Three-stage screw compressor

The invention relates to a multi step helical screw compressor unit which consists of a drive housing, wherein a first, second, and third helical screw compressor are secured in a protruding manner parallel to each other and are driven together by a drive toothed wheel in the drive housing. A gas-like fluid is compressed by the first helical screw compressor at a first intermediate pressure of approximately 3.5 bars, by the second helical screw compressor at a second intermediate pressure of approximately 12 bars and by the third helical screw compressor at an end pressure of approximately 40 bars. The driven toothed wheels of the first and the second helical screw compressors are in contact with the drive toothed wheel above the axes thereof, when the driven toothed wheel of the third helical screw compressor is in contact with the drive toothed wheel in the vicinity of the deepest point thereof (T). The position of the axis of the drive toothed wheel can be modified horizontally, and the position of the driven toothed wheel of the third helical compressor can be modified vertically, in order to install a wheel set having various diameter ratios.