Working Principle of Pneumatic Actuator

Pneumatic actuators drive mechanical motion through compressed air, and their specific working principle can be divided into the following three stages:

1. Energy input of gas source

Compressed air (pressure range 0.4-0.7MPa) is purified by pneumatic triple components (filter, pressure reducing valve, oil mist device) and then controlled by solenoid valve to enter the cylinder. According to Pascal's law (P=F/A), gas pressure acts on the effective area of the piston or diaphragm, generating axial thrust. For example, when a pressure of 0.6MPa is applied to a piston with a diameter of 80mm, the theoretical thrust can reach 3kN.

2. Mechanical motion conversion

• Piston type: Compressed air drives the piston (made of aluminum alloy/stainless steel material) to move in a straight line inside the cylinder body, and the PTFE sealing ring prevents gas leakage. The piston rod (surface treated with hard chrome) transmits linear displacement to the valve with a stroke accuracy of ± 0.5mm.

Thin film type: The rubber fiber composite membrane deforms under air pressure, driving the push rod to move, with a short stroke (<100mm) but a response speed of<0.5 seconds.

3. Motion control mode

Single acting type: single-sided intake pushes the piston, and the return spring provides return force. The structure is simple but the output force is asymmetric.

Double acting type: By switching the intake direction through a directional valve, the piston is alternately compressed on both sides to achieve bidirectional movement, with balanced thrust and precise positioning.