Abstract: A turbocharger, having an axial compressor wheel and an axial turbine wheel mounted on a first shaft supported by a housing, and a radial compressor wheel and a radial turbine wheel mounted on a second shaft, the second shaft concentrically extending around the first shaft and being supported by the housing. The housing defines a first duct extending axially from the exducer of the axial compressor to the inducer of the radial compressor, and a second duct extending axially from the exducer of the radial turbine to the inducer of the axial turbine. A plurality of controllable compressor guide vanes extend through the first duct, and a plurality of controllable turbine stator vanes extend through the second duct. The housing is provided with variable diffuser vanes at the exducer of the radial compressor, and with variable turbine vanes at the inducer of the radial turbine.

Abstract: A turbocharger with a two-stage compressor having first- and second-stage impellers mounted on a common shaft in a back-to-back configuration. The first-stage impeller has a boreless configuration, defining an unthreaded pilot hole receiving an unthreaded end of the shaft so as to establish a coaxial relationship between the impeller and the shaft. The first impeller further defines a hollow cylindrical pilot member that projects from the back of the impeller and is received in a portion of the bore through the second-stage impeller to position the impellers coaxially with each other. The shaft passes through the pilot member and is externally threaded for engaging threads on the inner surface of the pilot member to secure the impellers to the shaft. The bore of the second impeller has a second portion that engages an outer cylindrical surface of the shaft to establish a coaxial relationship between the shaft and impeller.

Abstract: Methods, devices, and/or systems for controlling intake to and/or exhaust from an internal combustion engine. An exemplary method for controlling intake charge pressure to an internal combustion engine includes determining one or more control parameters based at least partially on an intake charge target pressure; and outputting the one or more control parameters to control an electric motor operatively coupled to a compressor capable of boosting intake charge pressure and to control a variable geometry actuator capable of adjusting exhaust flow to a turbine.

Abstract: A low speed high pressure ration turbocharger incorporates a compressor impeller having impeller blades for a first stage of compression mounted on a first side of the wheel and impeller blades for a second stage of compression mounted on a second side of the wheel. Driving the dual sided compressor impeller on a common shaft from the turbine wheel allows reduction in rotational speeds while increasing compression ratio of the turbine. The scroll inlet and outlet volute for the second stage inducer are integrated with the compressor housing or other portions of the turbocharger case for compact packaging.