Servo valve is a key component in hydraulic control system, which is widely used in high-precision and high-response industrial equipment and aerospace fields. Among them, rotary valve servo valve is widely concerned because of its compact structure, fast response and high control accuracy. This paper will focus on the rotating principle, structure and working process of rotary valve servo valve.
First, the basic structure of rotary valve servo valve
Rotary valve servo valve is mainly composed of valve body, rotor, stator, coil, feedback mechanism and output shaft. Its core components are the rotating valve core (namely the rotor) and the fixed valve sleeve (namely the stator), and the control oil circuit is formed through precise matching between them. When the coil is energized, it generates electromagnetic torque, which drives the rotor to rotate for a certain angle, thus changing the flow direction and flow rate of oil and realizing accurate control of the actuator (such as hydraulic cylinder or hydraulic motor).
Second, the principle of rotation
The core working principle of rotary valve servo valve is to realize the controllable rotation of rotor through electromagnetic drive. When the control signal is input into the coil, a magnetic field is generated in the coil, and the magnetic field acts on the magnetic rotor, causing it to generate a rotating torque and rotate. The rotation angle of the rotor is determined by the input current, while the rotation direction is controlled by the current direction.
In the process of rotation, the throttle window on the rotor and the oil port on the stator form different openings, thus adjusting the flow and pressure through the valve port. This rotary motion enables the servo valve to realize efficient control of the hydraulic system in a small structural space.
Third, feedback and closed-loop control
In order to ensure the accuracy of rotation angle, rotary valve servo valve is usually equipped with angle feedback device, such as potentiometer or resolver. The feedback device converts the actual rotation angle of the rotor into an electrical signal and compares it with the input command signal to form a closed-loop control system.
When the deviation between the actual angle and the commanded angle is detected, the control system will automatically adjust the input current, so that the rotor will continue to rotate or rotate until it reaches the set angle. This closed-loop feedback mechanism greatly improves the dynamic response ability and control accuracy of the servo valve.
Four, the key factors in the process of rotation
1. Electromagnetic driving ability: The design of the coil and the selection of magnetic materials directly affect the rotating torque and speed of the rotor.
2. Friction and inertia: The mass and friction resistance of the rotor will affect the start and stop performance of the servo valve, and the inertia influence should be reduced through optimization design.
3. Cleanliness of oil: impurities in hydraulic oil may affect the cooperation between rotor and stator, resulting in poor rotation or wear, so the cleanliness of system oil must be ensured.
V. Application and Advantages
Rotary valve servo valve is widely used in CNC machine tools, robots, flight control systems and other occasions that need high-precision position, speed or force control. Compared with slide valve servo valve, it has the advantages of faster response, stronger anti-pollution ability and smaller volume.
tag
To sum up, the rotary valve servo valve can realize the controllable rotation of the rotor through electromagnetic drive, and realize high-precision closed-loop control with the help of feedback system. Although its rotation principle is complex, it has become an indispensable key component in modern hydraulic servo system with its excellent control performance and stability. With the development of material science and control technology, rotary valve servo valve will play a more important role in the future high-precision automation system.