Rapid and globally convergent method for dynamically loaded journal bearing design

Abstract

An approximate analytical pressure expression for dynamically loaded journal bearings is proposed. This approximation is applied to the solution of the finite journal bearing with a π-extent film. The starting and ending angular positions of the pressure curve are predicted by simple algebraic equations. The journal orbit is determined by treating it as an ‘inverse problem’ and evaluated by using the globally convergent Newton-Raphson method. To illustrate the validity of the present study, the Ruston and Hornsby big-end connecting rod bearing and an engine main bearing are analysed. The accuracy of the minimum film thickness and maximum film pressure values obtained by the proposed methodology is comparable to the more elaborate and time consuming finite element analysis, while the execution time is comparable to that required for the short bearing approximation.