US3596467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated fuel control system for a gas turbine engine
Assignee: Avco Corp
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Filing: 1969-10-31
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Granted: 1971-08-03
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Expires: 1989-10-31
Abstract
Abstract The disclosure illustrates an integrated fuel control system for a gas turbine engine. The system comprises a stepless variable speed ratio toroidal-type transmission driven by a rotor assembly of the engine. The output from the variable-speed transmission is connected to an alternator and a centrifugal fuel pump. The pump receives fuel from a suitable source and pressurizes it for delivery into the engine. An electrical computer generates a scheduled fuel flow signal and a flow transducer generates an actual fuel flow signal. These signals are fed to a comparator which supplies the resultant output to a torque motor. The torque motor causes a change in the speed ratio of variable speed drive to change the centrifugal pump r.p.m. and the resultant fuel flow to the engine. The electrical output of the alternator is used by the computer, comparator and actual flow-generating elements and other engine control devices. In an alternate design the variable-speed drive and centrifugal pump are used to maintain a constant pressure differential across a fuel flow metering valve which is driven by a hydromechanical fuel control.
Inventors
- 👤 Paul A Avery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:54
CPC Classifications
F; F04; F04D; F04D13/00; F04D13/02; F02; F02C; F02C9/00; F02C9/26; F02C9/30; F04D15/00; F04D15/0066; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
123 words
A fuel control system for a gas turbine engine having a rotor assembly rotatable over widely varying rates of rotation, said fuel control system comprising: means for providing a flow path for fuel from a supply to said engine for utilization thereby; a fuel pump having a rotatable drive shaft interposed in said flow path means for pressurizing fuel to a level depending upon the rate of rotation of the drive shaft of said pump; a stepless variable speed ratio transmission connecting the rotatable input to said pump with the rotor assembly of said engine; means for controlling the speed ratio of said variable transmission to satisfy fuel supply requirements of said engine irrespective of the rate of rotation of said rotor assembly.
Claim 2
Dependent Claim
123 words
A fuel control system for a gas turbine engine having a rotor assembly rotatable over widely varying rates of rotation, said fuel control system comprising: means for providing a flow path for fuel from a supply to said engine for utilization thereby; a fuel pump having a rotatable drive shaft interposed in said flow path means for pressurizing fuel to a level depending upon the rate of rotation of the drive shaft of said pump; a stepless variable speed ratio transmission connecting the rotatable input to said pump with the rotor assembly of said engine; means for controlling the speed ratio of said variable transmission to satisfy fuel supply requirements of said engine irrespective of the rate of rotation of said rotor assembly.
Claim 3
Dependent Claim
78 words
A fuel control system as in claim 1 wherein said speed ratio means comprises: means for generating a control signal reflecting a scheduled engine operating parameter; means for generating a control signal responsive to the actual engine-operating parameter; means for receiving the scheduled and actual signals and generating an output signal proportional to the difference between the signals; and means for actuating said variable speed ratio transmission to change its speed ratio in response to the error signal.
Claim 4
Dependent Claim
86 words
A fuel control system as in claim 2 wherein said engine-operating parameter is fuel flow to said engine and wherein: said means for generating a control signal reflecting a scheduled engine parameter comprises a computer generating a scheduled fuel flow signal in response to operator demands and other control inputs; said means for generating a signal reflecting the actual value of said parameter comprises a fuel flow meter interposed in said fuel flow path for generating a signal reflecting the actual fuel flow to said engine.
Claim 5
Dependent Claim
89 words
A fuel control system as in claim 1 wherein said speed ratio controlling means comprises: a variable-area orifice interposed in said fuel flow path; means for controlling the area of said variable-area orifice at a given value in response to operator demand and other control inputs; means for actuating said variable speed ratio transmission in response to the pressure differential across said variable-area orifice to maintain a constant pressure differential thereacross; whereby the fuel flow to said engine is directly proportional to the area of said variable area orifice.
Claim 6
Dependent Claim
126 words
A fuel control system as in claim 4 wherein said means for actuating said variable speed ratio transmission comprises: a cylinder and a piston displaceable therein, said piston having an actuating rod extending therefrom foR actuating said variable speed ratio drive in response to displacement of said piston in said cylinder; conduit means for connecting the upstream and downstream pressure across said variable-area orifice to opposite ends of said cylinder; means positioned in the end of said cylinder connected to the downstream side of said variable-area orifice or yieldably urging said piston to the opposite end of said cylinder with a predetermined force; whereby said piston is displaced to actuate said variable speed ratio transmission to maintain a predetermined pressure differential across said variable area orifice.
Claim 7
Dependent Claim
51 words
A fuel control system as in claim 5 wherein said infinitely variable speed ratio transmission comprises a toroidal-type transmission comprising input and output toroids and steerable drive wheels interposed therebetween, the plane in which the drive wheels rotates being variable to vary the speed ratio between said input and output toroids.
Claim 8
Dependent Claim
51 words
A fuel control system as in claim 1 wherein said infinitely variable speed ratio transmission comprises a toroidal-type transmission comprising input and output toroids and steerable drive wheels interposed therebetween, the plane in which the drive wheels rotates being variable to vary the speed ratio between said input and output toroids.
Claim 9
Dependent Claim
101 words
A fuel control system as in claim 1 wherein said means for controlling the speed ratio of said toroidal transmission comprises: means for generating a control signal reflecting a scheduled fuel flow to said engine in response to operator demand and other control inputs; means interposed in said fuel flow path for generating a control signal reflecting the actual flow of fuel to said engine; means receiving the signals from said fuel flow sensor and fuel schedule means for generating an error output signal; means for steering and steerable drive wheels of said toroidal transmission in response to said error signal.
Claim 10
Dependent Claim
60 words
A fuel control system as in claim 8 wherein said fuel flow transducer and said fuel flow scheduling means and said error signal generating means are adapted to provide electrical output signals, and wherein said means for steering the steerable drive wheels of said toroidal drive comprises a torque motor generating a rotatable output in response to electrical input signals.
Claim 11
Dependent Claim
72 words
A fuel control system as in claim 1 wherein the variation in the speed of said engine rotor assembly is relatively large and the variation in speed ratio of the drive shaft for said fuel pump is relatively small, and wherein said fuel control system further comprises an engine accessory having approximately the same speed ratio requirements of said fuel pump and is driven from the input shaft to said fuel pump.
Claim 12
Dependent Claim
54 words
A fuel control system as in claim 10 wherein said means for controlling the speed ratio of said variable drive requires a source of electrical power for operation; said accessory comprises an electrical generator driven by the input shaft to said pump for providing an electrical power source to said speed ratio controlling means.
Claim 13
Dependent Claim
106 words
A self-contained variable fuel delivery means for a gas turbine engine, said delivery means comprising: a generally cylindrical housing; an infinitely variable speed ratio toroidal-type transmission journaled in one end of said housing and having an input shaft extending from one end of said housing for a driving connection; a fuel pump journaled in said housing and having a rotatable drive shaft extending to and integral with the output shaft of said toroidal transmission; an accessory driven by the drive shaft extending between the output of said toroidal transmission and the fuel pump and positioned in said housing between said fuel pump and said toroidal drive.
Claim 14
Dependent Claim
106 words
A self-contained variable fuel delivery means for a gas turbine engine, said delivery means comprising: a generally cylindrical housing; an infinitely variable speed ratio toroidal-type transmission journaled in one end of said housing and having an input shaft extending from one end of said housing for a driving connection; a fuel pump journaled in said housing and having a rotatable drive shaft extending to and integral with the output shaft of said toroidal transmission; an accessory driven by the drive shaft extending between the output of said toroidal transmission and the fuel pump and positioned in said housing between said fuel pump and said toroidal drive.
Claim 15
Dependent Claim
114 words
A fuel delivery means as in claim 12 wherein said fuel pump is a centrifugal-type pump having a generally axially directed inlet and a radially directed outlet; said housing has an annular chamber formed around thE periphery of said centrifugal fuel pump and a radial port extending from said annular chamber for discharge of fuel from said device, said housing having a necked-down elongated inlet extending axially from the inlet to said centrifugal pump; the variable speed ratio controlling means comprises a signal-generating means comprising a generally cylindrical assembly telescoped over the elongated portion of said housing and a means responsive to the control signals of said cylindrical assembly for actuating said toroidal drive.
Claim 16
Dependent Claim
98 words
A fuel delivery device as in claim 13 wherein: said signal-generating assembly is adapted to generate electrical output signals; the variable speed ratio transmission actuating means comprises a torque motor providing a rotatable output in response to electrical control signals from said signal-generating means; and said accessory comprises an alternator having a rotor assembly secured on the drive shafts between said toroidal transmission and said centrifugal fuel pump and a stator assembly positioned radially outward from said rotor assembly and having coils of wire thereon for connection to said signal-generating assembly as a source of electrical power thereto.
References Cited (Backward Citations)
US2896700A
Cited
US3313106A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |