Patent US4023919A successfully refreshed from Google Patents.
US4023919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal actuated valve for clearance control
Assignee: General Electric Co
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Filing: 1975-10-29
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Granted: 1977-05-17
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Expires: 1995-10-29
Abstract
Abstract A shroud closely surrounding a high thermal inertia rotor is provided with a support structure having low thermal inertia characteristics. The support structure is selectively exposed to different temperature mediums during transient operation by way of a thermal actuated valve so as to cause a rapid growth thereof during periods of engine acceleration and a slow shrinkage thereof during periods of deceleration of the engine. In this manner the clearance relationship between the shroud and enclosed rotor is maintained at a minimum during periods of steady-state and transitional operation to thereby increase the efficiency of the combination.
Inventors
- 👤 William R. Patterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:34
CPC Classifications
F; F01; F01D; F01D11/00; F01D11/08; F01D11/14; F01D11/20; F01D11/24; F01D11/16; F01D11/18
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
112 words
In a gas turbomachine of the type having a rotor and surrounding shroud operating over a range of temperatures and speeds, a method of maintaining a minimum allowable clearance between the rotor and the surrounding shroud during periods of transient performance, the steps comprising: a. providing a support for radially positioning the shroud in response to machine speed changes, said support having a relatively low thermal inertia; b. exposing said support to a thermal fluid flow during periods of machine acceleration to cause rapid growth of said shrowd; and c. removing the flow of thermal fluid from said support during periods of machine deceleration to cause a slow shrinkage of said shroud.
Claim 2
Dependent Claim
112 words
In a gas turbomachine of the type having a rotor and surrounding shroud operating over a range of temperatures and speeds, a method of maintaining a minimum allowable clearance between the rotor and the surrounding shroud during periods of transient performance, the steps comprising: a. providing a support for radially positioning the shroud in response to machine speed changes, said support having a relatively low thermal inertia; b. exposing said support to a thermal fluid flow during periods of machine acceleration to cause rapid growth of said shrowd; and c. removing the flow of thermal fluid from said support during periods of machine deceleration to cause a slow shrinkage of said shroud.
Claim 3
Dependent Claim
23 words
A method as set forth in claim 1 and including the step of providing fluid flow over said support during steady-state machine operation.
Claim 4
Dependent Claim
21 words
A method as set forth in claim 1 wherein said fluid flow is derived from a compressor portion of said turbomachine.
Claim 5
Dependent Claim
24 words
A method as set forth in claim 1 wherein the temperature of said thermal fluid is substantially proportional to the speed of said turbomachine.
Claim 6
Dependent Claim
30 words
A method as set forth in claim 1 wherein said removing step is accomplished by way of a thermal valve operated in response to the temperature of said thermal fluid.
Claim 7
Dependent Claim
32 words
A method as set forth in claim 1 wherein said removing step includes the step of entrapping a portion of said thermal fluid in a cavity adjacent a portion of said support.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |