Application examples

2024-01
EC-4823

Ideal for Basis Weight Control

Rotary Motion Electric Actuator

Model: PRP
Maximum torque100N∙mModel: PRP-0

Stock Valve

Maximum torque200N∙mModel: PRP-1

MG CO., LTD.
(formerly M-System Co., Ltd.)
www.mgco.jp

4-2009Rev.

1

Actuator
Actuator Mechanism
Mechanism Ensuring
Ensuring
High
High Precision
Precision Control
Control ofof Stock
Stock Valves
ValvesBackupBackupbattery
battery(option)(option)Micro-processor
Micro-processorbased
based
control
controlcircuit
circuitboard
board

Indicator
Indicator

AllAllshafts
shaftsarearesupported
supportedwithwithballballbearings.
bearings.

ManualManualcontrol
controlshaft
shaft(hexagon(hexagonsocket)
socket)Terminal
Terminalcover
cover

Image
Image
withwithfailsafe
failsafefunctionfunction
optionoptionRotaryRotaryMotion
MotionElectricElectricActuator
Actuator

PRP
PRPSeries
SeriesMaximum
MaximumtorquetorqueMaximum
MaximumtorquetorqueModel:PRP-0
PRP-0
100
100N∙mN∙m Model:

200
200N∙mN∙m Model:
Model:PRP-1
PRP-1

Four
Fourreasonsreasonswhy
whythethePRP
PRPisisideal
idealforforbasis
basisweightweightcontrol
control
Valve
Valveopening
openingcontrol
controlinin1/1000
1/1000highhighresolution.
resolution.
Excellent
Excellentrepeatability
repeatabilityand
andlinearity
linearityofofpositioning.
positioning.
Opening/closing
Opening/closingspeed
speedprogrammableprogrammableininconjunction
conjunctionwith
withthetheB/M
B/Mcontrol
controlsystemsystem(16(16toto
999
999seconds
secondsper
perfullfullspan)span)totoadapt
adaptwithwithdesign
designspeed
speedchanges
changesofofthe
thepaperpapermachine.
machine.
The
Theactuator
actuatormass
masssignificantly
significantlyreduced
reducedfrom
fromconventional
conventionalones
onesthanks
thankstotothe
thehigh-torquehigh-torquedesign
designisisconvenientconvenientasasreplacement.
replacement.

22

Stopping at the target position without overshootingHigh resolution & precision
Micro-processor based

Electronic Motor Driver Circuit
Precisely tracking target position
by feedback control in combination
with predictive control

High Precision Position Sensor
High torque
1/1000 high resolution

Stepping Motor
Motor rotation control resolutionof 1.8 degrees per pulse
See Page 7

High precision torque control

3-step Reduction Gear Mechanism
High precision gear systemwith minimum backlash
Worm

Worm wheel

Compactly designedWorm Gear Mechanism
High reduction ratio
despite the compact size

Output shaft

Stock Valve
V-port ball valves are typically used.

3

INSTALLATION EFFECTS
The following positive effects have been observed byintroducing the PRP for a stock valve.

Overall cost ≈1/3
Calculation of the overall cost is based on an actual project in Japan, including
the net cost of a replacement of the existing actuator, a control panel andinstallation fee.
Consult us for detailed information.

Delivery leadtime ≈1/9
Delivering a replacement of the existing actuator typically takes 9 months.
1 month will suffice for delivery of the PRP.

Weight (mass) ≈1/10
Mass of the old actuator and the PRP is compared in the images below.
(In this project, the valve was also replaced.)zeizeSieS

allrg

Sm

La
BEFOREAFTER

The PRP is easily adaptable with future design speed changes of the paper machine thanks tothe opening/closing speed which is programmable in conjunction with the B/M control system.

4

APPLICATION EXAMPLE
Multilayer Paperboard Machine

PRP Series

FlowmeterWOLPFLPU

YokeValve

PICTURE 1

Electric Actuator PRP Series connected to the bottom-layer pulpstock valve in the multilayer paperboardmachine, with an electromagnetic flowmeter measuring pulp flow.

PRP

PRP

Flowmeter

LPPUOWFL

Yoke

CouplingValveFLOW

PICTURE 3

PRP connected to the top-layer pulpstock valve

PICTURE 2PULPValve

Closeup of Picture 1: PRP

5PULPSTOCK CONTROLSYSTEM CONFIGURATION

Onsite Panel
Rotary Motion
Electric Actuator
PRP

Manual Loader
STL

B/M
Control
SystemOpen Command

Position Setpoint

Dry Contact

4-20 mA DC

Close Command
Dry Contact

Position Feedback

Position Setting
MXCB

4-20 mA DC

B/M : Basis weight and Moisture content
Stock Valve(V-port ball valve)

RELATION BETWEEN POSITIONING COMMAND AND SETPOINT SIGNAL
Increased with
open command ONDecreased withclose command ON

Position setpointAnalog output
ONOpen command
Contact input

OFFClose command
Contact input

OFFONtimeONThe above diagram shows the control scheme of a stock valve operating system.
In the automatic operating mode, the B/M control system provides open and close contact command signals tothe MXCB which increases/decreases the analog output signal proportionally to the ON time duration of therespective contact signals. They are provided from the manual loader STL in case of manual operating mode.
The analog output accuracy is approximately 0.1%. The PRP actuator is able to control the valve with 1/1000resolution. The combination of these devices ensures the precise basis weight control.
The valve position signal is fed back to the B/M control system to quickly eliminate errors.
The travel time of an entire span (open from/to close) is programmable between 16 to 999 seconds depending
upon the parameter combinations of the PRP and the MXCB.

6STEPPING MOTOR

A stepping motor generates a torque ≈10 times higher
than an induction motor does.
The stepping-motor-driven actuator, PRP Series, is most suitable for operating stock valves that require highresolution, good linearity and high torque control ability.
The PRP is significantly smaller compared to conventional actuators using induction motors.

MECHANISMTORQUE COMPARISON TO AN INDUCTION MOTOR
1.2

StatorPhase ASTEPPING MOTOR

1.0

Phase A

0.8

10 TIMES HIGHER

Phase B

torque [N∙m]

Rotor

0.6
0.4
0.2

Phase B

Shaft

0500

1000

INDUCTION MOTOR1500

2000

2500

3000

3500

4000

rotating speed [rpm]2-phase/8-pole motor

A stepping motor rotates by a constant angle per pulse.
A stepping motor, also called a pulse motor, is a motor that rotates in synchronization with a command pulse
signal. The principle of rotation of a simplified 2-phase, 8-pole stepping motor model is shown in the figure below.
A stepping motor consists of a stator with windings and a rotor using a powerful neodymium magnet. Energizing
the stator windings to generate a magnetic force is called excitation. By sequentially exciting the multiple statorwindings based on the command pulse, the motor rotates stepwise, utilizing the action of attraction and repulsion
between the magnetic poles of the stator and rotor.
The rotation angle of a stepping motor is always determined by the constant mechanical accuracy (motorstructure and machining accuracy) for each command pulse signal. Therefore, a stepping motor performs highly
accurate positioning control.

NS

StatorStatorNS
SS

Rotor

Rotor

(Permanent magnet)(Permanent magnet)

7

COMMON SPECIFICATIONSPRP Series PRP-2

Input signal
Power input: Stepping motor
Motor: Potentiometer
Position detection: Provided
Manual control: 4-20 mA DC
Position output
Operating temperature : -20 to +55°C (Standard type),
5 to 70°C (Lloyd's Register approved type)Vibration: 2 G (19.6 m/s2) (Standard type),∙ Acceleration
0.7G (6.9 m/s2) (Lloyd's Register approved type): 4-20 mA DC or 1-5 V DC
: 100-120 V AC (Not selectablefor CE)
200-240 V AC
Protection level : IP66
Wiring conduit : G 1/2 (two)Standard Type

Lloyd's Register Approved(Environmental categories ENV3)

Maximum torque

600 N∙mModel : PRP-0x

IP66

Model: PRP-1x

IP66

Model : PRP-0xx-x/LR

IP66

Model: PRP-1xx-x/LR

IP66

Operational Angle

90°

Max. Torque

100 N∙m

200 N∙m

Operation Time(90°)

12 seconds (PRP-01)
24 seconds (PRP-03)
8.5 to 125 seconds (PRP-00)

16 seconds (PRP-11)
24 seconds (PRP-13)
16 to 125 seconds (PRP-10)

WeightApprox. 10.8 kg (approx. 12.1 kg with failsafe function option)

Resolution

1/200 (deadband set to 0.5 %), 1/1000 (deadband set to 0.1 %)· Contact us for network capability.

EXTERNAL DIMENSIONS unit: mm (inch)
312 [12.28][171 [6.73]]
141 [5.55]

174 [6.85](75 [2.95])

39 44[1.54] [1.73]

61[2.40]

156 [6.14]

146 [5.75]

50.1[1.97](257 [10.12])

Space requiredfor battery maintenance[171 [6.73]]

Battery box cover

50.1[1.97]

312 [12.28]
141 [5.55](162 [6.38])

134 [5.28]

61 [2.40]

55 [2.17]

1[.04]

122 [4.80](196[7.72])
61[2.40]

156 [6.14]

Failsafe function

146 [5.75]

93[3.66]Your local representative:

WebsiteRequest Info

MG CO., LTD.
(formerly M-System Co., Ltd.)
www.mgco.jp

Specifications are subject to change without notice. When ordering, use the latest data sheets available at our web site: www.mgco.jp

500488High Performance Electric Actuator for Stock ValvePRP SERIES SPECIFICATIONS