What is a pneumatic actuator?
As we all know, actuator is one of the very important knowledge points in our life, but in some textbooks or works, some knowledge points about actuator are worth discussing. Today, we will briefly introduce pneumatic actuators in the actuator type.
Pneumatic actuator actuator and regulating mechanism is a unified whole, the actuator includes film type, piston type, fork type and rack and pinion type. Piston stroke is long, suitable for large thrust occasions; Film stroke is small, can only drive the stem directly. Fork pneumatic actuator has large torque, small space, torque curve is more in line with the characteristics of valve torque curve, but not very beautiful; Often used for high torque valves. Rack and pinion pneumatic actuator has the advantages of simple structure, stable and reliable action, safety and explosion-proof. It is widely used in power plant, chemical industry, oil refining and other production processes with high safety requirements.
The working principle of pneumatic actuator
When the compressed air enters the pneumatic actuator from the nozzle of the A tube, the gas pushes the double piston to move in a straight line along the two ends (cylinder head end). The rack on the piston rotates the gear on the rotating shaft 90 degrees counterclockwise, and the valve opens. At this point, the pneumatic implementation valve at both ends of the gas with B tube. On the contrary, when the compressed air enters the two ends of the pneumatic actuator from the B official nozzle, the gas pushes the double plug to the middle linear motion, and the rack on the piston drives the gear on the rotating shaft to rotate 90 degrees clockwise, and the valve is closed. At this time, the gas in the middle of the pneumatic actuator is discharged with A nozzle. The above is the standard transmission principle. According to user needs, the pneumatic actuator can be installed with the opposite transmission principle of the standard type, that is, the selection shaft rotates clockwise to open the valve and counterclockwise to close the valve. Pneumatic actuator A nozzle is the air inlet, B nozzle is the vent (B muffler should be installed in the pipe mouth). A nozzle inlet is to open the valve, and the valve is closed by spring force when the air is broken.
Basic composition of pneumatic actuators
The type and structure of the regulating mechanism of the pneumatic actuator are roughly the same, mainly because the actuator is different. Therefore, when introducing the pneumatic actuator, it can be divided into two parts: the actuator and the regulating valve. The pneumatic actuator consists of two parts: the actuator and the regulating valve regulator). According to the size of the control signal, the corresponding thrust is generated to push the action of the regulating valve. The regulating valve is the regulating part of the pneumatic actuator. Under the thrust of the actuator, the regulating valve produces a certain displacement or Angle to directly regulate the flow of fluid.
