Paper 3: An Experimental Investigation of the Thermal Equilibrium of Steadily Loaded Journal Bearings

Abstract

In the optimum design of journal bearings it is important that the best possible estimate of the effective lubricant viscosity should be made. The temperature variation experienced by the lubricant is thus of con-siderable importance. Furthermore, the heat balance and the factors which influence the distribution of the heat produced by viscous dissipation are important when cooling characteristics are studied. This paper presents a report on the first stage of an investigation into the thermal equilibrium of steadily loaded journal bearings and an experimental investigation of temperature patterns and heat balance. The main objective of this part of the investigation was to provide background information for a theoretical analysis to be presented in a subsequent paper. The design and development of a swinging cradle type of testing machine are described, and the measure-ments of shaft torque, pressure distribution, oil flow rate, eccentricity, temperature distribution in the bush and shaft, and oil inlet and outlet temperatures have been recorded as functions of load and speed. A description of the appropriate instrumentation is also included. The essential characteristics of the experimental results are presented in graphical form and attention is drawn to several significant factors which provide the framework for subsequent theoretical analysis.