesel engine,the lubrication effect of the ninth main bearing is the worst,and the simulation result is consistent with the actual working condition of crankshaft bearing.Finally,the optimization study is carried out for the ninth main bearing.Combined with the orthogonal experiment method,the factors affecting lubrication friction are designed to be tested.The range analysis is used to determine the influence weight of each factor on the lubrication performance of crankshaft bearing.Based on the orthogonal experiment simulation result output optimization parameter scheme.The simulation results of multi-body dynamics before and after parameter optimization were compared,it’s verified that the optimized scheme can greatly improve the lubrication performance of crankshaft bearings.The scheme can be used for reference in the design of the factory and solve the practical engineering problems.