The Rotary Screw Air Compressor uses a positive displacement mechanism called a rotary screw air-end. These compressors are used most commonly for industrial applications due to their ability to produce large quantities of compressed air without substantial leakage, however, these compressors do not have as much success in smaller applications due to leakage, and thus are less successful in comparison to traditional reciprocating compressors.
The air is compressed in these machines by being pushed along between the screw and screw pump, with the only difference being the screw very slightly increases in size while the pump is symmetrical and this is how the air is compressed in the pockets of the machine. The nature of this machine allows for continuous compression of air and there is no pulsation or flow like there would be with reciprocating compressors. The male and female rotor heads are timed perfectly so that there is no contact between the two pieces of machinery. Typically this involves the male rotor having fewer lobes than the female so that the male rotor can spin faster.
Rotary Screw Compressors are typically used to supply air for large industrial applications with continuous air demand. These are usually places that are completely automated or have a high enough number of intermittent demands for the air to be needed frequently. Rotary Screw compressors can be tank mounted as well as other variations for mobile applications that need continuous airflow.