Wear simulation for the journal bearings operating under aligned shaft and steady load during start-up and coast-down conditions

This paper presents a wear analysis procedure and the wear calculation of journal bearings for a stripped-down single cylinder engine during start-up and coast-down. For this analysis, we assume that a steady load is applied to the journal bearings. We utilize lift-off speed to decide whether a journal bearing is in the mixed elasto-hydrodynamic lubrication (EHL) regime. We formulate an equation for the modified film thickness in a journal bearing considering the additional wear volume. Also, we calculate journal bearing wear by using a modified specific wear rate considering the mixed lubrication regime. We show that the accumulated wear volume after 1 turn-on and off of an ignition switch is normally increasing with increasing surface roughness, with a few exceptions.