A Study of Tensile Stresses in a Journal-Bearing Oil Film

Abstract

Tensile stresses of 740 kN/m² have been observed in the oil film of a steadily loaded journal bearing. A critical eccentricity ratio has been suggested below which, for a particular clearance, a tensile stress may be generated. An extensive literature survey indicates the sensitivity of the liquid's tensile strength to such factors as gas content, viscosity, particle content and the surface finish at the liquid/bearing material interface. It is suggested that previously attempted observations of liquid tensile stresses in journal bearings may have been limited by the configuration of the pressure-measuring device. The possibility of bearing Babbitt damage arising from transient and steady-state liquid tensile stresses is postulated.