| 摘要 |
<p>A multi-stage compression mechanism is constructed such that, out of a plurality of compression elements, the discharge sides of lower-stage compression elements (7a) are successively and directly connected to the suction sides of upper-stage compression elements (9a) through communicating paths, compressed gas is discharged into a discharge gas exhaust space from the last-stage compression element and an oil reservoir is disposed at the bottom of the discharge gas exhaust space, a bypass path (57) is formed between the communicating path and the discharge gas exhaust space or a space communicating therewith, and a bypass valve device (58) is provided at the intermediate portion of the bypass path (57), for allowing only the discharge gas exhaust space or the space communicating therewith to communicate with the communicating path when the pressure in the communicating path is higher than the pressure in the discharge gas exhaust space, thereby reducing the starting load, the vibration and noise of the compressor.</p> |
