A compressor pump is a device used to compress a gas, commonly preparing the gas to be used at high pressure. Found on air conditioning (AC) and refrigeration units, one of the most common types of compressor pump is used on air compressors. Using one of three typical methods of compressing air or gas, the compressor pump is most commonly turned via a rubber drive belt with most units being powered by an electric motor. There are two common types of pump, the single and dual stage version.
When used to compress air, the compressor pump is used to pack the air into a holding tank to be used a later time or to be used in a high-pressure/high-volume application. While a compressor pump may contain several pistons, the most common type of compressor uses a single- or double-cylinder design. The compressor functions much like a piston engine; the piston engine is commonly referred to as a type of air compressor. The most common type of compressor is made up of pistons and piston rings moving up and down in a cylinder by way of a connecting rod and a crankshaft.
The reciprocal or piston-type of compressor is the most used and relies on pistons to pump the gas. Another type of compressor is the screw compressor, which makes use of a set of enmeshed, screw-like components to trap air and push it along towards the tank. Other types of compressors use an eccentric to pump gasses and a diaphragm-type pump uses a solid rod/piston-type pump sealed in the cylinder by a flexible diaphragm. There are also single- and dual-phase compressors that can be found in most multiple-cylinder application while all single-cylinder compressors are single-stage units.
A single-stage compressor pushes a precise amount of air or gas with each stroke of the piston, turn of the screws or rotation of the eccentric. This type of compressor is the most common found in household garages, appliances and automotive applications. The dual stage compressor pump is used to provide the ultimate in high-pressure/high-volume compressor usage. Most common in a twin-cylinder design, the dual-stage pump uses each piston as an independent pump or stage. Air pumped by the first piston is pumped into the second cylinder, where it is compressed even further before being sent into the air tank or reservoir.