Turbocharger and variable-nozzle cartridge therefor

摘要

A variable-vane assembly for a turbocharger includes an annular nozzle ring (38) supporting an array of rotatable vanes (34), an insert having a tubular portion sealingly received into the bore of the turbine housing and having a nozzle portion extending radially out from one end of the tubular portion (54) and being axially spaced from the nozzle ring (38) with the vanes therebetween, and an annular retainer ring (64) disposed radially outward of the nozzle ring and extending generally radially inwardly. The nozzle ring's face is stepped, and a radially inner edge of the retainer ring (64) engages the face of the nozzle ring (38) radially outward of the step, the radially inner edge of the retainer ring having an axial thickness (t) that is less than the step height (h) such that a remaining portion of the step is presented to the exhaust gas flowing through the nozzle.