A New Design Method of Cylindrical Bearings Based on a Simplified Thermohydrodynamic Lubrication Model

Abstract

This paper proposes a new THL bearing design method based on an improved version of a precedent method. The precedent method used a model expression prepared in advance to easily and quickly find a crucial predicted data of the maximum bearing temperature. Three expressions were prepared for three different values of journal eccentricity ratio, 0.25, 0.50, and 0.75. Which one of the three should be used was determined, based on the preliminarily obtained value of journal eccentricity ratio derived from the initially analysis and t–test, for the crucial temperature for any value of journal eccentricity ratio. Furthermore, the new expression explicitly includes the four well-known dimensionless numbers used in THL analysis, that is, Sommerfeld number, bearing width-to-dimeter ratio, Peclet number and Khonsari number. The model expressions for other bearing characteristic performances were obtained in the same way. Compared with some measurements in test rigs of cylindrical bearings, the new improved method is confirmed to predict reasonably accurate bearing performances of cylindrical bearings faster and more easily than the precedent method over a wide range of operating conditions.

Keywords

• journal bearing
• bearing design
• thermohydrodynamic lubrication theory
• bearing performance
• optimal model equation
• student’s t-test