Axial Turbine With Meridionally Divided Turbine Housing

• US 20140219836A1
• Filed: 02/01/2013
• Published: 08/07/2014
• Est. Priority Date: 02/01/2013
• Status: Active Grant

• Current Assignee: Garrett Transportation I Inc. (Garrett Motion, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Kares, Vaclav, Houst, Vit
• Granted Patent: US 9,631,625 B2
• Time in Patent Office: Days
• US Class Current: 417/406
• CPC Class Codes: F01D 1/023 the working-fluid being divided into several separate flows F01D3/02 takes precedence; several separate fluid flows being united in a single flow; the machine or engine having provision for two or more different possible fluid flow paths
• CPC Class Codes: F01D 9/026 Scrolls for radial machines or engines
• CPC Class Codes: F02B 37/025 Multiple scrolls or multiple gas passages guiding the gas to the pump drive
• CPC Class Codes: F02C 3/28 using a separate gas producer for gasifying the fuel before combustion
• CPC Class Codes: F02C 3/34 with recycling of part of the working fluid, i.e. semi-closed cycles with combustion products in the closed part of the cycle
• CPC Class Codes: F02C 6/12 Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure
• CPC Class Codes: F02C 7/08 Heating air supply before combustion, e.g. by exhaust gases
• CPC Class Codes: F04D 25/04 the pump being fluid-driven pumps driven by exhaust gases F02B37/00, F02B39/00; turbochargers F02C6/12
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A statorless axial turbine for a turbocharger has a turbine housing assembly defining a meridionally divided scroll extending circumferentially and surrounding the turbine wheel, the meridionally divided scroll defining a first scroll extending substantially fully about the turbine wheel and a separate second scroll extending substantially fully about the turbine wheel. The turbine housing assembly defines a separate inlet for each of the first and second scrolls through which a separate exhaust gas stream is received, and separate first and second outlets for each of the first and second scrolls, respectively, through which the respective exhaust gas streams are fed into an inlet side of the turbine wheel generally in an axial direction of the turbine wheel.

Claims

1. An axial turbine for an exhaust-gas-driven turbocharger, the turbine having no inlet stator, and comprising:

an axial turbine wheel comprising a hub and a plurality of blades extending generally radially outward from the hub; and

a turbine housing assembly in which the turbine wheel is mounted, the turbine housing assembly comprising a turbine housing that defines a meridionally divided scroll extending circumferentially and surrounding the turbine wheel, the meridionally divided scroll defining a first scroll extending substantially fully about the turbine wheel and a separate second scroll extending substantially fully about the turbine wheel;

the turbine housing assembly defining a separate inlet for each of the first and second scrolls through which separate exhaust gas streams are received;

the turbine housing assembly defining separate first and second outlets for each of the first and second scrolls, respectively, through which the respective exhaust gas streams are fed into an inlet side of the turbine wheel.

2. The axial turbine of claim 1, wherein the first and second outlets are configured so that the respective exhaust gas streams are fed generally in an axial direction into the turbine wheel, and so that the first outlet is generally radially outward of the second outlet such that the exhaust gas from the first outlet is fed to a radially outer portion of the inlet side of the turbine wheel and the exhaust gas from the second outlet is fed to a radially inner portion of the inlet side of the turbine wheel.

3. The axial turbine of claim 2, wherein the turbine housing assembly defines a circumferentially and radially extending dividing wall that separates the first scroll from the second scroll, the first outlet being defined in part by a radially inner portion of the dividing wall and the second outlet being defined in part by the radially inner portion of the dividing wall.

4. The axial turbine of claim 3, wherein the radially inner portion of the dividing wall is curved so that a radially inner end thereof extends generally in the axial direction.

5. The axial turbine of claim 4, wherein the turbine housing assembly defines a wall spaced radially inwardly of the radially inner portion of the dividing wall, the second outlet being defined between said wall and the radially inner portion of the dividing wall.

6. The axial turbine of claim 5, wherein the turbine housing assembly comprises the turbine housing and a separately formed heat shroud, wherein the heat shroud defines said wall.

7. The axial turbine of claim 6, wherein the heat shroud is a formed sheet metal part.

8. The axial turbine of claim 6, wherein the heat shroud is curved similar to the radially inner portion of the dividing wall such that a radially inner end of the heat shroud extends generally in the axial direction.

9. The axial turbine of claim 8, wherein the radially inner end of the heat shroud is at a radial location corresponding to a radially inner end of a leading edge of the blades.

10. The axial turbine of claim 6, wherein the radially inner portion of the dividing wall is part of a dividing member that is a separately formed part from the turbine housing.

11. The axial turbine of claim 10, wherein the heat shroud defines a plurality of circumferentially spaced support members that extend axially and engage the dividing member to position the dividing member axially with respect to the heat shroud.

12. The axial turbine of claim 5, wherein the first outlet is defined between the radially inner portion of the dividing wall and a tip shroud of the turbine housing assembly, the tip shroud and the hub of the turbine wheel together bounding a flow path for the exhaust gases through the turbine wheel.

13. A turbocharger, comprising:

an axial turbine, the axial turbine having no inlet stator, and comprising;

an axial turbine wheel comprising a hub and a plurality of blades extending generally radially outward from the hub; and

a turbine housing assembly in which the turbine wheel is mounted, the turbine housing assembly comprising a turbine housing that defines a meridionally divided scroll extending circumferentially and surrounding the turbine wheel, the meridionally divided scroll defining a first scroll extending substantially fully about the turbine wheel and a separate second scroll extending substantially fully about the turbine wheel;

the turbine housing assembly defining a separate inlet for each of the first and second scrolls through which separate exhaust gas streams are received;

the turbine housing assembly defining separate first and second outlets for each of the first and second scrolls, respectively, through which the respective exhaust gas streams are fed into an inlet side of the turbine wheel;

a compressor comprising a compressor wheel mounted in a compressor housing, the compressor housing defining a compressor discharge scroll receiving pressurized air from the compressor wheel;

a shaft having one end affixed to the compressor wheel and an opposite end affixed to the turbine wheel; and

a center housing assembly connected between the turbine housing assembly and the compressor housing, the center housing assembly containing bearings for the shaft.

14. The turbocharger of claim 13, wherein the first and second outlets are configured so that the respective exhaust gas streams are fed generally in an axial direction into the turbine wheel, and so that the first outlet is generally radially outward of the second outlet such that the exhaust gas from the first outlet is fed to a radially outer portion of the inlet side of the turbine wheel and the exhaust gas from the second outlet is fed to a radially inner portion of the inlet side of the turbine wheel

15. The turbocharger of claim 14, wherein the turbine housing defines a circumferentially and radially extending dividing wall that separates the first scroll from the second scroll, the first outlet being defined in part by a radially inner portion of the dividing wall and the second outlet being defined in part by the radially inner portion of the dividing wall.

16. The turbocharger of claim 15, wherein the radially inner portion of the dividing wall is curved so that a radially inner end thereof extends generally in the axial direction.

17. The turbocharger of claim 16, wherein the turbine housing assembly defines a wall spaced radially inwardly of the radially inner portion of the dividing wall, the second outlet being defined between said wall and the radially inner portion of the dividing wall.

18. The turbocharger of claim 17, wherein the turbine housing assembly comprises the turbine housing and a separately formed heat shroud, wherein the heat shroud defines said wall.

19. The turbocharger of claim 18, wherein the heat shroud is a formed sheet metal part.

20. The turbocharger of claim 18, wherein the heat shroud is curved similar to the radially inner portion of the dividing wall such that a radially inner end of the heat shroud extends generally in the axial direction.

21. The turbocharger of claim 20, wherein the radially inner end of the heat shroud is at a radial location corresponding to a radially inner end of a leading edge of the blades.

22. The turbocharger of claim 17, wherein the first outlet is defined between the radially inner portion of the dividing wall and a tip shroud of the turbine housing assembly, the tip shroud and the hub of the turbine wheel together bounding a flow path for the exhaust gases through the turbine wheel.