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: An electric motor-driven compressor includes a housing assembly comprising a motor housing and a compressor housing mounted thereto. The compressor housing contains a centrifugal compressor wheel that is mounted on a shaft of the motor rotor and also defines an air inlet that leads air into the compressor wheel, and a volute that collects the compressed air. Air bearings rotatably support the shaft. Cooling air passages are defined in the housing assembly for supplying cooling air to the air bearings. A diffuser between the exit of the compressor wheel and the volute serves to diffuse the compressed air. The compressor includes a heat shield formed separately from the compressor housing and the motor housing and disposed between them. The heat shield defines one wall of the diffuser and also cooperates with the housing assembly to define part of the cooling air passages for the cooling air supplied to the bearings.

Abstract: A mechanism for differential pressure sealing for use in a compressor, such as for fuel cell applications, is described. In a dual-stage compressor, a low pressure side and/or a high pressure side of the dual-stage compressor may include a compressor wheel supported by a shaft that can rotate about an axis of the shaft. A seal carrier may be provided that rotates with the compressor wheel and includes a groove for receiving a sealing ring, which may be a split expansion ring. A static seal plate may be positioned around a periphery of a portion of the seal carrier, such that the sealing ring can seal against a contact surface of the static seal plate when received in the groove in order to create a pressure differential seal. The low pressure side may include one sealing ring, whereas the high pressure side may include two sealing rings positioned in series.

Abstract: A turbine or compressor wheel mounted in a housing. The wheel is carried on two radial bearings both mounted in a wall of the housing. The wall has a venting orifice that is not impeded by moving parts such as bearings. The wall also has a circular seal member extending toward a back-disk of the wheel with only a very small clearance. The seal member is composed of a material significantly softer than the material of the wheel.

Abstract: A butterfly bypass valve includes a housing defining a bypass flow passage with a pivotable throttle plate therein. An outer edge of the throttle plate in a closed position is in sealing engagement with a sealing portion of the housing such that the throttle plate restricts fluid flow through the bypass flow passage. The throttle plate is pivotable to an open position to allow fluid flow through the bypass flow passage. A port in the housing allows a portion of fluid passing through the bypass flow passage to be removed when the throttle plate is pivoted to the open position. A predetermined amount of pivoting of the throttle plate toward the open position can occur so as to allow flow through the port, while maintaining the edge of the throttle plate in substantially sealing engagement with the sealing portion so as to substantially prevent flow through the bypass passage.

Abstract: A flow-control assembly may include a fluid conduit and a flow-control valve in the fluid conduit. The flow-control assembly may further include a fluid expansion conduit with an inlet defined at least in part by the fluid conduit and configured to selectively receive flow of a fluid from the fluid conduit. The fluid expansion conduit may further include an outlet in fluid communication with the fluid conduit downstream of the flow-control valve. A rotating fluid expander in the fluid expansion conduit may be configured to expand the fluid and thereby rotate and in some embodiments generate electricity. In a first position flow is substantially blocked. In a second position flow is allowed through the fluid expansion conduit. In a third position flow through the fluid conduit is allowed without necessarily passing through the fluid expansion conduit.

Abstract: A turbomachinery device operable in either a compressor mode or a turbine mode. The device includes an impeller that rotates in the same direction in both modes, and the general flow direction remains the same in both modes. An inlet flow-guiding device may be included to direct fluid into the impeller. The impeller is coupled to a motor/generator, which operates as a motor to add power to the impeller in the compressor mode, and as a generator in the turbine mode to extract mechanical power from the impeller and convert it into electrical power. An outlet flow-guiding device may also be included. The inlet and outlet flow-guiding devices can be inlet and outlet guide vanes that are variable in setting angle or are extendable and retractable into and out of the flow path, or can be other types of flow-guiding devices.

Abstract: A single-shaft exhaust gas-driven turbocharger includes two parallel-flow first-stage centrifugal compressors in series with a single second-stage centrifugal compressor, and a one-stage turbine arranged to drive both the first- and second-stage centrifugal compressors via a single shaft on which the compressors and turbine are fixedly mounted. The compressor housing defines from one to a plurality of circumferentially spaced inlet ducts for the second wheel of the first stage, and from one to a plurality of circumferentially spaced interstage ducts leading from a vaneless diffuser of the first stage into the inlet of the second stage.

Abstract: A turbomachinery device operable in either a compressor mode or a turbine mode. The device includes an impeller that rotates in the same direction in both modes, and the general flow direction remains the same in both modes. An inlet flow-guiding device may be included to direct fluid into the impeller. The impeller is coupled to a motor/generator, which operates as a motor to add power to the impeller in the compressor mode, and as a generator in the turbine mode to extract mechanical power from the impeller and convert it into electrical power. An outlet flow-guiding device may also be included. The inlet and outlet flow-guiding devices can be inlet and outlet guide vanes that are variable in setting angle or are extendable and retractable into and out of the flow path, or can be other types of flow-guiding devices.

Abstract: A single-shaft exhaust gas-driven turbocharger includes two parallel-flow first-stage centrifugal compressors in series with a single second-stage centrifugal compressor, and a one-stage turbine arranged to drive both the first- and second-stage centrifugal compressors via a single shaft on which the compressors and turbine are fixedly mounted. The compressor housing defines from one to a plurality of circumferentially spaced inlet ducts for the second wheel of the first stage, and from one to a plurality of circumferentially spaced interstage ducts leading from a vaneless diffuser of the first stage into the inlet of the second stage.