Behavior of a Pivoted-Pad Thrust Bearing During Start-Up

Abstract

Starting tests were made on a pivoted-pad thrust bearing of 23-in. major diameter, subjected to a loading of 723 psi for various periods of time prior to start. Records of oil-film thicknesses and pressures, and of torque and individual thrust-pad loadings, showed details of the action of the bearing during torque buildup, at breakaway, and during acceleration. It was found that breakaway torques were lower than expected and were not influenced by the period of static loading prior to starting so long as the period exceeded 1 hr. The adverse effects of interruptions of the surface of the thrust-collar facing plates were shown.