The classical isoviscous hydrodynamic lubrication theory presupposes the replacement of three-dimensional viscosity existing in a lubricating oil film in actual sliding bearings by a hypothetic uniform equivalent viscosity. Due to the simplicity of processing, this theory has been used in practical designing of sliding bearings for many years. However, a speed acceleration of sliding bearings leads to minimal oil film thickness due to a decrease of e viscosity by a rise in the temperature of oil film. This results not only in a danger of seizure development, but also in a notable decrease of the strength of bearing material because of a temperature rise in a bearing. Therefore, when a sliding bearing is designed, it is necessary to predict the minimal oil film thickness and the maximal temperature on the bearing surface as accurately as possible. An accurate evaluation of the spring coefficient and the damping coefficient of an oil film requires an accurate prediction of the shape of an oil film at the static equilibrium state.
展开▼
