Abstract: A journal foil bearing includes a bearing retainer having one slot configured to receive a top foil leading edge tab and another slot configured to receive a top foil trailing edge tab. A backup support structure, integral to the bearing retainer, extends between and is at least partially defined by the slots. The retainer is configured so that, during operation, the trailing edge tab further contacts, at an increased contact pressure, the support structure at a position close to the friction force, thereby minimizing top foil bending stress and improving bearing strength.

Abstract: A radial inflow turbine may include a wheel, a first set of nozzle vanes surrounding the wheel and a second set of nozzle vanes surrounding the wheel. A first circumferential spacing between two adjacent nozzle vanes of the first set may differ from a second circumferential spacing between another two of the nozzle vanes of the first set.

Abstract: A journal foil bearing includes a bearing retainer having one slot configured to receive a top foil leading edge tab and another slot configured to receive a top foil trailing edge tab. A backup support structure, integral to the bearing retainer, extends between and is at least partially defined by the slots. The retainer is configured so that, during operation, the trailing edge tab further contacts, at an increased contact pressure, the support structure at a position close to the friction force, thereby minimizing top foil bending stress and improving bearing strength.

Abstract: A journal foil bearing includes a bearing retainer having one slot configured to receive a top foil leading edge tab and another slot configured to receive a top foil trailing edge tab. A backup support structure, integral to the bearing retainer, extends between and is at least partially defined by the slots. The retainer is configured so that, during operation, the trailing edge tab further contacts, at an increased contact pressure, the support structure at a position close to the friction force, thereby minimizing top foil bending stress and improving bearing strength.

Abstract: Embodiments of a gas turbine engine including a finger-foil seal are provided, as are embodiments of a finger-foil seal. In one embodiment, the finger-foil seal includes an aerodynamic foil having a generally annular body through which a first opening is formed. A finger seal retention structure is disposed around the aerodynamic foil. A finger seal backing spring is coupled to the finger seal retention structure and extends radially inward therefrom to contact an outer circumference of the aerodynamic foil. A first anti-rotation pin extends radially from the finger seal retention structure and into the first opening formed in the aerodynamic foil to inhibit rotation of the aerodynamic foil during operation of the finger-foil seal.

Abstract: An air bearing assembly is provided that includes a bearing sleeve that has two slots side-by-side having rectangular profiles for engaging the ends of first and second bearing foils for supporting a shaft of a dual-stage compressor. The first rectangular-profile slot, which may be made using a broaching process, is designed to receive first ends of the first bearing foil and the second bearing foil. The second rectangular-profile slot, which may also be made using a broaching process, is designed to receive a second end of the second bearing foil. This dual-slot design replaces the complex “L” shaped single slot design of conventional bearing sleeves, allowing for high-volume, low-cost manufacturing of the bearing sleeves. The dual-slot design also provides for robust engagement of the bearing foils with the bearing sleeves, while allowing easy assembly and installation of the air bearing assemblies.

Abstract: Rotor support structures including anisotropic foil bearings or anisotropic bearing housings are provided for controlling non-synchronous vibrations of rotating machinery. The rotor support structure comprises a foil bearing adapted to be disposed around a journal of a rotating rotor shaft and a bearing housing disposed around the foil bearing, wherein one of the foil bearing or the bearing housing is configured to be anisotropic. The anisotropic foil bearing and anisotropic bearing housing exhibit a stiffness in a first support direction that varies in magnitude from that in a second support direction that is substantially orthogonal to the first support direction.

Abstract: A journal foil bearing includes a bearing retainer having one slot configured to receive a top foil leading edge tab and another slot configured to receive a top foil trailing edge tab. A backup support structure, integral to the bearing retainer, extends between and is at least partially defined by the slots. The retainer is configured so that, during operation, the trailing edge tab further contacts, at an increased contact pressure, the support structure at a position close to the friction force, thereby minimizing top foil bending stress and improving bearing strength.

Abstract: A journal foil bearing includes a bearing retainer having one slot configured to receive a top foil leading edge tab and another slot configured to receive a top foil trailing edge tab. A backup support structure, integral to the bearing retainer, extends between and is at least partially defined by the slots. The retainer is configured so that, during operation, the trailing edge tab contacts the support structure at a position close to the friction force, thereby minimizing top foil bending stress and improving bearing strength.

Abstract: A turbomachine having gas cooled bearings may include an axially-oriented, cooling-gas passageway interconnecting first and second bearing chambers. The passageway may include grooves formed at an interface between an aerodynamic component of the turbomachine (e.g., a wheel or impeller) and a portion of a shaft assembly of the turbomachine.

Abstract: Embodiments of a gas turbine engine including a finger-foil seal are provided, as are embodiments of a finger-foil seal. In one embodiment, the finger-foil seal includes an aerodynamic foil having a generally annular body through which a first opening is formed. A finger seal retention structure is disposed around the aerodynamic foil. A finger seal backing spring is coupled to the finger seal retention structure and extends radially inward therefrom to contact an outer circumference of the aerodynamic foil. A first anti-rotation pin extends radially from the finger seal retention structure and into the first opening formed in the aerodynamic foil to inhibit rotation of the aerodynamic foil during operation of the finger-foil seal.

Abstract: A radial inflow turbine may include a wheel, a first set of nozzle vanes surrounding the wheel and a second set of nozzle vanes surrounding the wheel. A first circumferential spacing between two adjacent nozzle vanes of the first set may differ from a second circumferential spacing between another two of the nozzle vanes of the first set.

Abstract: Rotor support structures including anisotropic foil bearings or anisotropic bearing housings are provided for controlling non-synchronous vibrations of rotating machinery. The rotor support structure comprises a foil bearing adapted to be disposed around a journal of a rotating rotor shaft and a bearing housing disposed around the foil bearing, wherein one of the foil bearing or the bearing housing is configured to be anisotropic. The anisotropic foil bearing and anisotropic bearing housing exhibit a stiffness in a first support direction that varies in magnitude from that in a second support direction that is substantially orthogonal to the first support direction.

Abstract: A turbomachine having gas cooled bearings may include an axially-oriented, cooling-gas passageway interconnecting first and second bearing chambers. The passageway may include grooves formed at an interface between an aerodynamic component of the turbomachine (e.g., a wheel or impeller) and a portion of a shaft assembly of the turbomachine.

Abstract: A three journal bearing supported shaft with a link between two of the bearings may allow for longer spacing between the wheels supported by the shaft. The flexible shaft may move one bending critical speed below the minimum operating speed of the shaft and the next bending critical speed above the maximum operating speed of the shaft, thus extending the speed range significantly. A tie rod may be used as the link in the shaft.

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 vacuum generator seal can comprise an upstream annular cavity adjacent to the upstream side of the bearing, a downstream annular cavity adjacent to the downstream side of the bearing, and at least one drain slot positioned on the upstream side of the bearing housing. The vacuum generator seal can include a retainer that at least partially defines the upstream annular cavity. The retainer may be in contact with the bearing housing and may have a tight clearance with the impeller hub. The retainer along with a supply of grease packed within the annular cavities can seal the bearing; and the drain slot can direct water and waste away from the bearing and towards the scroll.

Abstract: A three journal bearing supported shaft with a link between two of the bearings may allow for longer spacing between the wheels supported by the shaft. The flexible shaft may move one bending critical speed below the minimum operating speed of the shaft and the next bending critical speed above the maximum operating speed of the shaft, thus extending the speed range significantly. A tie rod may be used as the link in the shaft.

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 vacuum generator seal can comprise an upstream annular cavity adjacent to the upstream side of the bearing, a downstream annular cavity adjacent to the downstream side of the bearing, and at least one drain slot positioned on the upstream side of the bearing housing. The vacuum generator seal can include a retainer that at least partially defines the upstream annular cavity. The retainer may be in contact with the bearing housing and may have a tight clearance with the impeller hub. The retainer along with a supply of grease packed within the annular cavities can seal the bearing; and the drain slot can direct water and waste away from the bearing and towards the scroll.