Years ago, it was common for shops to have a central power source that drove all the tools through a system of belts, wheels and driveshafts. The power was routed around the work space by mechanical means. While the belts and shafts may be gone, many shops still use a mechanical system to move power around the shop. It's based on the energy stored in air that's under pressure, and the heart of the system is the air compressor.
You'll find air compressors used in a wide range of situations—from corner gas stations to major manufacturing plants. And, more and more, air compressors are finding their way into home workshops, basements and garages. Models sized to handle every job, from inflating pool toys to powering tools such as nail guns, sanders, drills, impact wrenches, staplers and spray guns are now available through local home centers, tool dealers and mail-order catalogs.
The big advantage of air power is that each tool doesn't need its own bulky motor. Instead, a single motor on the compressor converts the electrical energy into kinetic energy. This makes for light, compact, easy-to-handle tools that run quietly and have fewer parts that wear out.
Air compressor types
While there are compressors that use rotating impellers to generate air pressure, positive-displacement compressors are more common and include the models used by homeowners, woodworkers, mechanics and contractors. Here, air pressure is increased by reducing the size of the space that contains the air. Most of the compressors you'll run across do this job with a reciprocating piston.
Like a small internal combustion engine, a conventional piston compressor has a crankshaft, a connecting rod and piston, a cylinder and a valve head. The crankshaft is driven by either an electric motor or a gas engine. While there are small models that are comprised of just the pump and motor, most compressors have an air tank to hold a quantity of air within a preset pressure range. The compressed air in the tank drives the air tools, and the motor cycles on and off to automatically maintain pressure in the tank.
