US3768933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fan for gas turbine unit
Assignee: Safran Aircraft Engines SAS
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Filing: 1971-06-17
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Granted: 1973-10-30
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Expires: 1991-06-17
Abstract
Abstract A gas turbine unit, in particular for an aircraft turbojet engine, comprises a fan rotating coaxially in front of an axial flow compressor. The fan has an outer blading ring fixed to a rim attached to a hub of the fan through an inner blading ring, and the inner blades are pivotally attached, at the root and tip ends respectively, to the hub and to the rim about pivot axes parallel to the axis of rotation of the hub. The inner blades are all inclined in the same direction and at the same angle in relation to the hub circumference. The rim can thus expand freely under the effect of the centrifugal forces applied to it in operation by the outer blading, without local distortion and without the application of any bending stresses to the inner blades.
Inventors
- 👤 J Bouiller
- 👤 L Bauger
- 👤 A Lacroix
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:44
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/02; F01D5/022; F02; F02K; F02K3/00; F02K3/02; F02K3/04; F02K3/06; F04; F04D; F04D19/00; F04D19/02; F04D19/022; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
189 words
In a gas turbine unit comprising axial-flow compressor means, a fan fitted with a hub and mounted for rotation coaxially in front of said axial compressor means, a rim mechanically connected to said hub to rotate therewith, an array of outer blading attached to said rim and extending outwardly thereof; means for rotating the fan in order that the outer blading produces an annular outer airflow surrounding the compressor means, and means for rotating the compressor means in order to compress an inner airflow passing between the hub and the rim and thus to supply combustion air to the gas turbine unit; and improved mode of mechanical connection of the rim to the hub comprising a plurality of blades each connected at its tip and root, respectively, to said rim and to said hub, for limited pivotal movement about pivot axes extending parallel to the axis of rotation of said hub, said blades all being inclined in the same direction and at the same angle in relation to the hub circumference whereby said pivoted blades can accommodate to expansion and contraction of said rim under inertial and thermal forces.
Claim 2
Dependent Claim
189 words
In a gas turbine unit comprising axial-flow compressor means, a fan fitted with a hub and mounted for rotation coaxially in front of said axial compressor means, a rim mechanically connected to said hub to rotate therewith, an array of outer blading attached to said rim and extending outwardly thereof; means for rotating the fan in order that the outer blading produces an annular outer airflow surrounding the compressor means, and means for rotating the compressor means in order to compress an inner airflow passing between the hub and the rim and thus to supply combustion air to the gas turbine unit; and improved mode of mechanical connection of the rim to the hub comprising a plurality of blades each connected at its tip and root, respectively, to said rim and to said hub, for limited pivotal movement about pivot axes extending parallel to the axis of rotation of said hub, said blades all being inclined in the same direction and at the same angle in relation to the hub circumference whereby said pivoted blades can accommodate to expansion and contraction of said rim under inertial and thermal forces.
Claim 3
Dependent Claim
63 words
A gas turbine unit as in claim 1 wherein each of said pivotally mounted blades is oriented at a setting angle selected to correspond when the unit is operating under design condition with the relative direction of said inner airflow considered in relation to said blades, whereby said blades are in a thrust-free condition, with respect to said airflow under said design conditions.
Claim 4
Dependent Claim
40 words
A gas turbine unit as claimed in claim 2, for an aircraft by-pass type gas turbine jet engine, wherein the means for driving said compressor means is a turbine and the means for driving said fan is a separate turbine.
Claim 5
Dependent Claim
58 words
A gas turbine unit as claimed in claim 3, wherein said separate turbine is adapted to drive said fan at a speed imparting to the outer blading a peripheral velocity sufficiently low as to produce a very low noise level, and the outer blading comprises a sufficient number of blades to achieve in operation a substantial compression ratio.
Claim 6
Dependent Claim
45 words
A gas turbine as in claim 4 wherein each of said pivotally mounted blades extends between said hub and said rim at an angle at least slightly inclined from a radius passing from the axis of fan rotation through a pivot axis of such blade.
Claim 7
Dependent Claim
43 words
A gas turbine as in claim 5 wherein said blades are inclined from root to tip at an angle having a direction opposite to the direction of fan rotation whereby the forces acting on said blades during fan rotation are substantially in tension.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |