| 摘要 |
A screw compressor having a discharge casing (16). The discharge casing (16) includes a discharge side end face that abuts on an end face of a main casing (15) to cover the opening of a bore (20), a discharge port (23A, 23B; 25A, 25B) that is formed on the discharge side end face, a discharge chamber (26) that discharges a compressed gas from a compression operation chamber (36A, 36B) through the discharge port (23A, 23B; 25A, 25B), a valve hole (28) that is disposed near the discharge port (23A, 23B; 25A, 25B) on the female rotor side of the discharge side end face and open at a position opposite the direction of female rotor rotation, a bypass groove (29) that permits the valve hole (28) to communicate with a discharge flow path, and a valve disc (31) that is disposed in the valve hole (28). The screw compressor also includes a valve disc drive device (30) that opens and closes the valve disc (31), and a control device (112) that detects whether the compression operation chamber (36A, 36B) is over-compressed, and if the compression operation chamber (36A, 36B) is over-compressed, controls the valve disc drive device (30) so as to open the valve disc (31). |
