Patent ID: 8348649

Claim:
A single screw compressor comprising: a screw rotor ( 40 ) formed with a plurality of spiral grooves ( 41 ) in an outer circumference; a casing ( 10 ) in which the screw rotor ( 40 ) is accommodated; and gate rotors ( 50 ) with a plurality of radially-formed gates ( 51 ) to be engaged with the spiral grooves ( 41 ) of the screw rotor ( 40 ), wherein the single screw compressor compresses fluid in a compression chamber ( 23 ) defined by the screw rotor ( 40 ), the casing ( 10 ), and the gate ( 51 ), by relatively moving the gate ( 51 ) from a start point to a terminal point in the spiral groove ( 41 ); and a first side wall surface ( 42 ) of a pair of side wall surfaces of the spiral groove ( 41 ) of the screw rotor ( 40 ), which is positioned on a front side in a traveling direction of the gate ( 51 ) is formed with a first suction-side area ( 45 ) where a portion of the first side wall surface ( 42 ), which extends from the start point to a point immediately before the compression chamber ( 23 ) is completely closed, is partially removed so as not to entirely contact a side surface of the gate ( 51 ).