Parametric Studies on Performance of Oil-Free Thrust Foil Bearings at Lower Speeds

The present work involves an experimental analysis on gas-lubricated foil thrust bearing (FTB) that has major applications in food processing units at lower operating speeds. Parametric studies include testing thrust foil bearings with various foil configurations in terms of foil thickness, foil geometry, and foil material. Novel bearing testing apparatus designed and fabricated for the purpose supported a larger diameter (224 mm) thrust foil bearing, operated at speeds ranging from 10,000 rpm to 18,000 rpm. Performance of air foil thrust bearing (AFTB) concerning static structural stiffness and load bearing capability was determined in optimizing the best foil configuration. A novel dimensionless number was formulated that emphasizes the affecting factors of thrust foil bearing with respect to axial loads.