US3922955A - Fail-fixed servovalve - Google Patents

Fail-fixed servovalve Download PDF

Info

Publication number
US3922955A
US3922955A US437667*A US43766774A US3922955A US 3922955 A US3922955 A US 3922955A US 43766774 A US43766774 A US 43766774A US 3922955 A US3922955 A US 3922955A
Authority
US
United States
Prior art keywords
spool
sleeve
liquid
servopiston
flow communication
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US437667*A
Other languages
English (en)
Inventor
Howard Berdolt Kast
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Priority to US437667*A priority Critical patent/US3922955A/en
Priority to GB3170/75A priority patent/GB1489321A/en
Priority to DE19752503067 priority patent/DE2503067A1/de
Priority to IT19604/75A priority patent/IT1031166B/it
Priority to JP50011021A priority patent/JPS604364B2/ja
Priority to FR7502749A priority patent/FR2259263B1/fr
Priority to BE152826A priority patent/BE824920A/xx
Application granted granted Critical
Publication of US3922955A publication Critical patent/US3922955A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • F15B11/12—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor providing distinct intermediate positions; with step-by-step action
    • F15B11/127—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor providing distinct intermediate positions; with step-by-step action with step-by-step action
    • F15B11/128—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor providing distinct intermediate positions; with step-by-step action with step-by-step action by means of actuators of the standard type with special circuit controlling means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
    • F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves
    • F15B13/0436—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves the pilot valves being of the steerable jet type
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/86582—Pilot-actuated
    • Y10T137/8659—Variable orifice-type modulator
    • Y10T137/86598—Opposed orifices; interposed modulator
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/8667—Reciprocating valve
    • Y10T137/86694—Piston valve
    • Y10T137/86702—With internal flow passage

Definitions

  • a fail-fixed servovalve includes a jet pipe for discharg- [211 App].
  • NO: 437,667 ing a pressurized liquid wherein the jet pipe may be selectively signaled to deflect and unbalance the pressures at opposing ends of a spool which would other- 37/ 137/625-68 wise remain centered within a sleeve by resilient l5 Clmeans at pposing ends thereof
  • the spool includes a Fleld of Search t plurality of circumferentially relieved areas inter- 91/461 spaced between a plurality of lands with interconnecting passages therebetween'wherein a servopiston may References Clted be actuated to move by pressurized liquid selectively UNITED STATES PATENTS received from the sleeve and spool such that a sudden 2.796.851 6/1957 Ziskal l37/625.68 loss of either the deflecting signal or the Pressurized
  • This invention relates to a fail-fixed servovalve and, more particularly, to a fail-fixed servovalve which remains fixed in place upon loss of either an input signal or hydraulic liquid, and which may function as either a digital or analog device depending upon the frequency of the input signal.
  • Servovalves of the electrohydraulic type have been used broadly as the interface between an electrical control signal and different types of actuating and metering devices. Servovalves may also be directly applicable to the fuel control of a gas turbine engine. For example, in a gas turbine engine fuel control system, there may be an electrical signal generated by a control which compares a reference engine speed with an actual operating speed. This electrical signal may then be connected to the input of a servovalve which in turn controls a servopiston wherein the mechanical output of the servopiston is connected to a fuel metering valve. Thus the fuel flow of the gas turbine engine can be varied as a function of the electrical signal in order to maintain the reference engine speed. Such a system would provide a highly stable and accurate control of the engine speed.
  • servovalves Todays applications for servovalves, particularly in gas turbine engines, demand that the servovalve be failfixed.
  • fail-fixed it is meant that the mechanical output of the servopiston, as may be provided by an actuator, will be locked in place immediately following a loss of either the electrical input signal or the hydraulic lines.
  • Present day servovalves may have a mechanical bias which permits the servopiston to move in a preselected direction upon loss of electrical signal.
  • the servopiston will be driven at a predetermined velocity in a preselected direction to the end of the piston stroke.
  • the preselected direction would effect either a complete shutoff or maximum flow of fuel.
  • Electrohydraulic stepping motors provide many of the features of servovalves and can be made fail-fixed; however, they are also relatively inefficient and incur many of the difficulties associated with servomotors.
  • the servovalve of this invention includes a deflecting means and a jet pipe for discharging a jet of pressurized liquid wherein the deflecting means is secured to the jet pipe so as to deflect the jet upon an input signal to the deflecting means.
  • a sleeve is provided with a plurality of ports therethrough, one of which receives an inlet flow of pressurized liquid.
  • An input signal to the deflecting means will operate to deflect the jet pipe so that the receiver passages receive unequal amounts of liquid and unbalance the pressure at opposing ends of the spool to translate the spool during which time a pulse of pressurized liquid is ported to one side of the piston which is brought into momentary flow communication with the pressurized liquid entering the sleeve by an internal spool passageway. At the same time a pulse of high pressure liquid is also ported away from the opposing side of the piston by another internal spool passageway thus having the net effect of moving the piston a discreet distance within the bore.
  • FIG. 1 shows a cross-sectional view of the fail-fixed servovalve of this invention.
  • FIG. 2 shows a cross-sectional view of a portion of the fail-fixed servovalve of FIG. 1 in another mode of operation.
  • FIG. 3 shows a cross-sectional view of a portion of the fail-fixed servovalve of FIG. 1 in still another mode of operation.
  • FIG. 4 shows a cross-sectional view of a portion of the fail-fixed serovalve of FIG. 1 in still another mode of operation.
  • FIG. 5 shows a cross-sectional view of a portion of the fail-fixed servovalve of FIG. 1 in still another mode of operation.
  • a fail-fixed servovalve 10 comprising a flexible jet pipe 12 together with a pivot seal 13 mounted in a housing 14.
  • the jet pipe 12 receives a pressurized liquid, which may be any suitable servo fluid, for discharge through a relatively small area nozzle 16 into a chamber 18.
  • the chamber 18 has an outlet 20 which connects by way of a return conduit 22 to a reservoir of low pressure liquid (not shown).
  • the pressure drop across the nozzle 16 of the jet pipe 12 causes a discharge of a high velocity jet of liquid into the chamber 18.
  • a pair of receiver passages 24, 26 are disposed to accept an equal amount of the high velocity liquid jet when the jet pipe 12 is at its illustrated neutral position.
  • the receiver passages 24, 26 connect with opposite ends of a sleeve 28 in which a spool 30 is slidably disposed.
  • Means are provided to deflect the jet pipe 12 and are herein shown as a torque motor 32 which is made responsive to electrical signals furnished through lines 36.
  • An armature 34 of the torque motor 32 is secured to the jet pipe 12 and the pivot seal 13, and exerts a bending moment thereon when differential current is applied to the lines 36.
  • the jet pipe 12 and pivot seal 13 exert a resisting moment which causes its displacement to be directly proportional to the magnitude of the differential current.
  • the spool 30 is maintained at the median position within the sleeve 28 by a pair of opposing springs 38, which are respectively engaged by one end of the sleeve 28 and by a plug 29 threadably inserted at the other end of the sleeve.
  • the spool 30 includes a plurality of circumferentially relieved areas 41, 42, 43, 44, 45, 46 and 47 which are interspaced between a plurality of circumferential lands 48, 49, 50, 51, 52, 53, 54 and 55. Flow communication is provided between the relieved areas 43, 44 and by a passageway 58 which is internal to the spool 30.
  • An inlet conduit 62 furnishes a supply of pressurized liquid from a source (not shown) wherein the pressurized liquid enters the space defined between the relieved area 44 and the sleeve 28 by way of an inlet port 64.
  • the pressurized liquid thereupon enters the space defined between the relieved areas 43, 45 and the sleeve 28 by way of the internal passageway 58.
  • Pressurized liquid also exits from the space defined between the relieved area 44 and the sleeve 28 by way of an outlet port 66 which communicates with a conduit 68 for supplying the high pressure liquid to the jet pipe 12.
  • outlet port 66 which communicates with a conduit 68 for supplying the high pressure liquid to the jet pipe 12.
  • outlet ports 70, 72 in the sleeve 28 which communicate respectively with the spaces defined between the relieved areas 41, 47 and the sleeve 28, whereby low pressure liquid is returned to a reservoir (also not shown).
  • the return conduit 22 is in flow communication with the outlet port by way of the space defined between the relieved area 41 and the sleeve 28.
  • a servo piston shown generally at as including a piston 84 disposed for translation within a bore 86 from which extends a connecting rod 88 in integral connection with the piston 84.
  • the head side of the piston 84 receives an inlet flow of pressurized liquid from an inlet port 81 which communicates with a port 76 in the sleeve 28 by way of an interconnecting conduit 78.
  • the connecting rod side of piston 84 receives an inlet flow of pressurized liquid from an inlet port 79 which communicates with a port 74 in the sleeve 28 by way of an interconnecting conduit 77.
  • O-ring seals 90 may be provided to insure that the piston 84 and connecting rod 88 both sealingly engage the bore 86.
  • thejet pipe 12 when in the neutral position, as shown in FIG. 1, directs a high velocity liquid jet at both receiver passages 24, 26 so that the pressures on opposite ends of the spool 30 are equal.
  • the distance between the nozzle 16 and the receiver passages 24, 26 is such that substantially all of the kinetic energy of the jet is converted to pressure in the passages.
  • the passages 24, 26 are full, the excess liquid flows through the outlet 20 to the conduit 22 from whence the liquid is passed to a low pressure reservoir (not shown).
  • the jet pipe 12 When a differential current is applied to the torque motor 32, the jet pipe 12 is deflected an amount directly proportional to the magnitude of the current differential. The high velocity jet from the pipe 12 then impinges to a greater extent on one of the receiver passages to increase the pressure on one end of the spool 30 and urge it into motion. Assuming now that a step input of positive maximum rated differential current is applied to the torque motor 32, the jet pipe 12 will then deflect in the direction of the receiver passage 26 which in turn will increase the pressure on one side of the spool causing the spool 30 to translate in the direction as shown in FIGS. 2 and 3. Before the spool 30 engages the end of the sleeve 28, as shown in FIG.
  • the jet pipe 12 will also return to the neutral position so that the pressures on the opposing ends of the spool 30 again become equalized.
  • the spool 30 will be translated by the coaction of the springs 38, 40 back to the median position as shown in FIG. 1, passing once again through the momentary alignment as shown in FIG. 2.
  • a second pulse of high pressure liquid will be applied to the connecting rod end of the piston 84 from the inlet port 64, which is brought into momentary flow communication with the port 74 by the internal spool passageway 58.
  • a second pulse of high pressure liquid will be ported away from the head side of the piston 84 by way of the port 76, which is brought into momentary flow communication with the outlet port 72 by the internal spool passageway 60.
  • a step input of maximum rated differential current to the torque motor 32 will operate to cause the piston 84 to translate a discreet distance as determined by the velocity of the spool, the area of the ports, and the liquid pressure differential.
  • the electrical input to the torque motor 32 were a series of square waves of current, stepping from zero to the maximum positive rated current and back to zero, then the piston 84 would move in small incremental steps in one linear direction.
  • FIG. 4 shows the instantaneous alignment between the spool 30 and sleeve 28 which allows a pulse of high pressure liquid to enter the head side of piston 84 from the inlet port 64 which is brought into momentary flow communication with the port 76 by the interconnecting spool .passageway 58.
  • a pulse of high pressure liquid is ported from the connecting rod side of piston 84 by way of the port 74 which is brought into momentary flow communication with the outlet port 70 by the internal spool passageway 56.
  • the jet pipe 12 will again return to the neutral position as shownin FIG. 1, thus equalizing the pressure on both sides of the spool 30.
  • the springs 38 and 40 will then operate .to return the spool 30 to the median positions as shown in FIG. 1 whereupon a second pulse of high pressure liquid will be applied to the head side of piston 84, and a corresponding pulse of high pressure liquid will be ported from the connecting rod side of piston 84 when the spool 30 momentarily aligns within the sleeve 28 as shown in FIG. 4.
  • the servopiston 80 will move so as to extend the connecting rod 88 a discreet distance as determined by the velocity of the spool, the area of the ports, and the liquid pressure difference. It is also apparent that if the input signal to the torque motor is a series of square waves of current, stepping from zero to the maximum positive rated current and back to zero, or stepping from zero to the maximum negative rated current and then back to zero, the servopiston will move in either direction in a series of small discreet steps.
  • servovalves of this type have broad application in the fuel controls of gas turbine engines wherein they may act as the interface between a digital electrical control and a metering valve or mechanical actuator.
  • the current input to the torque motor 32 may be an electrical signal generated by a control which compares a reference engine speed with an actual operating speed.
  • the piston 84 may be connected through the rod 88 to a fuel meteringcontrol valve (not shown).
  • the fuel flow to the gas turbine engine can be varied as a function of the electrical signal from the control to maintain the reference engine speed.
  • Such a control system would provide a highly stable and accurate control of the engine speed.
  • the servovalve of this invention is also fail-fixed in that if the differential current applied to the torque motor 32 should, for some reason, fail to return to zero, the spool 30 will then remain at an end position within the sleeve 28 and the piston 84 will remain locked in position due to the alignment of the spool lands which block the flow of liquid from the ports 74, 76. It will be further appreciated that the piston 84 remains locked in position regardless of the polarity of the differential,
  • the spool 30 will be returned to the medium position as shown in FIG. 1 by the co-action of the springs 38, 40.
  • a failure in either the electrical or hydraulic systems will not result in unpredicted movements of the servopiston.
  • the servovalve will operate as an analog device in the following manner. If the differential current input is varied rapidly from zero to its maximum rated value, at a frequency exceeding the frequency response time of the servovalve, then the spool 30 will assume the position as shown in FIG. 2 and allow a maximum continuous flow of liquid to the connecting rod side of piston 84, together with a maximum continuous flow of liquid away from the head side of piston 84. Piston 84 will thus move at a maximum continuous velocity as determined by the size of the ports and the pressure differen-' tial of the liquid.
  • the differential current may also be switched to a negative polarity at a rate exceeding the frequency response time of the servovalve 10, in which case for a maximum rated current amplitude applied for the maximum time not to exceed one-half of each cycle, there is shown in FIG. 4 the full alignment position assumed by the spool 30. This position provides for the maximum continuous flow of liquid to the head side of piston 84 together with a maximum flow of liquid away from the connecting rod side of the piston 84.
  • the velocity at which the connecting rod 88 moves out of the servopiston 80 'becomes an analog representation of either the amplitude of the differential current applied to the torque motor or the actual time that the differential current is applied.
  • the servovalve can be operated only as an analog device when the input differential current to the torque motor is switched at a frequency exceeding the frequency response of the servovalve. Otherwise, the servovalve will operate as the digital stepping device first described.
  • the output flow of liquid from the servovalve to the servopiston is proportional to either the amplitude of the high frequency current signal or the actual time the current is applied during each cycle.
  • the servovalve therefore has a multiplication capability. For instance, one variable such as servopressure may be used to vary the actual time the current is applied during each cycle while a speed error signal could be used to vary the current amplitude during each cycle.
  • One variable such as servopressure may be used to vary the actual time the current is applied during each cycle while a speed error signal could be used to vary the current amplitude during each cycle.
  • the ability to simultaneously vary two input signals to the servovalve permits the use of one signal to vary the gain of the servovalve for different operating modes of the system.
  • a servovalve comprising:
  • deflecting means responsive to an input signal for deflecting the jet pipe in a direction determined by the input signal
  • a sleeve having a plurality of ports therethrough one of which receives an inlet flow of pressurized liquid
  • a spool translatably disposed within the sleeve and centered therein by resilient means at opposing ends thereof wherein the spool includes a plurality of circumferentially relieved areas interspaced between a plurality of circumferential lands and wherein selected relieved areas may be placed in flow communication with selected ports in the sleeve by translation of the spool;
  • a pair of receiver passages in flow communication with opposite ends of the sleeve and disposed to accept an equal amount of liquid from the jet pipe when the jet pipe is in the non-deflected position and an unequal amount of liquid when the jet pipe is in the deflected position whereby an input signal to the deflecting means operates to deflect the jet pipe causing the receiver passages to receive unequal amounts of liquid and thereby unbalance the pressure at opposing ends of the spool to cause the spool to translate in the direction of lower pressure; servopiston having a piston translatably disposed within a bore each side of which communicates with separate ports in the sleeve; passage means internal to the spool and interconnecting selected relieved areas for delivering a pulse of pressurized liquid to a first side of the piston and porting away pressurized liquid from the opposite side of the piston when the spool is translated in one direction and delivering a pulse of pressurized liquid to the opposite side of the piston and porting away pressurized liquid from the first
  • the spool includes: a first centrally relieved area for receiving the inlet flow of pressurized liquid, second and third relieved areas each of which is adjacent on opposing end of the centrally relieved area and spaced apart therefrom by first and second respective lands wherein the second and third relieved areas are in flow communication with the centrally relieved area by a first internal spool passageway, fourth and fifth relieved areas adjacent the second relieved area and spaced apart therefrom by a third land with a fourth land interspaced between the fourth and fifth relieved areas wherein flow communication is established between the fourth and fifth relieved areas by a second internal spool passageway, and sixth and seventh relieved areas adjacent the third relieved area and spaced apart therefrom by a fifth land with a sixth land interspaced between the sixth and seventh relieved areas wherein flow communication is established between the sixth and seventh relieved areas by a third internal spool passageway.
  • a first port in flow communication with the space between the centrally relieved area and the sleeve for receiving the inlet flow of pressurized liquid
  • a second port spaced axially apart from the first port and in flow communication with one side of the servopiston wherein translation of the spool toward one end of the sleeve and back again operates to establish momentary flow communication between the second port and the space between the second relieved area and sleeve while translation of the spool in the opposing direction toward the other end of the sleeve and back again operates to establish momentary flow communication between the second port and the space between the fourth relieved area and sleeve; third port spaced axially apart from the first and second ports in flow communication with the other side of the servopiston wherein translation of the spool toward one end of the sleeve and back again operates to establish momentary flow communication between the third port and the space between the third relieved area and sleeve while translation of the spool in the opposing direction toward the other end of the sleeve and back again operates to establish momentary flow communication between the third port and the space between the sixth relieved area and sleeve;

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Servomotors (AREA)
US437667*A 1974-01-29 1974-01-29 Fail-fixed servovalve Expired - Lifetime US3922955A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US437667*A US3922955A (en) 1974-01-29 1974-01-29 Fail-fixed servovalve
GB3170/75A GB1489321A (en) 1974-01-29 1975-01-24 Servovalves and servomotors incorporating such valves
DE19752503067 DE2503067A1 (de) 1974-01-29 1975-01-25 Servoventil mit ausfall-blockierung
IT19604/75A IT1031166B (it) 1974-01-29 1975-01-27 Servovalvola a bloccaggio in cas di guasto
JP50011021A JPS604364B2 (ja) 1974-01-29 1975-01-28 サ−ボ弁
FR7502749A FR2259263B1 (enrdf_load_stackoverflow) 1974-01-29 1975-01-29
BE152826A BE824920A (fr) 1974-01-29 1975-01-29 Servo-distributeur

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US437667*A US3922955A (en) 1974-01-29 1974-01-29 Fail-fixed servovalve

Publications (1)

Publication Number Publication Date
US3922955A true US3922955A (en) 1975-12-02

Family

ID=23737390

Family Applications (1)

Application Number Title Priority Date Filing Date
US437667*A Expired - Lifetime US3922955A (en) 1974-01-29 1974-01-29 Fail-fixed servovalve

Country Status (7)

Country Link
US (1) US3922955A (enrdf_load_stackoverflow)
JP (1) JPS604364B2 (enrdf_load_stackoverflow)
BE (1) BE824920A (enrdf_load_stackoverflow)
DE (1) DE2503067A1 (enrdf_load_stackoverflow)
FR (1) FR2259263B1 (enrdf_load_stackoverflow)
GB (1) GB1489321A (enrdf_load_stackoverflow)
IT (1) IT1031166B (enrdf_load_stackoverflow)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4103592A (en) * 1975-12-19 1978-08-01 General Electric Company Valve operator
DE2831661A1 (de) * 1977-07-22 1979-03-29 Gen Electric Steuereinrichtung fuer ein gasturbinentriebwerk
FR2436926A1 (fr) * 1978-09-25 1980-04-18 Gen Electric Servo-distributeur perfectionne
US4220074A (en) * 1977-05-25 1980-09-02 Vapor Corporation Switching valve
US4276809A (en) * 1979-04-23 1981-07-07 General Electric Company Simplified fail-fixed servovalve
US4375780A (en) * 1980-01-28 1983-03-08 General Electric Company Fail-fixed electrohydraulic servosystem
US4510848A (en) * 1982-09-30 1985-04-16 General Electric Company Shear-type fail-fixed servovalve
WO1988004367A1 (en) * 1988-01-25 1988-06-16 Moog Inc. Fail-fixed servovalve with controlled hard-over leakage
US5622095A (en) * 1995-06-28 1997-04-22 Foster; Raymond K. Hydraulic drive and control system
US5735122A (en) * 1996-11-29 1998-04-07 United Technologies Corporation Actuator with failfixed zero drift
US20020043287A1 (en) * 2000-10-13 2002-04-18 Yakov Beyrak Proportional pilot operated directional valve
FR2818331A1 (fr) * 2000-12-19 2002-06-21 Snecma Moteurs Servo-valve a memoire de position
US20070023093A1 (en) * 2005-07-28 2007-02-01 Honeywell International Latchable electrohydraulic servovalve
EP1972798A1 (fr) * 2007-03-21 2008-09-24 Hispano-Suiza Dispositif de commande de position d'un actionneur par une servo-valve à mémoire de position en cas de panne
US20090146088A1 (en) * 2007-12-05 2009-06-11 Abb Ag Method for operation of a position regulator
US20110173988A1 (en) * 2008-11-13 2011-07-21 Sweet David H Adaptive fail-fixed system for fadec controlled gas turbine engines
US20130087223A1 (en) * 2011-10-10 2013-04-11 In-Lhc Method of detecting failure of a servo-valve, and a servo-valve applying the method
US20190024818A1 (en) * 2017-07-20 2019-01-24 Hamilton Sundstrand Corporation Servovalve
US11125342B2 (en) * 2018-12-28 2021-09-21 Ckd Corporation Spool valve
US11391301B2 (en) * 2020-04-14 2022-07-19 Honeywell International Inc. Electrohydraulic poppet valve device control that maintains the last commanded position of a device upon power interruption and provides back-up position control

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1140467B (it) * 1981-10-27 1986-09-24 Giorgio Cafarelli Valvola ad ugello oscillante

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2796851A (en) * 1954-03-30 1957-06-25 Int Harvester Co Valve operating mechanism for hydraulic steering systems
US3028880A (en) * 1960-04-05 1962-04-10 Sperry Rand Corp Fluid flow control valve
US3282283A (en) * 1963-12-23 1966-11-01 Gocko Regulator Co Ltd Hydraulic regulating system and apparatus
US3472278A (en) * 1966-10-27 1969-10-14 Henriksen & Henriksen I S Slide valve for opening and closing at least one passage for a flowing medium and an apparatus comprising at least one such slide valve
US3528446A (en) * 1968-02-27 1970-09-15 Sperry Rand Corp Servo valve with resiliently mounted jet pipe

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2161923A1 (de) * 1971-12-14 1973-06-20 Bosch Gmbh Robert Elektrohydraulische steuereinrichtung

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2796851A (en) * 1954-03-30 1957-06-25 Int Harvester Co Valve operating mechanism for hydraulic steering systems
US3028880A (en) * 1960-04-05 1962-04-10 Sperry Rand Corp Fluid flow control valve
US3282283A (en) * 1963-12-23 1966-11-01 Gocko Regulator Co Ltd Hydraulic regulating system and apparatus
US3472278A (en) * 1966-10-27 1969-10-14 Henriksen & Henriksen I S Slide valve for opening and closing at least one passage for a flowing medium and an apparatus comprising at least one such slide valve
US3528446A (en) * 1968-02-27 1970-09-15 Sperry Rand Corp Servo valve with resiliently mounted jet pipe

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4103592A (en) * 1975-12-19 1978-08-01 General Electric Company Valve operator
US4220074A (en) * 1977-05-25 1980-09-02 Vapor Corporation Switching valve
DE2831661A1 (de) * 1977-07-22 1979-03-29 Gen Electric Steuereinrichtung fuer ein gasturbinentriebwerk
FR2436926A1 (fr) * 1978-09-25 1980-04-18 Gen Electric Servo-distributeur perfectionne
US4227443A (en) * 1978-09-25 1980-10-14 General Electric Company Fail-fixed servovalve
US4276809A (en) * 1979-04-23 1981-07-07 General Electric Company Simplified fail-fixed servovalve
US4375780A (en) * 1980-01-28 1983-03-08 General Electric Company Fail-fixed electrohydraulic servosystem
US4510848A (en) * 1982-09-30 1985-04-16 General Electric Company Shear-type fail-fixed servovalve
WO1988004367A1 (en) * 1988-01-25 1988-06-16 Moog Inc. Fail-fixed servovalve with controlled hard-over leakage
US4827981A (en) * 1988-01-25 1989-05-09 Moog Inc. Fail-fixed servovalve with controlled hard-over leakage
US5622095A (en) * 1995-06-28 1997-04-22 Foster; Raymond K. Hydraulic drive and control system
US5735122A (en) * 1996-11-29 1998-04-07 United Technologies Corporation Actuator with failfixed zero drift
US20020043287A1 (en) * 2000-10-13 2002-04-18 Yakov Beyrak Proportional pilot operated directional valve
US6554014B2 (en) * 2000-10-13 2003-04-29 Hydraforce, Inc. Proportional pilot operated directional valve
FR2818331A1 (fr) * 2000-12-19 2002-06-21 Snecma Moteurs Servo-valve a memoire de position
US6640833B2 (en) 2000-12-19 2003-11-04 Snecma Moteurs Fail-freeze servovalve
US20070023093A1 (en) * 2005-07-28 2007-02-01 Honeywell International Latchable electrohydraulic servovalve
US7455074B2 (en) * 2005-07-28 2008-11-25 Honeywell International Inc. Latchable electrohydraulic servovalve
US8091584B2 (en) 2007-03-21 2012-01-10 Snecma Actuator position control device using a fail freeze servo-valve
US20080230127A1 (en) * 2007-03-21 2008-09-25 Hispano Suiza Actuator position control device using a fail freeze servo-valve
FR2914030A1 (fr) * 2007-03-21 2008-09-26 Hispano Suiza Sa Dispositif de commande de position d'un actionneur par une servovalve a memoire de position en cas de panne
EP1972798A1 (fr) * 2007-03-21 2008-09-24 Hispano-Suiza Dispositif de commande de position d'un actionneur par une servo-valve à mémoire de position en cas de panne
CN101270768B (zh) * 2007-03-21 2012-03-28 伊斯帕诺-絮扎公司 一种使用故障冻结伺服阀的制动器位置控制装置
US8317154B2 (en) * 2007-12-05 2012-11-27 Abb Ag Method for operation of a position regulator
US20090146088A1 (en) * 2007-12-05 2009-06-11 Abb Ag Method for operation of a position regulator
US20110173988A1 (en) * 2008-11-13 2011-07-21 Sweet David H Adaptive fail-fixed system for fadec controlled gas turbine engines
US9217376B2 (en) * 2008-11-13 2015-12-22 Sikorsky Aircraft Corporation Multi-mode adaptive fail-fixed system for FADEC controlled gas turbine engines
US20130087223A1 (en) * 2011-10-10 2013-04-11 In-Lhc Method of detecting failure of a servo-valve, and a servo-valve applying the method
US9897116B2 (en) * 2011-10-10 2018-02-20 In-Lhc Method of detecting failure of a servo-valve, and a servo-valve applying the method
US20190024818A1 (en) * 2017-07-20 2019-01-24 Hamilton Sundstrand Corporation Servovalve
US11060631B2 (en) * 2017-07-20 2021-07-13 Hamilton Sunstrand Corporation Servovalve
US11125342B2 (en) * 2018-12-28 2021-09-21 Ckd Corporation Spool valve
US11391301B2 (en) * 2020-04-14 2022-07-19 Honeywell International Inc. Electrohydraulic poppet valve device control that maintains the last commanded position of a device upon power interruption and provides back-up position control

Also Published As

Publication number Publication date
JPS50107387A (enrdf_load_stackoverflow) 1975-08-23
JPS604364B2 (ja) 1985-02-04
FR2259263B1 (enrdf_load_stackoverflow) 1980-11-07
FR2259263A1 (enrdf_load_stackoverflow) 1975-08-22
DE2503067C2 (enrdf_load_stackoverflow) 1989-09-28
BE824920A (fr) 1975-05-15
DE2503067A1 (de) 1975-07-31
GB1489321A (en) 1977-10-19
IT1031166B (it) 1979-04-30

Similar Documents

Publication Publication Date Title
US3922955A (en) Fail-fixed servovalve
US4227443A (en) Fail-fixed servovalve
US3524474A (en) Servo-valve with ceramic force motor
US3521535A (en) Time modulated pneumatically actuated position control mechanism
US2655939A (en) Solenoid hydraulic control valve
GB1510064A (en) Priority flow valve
KR940703974A (ko) 포펫 및 스풀형 밸브를 구비한 유압 제어 시스템(hydraulic control system having poppet and spool type valves)
US2964059A (en) Pressure-flow servo valve
EP0393195A4 (en) Fluid control mechanism for power shovels
US4625513A (en) Controlled flow hydraulic system
US4598626A (en) Feedback controlled hydraulic valve system
US3430536A (en) Time modulated pneumatically actuated control mechanism
US3101650A (en) Hydromechanical rate damped servo system
US3279323A (en) Electrohydraulic actuator
US2690192A (en) Pilot-operated control valve for hydraulic servo systems
US3732887A (en) Flow-pressure control valve system
US3783901A (en) Electro hydraulic control unit
US4276809A (en) Simplified fail-fixed servovalve
US3211182A (en) Servo valve with rotary first stage
US3516331A (en) Time modulated hydraulically actuated control mechanism
US3455330A (en) Single-stage proportional control servovalve
US3643699A (en) Torque motor operated valve
US4798126A (en) Load responsive system using load responsive pump control of a bypass type
US2969773A (en) Hydraulic valve-controlled servo device
US4342334A (en) Hydraulic servo valve