Abstract: The elastohydrodynamic lubrication properties of crankshaft bearings considering crankshaft deformation under load and surface roughness for a four-cylinder internal combustion engine are studied. The lubrication of crankshaft bearing is analyzed by kinetics method. The deformation of bush surface under pressure of oil film is calculated by deformation matrix method. The results show that surface roughness has great effect on crankshaft bearing orbit, the surface deformation of bearing affects crankshaft bearing orbit little. When surface roughness of bearing is considered, the highest film pressure of crankshaft bearing increases obviously, the least film thickness decreases remarkably, and the end flow-rate changes little in most time. When elastic deformation of bearing surface is considered, the highest film pressure of bearing decreases to different extent; the influence of elastic deformation of bearing surface on the end flow-rate, journal frictional coefficient and the least film thickness is very small.

Key words: Bearing, Crankshaft, Deformation, Elastohydrodynamic, Internal combustion engine, Lubrication, Roughness surface