A Study of the Lubricant Film Characteristics of Journal Bearings : Part 1, A Thermohydrodynamic Analysis with Particular Reference to the Viscosity Variation within Lubricant Film

Abstract

Recently, a precise estimation of the lubricant film characteristics of journal bearings has become necessary in designing bearings. In almost all the calculations previously performed, however, the effects of the thermal characteristics of a lubricant's viscosity and the effects of operating conditions (for example, journal eccentricity ratio, circumferential velocity and inlet temperature of a lubricant) on journal bearing performances were not taken into account because viscosity variation due to the viscosity dissipation of the lubricant film was not considered. In this paper, as the result of theoretical analysis in which the viscosity variation mentioned above was taken into account, it is shown that both the thermal characteristics of a lubricant's viscosity and the journal velocity have a great effect on the temperature and pressure distributions of the lubricant film and on the bearing load carrying capacity.