Directly-Controlled Servo Solenoid Valves - Siemens SINAMICS S120 System Manual

A.3.1.2

Directly-controlled servo solenoid valves

Mechanical design
The valve spool in its steel sleeve is pushed against the reset spring directly by the actuating
solenoid. The armature axis of the solenoid is mechanically coupled to the ferrite core of the
position sensor integrated in the solenoid.
This sensor is a proximity-type, wear-resistant differential transformer (Linear Variable
Differential Transducer LVDT).
The housing of the integrated valve amplifier (On Board Electronic OBE) is bolted directly
onto the solenoid/position sensor module.
Electrical power is supplied and the setpoint injected using a 7-pin connector.
If the valve is operating around its middle position, the solenoid is energized by about 50%.
When the power supply is switched off, it assumes a 4th position, known as the fail-safe
position. When switching on and switching off, it slides through the crossed position.
The valves are available with a variety of nominal flow rates and two different fail-safe
positions.
LVDT
Figure A-13
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Differential transformer
Directly-controlled servo solenoid valve
Linear variable differential transformer
Appendix
A.3 Hydraulic
245