Patent ID: 8105059

Claim:
A compressor comprising: a cylindrical-shaped screw rotor arranged to rotate about a screw rotor center axis, the screw rotor having an outer circumferential surface with at least one groove portion extending spirally about the screw rotor center axis; and a gate rotor arranged to rotate about a gate rotor center axis, the gate rotor having a plurality of tooth portions arrayed circumferentially on an outer circumference of the gate rotor, the groove portion of the screw rotor and the tooth portions of the gate rotor being engaged with each other to form a compression chamber, the screw rotor and the gate rotor being arranged such that a first plane contains the screw rotor center axis, a second plane intersects orthogonally with the screw rotor center axis and further intersects with the groove portion of the screw rotor, and a third plane intersects orthogonally with the first plane and the second plane and is separate from the groove portion of the screw rotor, and wherein the gate rotor center axis passes through an intersection point of the first plane, the second plane and the third plane, the gate rotor center axis is inclined by about 7 degrees relative to the second plane toward a same side as the groove portion of the screw rotor, as viewed in a direction perpendicular to the third plane, the at least one groove portion of the screw rotor includes three groove portions and the tooth portions of the gate rotor are twelve in number, and the tooth portions of the gate rotor have seal portions in contact with the groove portions of the screw rotor, and the seal portions are formed into a curved-surface shape.