The Effect of Pad Materials on the Limits of Operation for Tilting Pad Thrust Bearings

Abstract

The scope of this paper is to define the effect of pad materials on the limits of operation of tilting pad thrust bearings. In this paper, the Authors extend the work done by Martin on the limits of operation for steel/whitemetal bearings to other pad backing and lining materials widely used and accepted in the turbomachinery industry, such us, AlSn and PEEK for the lining and CuCr for the backing of the pad. This work has been achieved following a comprehensive experimental characterization of several different tilting pad thrust bearing sizes, with multiple pad backing/lining material options, over a wide range of speeds and loads. The Authors developed and validated a state-of-the-art thermo-elasto-hydrodynamic numerical model to predict the performance of tilting pad thrust bearings and define the limiting envelope. The numerical model couples the generalized Reynolds equation with a 3D heat transfer and structural-mechanics model of the pad, which allows to consider the effect of the pad material properties on the bearing performance. Experimental data along with numerical results reveal the effect that materials have on the limits of operation for a tilting pad thrust bearings for safe operating load and speed in hydrodynamic lubrication.