Impeller, turbocharger, and method for forming flow field for gas in impeller and turbocharger

Patent metadata

Field	Value
Publication number	US-11313229-B2
Application number	US-201616082855-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Mar 31, 2016
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

A turbine wheel ( 12 ) is provided with: a disc ( 22 ) provided so as to be capable of rotating about a center axis (C); and a plurality of blades ( 23 ) provided to a disc surface ( 22 f ) at intervals in a circumferential direction, the blades ( 23 ) causing a gas guided in from radially outward leading edges ( 23 f ) to be expelled from trailing edges ( 23 r ) disposed on one side of each of the blades along the direction of the center axis (C). In each of the blades ( 23 ), in an area on one side along the direction of the center axis (C) including the trailing edge ( 23 r ), there is provided a concave surface ( 27 ) in which a positive-pressure surface ( 23 p ) on the rear side in a rotational direction (R) is recessed forward in the rotational direction (R), causing the gas to be dispersed entirely in the radial direction of the blade ( 23 ).

First claim

The invention claimed is:

1. An impeller comprising:
a disk which is formed, on one side in a central axis direction, in a disk shape having a disk front surface of a generatrix gradually going further away from a central axis toward a radially outer side as a position on the generatrix in the central axis direction goes from said one side toward the other side in the central axis direction and is rotatably provided around the central axis; and
a plurality of blades which are provided on the disk front surface at intervals in a circumferential direction around the central axis and form a flow path through which a gas introduced from a leading edge on the radially outer side about the central axis is discharged from a trailing edge on the one side in the central axis direction while being introduced into a radially inner side,
wherein a pressure surface of each blade of said plurality of blades includes, in a trailing edge region thereof including the trailing edge, a concave curved surface which is recessed toward a suction surface side,
wherein the concave curved surface is formed such that an intermediate portion between a base portion and a tip portion of the blade offsets to a front side of the blade in the rotation direction with respect to an imaginary line which connects the base portion of the blade and the tip portion of the blade, and
wherein the curvature of the concave curved surface in a cross-section viewed in the central axis direction gradually decreases as the cross-section gets closer to the trailing edge.

2. The impeller according to claim 1 ,
wherein the concave curved surface is formed in only a partial region in the central axis direction including the trailing edge of the blade.

3. A turbocharger comprising:
a rotating shaft which extends along an axis;
a turbine wheel which includes the impeller according to claim 2 and is provided on a first end portion side of the rotating shaft;
a compressor wheel which is provided on a second end portion side of the rotating shaft;
a bearing housing which rotatably supports the rotating shaft; and
a turbine housing which accommodates the turbine wheel.

4. A turbocharger comprising:
a rotating shaft which extends along an axis;
a turbine wheel which includes the impeller according to claim 1 and is provided on a first end portion side of the rotating shaft;
a compressor wheel which is provided on a second end portion side of the rotating shaft;
a bearing housing which rotatably supports the rotating shaft; and
a turbine housing which accommodates the turbine wheel.

5. The turbocharger according to claim 4 , further comprising:
a scroll flow path which is formed in the turbine housing and is continuous in a circumferential direction on the radially outer side of the turbine wheel and through which the gas rotationally driving the turbine wheel flows;
a nozzle flow path which introduces the gas from the scroll flow path toward the radially, inner side and supplies the gas to the turbine wheel; and
a vane which adjusts an introduction amount of the gas in the nozzle flow path.

6. The impeller according to claim 1 ,
wherein when the disk rotates, the gas introduced from the leading edge forms a flow field, which flows from the radially outer side toward the radially inner side in the vicinity of the trailing edge, in the flow path.

7. A method for forming a flow field for a gas in an impeller including
a disk which is formed, on one side in a central axis direction, in a disk shape having a disk front surface of a generatrix gradually going further away from a central axis toward a radially outer side as a position on the generatrix in the central axis direction goes from said one side toward the other side in the central axis direction and is rotatably provided around the central axis, and
a plurality of blades which are provided on the disk front surface at intervals in a circumferential direction around the central axis and form a flow path through which a gas introduced from a leading edge on the radially outer side about the central axis is discharged from a trailing edge on the one side in the central axis direction while being introduced into a radially inner side,
wherein a pressure surface of each blade of said plurality of blades includes, in a trailing edge region thereof including the railing edge, a concave curved surface which is recessed toward suction surface side,
wherein the concave curved surface is formed such that an intermediate portion between a base portion and a tip portion of the blade offsets to a front side of the blade in the rotation direction with respect to an imaginary line which connects the base portion of the blade and the tip portion of the blade,
wherein the curvature of the concave curved surface in a cross-section viewed in the central axis direction gradually decreases as the cross-section gets closer to the trailing edge, and wherein when the disk rotates, the gas introduced from the leading edge forms a flow field, which flows from the radially outer side toward the radially inner side in the vicinity of the trailing edge, in the flow path.

8. A method for forming the flow field for the gas in a turbocharger including
a rotating shaft which extends along an axis,
a turbine wheel which includes the impeller capable of forming the flow field according to claim 7 and is provided on a first end portion side of the rotating shaft,
a compressor wheel which is provided on a second end portion side of the rotating shaft,
a bearing housing which rotatably supports the rotating shaft,
a turbine housing which accommodates the turbine wheel,
a scroll flow path which is formed in the turbine housing and is continuous in a circumferential direction on the radially outer side of the turbine wheel and through which the gas rotationally driving the turbine wheel flows,
a nozzle flow path which introduces the gas from the scroll flow path toward the radially inner side and supplies the gas to the turbine wheel, and
a vane which adjusts an introduction amount of the gas in the nozzle flow path,
wherein, in a state ere the nozzle flow path is narrowed by the vane, when the disk rotates, the gas introduced from the leading edge forms the flow field, which flows from the radially outer side toward the radially inner side in the vicinity of the trailing edge, in the flow path.

Assignees

• Mitsubishi Heavy Ind Engine & Turbocharger Ltd

Inventors

• Yoshida Toyotaka
• Hoshi Toru
• Dammoto Yosuke
• Akiyama Yoji

Classifications

• F02B37/24

  by using pumps or turbines with adjustable guide vanes · CPC title

• F05D2220/40

  in turbochargers · CPC title

• F02C6/12

  Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure · CPC title

• F01D5/048 Primary

  Form or construction · CPC title

• F02B39/00

  Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00 · CPC title