US3735593A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ducted fans as used in gas turbine engines of the type known as fan-jets
Assignee: MINI OF AVIAT SUPPLY IN HER BR
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Filing: 1971-02-11
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Granted: 1973-05-29
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Expires: 1991-02-11
Abstract
Abstract A ducted fan having more than one blade row has bleed means adjacent the tips of the blades in at least one upstream blade row. The bleed means are preferably connected by passages to a compressor, the compressor being separate from but driven by a gas generator with which the ducted fan is combined to provide a fan jet engine. Alternative forms of the invention also have bleed means adjacent the roots of the blades in at least one upstream blade row, and there may also be bleed means adjacent the trailing edges of the blades in such rows.
Inventors
- 👤 A Howell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:26
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/04; F02C7/045; F02K; F02K3/00; F02K3/02; F02K3/04; F02K3/06; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/321; F04D29/324; F04D29/40; F04D29/52; F04D29/522; F04D29/526; F04D29/66; F04D29/68; F04D29/681; F04D29/682; F05; F05D; F05D2240/00; F05D2240/20; F05D2240/30; F05D2240/304
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
139 words
In combination with a gas turbine engine of the type known as a fan-jet engine having a gas generator, a ducted fan comprising: at least one row of rotor blades mounted on a fan rotor shaft, at least one row of stator blades, at least some of which are hollow, an annular shroud enclosing said rows of rotor and stator blades and forming a duct for the passage of air, said rotor blades and said stator blades being axially spaced apart relative to the axis of the fan rotor shaft, annular bleed means adjacent the radially outermost tips of the blades of at least one upstream blade row, and a bleed compressor having an inlet and passages extending through said hollow stator blades connecting said bleed means adjacent said radially outermost tips to said inlet of said bleed compressor.
Claim 2
Dependent Claim
139 words
In combination with a gas turbine engine of the type known as a fan-jet engine having a gas generator, a ducted fan comprising: at least one row of rotor blades mounted on a fan rotor shaft, at least one row of stator blades, at least some of which are hollow, an annular shroud enclosing said rows of rotor and stator blades and forming a duct for the passage of air, said rotor blades and said stator blades being axially spaced apart relative to the axis of the fan rotor shaft, annular bleed means adjacent the radially outermost tips of the blades of at least one upstream blade row, and a bleed compressor having an inlet and passages extending through said hollow stator blades connecting said bleed means adjacent said radially outermost tips to said inlet of said bleed compressor.
Claim 3
Dependent Claim
27 words
A ducted fan as claimed in claim 1 wherein a rotor of said bleed compressor is connected so as to be directly driven by said gas generator.
Claim 4
Dependent Claim
22 words
A ducted fan as claimed in claim 2 wherein a rotor of said bleed compressor is mounted on said fan rotor shaft.
Claim 5
Dependent Claim
22 words
A ducted fan as claimed in claim 3 wherein a rotor of said bleed compressor is mounted on said fan rotor shaft.
Claim 6
Dependent Claim
39 words
A ducted fan as claimed in claim 1 further comprising a passage forming the inlet of said bleed compressor, and a plurality of variable guide vanes in said passage whereby the flow area of said passage can be varied.
Claim 7
Dependent Claim
25 words
A ducted fan as claimed in claim 1 further comprising bleed means adjacent the trailing edges of the blades of at least one blade row.
Claim 8
Dependent Claim
161 words
In combination with a gas turbine engine of the type known as a fan-jet engine having a gas generator, a ducted fan comprising: at least one row of rotor blades mounted on a fan rotor shaft, at least one row of stator blades, at least some of which stator blades are hollow, an annular shroud enclosing said rows of rotor and stator blades and forming a duct for the passage of air, said rotor blades and said stator blades being axially spaced apart relative to the axis of the fan rotor shaft, annular bleed means adjacent the radially outermost and the radially innermost tips of the blades of at least one upstream blade row, a bleed compressor having an inlet, passages connecting said bleed means adjacent said radially innermost tips to said inlet of said bleed compressor, and passages extending through said hollow stator blades connecting said bleed means adjacent said radially outermost tips to said inlet of said bleed compressor.
Claim 9
Dependent Claim
161 words
In combination with a gas turbine engine of the type known as a fan-jet engine having a gas generator, a ducted fan comprising: at least one row of rotor blades mounted on a fan rotor shaft, at least one row of stator blades, at least some of which stator blades are hollow, an annular shroud enclosing said rows of rotor and stator blades and forming a duct for the passage of air, said rotor blades and said stator blades being axially spaced apart relative to the axis of the fan rotor shaft, annular bleed means adjacent the radially outermost and the radially innermost tips of the blades of at least one upstream blade row, a bleed compressor having an inlet, passages connecting said bleed means adjacent said radially innermost tips to said inlet of said bleed compressor, and passages extending through said hollow stator blades connecting said bleed means adjacent said radially outermost tips to said inlet of said bleed compressor.
Claim 10
Dependent Claim
36 words
A ducted fan as claimed in claim 7 wherein said gas generator has at least one compressor, and in which said bleed compressor is connected to exhaust into one of said compressors of said gas generator.
Claim 11
Dependent Claim
27 words
A ducted fan as claimed in claim 8 wherein a rotor of said bleed compressor is connected so as to be directly driven by said gas generator.
Claim 12
Dependent Claim
22 words
A ducted fan as claimed in claim 9 wherein a rotor of said bleed compressor is mounted on said fan rotor shaft.
Claim 13
Dependent Claim
22 words
A ducted fan as claimed in claim 8 wherein a rotor of said bleed compressor is mounted on said fan rotor shaft.
Claim 14
Dependent Claim
38 words
A ducted fan as claimed in 8 further comprising a passage forming the inlet of said bleed compressor, and a plurality of variable guide vanes in said passage whereby the flow area of said passage can be varied.
Claim 15
Dependent Claim
31 words
A ducted fan as claimed in claim 7 whErein said bleed means comprises an annular diffusing passage in said annular shroud, leading downstream from adjacent said radially outermost tips to atmosphere.
Claim 16
Dependent Claim
25 words
A ducted fan as claimed in claim 7 further comprising bleed means adjacent the trailing edges of the blades of at least one blade row.
References Cited (Backward Citations)
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Cited
US2618433A
Cited
US2848155A
Cited
US3447741A
Cited
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Cited
US3572960A
Cited
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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) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |