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US4023919A Expired / Lapsed US ⏱️ 0.0 years remaining

Thermal actuated valve for clearance control

Assignee: General Electric Co
•
Filing: 1975-10-29
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Granted: 1977-05-17
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Expires: 1995-10-29
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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 06:06
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)

US2962256A Cited
US3575528A Cited
US3736069A Cited
US3814313A Cited
US3583824A Cited
US3807891A Cited
US3825365A Cited

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

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