Abstract: A multi-stage charging device includes a shaft that is supported for rotation about an axis. The charging device also includes a first compressor wheel of a first compressor stage. The first compressor wheel is fixed on the shaft. Furthermore, the charging device includes a second compressor wheel of a second compressor stage. The second compressor wheel is fixed on the shaft. Additionally, the charging device includes a turbine wheel of a turbine section. The turbine wheel is fixed on the shaft in a back-to-back arrangement with the second compressor wheel.

Abstract: A turbomachine includes a rotating group with a turbine wheel. The turbomachine also includes a housing that houses the rotating group, wherein the housing defines a turbine outlet passage for exhaust from the turbine wheel. The turbine outlet passage is directed in a downstream direction along an axis of the turbine outlet passage. The turbomachine includes an air bearing system with at least one bearing component that supports the rotating group for rotation relative to the housing. The air bearing system includes a bearing cooling path that is fluidly connected to the at least one bearing component and that has a bearing air line outlet. The bearing air line outlet is fluidly connected to the turbine outlet passage and is directed in the downstream direction along the axis.

Abstract: A turbine section of a turbomachine includes a housing that houses and supports the rotating group for rotation about an axis. The housing defines a circumferential inlet passage that extends about the axis. The housing defines a turbine wheel upstream area that is disposed downstream of the circumferential inlet passage and upstream of the turbine wheel. The housing defines an outlet that is downstream of the turbine wheel. Furthermore, the turbine section includes a first flow path that extends from the circumferential inlet passage, through the turbine wheel upstream area, across the turbine wheel, to the outlet. Moreover, the turbine section includes a recirculation flow path that extends from the circumferential inlet passage, through the turbine wheel upstream area, and back to the circumferential inlet passage.

Abstract: A turbomachine includes a housing and a rotating group that is supported for rotation about an axis within the housing. The rotating group includes a rotor shaft, a wheel, and a fastener that clamps the wheel to the rotor shaft. The fastener is unitary and includes a head and a shank. The shank includes a piloting feature on an arcuate surface that faces radially outward with respect to the axis. The shank is received in the wheel and is attached to the rotor shaft with the piloting feature being piloted to an arcuate inner radial surface of the wheel. The head abuts an axial surface of the wheel for axially clamping the wheel to the rotor shaft.

Abstract: A compressor device includes a housing and a shaft supported for rotation within the housing. The compressor device includes a compressor section with a compressor wheel. Also, the compressor device includes a thrust suppression section with a chamber and a thrust balance body disposed within the chamber. Moreover, the compressor device includes a motor configured to drivingly rotate the shaft, the compressor wheel, and the thrust balance body. The thrust balance body divides the chamber into a first sub-chamber and a second sub-chamber. Additionally, the compressor device includes a bleed air system that fluidly connects the compressor section and the thrust suppression section. The bleed air system is configured to bleed air from the compressor section, through the first sub-chamber, to the second sub-chamber, pressurizing the first sub-chamber and generating a counterbalancing thrust load that counterbalances a compressor thrust load on the shaft.

Abstract: A turbomachine includes a rotating group with a turbine wheel. The turbomachine also includes a housing that houses the rotating group, wherein the housing defines a turbine outlet passage for exhaust from the turbine wheel. The turbine outlet passage is directed in a downstream direction along an axis of the turbine outlet passage. The turbomachine includes an air bearing system with at least one bearing component that supports the rotating group for rotation relative to the housing. The air bearing system includes a bearing cooling path that is fluidly connected to the at least one bearing component and that has a bearing air line outlet. The bearing air line outlet is fluidly connected to the turbine outlet passage and is directed in the downstream direction along the axis.

Abstract: A turbine section of a turbomachine includes a housing that houses and supports the rotating group for rotation about an axis. The housing defines a circumferential inlet passage that extends about the axis. The housing defines a turbine wheel upstream area that is disposed downstream of the circumferential inlet passage and upstream of the turbine wheel. The housing defines an outlet that is downstream of the turbine wheel. Furthermore, the turbine section includes a first flow path that extends from the circumferential inlet passage, through the turbine wheel upstream area, across the turbine wheel, to the outlet. Moreover, the turbine section includes a recirculation flow path that extends from the circumferential inlet passage, through the turbine wheel upstream area, and back to the circumferential inlet passage.

Abstract: A turbomachine includes a housing and a rotating group that is supported for rotation about an axis within the housing. The rotating group includes a rotor shaft, a wheel, and a fastener that clamps the wheel to the rotor shaft. The fastener is unitary and includes a head and a shank. The shank includes a piloting feature on an arcuate surface that faces radially outward with respect to the axis. The shank is received in the wheel and is attached to the rotor shaft with the piloting feature being piloted to an arcuate inner radial surface of the wheel. The head abuts an axial surface of the wheel for axially clamping the wheel to the rotor shaft.

Abstract: A single-stage compressor device includes a housing and a rotating group with a shaft and a compressor wheel. The compressor wheel includes a front face and a back face. The front face cooperates with the housing to define a compressor flow path. A motor drives rotation of the rotating group within the housing. Furthermore, the compressor device includes a bleed system fluidly connected to the compressor flow path and configured to receive bleed fluid from the compressor flow path. The bleed system includes a bleed passage. At least a portion of the bleed passage is cooperatively defined by the back face of the compressor wheel and an opposing surface of the housing. The bleed system is configured to pass bleed air from the bleed passage, thereby alleviating thrust loading of the compressor wheel on the rotating group.

Abstract: A single-stage compressor device includes a housing and a rotating group with a shaft and a compressor wheel. The compressor wheel includes a front face and a back face. The front face cooperates with the housing to define a compressor flow path. A motor drives rotation of the rotating group within the housing. Furthermore, the compressor device includes a bleed system fluidly connected to the compressor flow path and configured to receive bleed fluid from the compressor flow path. The bleed system includes a bleed passage. At least a portion of the bleed passage is cooperatively defined by the back face of the compressor wheel and an opposing surface of the housing. The bleed system is configured to pass bleed air from the bleed passage, thereby alleviating thrust loading of the compressor wheel on the rotating group.

Abstract: A compressor device includes a housing and a shaft supported for rotation within the housing. The compressor device includes a compressor section with a compressor wheel. Also, the compressor device includes a thrust suppression section with a chamber and a thrust balance body disposed within the chamber. Moreover, the compressor device includes a motor configured to drivingly rotate the shaft, the compressor wheel, and the thrust balance body. The thrust balance body divides the chamber into a first sub-chamber and a second sub-chamber. Additionally, the compressor device includes a bleed air system that fluidly connects the compressor section and the thrust suppression section. The bleed air system is configured to bleed air from the compressor section, through the first sub-chamber, to the second sub-chamber, pressurizing the first sub-chamber and generating a counterbalancing thrust load that counterbalances a compressor thrust load on the shaft.

Abstract: A multi-stage charging device includes a shaft that is supported for rotation about an axis. The charging device also includes a first compressor wheel of a first compressor stage. The first compressor wheel is fixed on the shaft. Furthermore, the charging device includes a second compressor wheel of a second compressor stage. The second compressor wheel is fixed on the shaft. Additionally, the charging device includes a turbine wheel of a turbine section. The turbine wheel is fixed on the shaft in a back-to-back arrangement with the second compressor wheel.