Abstract: 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.

Abstract: A turbine shaft may be used to remove a heat load from pliant bearings without requiring the use of a process fluid for cooling the turbine shaft. The turbine shaft comprises a heat conductive sleeve disposed between an outer surface of a tie rod shaft and an inner surface of a bearing journal; the heat conductive sleeve having a sleeve inner surface separated from a sleeve outer surface by a sleeve thickness; the heat conductive sleeve having a first end separated from a second end longitudinally about a center axis; the sleeve outer surface being in physical contact with the inner surface of the bearing journal; and the heat conductive sleeve having a thermal conductivity that is greater than a thermal conductivity of the bearing journal.

Abstract: A seal assembly for deflecting contaminated fluid flowing through the seal assembly from an upstream space to a downstream space includes an annular housing, at least one vent hole peripherally disposed on the annular housing, a first set of seals disposed within the annular housing adjacent to the downstream space, the first set of seals having an inclined surface to deflect the flow of contaminated fluid through the at least one vent hole, and a second set of seals mounted on the shaft, disposed within the annular housing, adjacent to the first set of seals and adjacent to the upstream space. The second set of seals may have larger inside diameter than the first set of seals. The seal assembly may prevent contaminated fluid from entering an air bearing cooling circuit, thereby preventing bearing wear, erosion and failure.

Abstract: A journal foil bearing comprising a retaining member having an inner surface which defines a shaft opening within which a rotatable shaft is receivable for rotation; and a foil assembly affixed to and lining the inner surface and comprising a plurality of foil sub-assemblies each subtending a circumferential segment, of the inner surface.

Abstract: 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.

Abstract: A turbine shaft may be used to remove a heat load from pliant bearings without requiring the use of a process fluid for cooling the turbine shaft. The turbine shaft comprises a heat conductive sleeve disposed between an outer surface of a tie rod shaft and an inner surface of a bearing journal; the heat conductive sleeve having a sleeve inner surface separated from a sleeve outer surface by a sleeve thickness; the heat conductive sleeve having a first end separated from a second end longitudinally about a center axis; the sleeve outer surface being in physical contact with the inner surface of the bearing journal; and the heat conductive sleeve having a thermal conductivity that is greater than a thermal conductivity of the bearing journal.

Abstract: A turbine shaft may be used to remove a heat load from pliant bearings without requiring the use of a process fluid for cooling the turbine shaft. The turbine shaft comprises a heat conductive sleeve disposed between an outer surface of a tie rod shaft and an inner surface of a bearing journal; the heat conductive sleeve having a sleeve inner surface separated from a sleeve outer surface by a sleeve thickness; the heat conductive sleeve having a first end separated from a second end longitudinally about a center axis; the sleeve outer surface being in physical contact with the inner surface of the bearing journal; and the heat conductive sleeve having a thermal conductivity that is greater than a thermal conductivity of the bearing journal.

Abstract: A foil journal bearing with a dual stiffness spring comprises a housing, a shaft arranged for relative coaxial rotation with respect to the housing, and a single spring layer surrounding the shaft. The single spring layer may have a first linear spring rate and a second linear spring rate wherein the first linear spring rate is formed by first pitch corrugations along a length of the single spring layer and the second linear spring rate is formed by second pitch corrugations along a length of the single spring layer. In an aspect of the invention, the foil journal bearing provides a top foil having first and second ends positioned in a notch in the housing. In an aspect of the invention, the single spring layer maintains a ratio of three of the second pitch corrugations to each of the first pitch corrugations.

Abstract: A journal foil bearing comprising a retaining member having an inner surface which defines a shaft opening within which a rotatable shaft is receivable for rotation; and a foil assembly affixed to and lining the inner surface and comprising a plurality of foil sub-assemblies each subtending a circumferential segment, of the inner surface.

Abstract: 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.

Abstract: A high load capacity hydrodynamic journal foil bearing system is disclosed, which comprises a top foil and a plurality of undersprings. Preload forces are transferred from the undersprings to internal circumferential compressive forces within a top foil, resulting in low preload forces against the shaft, allowing the shaft to expand at high speeds without increasing the preload forces or overloading the fluid film. One underspring may have a different spring rate than another underspring. The top foil may be normalized to shaft shape and dimensions. These features may be accomplished with using less mechanical parts than other journal foil bearing system designs.

Abstract: A turbine shaft may be used to remove a heat load from pliant bearings without requiring the use of a process fluid for cooling the turbine shaft. The turbine shaft comprises a heat conductive sleeve disposed between an outer surface of a tie rod shaft and an inner surface of a bearing journal; the heat conductive sleeve having a sleeve inner surface separated from a sleeve outer surface by a sleeve thickness; the heat conductive sleeve having a first end separated from a second end longitudinally about a center axis; the sleeve outer surface being in physical contact with the inner surface of the bearing journal; and the heat conductive sleeve having a thermal conductivity that is greater than a thermal conductivity of the bearing journal.

Abstract: A high load capacity hydrodynamic journal foil bearing system is disclosed, which comprises a top foil and a plurality of undersprings. Preload forces are transferred from the undersprings to internal circumferential compressive forces within a top foil, resulting in low preload forces against the shaft, allowing the shaft to expand at high speeds without increasing the preload forces or overloading the fluid film. One underspring may have a different spring rate than another underspring. The top foil may be normalized to shaft shape and dimensions. These features may be accomplished with using less mechanical parts than other journal foil bearing system designs.

Abstract: 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.

Abstract: 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.

Abstract: A two-spool air cycle machine includes a high pressure cooling turbine section; a low pressure cooling turbine section; and first and second shafts that are concentrically arranged and that are independently rotatable with respect to one another. A turbine wheel of the high pressure turbine section is secured to the first shaft, and a turbine wheel of the second turbine section is secured to the second shaft. Such an air cycle machine may be used a variety of different aircraft environmental control systems.

Abstract: A foil bearing allows bi-directional rotation of a shaft. The foil bearing includes a plurality of thin compliant foils secured to a housing, and spring segments underlying the foils. Each spring segment has a first stiffness profile in a first zone and a second stiffness profile in a second zone. The first stiffness profile allows rotation in one direction, and the second stiffness profile allows rotation in an opposite direction.

Abstract: The present invention provides a foil journal bearing including at least one support pad mounted inside a journal sleeve, and onto which foils are mounted. The support pad is mounted to the journal sleeve in a manner allowing it to tilt in response to foil loading variations and shaft misalignment. The present invention further provides a foil thrust bearing including at least one support pad mounted to a thrust plate and onto which the foils are mounted. The support pad is similarly mounted in a manner allowing it to tilt. The support pads in either configuration may be tapered in thickness to provide an optimized compliant backing for the foils.