SCREW COMPRESSOR

PROBLEM TO BE SOLVED: To enhance the reliability of a compressor by enhancing a sealing function of a radial seal portion, and preventing fluid from leaking out toward an axial direction of a screw rotor. SOLUTION: A screw compressor includes a screw rotor 1 accommodated rotatably in a casing 6, a bearing box 2 for surrounding a shaft end at the discharge side of the screw rotor in the casing, and supporting the shaft via a bearing 8, and sealing portions (A) provided on counter surfaces of an open rim of the bearing box and the screw rotor for partitioning internal spaces of the bearing box with respect to a high pressure periphery zone 11 of the screw rotor at lower pressure than this. In the sealing portion, there is provided a radial seal portion B for causing the screw rotor and the bearing box to face each other in a radial direction. In one of the surfaces facing each other of the radial seal portion, there is formed a screw groove 4 for generating a lift force from a low pressure side to the high pressure periphery zone direction accompanied by the rotation of the screw rotor. COPYRIGHT: (C)2010,JPO&INPIT