G761 Series Servovalves ISO 137 Size 4
TWO STAGE SERVOVALVES G761 SERIES SERVOVALVES The G761 Series flow control servovalves are throttle valves for 3-, and preferably 4-way applications.they are a high performance, two-stage design that covers the range of rated flows from 1 to 16.5 gpm at 1 psi valve drop.the output stage is a closed center, four-way, sliding spool.the pilot stage is a symmetrical doublenozzle and flapper, driven by a double air gap, dry torque motor. Mechanical feedback of the spool position is provided by a cantilever spring.the valve design is simple and rugged for dependable, long life operation. These valves are suitable for electrohydraulic position, speed, pressure or force control systems with high dynamic response requirements. Principle of operation An electrical command signal (flow rate set point) is applied to the torque motor coils and creates a magnetic force which acts on the ends of the pilot stage armature.this causes a deflection of armature/flapper assembly within the flexure tube. Deflection of the flapper restricts fluid flow through one nozzle which is carried through to one spool end, displacing the spool. Movement of the spool opens the supply pressure port (P) to one control port while simultaneously opening the tank port (T) to the other control port. The spool motion also applies a force to the cantilever spring, creating a restoring torque on the armature/flapper assembly. Once the restoring torque becomes equal to the torque from the magnetic forces, the armature/flapper assembly moves back to the neutral position, and the spool is held open in a state of equilibrium until the command signal changes to a new level. In summary, the spool position is proportional to the input current.with constant pressure drop across the valve, flow to the load is proportional to the spool position. VALVE FEATURES -stage design with dry torque motor Low friction double nozzle pilot stage High spool control forces High dynamics High resolution, low hysteresis Completely set-up at the factory Optional fifth port for separate pilot supply Field replaceable first stage disk filter Rugged, long-life design The actual flow is dependent upon electrical command signal and valve pressure drop.the flow for a given valve pressure drop can be calculated using the square root function for sharp edge orifices: Q = QN p pn Q gpm[l/min] = calculated flow QN gpm[l/min] = rated flow p psi[bar] = actual valve pressure drop pn psi[bar] = rated valve pressure drop FM This catalog is for users with technical knowledge.to ensure that all necessary characteristics for function and safety of the system are given, the user has to check the suitability of the products described here. In case of doubt, please contact Moog Inc. Valves available with CENELEC approved intrinsically safe protection class EEx ia IIC T3 per EN 5 and FM approved intrinsically safe protection in Class I, II and III, Division 1 hazardous locations. Special data sheet on request.
GENERAL TECHNICAL DATA Operating Pressure* ports P, X, A and B port T Temperature Range Fluid Ambient Seal Material** Operating Fluid up to 4,5 psi [31 bar] up to 4,5 psi [31 bar] - to 75 F [-9 to 135 C] - to 75 F [-9 to 135 C] Viton Compatible with common hydraulic fluids, other fluids on request. Recommended viscosity 6 45 SUS @ 1 F System Filtration: High pressure filter (without bypass, but with dirt alarm) mounted in the main flow and, if possible, directly upstream of the valve. Refer to Moog filtration catalog for recommended filtration scheme. Class of Cleanliness: The cleanliness of the hydraulic fluid greatly effects the performance (spool positioning, high resolution) and wear (metering edges, pressure gain, leakage) of the servovalve. Recommended Cleanliness Class For normal operation ISO 446 < 14/11 For longer life ISO 446 < 13/1 Filter Rating recommended For normal operation ß 1 75 (1 µm absolute) For longer life ß 5 75 (5 µm absolute) Installation Operations Any position, fixed or movable. Vibration 3 g, 3 axes Weight.4 lb (4. lb for steel body) Degree of Protection EN559P: class IP65, with mating connector mounted. Shipping Plate Delivered with an oil sealed shipping plate. * Maximum special order is 8, psi [55 bar] ** Other seal material upon request Flow Rate Q (gpm) 4 3 1 5 1.5 16.5 gpm [63 lpm] 1. gpm [38 lpm] 5. gpm [19 lpm].5 gpm [1 lpm] 1. gpm [4 lpm] G761-35 G761-34 G761-33 G761-3 G761-31 4 6 1 3 45 Valve Pressure Drop p (psi) Valve Flow Diagram Valve flow for maximum valve opening (1% command signal) as a function of the valve pressure drop. P A T B X 3
TECHNICAL DATA Model Type G761- Mounting Pattern ISO 137-4 - 4 - - 9 Valve Body Version 4-way -stage with spool bushing assembly Pilot Stage Nozzle/Flapper Pilot Connection Optional, Internal or External Fluid Supply G761 series servovalves are intended to operate with constant supply pressure Supply Pressure Minimum psi [14 bar] Maximum Standard 4,5 psi [31 bar] Proof Pressure at P Port 6,75 psi [465 bar] at T Port 4,5 psi [31 bar] Rated Flow Tolerance @ 1, psi PN [%] ±1 Symmetry [%] < 1 Threshold* [%] <.5 Hysteresis* [%] < 3. Null Shift with Temp., 1 F [38 C] variation [%] <. with acceleration to 1 g <. For every 1, psi [7 bar] supply pressure change <. with return pressure to 5 psi [ to 35 bar] <. * Measured at 3, psi pilot or operating pressure ** High response is available, consult factory Frequency Response* Typical response charateristics for G761 series servovalves. Amplitude Ratio (db) - -4-6 1-8 1 ±4% -1 8 ±1% 6 4 1 1 1 Frequency (Hz) Frequency Response of 1,.5, 5 gpm Servovalves Phase Lag ( ) Amplitude Ratio (db) - -4-6 1-8 1 ±4% -1 8 ±1% 6 4 1 1 1 Frequency (Hz) Frequency Response of 1 gpm Servovalves Phase Lag ( ) Amplitude Ratio (db) - -4-6 1 ±4% -8 1 ±1% -1 8 6 4 1 1 1 Frequency (Hz) Frequency Response of 15 gpm Servovalves G761-31, 3, 33 G761-34 G761-35 Phase Lag ( ) Step Response* Typical transient response of G761 series servovalves. Control Flow % rated 1 1 8 6 4 3 1 3 1,.5, 5 gpm 1 gpm 15 gpm 3 6 9 1 15 Time milliseconds 4
INSTALLATION DRAWINGS 1.75 44.45.874. 3.7 94.1 3.19 81. 1.6 4.5 1.8 3.56.56 65.7 1.84 4X.37 [8.31].531 [13.49] THRU.197 [5.] 46.7.8 3.68 EXTERNAL NULL ADJUST 3/3 IN. HEX SOCKET.11 [53.6] ELECTRICAL CONNECTOR PIN D PIN C 93.5 PIN A PIN B.53 [13.5].11 53.5.7 69..9.3 1.3 33. P PORT X LOCATING PIN X PORT.9.3 DISC FILTER BEHIND COVER Y F1 F4 A G P T X B F F3 U.S. P A B T X G F1 F F3 F4 Ø.31 Ø.31 Ø.31 Ø.31 Ø.16 Ø.14 5 / 16-18 5 / 16-18 5 / 16-18 5 / 16-18 X.87.44 1.31.87 1.31.48 1.75 1.75 Y.84 1.8 1.8 1.7.34.78.56.56 METRIC P A B T X G F1 F F3 F4 Ø7.9 Ø7.9 Ø7.9 Ø7.9 Ø4. Ø3.6 M8 M8 M8 M8 X.1 11. 33.3.1 33.3 1. 44.5 44.5 Y 1.3 3.5 3.5 43.7 8.6 19.8 65. 65. Standard electrical connector mates with MS316F14S-S or equivalent. The mounting manifold must conform to ISO 137-4-4--9. Surface to which valve is mounted requires a 3 [ ] finish, flat within.1[.3] TIR. CONVERSION INSTRUCTION For operation with internal or external pilot connection. Pilot flow Set screw bore supply X (M4 X 6 DIN 91) P Internal P closed open External X open closed For external null adjust: flow out of port B will increase with clockwise rotation of null adjust (3/3 hex key). Flow bias is continually varied for a given port as the null adjust is rotated. 5
ELECTRICAL CONNECTIONS Rated current and coil resistance A variety of coils are available for G761 Series Servovalves. Coil connections A four-pin electrical box connector (that mates with an MS316F14SS cable connector) is standard. All four torque motor leads are available at the connector so external connections can be made for series, parallel, or single coil operation. Servoamplifier The servoamplifier responds to input current, so a servoamplifier that has high internal impedance (as obtained with current feedback) should be used. This will reduce the effects of coil inductance and will minimize changes due to coil resistance variations. ELECTRICAL CONNECTIONS (Examples with typical G761 series coils) Parallel Series Single A B C D A B C D A B C D Coil Resistance Rated Current Coil Inductance @ 5 Hz Electrical Power Polarity for Valve Opening P B, A T [Ω] [ma] [H] [W] 4 ±4.1.64 A and C (+) B and D (-) 16 ±.36.64 A (+), D (-) 8 ±4.1.18 A (+), B (-) or C (+), D (-) Note: Before applying electrical signals the pilot stage has to be pressurized. 6
ORDERING INFORMATION SPARE PARTS AND ACCESSORIES STANDARD MODELS Model Type Designation Rated Flow ( 1, psi) gpm lpm Internal Leakage (at 3, psi) gpm lpm Rated Current (Single Coil) ma Nominal Coil Resistance Ohms G761-31 S4JOGMJVPL 1 4 <.37 < 1. 4 8 G761-3 S1JOGMJVPL.5 1 <.48 < 1.5 4 8 G761-33 S19JOGMJVPL 5 19 <.7 <.4 4 8 G761-34 S38JOGMJVPL 1 38 <.7 <.4 4 8 G761-35 S63JOGMJVPL 16.5 63 <.7 <.4 4 8 Optional Feature Series specification Model Designation Assigned at the factory Model Number G761 Factory Identification (Revision Level) Valve Version S Standard response Rated Flow QN gpm [lpm] at PN = 5 psi [35 bar] per land 4 1. [4.] 1.5 [1] 19 5. [19] 38 1. [38] 63 16.5 [63] Maximum Operating Pressure (P) and Body Material J 4,5 psi [31 bar] aluminum Type Designation S J G M V P Signals for 1% Spool Stroke H ±7.5 ma (series) L ± ma (series) Valve Connector P Connector over P-side Seal Material V FPM (Viton) Pilot Connections 4 Internal 5 External Spool Position without Electrical Signal M Mid-position Pilot Stage G Standard dynamics Main Spool Type O 4-way / Axis cut / linear D 4-way / +/-1% overlap / linear SPARE PARTS AND ACCESSORIES Moog Part Size Moog Part Number FPM 85 Shore O-Rings (included in delivery), for P,T,A and B ID.46 x.7[1.8 x 1.8] P/N 451- for X ID.364 x.7[9.5 x 1.8] P/N 451-13 Mating Connector, waterproof IP 65 (not included in delivery) P/N 4954F14SS(MS316F14SS Flushing Block P/N 5514 Moog Part Size Moog Part Number Mounting Bolts (not included in delivery) (4 pieces) 5/16-18 NCX x 1-3/4 long P/N A3134-8B [M8-1.5 x 45 mm long] [B6499-8B45] Replaceable Filter P/N A67999-65 Set Screw M4 x 6 DIN 91 P/N 6698 4 6 Seal for Set Screw P/N A558 4 7
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