| 摘要 |
PCT No. PCT/SE95/00188 Sec. 371 Date Aug. 22, 1996 Sec. 102(e) Date Aug. 22, 1996 PCT Filed Feb. 23, 1995 PCT Pub. No. WO95/23290 PCT Pub. Date Aug. 31, 1995A rotary screw compressor having a balancing piston device for balancing an axial gas force exerted on a pair of rotors during operation of the rotary screw compressor. The balancing piston device is exposed in one axial direction to a high pressure source on at least one first pressure surface, and in an opposite axial direction to one of a low pressure source and an intermediate pressure source on at least one second pressure surface. A valve is provided for selecting the low or the intermediate pressure source connection with respect to the at least one second pressure surface, whereby the thrust balancing force can be adapted to different working conditions such as starting up and full load operation in order to avoid underbalancing or overbalancing of the axial gas force. |
