3‑Position Pneumatic Actuator
The three‑position pneumatic actuator is a special‑specification actuator, which provides three‑position operation modes of 0°, 45°, 90° or 0°, 90°, 180°. The intermediate position is realized by mechanical braking generated by the movement of two auxiliary pistons. The intermediate position is adjustable. For example, an actuator with 90° stroke can deliver intermediate positions such as 20°, 30°, 50°, 70°.
Output Torque
Please refer to the torque table for 90° stroke pneumatic actuators for output torque.
Its working principle is as follows:
Figure 1 | Fully‑closed Position As shown in Figure 1, the fully‑closed position is achieved when air supply enters port 4 and air exhausts from port 2. |
Figure 2 | Fully‑open Position As shown in Figure 2, the fully‑open position is achieved when air supply enters port 2 and port C simultaneously, and air exhausts from port 4 and port D. |
Figure 3 | Intermediate Position As shown in Figure 3, the intermediate position is achieved when air supply enters port 2 and port D respectively, and air exhausts from port 4 and port C. During the process of reaching the intermediate position, air is supplied to port D to push the auxiliary piston toward the center. The push rod acts as a mechanical stop to halt the inner piston at the preset intermediate position. |
