Frictional Characteristics of Tilt-Pad and Swing-Pad Thrust Bearings

This report presents frictional performance of oil-lubricated thrust bearings of conventional tilt-pad and swing-pad designs. Results from the conventional tilt-pad bearing are used as a baseline. All tests were conducted at a fixed speed and temperature, while load was varied. All bearings were tested with the pad surfaces in the centered and off-centered positions. Friction results in the hydrodynamic region compared favorably with conventional hydrodynamic theory. The hydrodynamic load capacities of the centered swing-pad bearing designs were 25 to 80 percent higher than that of the centered tilt-pad bearing. Improvements in performance were observed in the regions of hydrodynamic and mixed lubrication by off-setting the pad surfaces for both the tilt-pad and the elastomeric swing-pad designs. Breakaway friction of the laminated elastomeric swing-pad design was about 50 percent higher than that measured for either the conventional tilt-pad or hybrid-pad bearing designs.