US6155780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic radial flow turbine heat shield with turbine tip seal
Assignee: Capstone Green Energy Corp
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Filing: 1999-08-13
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Granted: 2000-12-05
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Expires: 2019-08-13
Abstract
Abstract A turbine engine includes a rotatable turbine having a peripheral tip and a backface. A heat shield is positioned adjacent the backface and includes an integral ring extending from a peripheral edge of the heat shield to a position spaced radially outwardly from the peripheral tip of the rotatable turbine to form a tip clearance between the ring and the peripheral tip. The turbine comprises a material having a coefficient of thermal expansion at least approximately four times greater than the coefficient of thermal expansion of the heat shield such that the turbine expands toward the ring as a result of heat within the engine, thereby reducing the tip clearance to minimize air flow along the backface and improve efficiency of the engine.
Inventors
- 👤 Gregory C. Rouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:23
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/02; F01D5/04; F01D5/043; F01D5/046; F01D11/00; F01D11/08; F01D11/14; F01D11/16; F01D11/18
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
124 words
A turbine engine comprising: a rotatable turbine having a peripheral tip and backface; and a heat shield positioned adjacent said backface and including an integral ring extending from a peripheral edge of the heat shield to a position spaced radially outwardly from the peripheral tip of the rotatable turbine to form a tip clearance between the ring and the peripheral tip; wherein said turbine comprises a material having a coefficient of thermal expansion at least approximately four times greater than the coefficient of thermal expansion of the heat shield such that the turbine expands more than the ring as a result of heat within the engine, thereby reducing the tip clearance to minimize air flow along the backface and improve efficiency of the engine.
Claim 2
Dependent Claim
124 words
A turbine engine comprising: a rotatable turbine having a peripheral tip and backface; and a heat shield positioned adjacent said backface and including an integral ring extending from a peripheral edge of the heat shield to a position spaced radially outwardly from the peripheral tip of the rotatable turbine to form a tip clearance between the ring and the peripheral tip; wherein said turbine comprises a material having a coefficient of thermal expansion at least approximately four times greater than the coefficient of thermal expansion of the heat shield such that the turbine expands more than the ring as a result of heat within the engine, thereby reducing the tip clearance to minimize air flow along the backface and improve efficiency of the engine.
Claim 3
Dependent Claim
20 words
The turbine engine of claim 1, wherein said heat shield comprises a ceramic, and said rotatable turbine comprises a metal.
Claim 4
Dependent Claim
19 words
The turbine engine of claim 2, wherein said ceramic comprises silicon nitride and said metal comprises a nickel-based alloy.
Claim 5
Dependent Claim
53 words
The turbine engine of claim 1, wherein said heat shield comprises a material having a coefficient of thermal expansion between approximately 1.4×10 -6 in/in/° F. and 0 in/in/° F. and said rotatable turbine comprises a material having a coefficient of thermal expansion between approximately 9.9×10 -6 in/in/° F. and 5.9×10 -6 in/in/° F.
Claim 6
Dependent Claim
36 words
The turbine engine of claim 1, wherein said rotatable turbine includes a knife edge extending radially outwardly from the peripheral tip to rub against the ring when the turbine expands as a result of engine heat.
Claim 7
Dependent Claim
144 words
A radial inflow turbine engine comprising: a rotatable turbine having a peripheral tip and a backface, the rotatable turbine being configured to receive heated air flowing radially inwardly toward the turbine and to redirect the heated air axially; and a heat shield positioned adjacent said backface and including an integral ring extending from a peripheral edge of the heat shield to a position spaced radially outwardly from the peripheral tip of the rotatable turbine along the entire peripheral tip to form a tip clearance between the ring and the peripheral tip; wherein said turbine comprises a metal material and said heat shield comprises a ceramic material such that the turbine expands more than the ring as a result of heat within the engine, thereby reducing the tip clearance to discourage flow of said heated air along the backface and improving efficiency of the engine.
Claim 8
Dependent Claim
144 words
A radial inflow turbine engine comprising: a rotatable turbine having a peripheral tip and a backface, the rotatable turbine being configured to receive heated air flowing radially inwardly toward the turbine and to redirect the heated air axially; and a heat shield positioned adjacent said backface and including an integral ring extending from a peripheral edge of the heat shield to a position spaced radially outwardly from the peripheral tip of the rotatable turbine along the entire peripheral tip to form a tip clearance between the ring and the peripheral tip; wherein said turbine comprises a metal material and said heat shield comprises a ceramic material such that the turbine expands more than the ring as a result of heat within the engine, thereby reducing the tip clearance to discourage flow of said heated air along the backface and improving efficiency of the engine.
Claim 9
Dependent Claim
20 words
The turbine engine of claim 6, wherein said ceramic comprises silicon nitride and said metal comprises a nickel based alloy.
Claim 10
Dependent Claim
53 words
The turbine engine of claim 6, wherein said heat shield comprises a material having a coefficient of thermal expansion between approximately 1.4×10 -6 in/in/° F. and 0 in/in/° F., and said rotatable turbine comprises a material having a coefficient of thermal expansion between approximately 9.9×10 -6 in/in/° F. and 5.9×10 -6 in/in/° F.
Claim 11
Dependent Claim
35 words
The turbine engine of claim 6, wherein said rotatable turbine includes a knife edge extending radially outward from the peripheral tip to rub against the ring when the turbine expands toward the ring under heat.
Claim 12
Dependent Claim
112 words
A radial inflow turbine engine comprising: a rotatable turbine having a peripheral tip and a backface; a heat shield positioned adjacent said backface and including an integral ring extending from a peripheral edge of the heat shield to a position spaced radially outwardly from the peripheral tip of the rotatable turbine to form a tip clearance between the ring and the peripheral tip; wherein said turbine and heat shield comprise materials having sufficiently different coefficients of thermal expansion such that the turbine expands significantly more than the heat shield as a result of engine heat, thereby reducing the tip clearance to minimize airflow along the backface and improve efficiency of the engine.
Claim 13
Dependent Claim
112 words
A radial inflow turbine engine comprising: a rotatable turbine having a peripheral tip and a backface; a heat shield positioned adjacent said backface and including an integral ring extending from a peripheral edge of the heat shield to a position spaced radially outwardly from the peripheral tip of the rotatable turbine to form a tip clearance between the ring and the peripheral tip; wherein said turbine and heat shield comprise materials having sufficiently different coefficients of thermal expansion such that the turbine expands significantly more than the heat shield as a result of engine heat, thereby reducing the tip clearance to minimize airflow along the backface and improve efficiency of the engine.
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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) | 2003-12-05 | 2004-06-05 | 2004-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-05 | 2008-06-05 | 2008-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-05 | 2012-06-05 | 2012-12-05 | $7700.00 | Window Closed / Lapsed |