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.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of an application filed on Jan. 22, 1999, Ser. No. 09/235,849.
This application also claims the benefit of U.S. Provisional Application filed Feb. 10, 1999, Ser. No. 60/119,581.
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 support for an axial thrust air bearing between a shaft and a housing with an annular thrust runner extending radially from the shaft having a runner bearing surface. The housing has a housing bearing surface and an air inlet in communication with a source of pressurized air. An annular foil support sleeve is disposed on the housing bearing surface, having an air foil surface with an array of foils. The foils serve to conduct air from the air inlet forming a pressurized air curtain between the runner bearing surface and foils on the the sleeve and is then disposed of through an air outlet. The sleeve has a compliant surface with at least one compliant annular ring. The compliant surface includes at least one compliant annular ring such as a fluorocarbon O-ring for low temperature service under 300.degree. F.; a fluorosilicon O-ring for mid-range temperature service 300-600.degree. F.; or a metallic mesh ring for high temperature service over 600.degree. F.
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.
