Servo Valves (Electro-hydraulic Amplifiers)
Servo valves are the heart of many hydraulic control systems. In the design of control circuits for position control, the current actuator position is usually fed back using electrical signals. Sensors detect the position of the actuator and convert this position into an electrical signal. The signal conversion and processing in the controller are the limiting factors for position accuracy and the dynamic behavior of the control system.
With Voith servo valves (electro-hydraulic amplifiers), the current actuator position is fed back using a direct mechanical linkage and consequently in real time. This feedback uses either a gear rack, a spindle or a toothed belt directly to the valve piston.
As a result, short-stroke actuator movements can be realized freely programmable, highly dynamic and with maximum process reliability. This is the basis for high productivity of your machine or system. At the same time, tools have a long service life and the parts produced are of high quality.
Voith GmbH & Co. KGaA
71277 Rutesheim, Germany
Tel. +49 7152 992-3
Fax +49 7152 992-400
|Volume flow||Up to 1,500 l/min|
|Operating pressure||280 bar maximum|
|Settling time||5 – 10 ms typically|
|100% control time||10 – 15 ms typically|
|Control||Using HS4 electronic control (RS-232, CAN, Profibus, Ethernet, USB)|
|Methods of mechanical position feedback||
- Machines with highly dynamic, short stroke actuator movements
- Punching machines
- Shearing machines
- Cutting machines
- Stamping machines
Advantages and benefits
Type SVIZ servo valve with a gear rack to mechanically feed the current actuator position back
The stepper or servo motor specifies the position setpoint and actuates a nut-shaft drive that moves the individual valve pistons. The valve pistons open the valve and the actuator moves. The gear rack is linked to the actuator and feeds the actual position back to the valve piston actuation system directly using the pinion (mechanical feedback). As soon as the actuator has reached the programmed position, the pinion returns the valve piston to its initial position. The valve closes again.
- Stepper or servo motor
- Nut-shaft drive
- Gear rack
- Valve piston
- Valve piston actuation system