US3866416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel control apparatus for gas turbine engine
Assignee: Northrop Grumman Properties Ltd
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Filing: 1973-04-06
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Granted: 1975-02-18
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Expires: 1993-04-06
Abstract
Abstract A fuel control apparatus for a gas turbine engine having first, second and third burners has first, second and third variable metering orifices for controlling fuel flow to the respective burners. The first metering orifice is responsive to first and second engine operating parameters, as for example inlet temperature and compressor outlet pressure, and the second and third metering orifices are responsive to the position of the first metering orifice and to a third engine operating parameter, as for example the angle of an engine control lever.
Inventors
- 👤 Geoffrey Arthur Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:47
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/22; F02C7/228
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
184 words
A fuel control apparatus for a gas turbine engine reheat system having a plurality of reheat burners, comprising a pump, a first control means means for imparting first and second motions to said first control means in response to variations in an engine temperature and an engine compressor pressure respectively, said first control means comprises a compound cam having a plurality of profiles which correspond to functions of said engine temperature for a plurality of values of said compressor pressure, a first variable metering orifice including a control member responsive only to said first and second motions of said first control means to regulate fuel flow from said pump to a first reheat burner, a second control means positioned in response to the setting of an engine power demand device, and second and third variable metering orifices each including a control member responsive to said first and second motions of said first control means and to the position of said second control means, said second and third orifices regulating, in use, fuel flow from said pump to said second and third reheat burners respectively.
Claim 2
Dependent Claim
184 words
A fuel control apparatus for a gas turbine engine reheat system having a plurality of reheat burners, comprising a pump, a first control means means for imparting first and second motions to said first control means in response to variations in an engine temperature and an engine compressor pressure respectively, said first control means comprises a compound cam having a plurality of profiles which correspond to functions of said engine temperature for a plurality of values of said compressor pressure, a first variable metering orifice including a control member responsive only to said first and second motions of said first control means to regulate fuel flow from said pump to a first reheat burner, a second control means positioned in response to the setting of an engine power demand device, and second and third variable metering orifices each including a control member responsive to said first and second motions of said first control means and to the position of said second control means, said second and third orifices regulating, in use, fuel flow from said pump to said second and third reheat burners respectively.
Claim 3
Dependent Claim
40 words
An apparatus as claimed in claim 1 in which said means for imparting said first motion comprises means for rotating said cam about its axis, and said means for imparting said second motion comprises means for moving said cam axially.
Claim 4
Dependent Claim
46 words
An apparatus as claimed in claim 2 in which said means responsive to said engine temperature comprises a first piston coacting with said cam and a first servo valve arrangement responsive to said first parameter to provide first servo pressure signals to position said first piston.
Claim 5
Dependent Claim
54 words
An apparatus as claimed in claim 3 which includes means responsive to the angular position of said cam for generating a first electrical signal, and means responsive to said first electrical signal and to said first parameter to generate second electrical signals, said first servo valve arrangement being responsive to said second electrical signals.
Claim 6
Dependent Claim
46 words
An apparatus as claimed in claim 2 in which the means for moving said cam axially comprises a second piston connected to said cam, and a second servo valve arrangement responsive to said compressor pressure to provide second servo pressure signals for positioning said second piston.
Claim 7
Dependent Claim
127 words
An apparatus as claimed in claim 5 in which said second servo valve arrangement comprises a first control valve in series with a first restricted orifice, a second control valve in series with a second restricted orifice, and a control member responsive to said compressor pressure to vary the flow areas of the first and second control valves simultaneously, said first control valve and said first restricted orifice being in parallel with said second control valve and said second restricted orifice and being connected between a delivery connection from said pump and a low pressure connection, pressures between said first control valve and said first restricted orifice, and between said second control valve and said second restricted orifice being applied to respective sides of said second piston.
Claim 8
Dependent Claim
66 words
An apparatus as claimed in claim 1 in which said variable metering orifices include control elements in the form of pistons, said control elements being responsive to an increase in the pressures downstream of the respective orifices to reduce fuel flow, said control elements including pilot valves operable by said first control means to aPply to the respective pistons servo signal pressures opposing said downstream pressures.
Claim 9
Dependent Claim
25 words
An apparatus as claimed in claim 7 in which each said metering orifice includes a ported sleeve within which the associated control element is slidable.
Claim 10
Dependent Claim
30 words
An apparatus as claimed in claim 8 in which each control element includes a port which cooperates with the port in the associated sleeve to define the corresponding metering orifice.
Claim 11
Dependent Claim
30 words
An apparatus as claimed in claim 7 which includes means for rotating the control elements of said second and third metering orifices in response to said power demand device setting.
Claim 12
Dependent Claim
27 words
An apparatus as claimed in claim 10 in which said control element rotating means comprises an edge cam rotatable in response to said power demand device setting.
Claim 13
Dependent Claim
37 words
An apparatus as claimed in claim 10 which includes a third piston coacting with said edge cam and a third servo valve arrangement responsive to said setting to supply third servo pressure signals to said third piston.
Claim 14
Dependent Claim
109 words
An apparatus as claimed in claim 8 which includes throttle valves between the metering orifices and their associated burners, a first throttle valve associated with the first metering orifice being responsive to a first control pressure, means responsive to the pressures downstream of said second and third metering orifices respectively for generating second and third control pressures, second and third throttle valves respectively associated with the second and third metering orifices being respectively responsive to said second and third control pressures, and means for providing said first control pressure from whichever of the pressures downstream of said second and third throttle valves or said reference pressure is the highest.
Claim 15
Dependent Claim
134 words
An apparatus as claimed in claim 13 in which said second control pressure generating means comprises a first valve spool movable in response to the difference between the pressures downstream of the first and second metering orifices, and a second valve spool movable in response to the difference between the pressures downstream of the first and third metering orifices an increase in the pressure downstream of said second metering orifice or a decrease in the pressure downstream of said first metering orifice urging said first valve spool in a direction to decrease said second control pressure, and an increase in the pressure downstream of said third metering orifice or a decrease in the pressure downstream of said first metering orifice urging said second valve spool in a direction to decrease said third control pressure.
Claim 16
Dependent Claim
28 words
An apparatus as claimed in claim 1 which includes regulating means for maintaining the pressure drop across the first metering orifice substantially constant for a given engine speed.
Claim 17
Dependent Claim
55 words
An apparatus as claimed in claim 15 in which said regulating means comprises means for driving said pump at a speed proportional to the engine speed, and valve means responsive to the pump delivery pressure, to the engine speed, and to the pressure downstream of the first metering orifice to vary the pump delivery pressure.
Claim 18
Dependent Claim
92 words
An apparatus as claimed in claim 16 in which said valve means includes a third valve spool responsive to pump delivery pressure, to engine speed end to the pressure downstream of said first metering orifice to generate a fourth control signal, a decrease in pump delivery pressure, an increase in engine speed, or an increase in the pressure downstream of said first metering orifice acting to increase said fourth control signal, and a fourth throttle valve responsive to an increase in said fourth control signal to reduce fuel flow through the pump.
Claim 19
Dependent Claim
63 words
An apparatus as claimed in claim 1 which includes a priming valve arrangement in parallel with said variable metering orifices, said priming valve arrangement including a control member movable in response to an increase in the delivery pressure of said pump first to open and then to shut said priming valve arrangement, and thereby to deliver a charge of fuel to the burners.
Claim 20
Dependent Claim
39 words
An apparatus as claimed in claim 18 which includes an ignition device for said reheat system, said ignition device being responsive to operation of said priming valve arrangement control member to deliver a further fuel charge to said engine.
Claim 21
Dependent Claim
44 words
An apparatus as claimed in claim 1 which includes a low pressure drain and a distributor valve arrangement operable in one position to connect the metering orifices to the respective burners and in another position to connect said burners to the low pressure drain.
Claim 22
Dependent Claim
84 words
An apparatus as claimed in claim 20, in which said distributor valve arrangement comprises, first, second and third ports respectively communicating with said metering arrangement, said burners and said drain, valve seats between said second and third ports, a closure member movable to selectively engage said valve seats, means biasing said closure member towards engagement with one of the seats, and means responsive to a control signal to move said closure member against said biasing means into engagement with the other of said seats.
Claim 23
Dependent Claim
65 words
An apparatus as claimed in claim 20 in which said distributor valve arrangement comprises a plurality of first ports communicating respectively with said first, second and third metering orifices, a plurality of second ports respectively associated with said first ports and communicating with respective burners of said reheat system, a plurality of third ports commonly connected to said drain, and a plurality of closure members.
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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |