Screw Compressor

Two spiral rotors that are extremely closely mated compress the gas in rotary screw compressors.

The only difference between the screw compressor and the screw pump is that the pockets of trapped material get smaller as they go up the screw, compressing the material therein. As a result, a screw pump's screw is symmetrical all the way around, but a screw compressor's screw is asymmetrical along its length.

Timing gears in a dry-running rotary-screw compressor keep the male and female rotors precisely aligned without coming into touch, which would hasten wear. Lubricating oil bridges the gap between the rotors in an oil-flooded rotary-screw compressor, acting as both a hydraulic seal and a means of transferring mechanical energy, enabling one rotor to be completely driven by the other.