Patent ID: 8113770

Claim:
A turbine assembly for an exhaust gas-driven turbocharger having a variable nozzle, comprising: a turbine housing defining at least part of a generally annular chamber extending circumferentially about a longitudinal axis of the turbine housing, the turbine housing defining a bore extending along the longitudinal axis; a turbine wheel disposed in the turbine housing; a nozzle passage leading from the chamber radially inwardly into the turbine wheel, the nozzle passage being defined between two walls spaced apart in a longitudinal direction; and a variable nozzle assembly comprising: a stator that is fixed in a rotational sense with respect to the turbine housing and that defines a plurality of circumferentially spaced fixed vanes extending into the nozzle passage, the stator defining a bypass opening that is exposed to exhaust gas within the chamber; and a rotor that is rotational with respect to the turbine housing about the longitudinal axis, the rotor defining a bypass channel having an inlet and an outlet, the outlet being in fluid communication with the bore at a position spaced downstream from the nozzle passage with respect to flow of exhaust gas through the bore, and wherein the rotor is rotatable between a closed position in which the inlet is closed by the stator and an open position in which the inlet is aligned with the bypass opening in the stator such that exhaust gas flows from the chamber through the bypass opening and through the bypass channel into the bore, bypassing the turbine wheel.