| 摘要 |
PURPOSE:To seal the rotor shaft of a compressor in a most suited manner according to the operational conditions of the compressor, by sealing the rotor shaft by means of screw seal, forming an injection hole in the screw seal, and connecting a circuit capable of feeding oil or compressed air selectively to the injection hole. CONSTITUTION:In no-load operation of a compressor, airtightness at a suction port 3 of the compressor is maintained by injecting injecting oil into a non- contact type screw seal 18 through an injection hole 20 and thereby preventing intrusion of air into a bearing room 11 by this oil. In stopping operation of the compressor, on the other hand, compressed air is injected into the screw seal 18 to prevent backflow of oil from the screw seal 18. Further, in full load operation of the compressor, the injection hole 20 is closed so that the shaft is sealed by the sealing function of the screw seal 18 itself. Thus, the rotor shaft can be sealed in a most suited manner according to the operational conditions of the compressor. |
