MFB Training [PDF]

Zitiervorschau

Introduction into the Mechanical FeedBack (MFB) Servovalves

Assembly of MFB Principle assembly of the a Mechanical FeedBack Valve 1

2

1

Connector

2

Pilotstage - Torque Motor

3

Feedback wire

4

Bushing

5

Spool

6

Orifice

7

Valve body

8

Filterplate (In P for Pilotstage)

9

Mounting manifold

3

4

5

6

6

9 MOOG Training

8

7

Page 2

Assembly / Torque Motor

Electro Mechanical Amplifier

Hydraulic Amplifier Nozzle

Flapper

Feedback Wire

This valve type is also called:

Nozzle Flapper Stage MOOG Training

Page 3

Assembly / Torque Motor Function of Electro-Mechanical Amplifier

Ø Charged permanent magnets polarize the pole pieces Ø DC current in coils causes increased force in diagonally opposite air gaps N

N

N

S

S

MOOG Training

S

coil flux

Ø Magnetic charge level sets magnitude of decentering force gradient on armature

Page 4

Assembly / Torque Motor Function of the Hydraulic Amplifier

FROM SPOOL END

RETURN ORIFICE

Ø

Ø

Armature and flapper rigidly joined and supported by thin-wall flexure sleeve.

Ø

Ø Fluid continuously flows from pressure Ps, through both inlet orifices, via the nozzles into the flapper chamber and finally through the drain orifice to tank T.

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TO SPOOL END

Rotary motion of armature / flapper throttles flow through one nozzle or the other This diverts flow to one end of the spool

Page 5

Function MFB Valve

Null Position: Null current is supplied to the coils of the Torque Motor and the motor stand in his middle position. The gabs between the right-and-left nozzle are the same. Due to the same gabs the pressure on both spool ends is symmetric. The Spool of the main stage is also located in middle position. Port A and B are closed MOOG Training

Page 6

Function MFB Valve

bent feedback wire

Movement of spool

Operating: If an input signal is applied the Torque Motor will pull out, therefore the gab between the right-and-left nozzle will change and a different pressure will arise at both sites of the spool. Due to the Delta P on the spool ends the spool will move. Thus the feedback wire will bent according to the displacement of a spool. The Ports P to A and the Port B to T will open and oil will flow through the BSA of the main stage. MOOG Training

Page 7

Function MFB Valve

Position reached: As feedback torque becomes equal to torque from the magnetic forces, the Flapper moves back to centered position. Then the gab between the Nozzles and the Flapper and the pressure at both spool ends will be the same. The spool stops at the position where the torque of the feedback spring is alike the torque induced by the applied current to the coil. MOOG Training

Page 8

MFB - Advantages ¤ ¤ ¤ ¤ ¤ ¤ ¤ ¤ ¤ ¤ ¤

MOOG Training

2 stage design with dry torque motor Low friction double nozzle pilotstage High spool control forces High dynamics Replaceable pilot stage filter Rugged and long-life design High resolution, low hysterese Completely set up at the factory Optional fifth port for separate pilot supply Low power consumption Precise axis cut Page 9

MFB - Family

77 Series

72 Series

G631 Series

D630 Series

78 Series

G761 Series MOOG Training

0062 Series Page 10

MFB - Comparison Manifold

Max Pressure

Flow Rate

Port P,X,A,B

at 70 bar Delta P

D062

ISO 10372-04-04-0-92

3000 psi / 210 bar

10 l/min -> 40 l/min

G631

ISO 4401-05-05-0-94

4500 psi / 315 bar

5 l/min -> 75 l/min

072

ISO 10372-06-05-0-92

3000 psi / 210 bar

95 l/min -> 230 L/min

D630

ISO 10372-04-04-0-92

4000 psi / 280 bar

05 l/min -> 40 l/min

G773

Moog Norm

3000 psi / 210 bar

57 l/min

G772

ISO 10372-03-03-0-92

3000 psi / 210 bar

19 l/min -> 38 l/min

G771

Moog Norm

3000 psi / 210 bar

4 l/min -> 10 l/min

G761

ISO 10372-04-04-0-92

4500 psi / 315 bar

4 l/min -> 63 l/min Standard katalog values

MOOG Training

Page 11

MFB - Comparison Rated Flow *1 230

072

95 l/min 80

G631*4 G761-S63 G773

40

D062*4

G772

D630-S *3

G761-H38 D630-S *3

G771

5 50

100

*1) Q at 70 bar Delta P. *3) 280 bar and 90° Phaseangle and +/- 40% Sig MOOG Training

150

G761-H19 G761-H10 G761-H04

200 Dynamic Hz *2

*2) 210 bar and 90° Phaseangle and +/- 40% Sig *4) 210 bar and 90° Phaseangle and +/- 25% Sig Page 12

MFB - Comparison Typical dynamic characteristics (standard valves) *2

D062

*2

G631 072G773 G772 G771

*3 D630

G761

100 200 Hz at 90° Phaseangle *1 *1) At 210 bar ; 90° Phaseangle ; +/- 40% Signal *3) At 280 bar ; -3 dBAmplitude ; +/- 40% Signal MOOG Training

200 100 Hz at -3db Amplitude *3

*2) At 210 bar ; 90° Phaseangel ;+/- 25 Signal *4) At 210 bar ; 90° Phaseangel ;+/- 25 Signal Page 13

MFB - Comparison Rated Flow at 70 bar Delta P D062 G631 072G773 G772 G771 D630 G761

15

MOOG Training

30

45

60

75 l/min

90

160

230 l/min

Page 14

MFB - Applications

MOOG Training

62 / D062 D631

Low performance position control ddd

D630

Pilotstage for Proportional valves

G760 / G761 G77X

Material Testing, Turbine, Simulators Turbine

78

Wood, Old flight simulators

72

Steel Mills, Mat. Testing

Page 15

MFB - Interface

Hydraulic Interface 4-Port valve / ISO 10372 / ISO 4401

Standard Manifold

Manifold example

Detailed information see individual catalogs

MOOG Training

Page 16

MFB - Interface

Hydraulic Interface 5-Port valve / ISO 10372 / ISO 4401 External Pilot supply

Manifold example

Detailed information see individual catalogs

MOOG Training

Use of External 5 Port ¤ The Pilotstage (Torque Motor) can be separatly supplied from the mainstage. Advantages of the fifth Port ¤ Increasing the danymic and the spool control force due to a higher pilotspressure. ¤

Additional filtration for Piltostage possible.

¤

For Failsafe condition the Pilotstage can be controlled by an external solinoid valve. Page 17

MFB - Interface

Electrical Interface 4 Pin Valve Connectors e.g.: 4 Pin MIL-C-5015/14S-2S

Coils wire leads are available at the connector allowing for single, series, or parallel connections

Valve

Valve

Valve

Co nnect or

Co nnect or

Co nnect or

Detailed information see individual catalogs MOOG Training

Page 18

MFB - Family

77 Series

72 Series

G631 Series

D630 Series

78 Series

G761 Series MOOG Training

0062 Series Page 19