CHAPTER 14SERVO VALVES Shited spoolFlow Into cylinderannulusarea retracts fad Load moves valve bodyto certerspool, Which stops load movyemert Figure 14-1 Mechanical servo据llow?valvecopymhr 器 pmD aroncompoppTon Actuator|Position Sensor(Transgucen) Figure 142 Basic sevo valve in aclosedloop position contrmol circuitcomhT回 mmearoncoppomaroh Permanent上 Magnets ArmatureFlexureTube 一 Flapper由 一Feedback wire Fiure 14-3 Torque motor assemblyarapir四Cayenneonmaamy Figure 14-4 Energized coilcauses armature to 地Corner gmnEhronconpopmrn 】 NIGEzIE BIGEKDrrice OriiceFigure 14-5 ”Position ofthe flapperbetween two nazzlesCopymhr回 pmm moncopponrph Torque MotorAssembly FlappenFeedback WireSpoolFilterDriiceFigure 14-6 Flapperassembly cornected to the spoolcpmmEHTrO eann ENconpomaroh 册ulDemFigure 14-7 Defected FlapperIncreases Pressure Behind Dne NozzlecamhrO eaoy Emowcompomhroh和 Figure 148 Sponl Movemert Centers Flapper Neutralzing Spool Forcescamhr 器 pmm earoncoppophTion和G Null adjusteraz人ITNull adustment slot SleeveFigure 14-9 Spool movement centers flapper neutralizing spoolforcescomHrG emmearoncompomamon