Effect of Lubrication Status of Bearing on Crankshaft Strength

Abstract

There is direct interaction between crankshaft and bearing in an internal combustion engine. The effect of lubrication status of bearing was not considered in the present calculation of crankshaft strength. A given oil film pressure distribution of bearing was generally used as load acted on journal. In this paper, a crankshaft-bearing system was taken as the study object. On the basis of lubrication analysis of misaligned bearing caused by crankshaft deformation, the stress and strength of-crankshaft were calculated using analytical oil film pressure of bearing as the load boundary condition. Crankshaft deformation and bearing load were calculated by whole crankshaft beam-element method. The lubrication of crankshaft bearing was analyzed by the kinetics method. Crankshaft stress was calculated by the finite-element method. The results show that when the effect of crankshaft deformation under load is considered, the offset distribution of oil film pressure of bearing appears and the highest oil film pressure increases remarkably, which result in the stresses of local area on fillet surface of crankshaft journal increase obviously and the safety factor of crankshaft decreases.