A squeeze film damper bearing comprises a bearing metal 2 for supporting a rotation shaft 1, a bearing casing 3 for covering the bearing metal 2 and a concentricity spring 4 between the bearing metal 2 and the bearing casing 3. The bearing casing 3 is provided at its inner periphery with a circumferential groove 3a for accommodating the spring. The spring 4 is made of an elongate steel sheet 4a and has a plurality of recesses 4b formed on a surface of the steel sheet 4a to provide a plurality of longitudinally aligned projections 4c on the other surface of the steel sheet. The steel sheet is bent into cylindrical shape. Each of the projections 4c has a curved surface with a generating line in parallel with the rotation shaft 1.

The leading edges of the segmented corrugated springs of each of the two bump foils of a hydrodynamic thrust bearing are offset such that the leading edge in the upper segmented corrugated springs are circumferentially spaced relative to the leading edge of the lower segmented corrugated springs that is underlying each respective segment of the bump foils. In some embodiments the leading edge of the bump foil is attached and the trailing edge is free to move axially and in other embodiments the reverse occurs where the trailing edge of the bump foil is attached and the leading edge is free to move axially.

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.

A hydrodynamic fluid film bearing has a stationary retaining member (12) having a cylindrical opening (14) to receive for rotation therein a rotatable shaft (16). The inner surface (20) of the opening (14) is lined by a generally cylindrical-shaped foil assembly (18) comprised of a plurality of foil sub-assemblies (24) each comprised of spring foils (26), contact foils (30) and, optionally, inner foils (32). Each foil sub-assembly (24) subtends a rotational segment, less than all, of the inner surface (20), e.g., from about 45 degrees to 120 degrees of rotation. The spring foils (26) and contact foils (30) are affixed to the retaining member (12) in such a way that sliding travel of the spring foils (26) along the inner surface (20) is in the opposite rotational direction of sliding travel of the contact foils (30) along the inner surface (20). The foil sub-assemblies (24) may be affixed to the retaining member (12) by means of keyways (22a-22e) within which the foil sub-assemblies (24) are mounted.

A cylindrical shaft including a rotor rotates within a housing. A foil bearing comprised of flexible foil segments encircles the rotor, and is located in between the rotor and the housing. The foil segments are attached to the housing, and are installed with a flexion to press against the rotor. A split ring is situated near each end of the foil bearing. Each ring is suspended in an circumferential groove in the rotor by springs which also apply a force tending to keep the ring closed. When the rings are closed, the foil segments can press against and support the rotor. The rings can be opened by respective solenoid-operated plungers to press against the foil segments and force them apart from the rotor.