Introduction Into EFB Valve

EFB Valves Training Assem bly and function functi on of Electr Elect r ical Feed back va lves

Introduction

Terminology of EFB The Moog term EFB describes proportional valves with integrated Electrical FeedBack system

Moog EFB valves are 2 or 3 stage proportional valves with pilotstage

Assem bly Failsafe

Pilotstage

Electrical Interface

Integrated

Mechanic

(First stage)

valve connector

Electronic

Main Stage

Feedback System

(Hydraulic Amplifier)

Position transducer

E FB F B P il ilo t s t a g e

ServoJet®

Moog’s

2 Stage Servovalve

Pilotstages

Strahlrohr/ Jet-Pipe

Linear Motor Drive

S e r v o J e t / H i s t o r ie ie

ServoJet®

Strahlrohr/ Jet-Pipe Nozzle-Flapper

S e r v o J e t / A s s em e m b ly ly The Servojet stage consist of the Electro-Mechnical Electro-Mechnical Amplifier and the Hydraulic Amplifier

Electro Mechanical Amplifier

Hydraulic Amplifier

S e r v o J e t / A s s em e m b ly ly

1) Coil 2) Armature

1

3) Permanent Magnets

4

4) Spring-Rod

2

5) JetPipe 3

7

6) Receiver 7) Power Supply

5

8) Jet 9) Drain Line / to Tank

6

7 8 9

S e r v o J e t / M o t o r Op Op e r a t i on An armature/jet armature/jet pipe assembly is mounted on two rods. The single single jet sprays between two holes in the receiver. An electrical command is applied to the torque motor coil and creates a induced magnetic force which is superposed to the permanent magnetic flux. This causes deflection of the armature/jet assembly. The deflection of the jet pipe is proportional to the input current which is applied.

+ Permanent

Coil Induced

Permanent Magnetic Flux

S e r v o J e t / H y d r a u lic O p e r a t i o n Current applied. Pipe will deflect. Jet is devided and a Delta P is generated.

No current applied. Pipe stand in his middle postion.

P

A

T

B

P

A

T

B

S er v o J et / A d v a n t a g es Advantages of the of ServoJet Pilotstage Reduced Leakage at null (energy saving) High Natural Frequency of approx. (500Hz) Defined Failsafe end position for Failsafe requirements Pressure range form 15 bar up to 280 bars High Pressure gain for precise position controlling. Reduced Hysteresis and Threshold

and ...

S er v o J et / A d v a n t a g es Advantages of the of ServoJet Pilotstage High Resistance against contamination due to increase gab between Receiver and Jet

Gap between Jet and Receiver is 0,3 -0,4 mm

The recommended fluid cleanliness class for all D660 valves per ISO 4406 is <16/13 for normal operation, and <14/11 for longer life.

E FB F B P il ilo t s t a g e

The selection of ServoJet, 2 stage Servovalve or Mini DDV depends on the application and the specified features.

The JetPipe stage will only be used at Explosion Protected Valves according ATEX 95 // // 94/9/EU 94/9/EU

E FB FB M a i n S t a g e

Comparison of the main stage types

Servo Valve

• very accurate axis cut (+- 1%) • very high hydraulic gain • very high pressure gain possible p ossible • higher manufacturing costs

Proportional Valve • accurate axis cut (< +- 3%) • Each overlap condition easily possiple (e.g +-10%) • high hydraulic gain • high pressure gain possible • Mechnical Failsafe possible

E FB FB M a i n S t a g e Type of Main Stage (Size NG10)

Proportional Valves: Spool in Body

Modell Series D661 and D681

Servo Valve: Bushing Spool Assembly BSA

Modell Series D661- H

E FB FB M a i n S t a g e Type Main stage (Size NG16-25-32) Standard spool in Body Used only with “MiniDDV” or 2 Stage “MFB-Valves“

Proportional Valve: Spool in Body Standard

Modell Series D662/3/4/5 and D682/3/4/5 Standard Spool with stubshuft Used only with “ServoJet” and “Mini DDV” Reduced the space and thus the needed oil from Pilotstage to fill up this space.

Modell Series D662/3/4/5 and D682/3/4/5

E FB F B P o s it it i o n T r a n s d u ce r

he electrical feedback system exists off •

Non-contacting position transducer (Iron Core and LVDT)

•

and valve electronic for the evaluation of the LVDT Signal

Iron Core

LVDT

E FB F B P o s it it i o n T r a n s d u ce r Principle function of electrical Feedback system 2 Secondary coils

Demodulator 0V

Iron Core Primary coil

Modulator

Spool in middle Position

• The primary coil is supplied with AC Voltage. Due to the iron core a changing magnetically field will be generated. This changing magnetically field induces in both secondary coils a voltage Both secondary coils are mutual connected together. Therfore, if the iron iro n core is

E FB F B P o s it it i o n T r a n s d u ce r Principle function of electrical Feedback system 2 Secondary coils

Demodulator 10V

Iron Core Primary coil

Modulator

Spool in end position

If the iron core moved out of the middle position, the induced voltage in one secondary coil will encrease and in the other one the induced voltage will decrease. Due to the diffent level of the induced voltage, a AC output voltage will arise. The value of the voltage is proportional proportional to the spool stoke. The sign +/- will show the direction. The AC signal at the input of the demodulator will be converted into a +/- DC D C Signal

E FB F B V a l v e e le le c t r o n ic he intergrated electonic board include the - power amplifier for the Pilotstage - the evaluation of the Position Transducer signal - Circuits to prozess the input signals (Input-Signal, Logic-Signal) - the position contoller - circuits to prozess the output signals (Spool position, Logic-Signal)

S t r u k t u r e o f P o s it i t io i o n C o n t r o ll lle r This components are part of the integrated position controller of the EFB Valve and guaranty the repeatable, proportional property with high performance. Input Electricalsignal

Output - Flow - Pressure

U I-sig U

Position Controller & Amplifier

Pilotstage

Upt

Feedback System Valve

Main Stage

E FB FB V a l v e o p e r a t i n g 0% Input Signal

Null Position

Output Flow 0% cis

U I-sig

U


Pilotstage

Upt Feedback System

Spool Position 0%

The controller board permanently measure the position of the Spool and compare ist with the input signal (in this case 0%).

Main Stage

The Spool is position in his middle position.


Operating

Output Flow 0% cis

U I-sig

U


max. mA

Pilotstage

Main Stage

Upt Feedback System

Spool Position 0%

Because of the different signal of U I-sig and U pt the amplifier of the contoller board will provide the pilotstage with the the maximum current. The Pilotstage will deflect and generate a Delta P on the two ends of the spool.

An electric command signal (setpoint UI-sig) is applied to the integrated position control.


Operating

Output Flow 60% cis

U I-sig

U


Reduced mA

Pilotstage

Upt Feedback System

Spool Position 70%

The land open and the medium will flow over the opened lands. The controler permenently compare U I-sig and U pt . If the two signals come closer, the amplifier will reduce the current to the Pilotstage and the pilotstage deflect back into the null direction.

Main Stage

Due to the Delta P at the end side of the spool, the spool will move into the direction with the lower Pressure.


End Position

Output Flow 80% cis

U I-sig

U


Pilotstage

Upt Feedback System

Spool Position 80%

The contoller board will control the pilotstage back into it’s null position. Therfore there will be no Delta P at the two ends of the spool anymore, so the spool will stop s top moving. Every distribution which try to change the position of the spool will be permanently compensate by the controller board.

Main Stage

If the spool reached the defined position the different between U I-sig and U pt will be cero.

E FB F B Fa F a i l s a f e M e ch ch n is m e n

Moog Proportional valves are available with several Failsafemechanismen

Attention :

Depending on demanded safety standard, a simple failsafe protection due to the in Moog valve intergrated failsafe systems, does mostly not suffice. For the protection of plants and machines against accidents, the goverments goverments demands repeatedly, redundant safety Failsafesystemes. F ailsafesystemes.

E FB F B Fa F a i l s a f e M e ch ch n is m e n xamples of Failsafe Mechanismen Shifted null bias of the first Stage

E FB F B Fa F a i l s a f e M e ch ch n is m e n - Spring centred spool - with solinoid valve Short cut between the A and B port of the first stage

- Spring centred spool - solinoid valve Solinoid valve block the pressure supply to the fist stage

E FB FB I n t e r f a c e Hydraulic Interface for Proportional - Valves according ISO standard D661 / 681

ISO 4401-05-05-0-94

NG10

D662 / D682

ISO 4401-07-06-0-94

NG16

D663 / D683

ISO 4401-08-07-0-94

NG25

D664 / D684

ISO 4401-08-07-0-94

NG25

D665 / D685

ISO 4401-10-08-0-94

NG32

Hydraulic Interface for Servo- Valves according iso standard D661

IS O 4 4 0 1 - 0 5 - 0 5 - 0 - 9 4

N G 10

D662*

IS O 4 4 0 1 - 0 7 - 0 6 - 0 - 9 4

N G 16

D 663 **

IS O 4 4 0 1 - 0 8 - 0 7 - 0 - 9 4

N G 25 * Prototype-Phase

D 664 **

IS O 4 4 0 1 0 8 0 7 0 9 4

N G 25

E FB FB I n t e r f a c e Electrical Interface

6+PE

Wiring for valves with 6+PE pole connector EN 175201 Part 804

E FB FB I n t e r f a c e Electrical Interface

11+PE

Wiring for valves with 11+PE pole connector EN 175201 Part 804

D 6 6 0 S e r ie s Type D661-.....NG10 D661-.....NG10 at Delta p = 5 bar/land bar/l and Rated Flow System Pressure Onboard Electronic

: : :

30,60,80 l/min 350 bar 24V= Analog Electronic

Type D662-....NG16 D662-....NG16 at Delta p = 5 bar/land Rated Flow System Pressure Onboard Elect ectronic nic

: : :

150,250 l/min 350 bar 24V= Analog Electronic

D 6 6 0 S e r ie s Type D663-.....NG25 D663-.....NG25 at Delta p = 5 bar/land Rated Flow System Pressure Onboard Electronic

: : :

350 l/min 350 bar 24V= Analog Electron oniic

Type D664-....NG25 D664-....NG25 at Delta p = 5 bar/land Rated Flow System Pressure Onboard Electronic

: : :

550 l/min 350 bar 24V= Analog Electron oniic

D 6 6 0 S e r ie s Type D665-.....NG32 D665-.....NG32 at Delta p = 5 bar/land Rated Flow System Presssure Onboard Electronic

: : :

1000 l/min 350 bar 24V= Analog Electronic

Type D665-....NG32 D665-....NG32 at Delta p = 5 bar/land Rated Flow System Presssure Onboard Electronic

: : :

1500 l/min 350 bar 24V= Analog Electronic

D680

Mini DDV Pilotstufe

D 6 8 0 S e r ie s

D681 (NG10)

Technical datas see D660 Series

D683 / D684 (NG32)

Pr o d u ct A d v a n t a g e s D 6 6 0 / D 6 8 0 • High dynamic • Robust • Cu Cust stom omiz ized ed Mo Mode dellll po poss ssib iblle • Cont ntro rolller acc accurac racy • ServoJet : Co Contamination re resistant • Hi High gh flow flow at stabl stable e spo spool ol po posi siti tion on.. • In Inte tegr grat ated ed Fail Failsa safe fe Fun Funct ctio ione nen n • Hi High gh flow flow at stabl stable e spo spool ol po posi siti tion on.. • In Inte tegr grat ated ed Fail Failsa safe fe Func Functi tion on • Mini MiniDD DDV V : Le Less ss leak leakag age e wi with th Mini MiniDD DDV V • Mini MiniDD DDV V : pres pressu sure re inde indepe pend nden entt

Introduction Into EFB Valve

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