On the Static Load Performance of a Large Size, Heavily Loaded Spring Supported Thrust Bearing

Abstract

This abstract describes a thermo-elasto-hydrodynamic (TEHD) analysis for prediction of the static load performance of a large size spring-supported thrust bearing (SSTB) operating at a mean surface speed of 20 m/s and 4 MPa specific load. The bearing pads include pockets for hydraulic lift and an internal cooling system with pipes laid out along the radial direction. Pressure induced deformations significantly enlarge the film thickness at the pads’ leading and trailing edges. Pad thermal deformations are lesser, except at the pad trailing edge where cooling lines do not reach. Bearing operation transitioning from a nominal rotor speed to a low rotor speed while the bearing pads remain hot simulates a quick shut-down process. With a hot pad the predictions produce a much lesser fluid film thickness than that arising during a slow shut-down process where the bearing pads cool at a steady rate. The gradient of minimum film thickness versus rotor speed is much higher during the fast shutdown process and which could produce a sudden bearing failure (seizure).