US4525998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Clearance control for gas turbine engine
Assignee: RTX Corp
•
Filing: 1982-08-02
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Granted: 1985-07-02
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Expires: 2002-08-02
Abstract
Abstract Insulation material lines the inner wall of the case of a gas turbine engine and controlled hot and/or cold air is selectively impinged on the outer wall of the case so as to maintain a minimum gap between the outer peripheral edge of the rotating blades relative to their tip seal means for increased thrust specific fuel consumption (TSFC).
Inventors
- 👤 Frederick M. Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:55
CPC Classifications
F; F01; F01D; F01D25/00; F01D25/08; F01D25/14; F01D25/145; F01D11/00; F01D11/08; F01D11/14; F01D11/20; F01D11/24; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
160 words
For a fan jet engine for powering aircraft having an engine case supporting a fan section, a compressor section, a combustion section, and a turbine section having rotating turbine blades therein, an active clearance control including a plurality of spraybars circumscribing the exterior of said case in proximity to the rotating turbine blades of one of said sections, a first source of air from said compressor section and a second source of air from said fan section, ducting means interconnecting said spraybars with said source from said fan section and said source from said compressor section, and valve means in said ducting means for selectively turning on and off either source so that one of said sources is operatively connected at a predetermined time of the flight envelope, and insulating lining means attached on the inner circumference of said engine case between said rotating blades and said spraybars for insulating the case from the heat being carried in proximity thereto.
Claim 2
Dependent Claim
160 words
For a fan jet engine for powering aircraft having an engine case supporting a fan section, a compressor section, a combustion section, and a turbine section having rotating turbine blades therein, an active clearance control including a plurality of spraybars circumscribing the exterior of said case in proximity to the rotating turbine blades of one of said sections, a first source of air from said compressor section and a second source of air from said fan section, ducting means interconnecting said spraybars with said source from said fan section and said source from said compressor section, and valve means in said ducting means for selectively turning on and off either source so that one of said sources is operatively connected at a predetermined time of the flight envelope, and insulating lining means attached on the inner circumference of said engine case between said rotating blades and said spraybars for insulating the case from the heat being carried in proximity thereto.
Claim 3
Dependent Claim
16 words
For a fan jet engine as in claim 1 wherein said spraybars circumscribe said turbine section.
Claim 4
Dependent Claim
33 words
For a fan jet engine as in claim 2 including a sheet metal sheath circumscribing said insulation lining means to hold it in contiguous relationship with the inner surface of said engine case.
References Cited (Backward Citations)
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Cited
US4101242A
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US4019320A
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US4069662A
Cited
US4213296A
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US4230439A
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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) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-01 | 1992-12-31 | 1993-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-01 | 1996-12-31 | 1997-07-02 | $7700.00 | Window Closed / Lapsed |