A thrust bearing designed to support a rotational shaft within a turbo compressor, and including foils subjected to a friction with gas. The bearing includes a plurality of elastic foils having different stiffnesses from each other.

A compliant foil fluid thrust bearing has a single sided or two sided thrust disk rotor, an integrally formed compliant foil member, and an underspring member. The non-rotating but compliant foils are located adjacent to the thrust face or faces or the rotatable disk and are formed as arcuate segments on washer-shaped disk members. The underspring member consists of three washer-shaped disk elements that together provide variable spring stiffness in both the circumferential and radial directions.

A hydrodynamic bearing set, for use with a thrust disk disposed between planar surfaces of a housing, includes first and second topfoils disposed adjacent first and second thrust disk axial bearing surfaces and removably secured to the housing. An underspring is secured between each planar housing surface and the corresponding topfoil. Dual-leaf spring pairs attached to at least one topfoil periphery function to urge the topfoils away from the thrust disk axial bearing surfaces by applying a force against a planar housing surface, another topfoil, or a spacer washer secured between adjacent topfoil dual-leaf pairs or frictionally retained within the housing. Alternatively, a wavy washer, a conical spring, a Belleville washer, or a coil spring can be substituted for the dual-leaf spring pairs.

A compliant hydrodynamic fluid film journal bearing for handling high loads. The bearing assembly includes a first thin smooth compliant sheet for facing a shaft, one or more corrugated foils, and a second sheet between the foils and the compliant sheet for supportedly underlying the compliant sheet for preventing sagging of the first sheet between ridges of the foils. A foil element is anchored at a position intermediate its ends to the bearing sleeve whereby both ends thereof are unanchored. A pair of radially outer and inner corrugated foils have outer foil ridges which underlie some inner foil ridges and outer foil furrows which underlie others of the inner foil ridges. A bearing assembly includes a plurality of rows of corrugated foil elements wherein ends of foil elements are offset circumferentially from ends of foil elements in adjacent rows symmetrically from the radial centerplane to provide a herringbone pattern effect. At least some ridges on at least one of inner and outer corrugated foils have truncated apex portions.

An improved foil thrust bearing includes a cooling fluid flow turbulence generating disk placed between other foil thrust bearing elements, such as thrust bearing elements and underspring elements. The inventive turbulence generating disk generally provides improved transfer of heat through the foil and into the cooling fluid of foil thrust bearings that may be used for high rotor speed applications. It accomplishes this by improving the transfer of heat through the foil and into the cooling fluid by generating turbulent cooling flow adjacent to the back of the top foil. The turbulent flow is generated primarily by a series of turns or protrusions introduced into the cooling flow stream. Alternate embodiments are disclosed that provide the turbulence generating elements as part of the underside of thrust bearing elements.