What is the application principle of the pneumatic actuator?

The application principle of the pneumatic actuator is mainly based on the conversion of the pressure energy of gas into mechanical energy to drive the movement of mechanical components, so as to realize the control of equipment such as valves. The details are as follows:

1. Principle of double - acting pneumatic actuator:

Intake air pushing the piston to move: When compressed air enters from one air inlet (such as nozzle A) of the pneumatic actuator, the gas pressure pushes the internal double pistons to make a linear motion towards both ends (the cylinder head end).

Rack and pinion transmission: There is usually a rack structure on the piston, and the linear motion of the piston drives the gear on the rotating shaft meshed with the rack to rotate. For example, the gas pushes the piston, causing the rack to drive the gear to rotate counterclockwise, thereby driving the connected valves and other equipment to move, achieving the opening action.

Gas discharge and reverse movement: At this time, the gas at the other end of the pneumatic actuator is discharged through another air outlet (such as nozzle B). Conversely, when compressed air enters from nozzle B, the gas pushes the double pistons to move linearly towards the middle. The rack on the piston drives the gear on the rotating shaft to rotate clockwise, achieving the closing action of valves and other equipment.

2. Principle of single-acting pneumatic actuator (spring return type)

Intake action: Nozzle A is the air inlet. When compressed air enters from nozzle A, the gas pushes the piston to move, overcoming the resistance of the spring, causing the piston to move in the direction of spring compression, thereby driving the relevant mechanical components to move and achieving the opening of the valve.

Gas cut-off reset: When the gas source is interrupted, that is, the gas supply stops, the piston moves in the reverse direction under the elastic force of the spring and returns to its initial position, thus closing the valve. This type of single-acting pneumatic actuator is often used in scenarios where the valve needs to be automatically closed in case of sudden situations such as power outages or gas cut-offs to ensure the safety of the system.