Patent US3824786A successfully refreshed from Google Patents.
US3824786A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel control apparatus for gas turbine engine
Assignee: Northrop Grumman Properties Ltd
•
Filing: 1972-09-25
•
Granted: 1974-07-23
•
Expires: 1992-09-25
Abstract
Abstract A fuel control apparatus for a gas turbine engine reheat system which includes a plurality of burners has a plurality of variable metering orifices associated with the respective burners and a plurality of servo-responsive throttle valves downstream of the respective orifices. The apparatus includes an arrangement for controlling the servo pressures applied to the throttle valves, this arrangement including a governer driven by the engine and mounted on an internal ring gear. A first valve spool is coupled to the ring gear and is axially movable by the governer. The ring gear includes a coaxial spur gear which meshes with further spur gears forming parts of respective valve spools which control the servo pressures for associated throttle valves.
Inventors
- 👤 R Skinner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:13
CPC Classifications
F; F02; F02C; F02C9/00; F02C9/26; F02C9/32; F02K; F02K3/00; F02K3/08
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
281 words
A fuel control apparatus for a gas turbine engine reheat system which includes a plurality of burners, comprising a first variable metering orifice including a control member movable to control fuel flow to a first reheat burner in accordance with a first engine operating parameter, second and third variable metering orifices to control fuel fLow to second and third reheat burners respectively, said second and third orifices each including a control member movable in response to the position of the control member of the first metering orifice and also in response to second and third engine operating parameters, throttles between the metering orifices and their associated burners, the throttle associated with the first metering orifice being responsive to a first servo pressure signal dependent on the pressures downstream of both the second and third metering orifices, and the throttles respectively associated with the second and third metering orifices being responsive to second and third servo pressure signals respectively dependent on the pressures downstream of the associated metering orifices, and an arrangement for controlling said servo pressure signals in accordance with said downstream pressures and with the speed of the engine, said arrangement having an internal ring gear, a first spur gear driven, in use, by the engine and meshing with the ring gear, a speed responsive governor driven by the ring gear, a valve spool rotatable by the ring gear and axially movable by the governor, a second spur gear secured coaxially to the ring gear, a plurality of further valve spools respectively axially movable in response to said downstream pressures and a plurality of further spur gears respectively secured to said further spools and meshing with said second spur gear.
Claim 2
Dependent Claim
281 words
A fuel control apparatus for a gas turbine engine reheat system which includes a plurality of burners, comprising a first variable metering orifice including a control member movable to control fuel flow to a first reheat burner in accordance with a first engine operating parameter, second and third variable metering orifices to control fuel fLow to second and third reheat burners respectively, said second and third orifices each including a control member movable in response to the position of the control member of the first metering orifice and also in response to second and third engine operating parameters, throttles between the metering orifices and their associated burners, the throttle associated with the first metering orifice being responsive to a first servo pressure signal dependent on the pressures downstream of both the second and third metering orifices, and the throttles respectively associated with the second and third metering orifices being responsive to second and third servo pressure signals respectively dependent on the pressures downstream of the associated metering orifices, and an arrangement for controlling said servo pressure signals in accordance with said downstream pressures and with the speed of the engine, said arrangement having an internal ring gear, a first spur gear driven, in use, by the engine and meshing with the ring gear, a speed responsive governor driven by the ring gear, a valve spool rotatable by the ring gear and axially movable by the governor, a second spur gear secured coaxially to the ring gear, a plurality of further valve spools respectively axially movable in response to said downstream pressures and a plurality of further spur gears respectively secured to said further spools and meshing with said second spur gear.
Claim 3
Dependent Claim
30 words
An apparatus as claimed in claim 1 in which said first variable metering orifice comprises a first valve spool axially slidable to vary the size of said first metering orifice.
Claim 4
Dependent Claim
35 words
An apparatus as claimed in claim 2 which includes a piston responsive to first and second servo operating pressure dependent on the engine compressor pressures, said piston being operatively connected to said first valve spool.
Claim 5
Dependent Claim
60 words
An apparatus as claimed in claim 3 which includes a pilot valve arrangement responsive to said compressor pressures to control the relative magnitudes of said servo operating pressures and means connecting said first valve spool to said pilot valve arrangement so as to urge the latter to vary said servo operating pressure to oppose movement of said first valve spool.
Claim 6
Dependent Claim
49 words
An apparatus as claimed in claim 4 which includes a bellows unit responsive to an air pressure signal derived from the engine compressor, and said pilot valve arrangement includes a pair of closure members movable by said bellows unit to vary said first and second servo operating pressures respectively.
Claim 7
Dependent Claim
33 words
An apparatus as claimed in claim 1 in which the control members for said second and third orifices respectively comprise first and second piston elements slidable in response to said second operating parameter.
Claim 8
Dependent Claim
28 words
An apparatus as claimed in claim 6 in which each of said second and third orifices includes a ported sleeve within which the associated piston element is movable.
Claim 9
Dependent Claim
34 words
An apparatus as claimed in claim 7 in which each said piston element includes a port which co-operates with the port in the associated sleeve to define said second and third variable metering orifices.
Claim 10
Dependent Claim
28 words
An apparatus as claimed in claim 6 which includes means for rotating the control member of said first metering orifice in response to said second engine operating parameter.
Claim 11
Dependent Claim
47 words
An apparatus as claimed in claim 9 which includes a three-dimensional cam secured to the first metering orifice control member for movement therewith, and first and second cam follower elements movable by said cam and respectively coacting with said piston elements to vary the sliding positions thereof.
Claim 12
Dependent Claim
55 words
An apparatus as claimed in claim 10 in which said piston elements are respectively responsive to third and fourth servo operating pressures, and each said piston element includes valve means responsive to the relative positions of the piston element and the associated cam follower element to vary the magnitude of the corresponding servo operating pressure.
Claim 13
Dependent Claim
22 words
An apparatus as claimed in claim 6 which includes means for rotating said piston elements in response to said third operating parameter.
Claim 14
Dependent Claim
45 words
An apparatus as claimed in claim 12 in which said piston element rotating means comprises an edge cam rotatable in response to said third operating parameter, and two cam follower assemblies biased into engagement with said edge cam and secured to said respective piston elements.
Claim 15
Dependent Claim
22 words
An apparatus as claimed in claim 1 in which said second engine operating parameter comprises the temperature at the engine compressor intake.
Claim 16
Dependent Claim
25 words
An apparatus as claimed in claim 1 in which said third engine operating parameter comprises the position of a power demand control for the engine.
Claim 17
Dependent Claim
28 words
An apparatus as claimed in claim 1 in which said throttles associated with said first, second and third metering orifices respectively include third, fourth and fifth piston elements.
Claim 18
Dependent Claim
55 words
An apparatus as claimed in claim 16 in which said third, fourth and fifth piston elements are respectively responsive to an increase in the pressures downstream of the associated metering orifices to open said throttles, and are also responsive to increases in said first, second and third servo pressure signals respectively to shut said throttles.
Claim 19
Dependent Claim
58 words
An apparatus as claimed in claim 17 in which said servo pressure control arrangement comprises a second valve spool movable in response to the difference between the pressures downstream of the first and second metering orifices, and a third valve spool movable in response to the difference between the pressures downstream of the first and third metering orifices.
Claim 20
Dependent Claim
54 words
An apparatus as claimed in claim 18 in which said second servo pressure signal is responsive to the position of said second valve spool, an increase in the pressure downstream of said metering orifice or a decrease in the pressure downstream of said first metering orifice acting to decrease said second servo pressure signal.
Claim 21
Dependent Claim
55 words
An apparatus as claimed in claim 18 in which said third servo pressure signal is responsive to the position of said third valve spool, an increase in the pressure downstream of said third metering orifice or a decrease in the pressure downstream of said first metering orifice acting to decrease said third servo pressure signal.
Claim 22
Dependent Claim
56 words
An apparatus as claimed in claim 18 in which said second and third valve spools are movable to increase said first servo pressure signal when the difference between the pressures downstream of the first and second metering orifices or the difference between the pressures downstream of the first and third metering orifices exceeds a predetermined value.
Claim 23
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 any given engine speed.
Claim 24
Dependent Claim
60 words
An apparatus as claimed in claim 22 in which said regulating means comprises a fuel pump driven, in use, at a speed proportional to the speed of the engine, and valve means responsive to the delivery pressure of the pump, to the engine speed, and to the pressure downstream of said first metering orifice, to vary said pump delivery pressure.
Claim 25
Dependent Claim
30 words
An apparatus as claimed in claim 23 in which said valve means comprises a control valve responsive to a fourth servo pressure signal to vary the flow through the pump.
Claim 26
Dependent Claim
60 words
An apparatus as claimed in claim 24 in which said regulating means includes a fourth valve spool responsive to an increase in said pump delivery pressure to reduce said fourth servo pressure signal, and to a decrease in the pressure downstream of said first metering orifice or to an increase in engine speed to increase said fourth servo pressure signal.
Claim 27
Dependent Claim
45 words
An apparatus as claimed in claim 6 which includes a three-dimensional cam rotatable in response to said second engine operating parameter, and first and second cam follower elements movable by said cam and respectively coating with said piston elements to vary the sliding positions thereof.
Claim 28
Dependent Claim
55 words
An apParatus as claimed in claim 26 in which said piston elements are respectively responsive to third and fourth servo operating pressures, and each said piston element includes valve means responsive to the relative positions of the piston element and the associated cam follower element to vary the magnitude of the corresponding servo operating pressure.
Claim 29
Dependent Claim
39 words
An apparatus as claimed in claim 26 which includes means for moving said three-dimensional cam axially in accordance with the position of the control member of said first metering orifice and also in accordance with said third operating parameter.
Claim 30
Dependent Claim
90 words
An apparatus as claimed in claim 28 in which said means for axially moving said cam comprises a quadrilateral linkage having one arm movable about a first pivotal axis by movement of the control member of said first metering orifice, an arm adjacent said one arm and pivotally movable about said first pivotal axis to cause axial movement of said cam, and means for varying the locus of movement of second pivotal axis of said linkage in accordance with said third parameter, said second axis being opposite said first axis.
Claim 31
Dependent Claim
46 words
An apparatus as claimed in claim 29 in which said locus varying means comprises a crank rotatable about a third axis in accordance with said third parameter and a link interconnecting said second pivotal axis and the end of the crank remote from said third axis.
Claim 32
Dependent Claim
45 words
An apparatus as claimed in claim 29 which said arms of said linkage each include a gear sector centred about said first pivotal axis, said gear sectors meshing with respective raks which respectively coact with said first metering orifice control member and said three-dimensional cam.
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) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |