TURBOCHARGER

摘要

A variable-geometry turbocharger comprising a bearing housing which supports a turbine impeller rotatably, a turbine housing in which a scroll channel for supplying exhaust gas to the turbine impeller is formed, and an exhaust nozzle which can change the flow velocity and flow angle of the exhaust gas to be supplied from the scroll channel to the turbine impeller side, wherein the exhaust nozzle is equipped with a pair of exhaust gas introduction walls which form an exhaust gas channel, and a plurality of nozzle vanes which are arranged between the pair of exhaust gas introduction walls and supported rotatably on the periphery of the turbine impeller, and wherein the nozzle vane has a high pressure-side wall surface facing the scroll channel and is provided in such a manner that the bearing housing side of the high pressure-side wall surface is closer to the turbine impeller than the turbine housing side, and the nozzle vane moves to the turbine housing side or pushes the exhaust gas introduction wall on the turbine housing side so that the clearance between the exhaust gas introduction wall provided on the turbine housing side, out of the pair of exhaust gas introduction walls, and the nozzle vane is narrowed when the turbine impeller is rotating.