US3825364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous abradable turbine shroud
Assignee: General Electric Co
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Filing: 1972-06-09
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Granted: 1974-07-23
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Expires: 1992-06-09
Abstract
Abstract A turbine blade tip-sealing shroud between a rotating bladed turbine and the surrounding casing of a turbojet engine is formed of substantially cylindrical inner and outer layers of porous sintered metal or similar material. The porosity of the radially inner layer is greater than the porosity of the outer layer and is adapted to withstand frictional rubbing contact with the turbine. The outer layer of the shroud is impinged by cooling air for transpiration cooling of the shroud, the amount of cooling air passed therethrough being metered by the porosity of the outer layer. The relative porosities of the two layers enable the shroud to meter the flow of cooling air to maintain this flow in spite of abrasion of the inner layer and the constriction of the pores thereof by the rotating bladed turbine.
Inventors
- 👤 E Halila
- 👤 A Sterman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:58
CPC Classifications
F; F01; F01D; F01D11/00; F01D11/08; F01D11/12; F05; F05D; F05D2260/00; F05D2260/20; F05D2260/201; F05D2260/203; Y; Y10; Y10S; Y10S165/00; Y10S165/907; Y10S165/908; Y10S277/00; Y10S277/93
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
165 words
A turbomachine comprising: a rotatable bladed turbine rotor; a casing surrounding said turbine rotor; a blade-tip sealing shroud carried by said casing and encircling said turbine rotor, said shroud including radially outer and inner layers of porous material, the porosity of the inner layer being greater than the porosity of the outer layer, and the inner layer abradable by frictional engagement with said turbine rotor; said radially outer and inner layers of porous material being formed in a single unit of sintered metal having controlled first and second porosities respectively; a plenum of air for cooling said shroud carried by said casing and surrounding said blade-tip sealing shroud; and means for delivering to said outer layer cooling air from said plenum for cooling said shroud by transpiration; and wherein the porosity of said outer layer meters a predetermined flow through said shroud of cooling air from said plenum, and the porosity of said inner layer maintains said predetermined flow despite abrasion by said turbine rotor.
Claim 2
Dependent Claim
165 words
A turbomachine comprising: a rotatable bladed turbine rotor; a casing surrounding said turbine rotor; a blade-tip sealing shroud carried by said casing and encircling said turbine rotor, said shroud including radially outer and inner layers of porous material, the porosity of the inner layer being greater than the porosity of the outer layer, and the inner layer abradable by frictional engagement with said turbine rotor; said radially outer and inner layers of porous material being formed in a single unit of sintered metal having controlled first and second porosities respectively; a plenum of air for cooling said shroud carried by said casing and surrounding said blade-tip sealing shroud; and means for delivering to said outer layer cooling air from said plenum for cooling said shroud by transpiration; and wherein the porosity of said outer layer meters a predetermined flow through said shroud of cooling air from said plenum, and the porosity of said inner layer maintains said predetermined flow despite abrasion by said turbine rotor.
Claim 3
Dependent Claim
40 words
The turbomachine of claim 1 further comprising: an apertured plate disposed between said plenum and said shroud for directing said cooling air onto said Outer layer in a plurality of spaced impinging jets, whereby said shroud is substantially evenly cooled.
Claim 4
Dependent Claim
17 words
The turbomachine of claim 1 wherein: said radially outer layer is formed of laminated wire cloth matrix.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |