Patent ID: 8348648

Claim:
A single screw compressor comprising: a screw rotor ( 40 ) formed with 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 discharge-side portion ( 46 ) is a portion of the spiral groove ( 41 ) from a predetermined position in a compression stroke to the terminal point, and a clearance between a wall surface in a suction-side portion ( 45 ) which is a portion of the spiral groove ( 41 ) other than the discharge-side portion ( 46 ), and the gate ( 51 ) is wider than that between a wall surface in the discharge-side portion ( 46 ) and the gate ( 51 ).