The screw-compressor

Two parallel positioned and counter-directional rotating axes are fitted with a screw-like profile and gear into each other.

In-between the screw-profiles and the chambers in which it is all housing an amount of air will be enclosed which will be pushed forward by the rotation of both axes.

Continues compression is one of the advantages this sort of compressor has. Besides single stage also multi-stage compressors and oil free srew-compressors exist