STRUCTURE OF RADIAL TURBINE SCROLL

• US 20110008162A1
• Filed: 10/14/2009
• Published: 01/13/2011
• Est. Priority Date: 10/20/2008
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Yokoyama, Takao, Ebisu, Motoki, Osako, Katsuyuki
• Granted Patent: US 8,591,177 B2
• Time in Patent Office: Days
• US Class Current: 415/204
• CPC Class Codes: F01D 9/026 Scrolls for radial machines or engines
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: F05D 2260/94 Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF]
• CPC Class Codes: F05D 2260/941 particularly aimed at mechanical or thermal stress reduction

Abstract

A structure of a radial turbine scroll avoids a gas flow heading from a radially outer side toward a radially inner side in the vicinity of a tongue portion so as to restrain turbine performance from deteriorating and also reduces, to a maximum, thermal stress caused by the formation of the tongue portion. In the structure of a radial turbine scroll, an operating gas is led to flow in the radial direction from a spiral scroll formed in a turbine casing into turbine moving blades of a turbine rotor, which is positioned on the inner side of the scroll, so as to act on the turbine moving blades, and then led to flow outside in an axial direction, thereby rotatively driving the turbine rotor, wherein the scroll 4 has a partition plate 20 formed to have a length of a certain range on a line of a tongue portion formed on the inner periphery of a gas inlet portion or has a reduced height between scroll side walls at an outlet portion of a tongue portion 21 formed on the inner periphery of a gas inlet portion of the scroll, thereby avoiding a gas flow heading from the radially outer side to the radially inner side in the vicinity of the tongue portion.

Claims

1-8. -8. (canceled)

9. A structure of a radial turbine scroll in which an operating gas flows from a spiral scroll formed in a turbine casing into turbine moving blades of a turbine rotor, which is positioned on the inner side of the scroll, in a radial direction to act on the turbine moving blades, and then flows out in an axial direction, thereby rotatively driving the turbine rotor,

wherein the scroll has a partition plate formed to have a length of a certain range on a line of a tongue portion formed on the inner periphery of a gas inlet portion, said partition plate has an opening which provides communication between an upper space on the outer side and a lower space on the inner side in the radial direction of the scroll, further wherein a passage width of said opening is changed in the circumferential direction of said partition plate or in a cross-section direction from said upper space to the lower space said partition plate of the partition plate.

10. The structure of a radial turbine scroll according to claim 9,

wherein said opening that provides communication between the upper space and the lower space of said partition plate is formed such that the passage width of said opening becomes smaller toward the tongue portion along the circumferential direction.

11. The structure of a radial turbine scroll according to claim 9,

wherein a section of an end portion of the partition plate has a shape that is cut from the upper space side to the lower space side such that an opening width relative to an inner wall surface of the scroll decreases toward radial inner side.

12. The structure of a radial turbine scroll according to claim 11,

wherein the end portion of the partition plate is shaped to have an inclined surface the opening width relative to the inner wall surface of the scroll decreases toward the radial inner side.

13. The structure of a radial turbine scroll according to claim 9,

wherein the partition plate is protrusively provided on a turbine casing wall surface continuing to a shroud side of the turbine moving blades of the scroll.

14. The structure of a radial turbine scroll according to claim 10,

wherein the flow passage area of the lower space of the partition plate is reduced in the circumferential direction to induce a narrowing effect, thereby generating a gas flow from the lower space to the upper space of the partition plate.

15. The structure of a radial turbine scroll according to claim 9,

wherein the flow passage area of the lower space of the partition plate is reduced in the circumferential direction rather than reducing the flow passage area of the upper space of the partition plate, thereby restraining a gas flow from the upper space to the lower space.

16. The structure of a radial turbine scroll according to claim 9,

wherein the height between the scroll side walls at the outlet portion of the tongue portion formed on the inner periphery of the gas inlet of the scroll is reduced to decrease the sectional area of the passage at the outlet portion of the tongue portion.