an improved foil thrust bearing includes a pair of members arranged for relative rotation with respect to one another . one of the pair of members is adapted to rotatably support the other . a thrust bearing disk is operatively disposed between the pair of relatively rotatable members . the thrust bearing disk has a plurality of diverging surface ramps . the surface ramps can comprise an inner ramp and an outer ramp . the thrust bearing disk can also comprise a plurality of radial slots . a plurality of separately formed , converging surface compliant foils are disposed on the thrust bearing disk and between the ramps . an underspring element is operatively disposed between the thrust bearing disk and one of the rotatable members , with the underspring element having a plurality of alternating upper and lower ridges .