VARIABLE NOZZLE UNIT AND VARIABLE GEOMETRY SYSTEM TURBOCHARGER

摘要

A base portion of the support ring includes as many joining areas as connection pins. The joining areas respectively surround pin holes through which to insert end portions of the connection pins, and are arranged in a circumferential direction of the support ring. Cuts are formed around each joining area of the support ring in order to allow deformation of an intermediate portion of the support ring relative to the joining area.

主权项

1. A variable nozzle unit configured to be placed surrounding a turbine impeller inside a turbine housing of a variable geometry system turbocharger, and capable of varying an area of a passage of an exhaust gas to be supplied to the turbine impeller, comprising:
a support ring configured to be placed inside the turbine housing, and including
an annular base portion,a cylindrical intermediate portion integrally formed on an outer peripheral edge of the base portion to project toward one side in an axial direction of the turbine impeller, andan annular tip end edge portion integrally formed on a tip end edge of the intermediate portion to project outward in a radial direction of the support ring, and held between the turbine housing and a bearing housing of the variable geometry system turbocharger; a nozzle ring integrally provided to the base portion of the support ring by joining end portions of three or more connection pins to the base portion thereof, the connection pins arranged in a circumferential direction of the base portion; a shroud ring integrally provided to the nozzle ring by joining opposite end portions of the plurality of connection pins to the shroud ring at a position away from the nozzle ring in the axial direction, and covering tip end edges respectively of a plurality of turbine blades of the turbine impeller; and a plurality of variable nozzles placed between mutually-facing surfaces of the nozzle ring and the shroud ring in a circumferential direction of the nozzle ring or the shroud ring, and capable of turning on axes thereof in forward and reverse directions, the axes being in parallel with an axis of the turbine impeller, wherein the base portion of the support ring includes as many joining areas as the connection pins, the joining areas respectively surround pin holes through which to insert the end portions of the connection pins, the joining areas are in contact with an opposite surface of the nozzle ring from the facing surface of the nozzle ring, and the joining areas are arranged in a circumferential direction of the support ring, and a cut is formed in each of parts of the support ring which are located outward of the respective joining areas in the radial direction of the support ring.