US3672169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drive engine having shrouded propeller with a variable outlet cross section
Assignee: Airbus Defence and Space GmbH
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Filing: 1970-10-05
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Granted: 1972-06-27
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Expires: 1990-10-05
Abstract
Abstract A drive engine includes a rotatable propeller with a shroud around the propeller which carries flaps which extend in the flow direction and which may be moved inwardly and outwardly for varying the shroud outlet cross section. A drive engine is operated to produce a high specific static thrust using the shrouded propeller, for example during take off, when it is in an outward position at which the discharge or outlet is expanded. For a high speed flight the outlet of the shroud is narrowed by moving the trailing ends of the flaps inwardly, for example; this accelerates the main air current inside the shroud for a great specific thrust with reduced shroud drag. In one embodiment, the mounting body for the propeller and the flaps is provided with an annular slot having an auxiliary air current feed for stabilizing potential vortices. Similar potential vortices adjacent the shroud are controlled either by the use of a separate auxiliary ring member associated with the shroud or by using a closed ring having means for discharging a fluid current in the vicinity of the vortex generation. The shroud itself may advantageously be either also provided with or alternatively provided with an annular groove for controlling any vortices in this location.
Inventors
- 👤 Erich Ufer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:42
CPC Classifications
B; B64; B64C; B64C11/00; B64C11/001
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
82 words
A shrouded propeller drive comprising a rotatable propeller, shroud means around said propeller including a shroud ring, said propeller having a streamlined hub portion which together with said ring defines a boundary over which a layer of air is moved by rotation of said propeller, means associated with said ring for varying the outlet cross section from said propeller downstream of said ring, and means adjacent said propeller for generating stabilized potential vortices to influence the air flowing over the boundary surfaces.
Claim 2
Dependent Claim
82 words
A shrouded propeller drive comprising a rotatable propeller, shroud means around said propeller including a shroud ring, said propeller having a streamlined hub portion which together with said ring defines a boundary over which a layer of air is moved by rotation of said propeller, means associated with said ring for varying the outlet cross section from said propeller downstream of said ring, and means adjacent said propeller for generating stabilized potential vortices to influence the air flowing over the boundary surfaces.
Claim 3
Dependent Claim
63 words
A shrouded propeller drive, according to claim 1, wherein said means for generating stabilized potential vortices comprises a body on which said hub portion is rotatably mounted including an outer cylindrical portion and an inner portion tapered toward said hub of said propeller, an annular recess defined between said inner tapered portion and said outer portion providing an annular slot for potential vortices.
Claim 4
Dependent Claim
47 words
A shrouded propeller drive, according to claim 1, wherein there are first and second axially spaced shroud rings separated by a flow slot therebetween, said first shroud ring having a surface tapered inwardly toward said second ring, said second ring providing means for generating a potential vortices.
Claim 5
Dependent Claim
46 words
A shrouded propeller drive, according to claim 1, wherein said means for generating a stabilized potential vortices comprises a ring-shaped tube forming said shroud ring and having a trailing edge with an annular discharge connected to said tube for the delivery of an auxiliary current therethrough.
Claim 6
Dependent Claim
28 words
A shrouded propeller drive, according to claim 1, wherein said means for generating stabilized potential vortices comprises an annular groOve formed on the trailing end of said ring.
Claim 7
Dependent Claim
69 words
A shrouded propeller drive, according to claim 1, including a nacelle mounting said propeller ahead of said nacelle for rotation, and means on said nacelle for supporting said ring in front of said nacelle, said means for varying the outlet cross section from said propeller downstream of said ring comprising a flap pivotally mounted on said ring, and means connected to said flap for moving it outwardly and inwardly.
Claim 8
Dependent Claim
26 words
A shrouded propeller drive, according to claim 1, wherein said means for varying the outlet cross section comprises at least one inwardly and outwardly movable flap.
Claim 9
Dependent Claim
26 words
A shrouded propeller drive, according to claim 1, including means for directing an auxiliary current in the vicinity of said ring for stabilizing the air flow.
Claim 10
Dependent Claim
23 words
A shrouded propeller drive, according to claim 8, including means for directing flow from the main current stream into said auxiliary current flow.
Claim 11
Dependent Claim
28 words
A shrouded propeller drive, according to claim 8, including means defining a pressure chamber in the vicinity of said ring for feeding flow energy into an auxiliary current.
Claim 12
Dependent Claim
52 words
A shrouded propeller drive, according to claim 1, including a body member rotatably supporting said propeller and having a widened portion upstream of said propeller with an annular trough defined in an end face adjacent said propeller and providing a flow area for influencing the boundary layer in front of said shroud.
Claim 13
Dependent Claim
83 words
A shrouded propeller drive, comprising a main body having a hub portion which is rotatable adjacent an end thereof, a propeller carried by said hub portion, a shroud ring surrounding said propeller, at least one annular air outlet defining a flap extending around the circumference of said ring and being pivotal on said ring between inner and outer positions, said flap extending downstream of said ring and being movable outwardly and inwardly at such location for varying the outlet opening from said ring.
Claim 14
Dependent Claim
83 words
A shrouded propeller drive, comprising a main body having a hub portion which is rotatable adjacent an end thereof, a propeller carried by said hub portion, a shroud ring surrounding said propeller, at least one annular air outlet defining a flap extending around the circumference of said ring and being pivotal on said ring between inner and outer positions, said flap extending downstream of said ring and being movable outwardly and inwardly at such location for varying the outlet opening from said ring.
Claim 15
Dependent Claim
29 words
A shrouded propeller drive, according to claim 12, wherein said main body includes a widened portion upstream of said shroud ring having an annular recessed area defining a trough.
Claim 16
Dependent Claim
32 words
A shrouded propeller drive, according to claim 13, including means for introducing a flow in the vicinity of said trough in a direction to stabilize vortices which may develop in such location.
Claim 17
Dependent Claim
37 words
A shrouded propeller drive, according to claim 12, including an auxiliary ring arranged forwardly of said shroud ring and having an axially extending tip portion spaced forwardly of said shroud ring and defining an annular opening therewith.
Claim 18
Dependent Claim
37 words
A shrouded propeller drive, according to claim 15, including means on said additional ring for pivotally supporting said flap said additional ring twirling flap portion providing means for stabilizing vortices in the vicinity of said shroud ring.
Claim 19
Dependent Claim
52 words
A shrouded propeller drive, according to claim 12, wherein said shroud ring comprises an annular duct having a fluid pressure supply and including at least one passage extending outwardly from said duct for directing a portion of the fluid pressure supply into the air stream flowing around the periphery of said propeller.
Claim 20
Dependent Claim
46 words
A shrouded propeller drive, according to claim 12, wherein said ring is arranged forwardly of said body, said body comprising a nacelle, and means in said body connected to said flap for moving said flap inwardly and outwardly to vary the outlet opening of said shroud.
Claim 21
Dependent Claim
27 words
A shrouded propeller drive, according to claim 18, wherein said ring includes an annular recess on its trailing end defining a trough for stabilizing the air flow.
Claim 22
Dependent Claim
91 words
A shrouded propeller drive, comprising rotatable propeller, a shroud ring disposed around said propeller adjacent the periphery thereof and defining with said ring an upstream inlet to said propeller, a flap connected to said ring and extending downstream therefrom and having at least a downstream portion which is pivotal radially outwardly and inwardly in respect To said shroud ring and which defines a variable dimension downstream discharge passage from said propeller, and means adjacent said propeller for generating stabilized potential vortices for stabilizing the air flow to and from said propeller.
Claim 23
Dependent Claim
91 words
A shrouded propeller drive, comprising rotatable propeller, a shroud ring disposed around said propeller adjacent the periphery thereof and defining with said ring an upstream inlet to said propeller, a flap connected to said ring and extending downstream therefrom and having at least a downstream portion which is pivotal radially outwardly and inwardly in respect To said shroud ring and which defines a variable dimension downstream discharge passage from said propeller, and means adjacent said propeller for generating stabilized potential vortices for stabilizing the air flow to and from said propeller.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |