Pneumatics

Definition

Pneumatics is the use of pressurized air to do a mechanical motion. Pneumatic power is used in industry, dentistry, construction, mining, and other areas.

Pneumatics works by taking the air around us and compressing or ‘squishing’ it into a smaller volume which increases it’s pressure. That pressure is then used to apply a force to create a movement. To understand, think of those joke snakes in a can, when it is out of the can, it just lays there, but when pushed into the small space it wants to extend, so when the lid comes off, “pow”.

Robotics Application

In robotics, pneumatics are usually used to do a game task. It may be to lift, push, pull or strike an object or lift the robot. Pneumatics can be a quick way to apply a force. Pneumatics can also be quite strong, which is why there are strict safety rule about the use of pneumatics within the robotics program.

A pneumatic system (see diagram) would usually have the following parts:

  1. Air compressor: to squeeze the air
  2. Air tank(s): to hold the compressed air until needed
  3. Air line or hose: to carry the air between the other parts
  4. Fittings: to connect the parts and split the line into multiple paths.
  5. Pressure gauges: to show what pressure the stored air is at compared to normal atmospheric pressure
  6. Regulators: a combination guage and valve part that adjusts the air pressure to a specified setting as it travels the system.
  7. Valves: to control the movement of the air through the system, there can be various kinds, one that is always included is a special relief valve that removes the air from the system.
  8. Actuators: This is the part that converts the air pressure into a mechanical force, such as an air cylinder or piston.

Pneumatic system Diagram (from usfirst.org, pneumatics manual)

Vocabulary

Definitions Vocabulary words Your answers Key
  1. That which causes an object to move. Often thought of as pushes or pulls.
  2. A hollow metal cylinder used to store pressurized air.
  3. A device that regulates the flow of air by opening, closing, or partially obstructing various passageways. Can be moved by mechanically or triggered electrically. Can also be used to switch the flow of air between different pathways, rather like a traffic light determines which road goes and which stops.
  4. A mechanical device that increases the pressure of a gas by reducing its volume (size). Compressors are similar to pumps: both increase the pressure on a gas or fluid and both can transport it through a pipe. There are many types of compressors see Gas Compressor on Wikipedia for more information.
  5. The expansion of air into a chamber pushes a piston attached to a rod which is connected to an object to be moved. See Pneumatic Cylinder on Wikipedia for more information.
  6. A valve and gauge/switch system which limits the airflow to a specific amount of pressure.
  7. How much three-dimensional space an object occupies, often thought of as the size of an object.
  8. Various metal or plastic components that link tubing together. May be used to make multiple pathways or change direction.
  9. The measuring unit of air pressure – pounds per square inch.
  10. A condition where matter (particularly air) has been removed entirely or in part from an enclosed space in order to make the pressure in that space less. This usually creates suction.
  11. A mechanical device that transfers the force of the compressed air into a mechanical motion. The most common is an air cylinder or piston.
  12. When the amount of air pressure within a system remains constant. No leaks.
  13. A mechanical device which measures air pressure and displays it.
  14. Solid, Liquid and Gas are three forms or states of matter. Many substances will change their state of matter if temperature or pressure changes are applied. For example water at room temperature is a liquid, but chill it and it becomes ice (a solid), heat it and it turns to steam (a gas).
  15. Pressure is the amount of force acting on a unit area. Pressure can be defined simply as ‘pushing’.
  1. Actuator
  2. Closed system
  3. Compressor
  4. Fittings
  5. Force
  6. Gauge
  7. Pneumatic cylinders
  8. Pressure
  9. PSI
  10. Regulator
  11. State of Matter
  12. Tank
  13. Vaccuum
  14. Valve
  15. Volume

Activities

If you wish to experiment with pneumatics and air pressure you can download these instruction sheets:

Balloon Car
Cork Popper