Mitsubishi Heavy Industries Limited

Mitsubishi Heavy Industries Engine & Turbocharger, Ltd.

Satomi Nagae

Takao Yokoyama

Masaki Tojo

Isao Tomita

Motoki Ebisu

Yasuaki Jinnai

Toru Kikuchi

Katsuyuki Osako

Daigo Watanabe

Michio Kyoya

Masaki Osako

An object is to is to reduce a leakage flow by reducing a clearance between an end surface of a nozzle vane, forming a variable nozzle mechanism of a variable geometry turbocharger, and a wall surface facing the end surface, and prevent the nozzle vane from being stuck due to contact of the end surface. A variable geometry turbocharger includes a nozzle shaftwhich protrudes on one of the both end surfacesof a nozzle vaneand rotatably supports the nozzle vane, a shaft holein which the nozzle shaftfits with a gap in between, a distal end surfaceof the nozzle vane with which a clearance is reduced when the nozzle vanewhich has received exhaust-gas pressure is inclined toward an inner diameter side due to a fitting gap formed between the shaft holeand the nozzle shaftfit to each other, the clearance being formed between the distal end surfaceand a wall surfaceof another one of the parallel walls, and a clearance reduction promotion portionwhich promotes reduction of the clearance with an increased inclination angle of the distal end surfaceor an increased exhaust-gas-affected surface of the nozzle vane

Variable geometry turbocharger

In a variable geometry turbocharger including a variable nozzle mechanism, an object is to enhance safety upon malfunction of the variable nozzle mechanism as well as to improve accuracy in the control of the variable nozzle mechanism by applying a moment that acts on the nozzle vanes in an opening direction securely and stably. A variable geometry turbocharger includes a plurality of nozzle vanesdisposed at predetermined intervals around a rotational shaft center of a turbine wheelso as to surround an outer circumferential side of the turbine wheeland a variable nozzle mechanism configured capable of changing a blade angle of each of the nozzle vanes, each of the nozzle vaneshaving a blade cross-section orthogonal to a nozzle shaftof each nozzle vane, the blade cross-section having: a concave portioncurved into a concave shape on at least a part of a pressure surfaceside, the part being disposed at a trailing edgeside with respect to the rotational center C; and a convex portion at a leading edgeside with respect to the rotational center C, so that a surface shape of the pressure surfaceside is a substantially S-shape having the concave portion and the convex portion across a boundary at a same longitudinal position as the rotational center.

An object is to provide a radial turbine blade that can reduce an impact loss of inflowing gas at a leading edge of the turbine blade and achieve a higher turbine efficiency, even in a case of a flow field corresponding to a low turbine operational velocity ratio U/C0 due to a throttling operation on a variable nozzle mechanism of a variable geometry turbocharger. In a radial turbine blade, a hub-side end portion Pa at a leading edgeof a turbine bladeis formed to be positioned more on a rear side in a rotation direction R of the turbine bladethan a shroud-side end portion Sc at the leading edge, and a straight line connecting between the shroud-side end portion Sc and the hub-side end portion Pa is inclined with respect to a straight line extending in a rotation axis direction from the shroud-side end portion Sc at the leading edgeonto a hubsurface by an angle in a range from 30&#xb0; to 70&#xb0; as viewed in the radial direction of the turbine blade

Radial turbine blade

The turbine housingis formed by sheet metal scroll membersandbutted opposite each other and welded together. A center core partarranged in a central part of the scroll partis integrally formed in one piece from a steel pipe member such as to include a housing portionsurrounding a turbine wheel, a bearing receiving portionaxially supporting the turbine wheel, and a plurality of circumferentially spaced supportsbridging a gap between the housing portionand the bearing receiving portion

Sheet metal turbine housing

Growing community of inventors

Tokyo, Japan

Satomi Nagae