Samson 3767 - Page 30

30 EB8355-2EN
Mountingoncontrolvalves
Double-acting,springlessrotaryactuatorwithreversingamplier
Linearcamdisk(equalpercentagecamdiskisrepresentedbyabrokenanddottedline)
View from the positioner onto the actuator shaft
Controlvalveopenscounterclockwise–Basedonaclosedvalve
Directoperatingdirection>> Reverseoperatingdirection<>
Reference
variable
Signal pressure Valve
Charac-
teristic
increases
A1 increases, A2
decreases
opens N
Reference
variable
Signal pressure Valve
Charac-
teristic
decreases
A1 increases, A2
decreases
opens I
90˚
60˚
30˚
0˚
90˚
60˚
30˚
0˚
Feeler roll
Starting point N
Starting point I
Hole to secure the cam disk
Insertclipandpresstheaps
outwards
View from the positioner onto the actuator shaft
Controlvalveopenscounterclockwise – Based on a closed valve
Directoperatingdirection>> Reverseoperatingdirection<>
Reference
variable
Signal pressure Valve
Charac-
teristic
increases
A1 increases, A2
decreases
opens N
Reference
variable
Signal pressure Valve
Charac-
teristic
decreases
A1 increases, A2
decreases
opens I
0˚
90˚
60˚
30˚
0˚
90˚
60˚
30˚
Feeler roll
Starting point N
Starting point I
Fig.10:Cam disk settings for double-acting actuators