Pneumatic Cylinders and Actuators

Pneumatic cylinders are mechanical devices which use the power of compressed air to produce force in reciprocal linear motion. The compressed air enters the tube at one end of the piston and imparts force on it to move. An actuator consists of a piston, cylinder and valves or ports. The piston is covered by a diaphragm or seal. Keeping air in the cylinder's upper portion allows air pressure to force the diaphragm down which in turn moves the piston and then the internal parts of the actuator. The basic types of cylinders are single-acting (SAC); the piston moves in one direction and is returned by a spring. The double-acting version (DAC) uses force on both extension and retraction. The multi-stage telescoping cylinder can be single- or double-action and extends like a segmented piston. One of the most common actuators is the tie rod which is considered the safest. Other types include the flanged-type, one-piece welded and threaded-end cylinders. Pneumatic cylinders and actuators are used in factory automaton as well as compression brakes on vehicles. Rotary-driven machinery like rock drills, grinders and buffers contain these components. They are also found in dental drills and HVAC systems.