4WS Servo Valves

The Bosch Rexroth 4WS series are high-precision, two-stage (4WS2EM) or three-stage (4WSE3E) directional servo valves primarily used for closed-loop control of an actuator's position, force, pressure, or velocity. They work by converting an electrical input signal into precise hydraulic flow. In the two-stage versions, the torque motor and nozzle flapper plate amplifier create a pressure differential that moves the main control spool, with a mechanical feedback system ensuring proportional control to the electrical signal. These valves are designed to provide fast response times, very low hysteresis, and high control accuracy, making them ideal for dynamic, high-performance applications in industrial and mobile hydraulic systems. They are available for either external control electronics or with integrated On-Board Electronics.