A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

A compressor cover covering a delivery fan radially outwardly discharging a fluid from an axial direction by rotating around the axis, the compressor cover comprising: a cover body including a tubular part in which a tubular inner peripheral surface along the axis and a shroud surface disposed on an axially downstream side of the tubular inner peripheral surface and expands in diameter toward the downstream side are formed; and a sleeve including an outer tube having an outer peripheral surface fitted to the tubular inner peripheral surface, an inner tube disposed on a radially inner side of the outer tube and defines a recirculation flow path in which a portion of the fluid circulates between the inner tube and the outer tube, and a plurality of struts disposed at intervals in the peripheral direction.

Turbine housing assemblies and related turbocharger systems are provided. One exemplary turbine housing assembly includes and inner shell and an outer shell. The inner shell includes an inner base portion defining an inlet and a volute portion defining an outer contour of a volute in fluid communication with the inlet. The outer shell circumscribing the volute portion in a radial plane and includes an outer base portion circumscribing the inner base portion. The inner shell includes a first plurality of sheet metal structures joined to one another in the radial plane, the outer shell includes a second plurality of sheet metal structures, and first portions of the second plurality of sheet metal structures surrounding the volute portion are joined to one another in an axial plane transverse to the radial plane.

A required opening correction amount is calculated based on a target supercharging pressure and an actual supercharging pressure, a target opening is calculated based on a required opening and the required opening correction amount, an actual operating position of a wastegate valve is determined to correspond to a fully closed position when the wastegate valve is in a fully closed condition, an actual opening of the wastegate valve is calculated based on the fully closed position and the actual operating position, an operation amount of an actuator for aligning the target opening with the actual opening is calculated based on the target opening and the actual opening, and when the target opening corresponds to the fully closed condition and the actual operating position is not decreased at or above a prescribed rate, the fully closed position is updated to the actual operating position.

A required opening correction amount is calculated based on a target supercharging pressure and an actual supercharging pressure, a target opening is calculated based on a required opening and the required opening correction amount, an actual operating position of a wastegate valve is determined to correspond to a fully closed position when the wastegate valve is in a fully closed condition, an actual opening of the wastegate valve is calculated based on the fully closed position and the actual operating position, an operation amount of an actuator for aligning the target opening with the actual opening is calculated based on the target opening and the actual opening, and when the target opening corresponds to the fully closed condition and the actual operating position is not decreased at or above a prescribed rate, the fully closed position is updated to the actual operating position.

A turbocharger includes a turbine housing defining a turbine housing interior, a turbine wheel disposed within the turbine housing interior, a shaft coupled to and rotatable by the turbine wheel, a compressor housing defining a compressor housing interior and a flow path, and a compressor wheel disposed within the compressor housing interior and coupled to the shaft. The compressor wheel has a hub coupled to the shaft, and a plurality of impeller blades extending radially from the hub. The plurality of impeller blades define an inducer end having an inducer diameter, and an exducer end having an exducer diameter greater than the inducer diameter. The inducer diameter and the exducer diameter establish a compressor trim. The compressor wheel also has a compressor wheel shroud disposed about the plurality of impeller blades. The compressor wheel shroud encloses the plurality of impeller blades to define a shroud interior.

A turbocharger includes a turbine housing defining a turbine housing interior, a turbine wheel disposed within the turbine housing interior, a shaft coupled to and rotatable by the turbine wheel, a compressor housing defining a compressor housing interior and a flow path, and a compressor wheel disposed within the compressor housing interior and coupled to the shaft. The compressor wheel has a hub coupled to the shaft, and a plurality of impeller blades extending radially from the hub. The plurality of impeller blades define an inducer end having an inducer diameter, and an exducer end having an exducer diameter greater than the inducer diameter. The inducer diameter and the exducer diameter establish a compressor trim. The compressor wheel also has a compressor wheel shroud disposed about the plurality of impeller blades. The compressor wheel shroud encloses the plurality of impeller blades to define a shroud interior.

An engine system includes an engine with a crankshaft. The crankshaft is rotatable about a crankshaft axis that is defined in a first plane. A turbocharger includes a turbine and a compressor. The turbine is configured to be driven by an exhaust gas flow from the engine and drive the compressor about a common turbocharger axis. An included angle defined between a projection of the common turbocharger axis onto the first plane and the crankshaft axis is an acute angle.

An engine system includes an engine with a crankshaft. The crankshaft is rotatable about a crankshaft axis that is defined in a first plane. A turbocharger includes a turbine and a compressor. The turbine is configured to be driven by an exhaust gas flow from the engine and drive the compressor about a common turbocharger axis. An included angle defined between a projection of the common turbocharger axis onto the first plane and the crankshaft axis is an acute angle.