Actuator and Isolation

The most familiar industrial pneumatic actuator is a rod-style cylinder. A rod attached to a piston inside a barrel or tube extends through a sealed opening at one end. The load is connected to, or contacted by, the rod. Compressed air controlled by a valve enters the barrel and moves the piston, which moves the rod. A port at the other end allows the air to escape. The rods of single-acting actuators are moved by compressed air and go back to their starting position by means of a spring return. Double-acting actuators are moved by compressed air in both directions.

Another type of pneumatic actuator is the rodless cylinder. Instead of being moved by a rod, the load is moved by an external carriage along the tube's surface. Rodless cylinders save space and can deliver longer strokes than rod-style cylinders because the stroke is contained within the overall envelope of the cylinder. Rodless cylinders also handle high moment—the forces acting above, below, or to one side of the center of the piston.