US3738771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor blades of rotary machines, provided with an internal cooling system
Assignee: Office National d'Études et de Recherches Aérospatiales
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Filing: 1971-07-15
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Granted: 1973-06-12
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Expires: 1991-07-15
Abstract
Abstract The cooling system is by phase transition in circulation in a closed cycle of a cooling fluid. The blade includes several closed elemental cavities, the wall of each elemental cavity including at least one continuous stria extending over its length along a helicoidal track. It is useful for aircraft gas turbine blades.
Inventors
- 👤 J Delarbre
- 👤 Grives E Le
- 👤 G Berland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:34
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/18; F01D5/181; F05; F05D; F05D2250/00; F05D2250/20; F05D2250/25; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
183 words
Rotor blade provided with an internal cooling system by phase transition and circulation in a closed cycle of a cooling fluid of which the liquid phase occupies one portion only of an internal cavity provided in the blade, the physical properties of said cooling fluid being such that it is vaporized in certain regions of said internal cavity during normal conditions of operation of the blade, said internal cavity being constituted by a plurality of closed elemental cavities, each extending from the root of the blade to its tip along substantially the average radial direction of the blade, and each elemental cavity having over its whole length a cross-section of which the contour is a rounded continuous line, and the wall of each said elemental cavity having a plurality of continuous hollow or projecting striae extending over a portion at least of the length of the elemental cavity by following helicoidal tracks, with parallel or substantially parallel turns, the average angle formed by the helicoidal track of each stria and the average radial direction of the blade being comprised between 10* and 50*.
Claim 2
Dependent Claim
183 words
Rotor blade provided with an internal cooling system by phase transition and circulation in a closed cycle of a cooling fluid of which the liquid phase occupies one portion only of an internal cavity provided in the blade, the physical properties of said cooling fluid being such that it is vaporized in certain regions of said internal cavity during normal conditions of operation of the blade, said internal cavity being constituted by a plurality of closed elemental cavities, each extending from the root of the blade to its tip along substantially the average radial direction of the blade, and each elemental cavity having over its whole length a cross-section of which the contour is a rounded continuous line, and the wall of each said elemental cavity having a plurality of continuous hollow or projecting striae extending over a portion at least of the length of the elemental cavity by following helicoidal tracks, with parallel or substantially parallel turns, the average angle formed by the helicoidal track of each stria and the average radial direction of the blade being comprised between 10* and 50*.
Claim 3
Dependent Claim
15 words
Blade according to claim 1, wherein the said angle is comprised between 20* and 35*.
Claim 4
Dependent Claim
67 words
Blade according to claim 1, wherein each stria defines a flat path oriented substantially perpendicularly to the average radial direction of the blade and turned towards the foot of the blade, the width of this flat path being comprised between 1/10 and 5/10mm, the number of striae being then such that the separation of two successive flat paths is comprised between two and five times their width.
Claim 5
Dependent Claim
27 words
Blade according to claim 1, wherein, in eacH elemental cavity, the residual pressure of the uncondensable gases is reduced to a value less than 10 5 Torr.
Claim 6
Dependent Claim
64 words
Blade according to claim 1, for mounting on a turbine whose wheel is cooled by an internal circulation of a secondary cooling fluid, and wherein the foot of the blade is extended in the direction of the axis of rotation of the wheel by a cooling device with fins, each of the elemental cavities of said blade being extended into said finned cooling device.
Claim 7
Dependent Claim
21 words
Blade according to claim 1, wherein the contour of the cross section of each elemental cavity is circular or substantially circular.
Claim 8
Dependent Claim
33 words
Blade according to claim 1, wherein the contour of the cross section of each elemental cavity has three of four sides, rectilinear or substantially rectilinear, connected between themselves by portions with rounded curves.
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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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |