Patent ID: 9695706
Date: 2017-07-04
CPC Classifications: F01D,F05D

Claim:
1. A variable nozzle turbocharger comprising: a variable nozzle mechanism for controlling a flow velocity of exhaust gas to a turbine wheel, the variable nozzle mechanism having a unison ring, a drive arm, and a plurality of variable nozzles having nozzle vanes, the unison ring configured to adjust a degree of opening of the plurality of variable nozzles through rotation of the unison ring, the unison ring having a first surface facing the variable nozzles, the first surface having a first fit-engagement groove formed in the first surface and extending from the first surface in a radial direction, the first fit-engagement groove having a closing contact side surface of a concave arcuate shape and an opening side surface of a convex arcuate shape facing the closing side surface with a fixed groove width therebetween, the drive arm having a first fit-engagement portion engaged with the first fit-engagement groove so that the first fit-engagement portion is rotatable and movable in the radial direction of the unison ring along the first fit-engagement groove; and the first fit-engagement portion having a closing side contact surface of a convex arcuate shape that is able to contact the closing side surface of the first fit-engagement groove.