A Theoretical Model for Microgrooved Bearings under Mixed Lubrication: Application to Partial Journal Bearings under Static Load

摘要

In designing of engine bearings for automobiles, we need to establish a mixed lubrication model that considers the asperity contact between bearings and journal surfaces. However, as far as we know, there is no literature treating such problems. This paper describes theoretical modeling for microgrooved bearings under the mixed lubrication conditions. In this modeling, the sectional shape of the microgrooved bearing was approximated to be a circular sectional shape. Contact pressure between bearings and journal surfaces was calculated using the Hertzian contact model, and the effects of elastic deformation of bearing surface due to hydrodynamic and contact pressures were considered. A numerical calculation model was developed to predict bearing performance under the mixed lubrication condition in microgrooved bearings. The simultaneous solutions of oil film thickness, hydrodynamic and contact pressure distributions, and real contact area between the bearing and journal surfaces were obtained. From the results, we found that the oil film thickness predicted by the present theory decreases about 30%-50% as compared with those by the conventional hydrodynamic lubrication theory.