Inlet-adjustment mechanism for turbocharger compressor, having sealing means preventing recirculation and/or oil migration into the mechanism

摘要

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.