Analysis of Elastohydrodynamic Lubrication of Crankshaft Bearing Considering Deformation of Engine Block and Crankshaft

Analysis of elasto-hydrodynamic lubrication of crankshaft bearings considering deformation of whole cylinder block and crankshaft under load were carried out on the crankshaft-bearing system of a fourstroke four-cylinder internal combustion engine.Lubrication of crankshaft bearing was analyzed by dynamic method.Deformation of bearing surface under pressure of oil film was calculated by deformation matrix method.The results show that when deformation of crankshaft is considered,compared with those without considering deformation of cylinder block,the maximum film pressure is decreased,the minimum film thickness is increased,and the end flow-rate and journal frictional coefficient vary little over engine working cycle when considering deformation of cylinder block.The models of whole cylinder block and single bearing house were used to calculate deformation of bearing surface.Results show that engineering calculation accuracy of elasto-hydrodynamic lubrication of crankshaft bearings can be met basically by applying the model of simple single bearing house to calculate the deformation of bearing surface.