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 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 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 turbomachine includes a housing assembly having a first housing member with a shroud surface, a bearing housing, and a second housing member. The turbomachine further includes a bearing that supports rotation of a rotating group within the housing assembly. The first housing member has a first axial surface and the bearing housing has a second axial surface that is substantially flush with the first axial surface. The second housing member has a third axial surface facing in an axial direction opposite that of the first and second axial surfaces. The first housing member has a first radial surface and the bearing housing has a second radial surface. The first housing member and the bearing housing are attached to the second housing member. The first and second axial surfaces abut against the third axial surface, and the first radial surface abutting against the second radial surface.

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.