Abstract: A compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position. The inlet-adjustment mechanism includes a plurality of blades disposed about the air inlet, the blades being movable radially inwardly from an annular space of the air inlet wall, into the air inlet, so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. A noise-attenuator is disposed in the annular space, downstream of the inlet-adjustment mechanism, for attenuating aerodynamic noise induced by the inlet-adjustment mechanism when it is closed.

Abstract: A compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position. The inlet-adjustment mechanism includes a plurality of blades disposed about the air inlet, the blades being movable radially inwardly from an annular space of the air inlet wall, into the air inlet, so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. A noise-attenuator is disposed in the annular space, downstream of the inlet-adjustment mechanism, for attenuating aerodynamic noise induced by the inlet-adjustment mechanism when it is closed.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism operable to move between an open position and a closed position. The inlet-adjustment mechanism includes a plurality of blades disposed about the compressor air inlet and located between an upstream wall surface and a downstream wall surface of an annular space within the air inlet wall. The blades are pivotable about respective pivot points such that the blades extend radially inward from the annular space into the air inlet when the blades are in the closed position so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. Aerodynamic pressure balancing across the blades is achieved by spacing features that space a majority of the upstream surface of each blade from the opposing upstream wall surface.

Abstract: A turbocharger compressor includes an inlet-adjustment mechanism operable to move between an open position and a closed position. The mechanism includes a plurality of movable blades disposed about the compressor air inlet and located between an upstream wall surface and a downstream wall surface of an annular space within the air inlet wall. The blades move radially inward from the annular space into the air inlet when the blades are in the closed position so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. Recirculation of air upstream through the mechanism is prevented by a downstream blade seal. When EGR is employed, an upstream blade seal is included, preventing oil-laden air from migrating into the mechanism. The blade seals can be of various types, including O-ring seals or labyrinth seals.

Abstract: A turbocharger compressor includes an inlet-adjustment mechanism operable to move between an open position and a closed position. The mechanism includes a plurality of movable blades disposed about the compressor air inlet and located between an upstream wall surface and a downstream wall surface of an annular space within the air inlet wall. The blades move radially inward from the annular space into the air inlet when the blades are in the closed position so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. Recirculation of air upstream through the mechanism is prevented by a downstream blade seal. When EGR is employed, an upstream blade seal is included, preventing oil-laden air from migrating into the mechanism. The blade seals can be of various types, including O-ring seals or labyrinth seals.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism operable to move between an open position and a closed position. The inlet-adjustment mechanism includes a plurality of blades disposed about the compressor air inlet and located between an upstream wall surface and a downstream wall surface of an annular space within the air inlet wall. The blades are pivotable about respective pivot points such that the blades extend radially inward from the annular space into the air inlet when the blades are in the closed position so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. Aerodynamic pressure balancing across the blades is achieved by spacing features that space a majority of the upstream surface of each blade from the opposing upstream wall surface.