Study On Lubrication Of Crankshaft Bearing Of 48V BSG Gasoline Engine

The main bearing of the engine,as the most important friction pair of the power output end,its lubrication performance directly affects the stability and reliability of the engine operation,and indirectly affects the fuel consumption.In the development process of new engine or modified engine,the lubrication performance of the main bearing in the engine system is analyzed in detail,considering the influence of various factors on lubrication,which can effectively shorten the development cycle and save the development cost,which is of great significance for the development of engine.Based on a 1.5L engine,this paper studies the lubrication of main bearing after adding 48 V BSG motor(the main research object is the first main bearing).According to the known lubrication research theory,the reduced engine model of piston,cylinder liner,connecting rod,crankshaft,cylinder block,etc.is established in AVL excite software by using the finite element analysis method and multi-body dynamics research method.The driving torque of 48 V BSG motor and the maximum lateral tension at the damping pulley of crankshaft are taken as the input boundary conditions.The variation of the main bearing’s contact pressure,rough contact pressure,minimum oil film thickness and other parameters under the starting,boosting and energy recovery conditions are simulated and analyzed to determine whether the bearing can meet the design requirements.Instead of checking the reliability of bearings,the performance of the main bearing in the comprehensive durability of the stand is verified,and whether the bearing can be applied in the project is determined.In this paper,instead of testing the temperature,contact pressure,rough contact pressure,minimum oil film thickness and other parameters at the bearing,the reliability of the bearing in the durability test is verified by replacing the test method.Instead,the test is carried out from the actual use,saving money,time and manpower for the project,and meeting the most important reliability needs for the project.Through the verification of actual durability reliability,the main bearing can meet the requirements of reliability,and the accuracy of simulation analysis can be verified in disguised form.