An Approximate Solution Technique for Multilobe Journal Bearings Including Thermal Effects, with Comparison to Experiment

An approximate solution method for multilobe journal bearings that includes thermal effect is presented. The method is based on the assumption of an axial pressure distribution in the form of a polynomial, which allows the solution of Reynolds' equation by a one-dimensional finite element routine with little loss in accuracy from two-dimensional methods. A first order form of the energy equation for an adiabatic film is used to predict temperatures within the bearing, and the viscosity is determined as an exponential function of temperature. Comparison of solutions obtained by the variable viscosity method to effective viscosity solutions after Lund and Thomsen illustrates discrepancies in operating eccentricity and stiffness coefficients between the two approaches. Good correlation was obtained between the variable viscosity solutions and experimental measurements reported by Tonnesen and Hansen of eccentricity, pressures, and temperatures in a two-axial groove bearing. Presented as an American Society o...