Thermohydrodynamic Lubrication Analysis Of Crankshaft Bearing Considering Crankshaft Deformation Under Load

In the unchangeable temperature lubrication analysis of bearing, the temperature of lubricant is assumed as an unchangeable value, so the factual condition of lubricant temperature in bearing can not be affected correctly and the calculating accuracy of lubrication analysis will be affected. Journal misalignment exists generally in journal bearing when working. When the shaft at high speeds, the temperature becoming high and the effect becoming more marked. So, the thermal effect must be considered in lubrication.The present lubrication analyses of misaligned journal bearing were carried out in unchangeable condition. In this paper, the temperature distributions of journal, bearing and lubricant were calculated, and the thermohydrodynamic performances of misaligned journal bearings were analyzed by solving 3-D energy equation and heat conduction. The results of compared with unchangeable temperature condition show that the thermal effect has a great effect to the lubrication performances of misaligned journal bearing.The thermohydrodynamic lubrication properties of crankshaft-bearing system considering crankshaft deformation under load for IC engine are studied based on the analysis of the themohydrodynamic of misalignment journal bearing. The results show that the thermal affect have great effect on the bearing orbit. And the thermal affect have great effect on the highest oil film pressure and minimum oil film thickness increased obviously; and have small effect on the lubricant flow-rate, journal friction coefficient. The elastic deformation haves effect on the bearing lubrication, but the effect not obviously. It's can be unconsidered.