Turbocharger variable-nozzle assembly with vane sealing arrangement

A turbocharger having a variable-nozzle assembly, comprising:

• a compressor housing and a compressor wheel mounted in the compressor housing and connected to a rotatable shaft, and a turbine housing and a turbine wheel mounted in the turbine housing and connected to the rotatable shaft, the turbine housing defining a chamber surrounding the turbine wheel for receiving exhaust gas from an engine and for supplying the exhaust gas through a nozzle leading from the chamber generally radially inwardly to the turbine wheel, the turbine housing further defining an axial bore;
• an insert formed separately from the turbine housing, the insert having a tubular portion received into the axial bore of the turbine housing and an annular nozzle portion joined to one end of the tubular portion and extending radially outward therefrom;
• a nozzle ring having opposite first and second faces, the nozzle being defined between the second face and the nozzle portion of the insert, the nozzle ring having a plurality of circumferentially spaced-apart bearing apertures each extending axially from the first face to the second face;
• a plurality of vanes disposed in the nozzle and each having a proximal end and a distal end, axles being joined to the proximal ends and being received into the bearing apertures of the nozzle ring and being rotatable in the bearing apertures, the distal ends of the vanes being proximate the nozzle portion of the insert, the vanes being rotatable between a closed position and an open position;
• and
• a generally annular vane sealing member formed separately from the insert and supported on the nozzle portion of the insert, the vane sealing member having a portion that is disposed between the distal ends of the vanes and the nozzle portion of the insert;
• wherein said portion of the vane sealing member is configured to contact leading and trailing edge portions of the distal ends of the vanes and to exert an axial load on the vanes tending to urge the vanes toward the nozzle ring when the vanes are in the closed position, while a clearance exists between said portion of the vane sealing member and said leading and trailing edge portions of the distal ends of the vanes when the vanes are in the open position.