US4422648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic faced outer air seal for gas turbine engines
Assignee: RTX Corp
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Filing: 1982-06-17
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Granted: 1983-12-27
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Expires: 2002-06-17
Abstract
Abstract Outer air seal structures of particular suitability for use in gas turbine engines are disclosed. Techniques for improving resistance to erosion while maintaining good abradability are discussed. In one particular structure the ceramic facing material of an outer air seal (30) at the leading edge region (36) is densified by a plasma gun to produce a glazed area (52) which is resistant to erosion.
Inventors
- 👤 Harry E. Eaton
- 👤 Richard C. Novak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:47
CPC Classifications
F; F01; F01D; F01D11/00; F01D11/08; F01D11/12; Y; Y10; Y10S; Y10S277/00; Y10S277/935; Y10S277/943
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
68 words
In an outer air seal of the type circumscribing the turbine rotor blades of a gas turbine engine and having a leading edge region forward of the blades, a midregion opposing the blades and a trailing edge region rearward of the blades, the improvement comprising: an abradable ceramic coating having higher surface density at the leading edge region of the seal than at the midregion of the seal.
Claim 2
Dependent Claim
68 words
In an outer air seal of the type circumscribing the turbine rotor blades of a gas turbine engine and having a leading edge region forward of the blades, a midregion opposing the blades and a trailing edge region rearward of the blades, the improvement comprising: an abradable ceramic coating having higher surface density at the leading edge region of the seal than at the midregion of the seal.
Claim 3
Dependent Claim
30 words
The invention according to claim 1 wherein said coating further has a higher surface density at the trailing edge region of the seal than at the midregion of the seal.
Claim 4
Dependent Claim
31 words
The invention according to claim 1 or 2 wherein said region of higher density extends to a depth of approximately five to ten thousandths (0.005-0.010) of an inch into the coating.
Claim 5
Dependent Claim
17 words
The invention according to claim 3 wherein said abradable ceramic coating is zirconium oxide (ZrO 2 ).
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-26 | 1987-06-27 | 1987-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-26 | 1991-06-27 | 1991-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-26 | 1995-06-27 | 1995-12-27 | $7700.00 | Window Closed / Lapsed |