Screw-type compressor

摘要

The cylinder chamber(44) of the compressor has a backflow orifice(58) and at least one intermediate backflow orifice(74,76) establishing a minimum position(Mi) and intermediate position(Z1,Z2) respectively. The control unit(66) in the mode for stepless control of the piston positions in a range between the intermediate position and minimum position activates the backflow orifice, and for stepless control of the piston positions outside the range between the intermediate position and minimum position activates the intermediate backflow orifice. An Independent claim is included for a control unit which activates feed flow in an established cycle.