Electrohydraulic digital control valve structure and working principle
Specialty Magnets & Assemblies Ningbo Hope Magnet Co.,Ltd , https://www.hopemagnets.com
October 13 04:06:56, 2025
In the early 1980s, significant progress was made in developing computer-controlled electro-hydraulic systems, particularly with the introduction of new components. Among the various control methods used today, incremental digital valves stand out as a key category. These include digital flow valves, digital pressure valves, and digital directional flow valves. A typical example is the incremental digital flow valve, which consists of several essential parts: a stepper motor, ball screw, valve spool, valve sleeve, stem, and sensors.
The working principle of this system begins when a computer sends a control signal. The stepper motor then rotates, converting this rotational motion into linear movement via the ball screw. This movement drives the valve spool to open gradually—starting with partial throttling, which results in a low flow rate. As the spool continues to move, it eventually reaches full throttling, allowing the flow to increase significantly, up to 3600 liters per minute.
One of the notable features of this design is its ability to compensate for thermal expansion between the valve core, valve sleeve, and valve stem. This temperature compensation ensures that the flow remains stable under varying conditions. Additionally, although the valve lacks a feedback mechanism, it incorporates a zero displacement sensor. After each control cycle, the valve core can be precisely returned to its initial position, ensuring high repeatability and accuracy in operation. This makes it ideal for applications requiring consistent and reliable performance.