760 Series Installation and Operation Instruction ...

1 1. INTRODUCTIONThis manual provides instructions and procedures necessary to install,operate and troubleshoot the Moog 760 Series Industrial instructions are outlined so that only the specific component(s)suspected of failure may be OPERATIONThe Moog 760 Series Industrial Servovalve consists of a polarized electricaltorque motor and two stages of hydraulic power amplification .The motorarmature extends into the air gaps of the magnetic flux circuit and is supportedin this position by a flexure tube flexure tube acts as a sealbetween the electromagnetic and hydraulic sections of the two motorcoils surround the armature, one on each side of the flexure flapper of the first stage hydraulic amplifier is rigidly attached to themidpoint of the flapper extends through the flexure tube andpasses between two nozzles, creating two variable orifices between the nozzletips and the pressure controlled by the flapper and nozzle variableorifice is fed to the end areas of the second stage second stage is a conventional 4-way spool design in which outputflow from the valve, at a fixed valve pressure drop, is proportional to spooldisplacement from the null cantilever feedback spring is fixed to theflapper and engages a slot at the center of the spool.

2 Displacement of the spooldeflects the feedback spring which creates a force on the signal induces a magnetic charge in the armature and causes adeflection of the armature and assembly pivots about the flexuretube and increases the size of one nozzle orifice and decreases the size of action creates a differential pressure from one end of the spool to theother and results in spool spool displacement causes a force inthe feedback wire which opposes the original input signal torque. Spoolmovement continues until the feedback wire force equals the input signal Series Installation andOperation InstructionElectrohydraulic ServovalveELECTROHYDRAULIC VALVE CUT-AWAYCAUTIONDISASSEMBLY, MAINTENANCE, OR REPAIR OTHER THAN IN ACCORDANCE WITH THEINSTRUCTIONS HEREIN OR OTHER SPECIFIC WRITTEN DIRECTIONS FROM MOOG WILLINVALIDATE MOOG S OBLIGATIONS UNDER ITS 1 Moog Series 760 Upper PolepieceFlexure TubeFlapperLower PolepieceFeedback WireInlet OrificeMagnetCoilArmatureNozzleSpoolCont rol Port BReturnControl Port APressureFilter3.

3 HYDRAULIC SYSTEM PREPARATIONTo prolong servovalve operational life and to reduce hydraulic systemmaintenance, it is recommended that the hydraulic fluid be kept at a cleanlinesslevel of ISO DIS 4406 Code 16/13 maximum, 14/11 mosteffective filtration scheme incorporates the use of a kidney loop or off-line filtration as one of the major filtration filter for the off-line filtration scheme should be a B3 75 filter for maximum system startup, and prior to mounting the servovalve, the entirehydraulic system should be purged of built-in contaminating particles by anadequate servovalve should be replaced by a flushing manifold andthe hydraulic circuit powered up under conditions of fluid temperature and fluidvelocity reasonably simulating normal operating conditions. New system filtersare installed during the flushing process whenever the pressure drop across thefilter element becomes flushing processes should turn over thefluid in the reservoir between fifty to one hundred maintain a clean hydraulic system, the filters must be replaced on aperiodic basis.

4 It is best to monitor the pressure drop across the filter assemblyand replace the filter element when the pressure drop becomes excessive. Inaddition to other filters that are installed in the hydraulic circuit, it isrecommended that a large capacity, low pressure 3 75 filter be installed in thereturn line. This filter will increase the interval between filter elementreplacement and greatly reduce the system contamination INSTALLATIONThe Moog 760 Series Industrial Servovalve may be mounted in anyposition, provided the servovalve pressure, piston, and return ports matchrespective manifold mounting pattern and port location of the servovalve is shown onfigure servo-valve should be mounted with 5/16-18 x inch long,socket head cap a light film of oil to the screw threads and torqueto 96 inch mating connector for desired coil configuration and polarity. Threadconnector to MECHANICAL NULL ADJUSTMENTIt is often desirable to adjust the flow null of a servovalve independent ofother system mechanical null adjustment on the Moog 760 Series servovalve allows at least 20% adjustment of flow mechanical null adjustor is an eccentric bushing retainer pin, locatedabove the return port designation on the valve body (see Figure 2) which,when rotated, provides control of the bushing position.

5 Mechanical feedbackelements position the spool relative to the valve body for a given input , a movement of the bushing relative to the body changes the flow ProcedureUsing a 3/8inch offset box wrench, loosen the self-locking fitting until the null adjustor pin can be rotated. (This should usually be less than 1/2 turn).DO NOT remove self-locking fitting. Insert a 3/32inch Allen wrench in nulladjustor pin. Use the 3/32 Allen wrench to rotate the mechanical null adjustor pin to obtain desired flow self-locking fitting to 57 inch :Clockwise rotation of null adjustor pin produces open loop flow from port B to port and Equipmenta. Blade screwdriverb. Allen wrench set (3/32,5/32,1/4inch)c. No. 2-56 NC by 1-1/2inch screwd. Torque wrenches (57 and 96 inch-pounds) offset box wrenchf. SERVICING RECOMMENDATIONSa. Disconnect the electrical lead to the Relieve the hydraulic system of residual Remove the 1. Replacement PartsPart Number760 Series Filter Replacement Kit 1 B52555RK004K001 Inlet Orifice - Body O-Ring (1)2-42082-059 Filter Plug - Body O-Ring (1)2-42082-060 End Cap - Bushing O-Ring (1)2-42082-042 End Cap - Body O-ring (1)2-42082-001 Filter Tube (1)1-23020 Base O-Rings4-42082-022(1) Included in Filter Replacement KitFigure 2 Mechanical Null Adjustment Potential TroubleServovalve does not follow input commandsignal.

6 (Actuator or components arestationary or creeping slowly).High threshold. (Jerky, possible oscillatoryor "hunting" motion in closed loop system).Poor response. (Servovalve output lagselectrical command signal).High Null Bias, (High input current requiredto maintain hydraulic cylinder or motorstationary).Probable Cause1. Plugged inlet filter Plugged filter Partially plugged filter Incorrect null Partially plugged filter Replace filter Replace filter Replace filter for dirty hydraulic fluid in Readjust Replace filter element and check for dirtyhydraulic fluid in CHARTThe following troubleshooting chart list potential troubles encountered, probable causes, and FILTER ASSEMBLY REPLACEMENTa. Remove eight socket head cap screws and lockwashers using a 5/32inch Allen wrench. Remove end Remove O-Rings from end Remove filter plug and inlet orifice assembly from both sides of : 2-56 screw threads into the filter plug and inlet orifice inlet orifice assemblies are matched to each other and are therefore :These assemblies seat in body and cannot go through bore during Remove O-Rings from filter plugs and O-Rings from inlet orifice Visually inspect filter orifice assemblies for damage or foreign Discard O-Rings and Install O-Rings on filter plugs, and O-Rings on inlet Install filter, inlet orifice assembly, and a filter plug in body.

7 Inlet orifice assembly pilots into filter. Install the other inlet orifice assembly andfilter plug into other end of filter. Inlet orifice assemblies are Install O-Rings on end Install end caps on body and install eight socket head cap screws and the screws to 57 FUNCTIONAL CHECKOUT AND CENTERINGa. Install servovalve on hydraulic system or test fixture, but do not connect electrical Apply required system pressure to servovalve and visually examine for evidence of external leakage. If leakage is present and cannot be rectified by replacing O-Rings, remove the discrepant component and return for repair or :If the system components are drifting or hardover, adjust the mechanical null of the Connect electrical lead to servovalve and check phasing in accordance with system REPAIR FACILITIESMoog does not authorize any facilities other than Moog or Moog subsidiaries torepair its servovalves. It is recommended you contact Moog at (716) 652-2000to locate your closest Moog repair facility.

8 Repair by an independent(unauthorized) repair house will result in voiding the Moog warranty and couldlead to performance degradation or safety 3 Inlet Orifice Assemblies (one each end of body)End PlateFilter TubeOrifice AssemblyEnd Cap-BodyO-RingsFilter PlugFilter PlugO-RingInlet Orifice O-Ring760 Series Installation AND Operation INSTRUCTIONNOTESTYPICAL WIRING SCHEMATICThe products described herein are subject to change at any time without notice, including, but not limited to, product features, specifications, and Valve lbs ( kg)2 Polarity:A&C (+), B&D (-) produces flow outport B3 Manifold O-Rings ( ) sect x ( ) (Universal dash No. 13)4 Surface:Surface to which valve is mounted requires 32( ) finish, flatwithin .001 [ ] TIR5 Electrical Connector:Mates with MS3106-14S-2S or equivalent6 Null Adjust:Flow out of port B will increase withclockwise rotations of null adjust pin7 Compressed Oil Volume for one control port: in3 ( cm3)8 Suggested Mounting x lg (M8 x 45) socket head screw (4 req'd)Dimensions in parenthesis are in Figure 4 RETURN PORT TPRESSURE PORT PCONTROL PORT.

9 875 .670 .875 .437 CONTROL PORT A .500 .390 VALVE MOUNTS ON THISMANIFOLD .670 1 PORT PER SAE UN-2B DASH 12 STR THD O-RING BOSS(.75 [ ] TUBE OD REF)4 PRESS760 PORT PER SAE UNF-2B DASH 4 STR THD O-RING BOSS(.25 TUBE OD REF) .001 .156 ( ) AUXILIARYPILOT PRESSURE M4X .312 [ ].014 M4X .3125-18 UNC-2B ..634X .344 [ ] THRU[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]PPIN BPIN DPIN CPIN [ ].09[ ].09[ ][ ] [ ].875 [ ] [ ] [ ] MAX[ ] MAX[ ] MAX[ ] MAX[ ]ELECTRICAL LOCATING [ ] [ ] MAX[ ]EXTERNAL NULL ADJUST3/32 IN. HEX [ ] THRUTO DEPTH SHOWN ( REF) .008 [ ]CONNECTORMoog Inc., East Aurora, NY 14052-0018 Telephone: +1-716-652-2000 Fax: +1-716-687-7910 Toll Free: + Rev G 500-315 040856