| 摘要 |
PCT No. PCT/SE89/00227 Sec. 371 Date Oct. 23, 1990 Sec. 102(e) Date Oct. 23, 1990 PCT Filed Apr. 24, 1989 PCT Pub. No. WO89/10489 PCT Pub. Date Nov. 2, 1989.The invention relates to a pressure actuated lift valve in a rotary screw machine mounted in one of the end walls of the machine, e.g. for the purpose of controlling the built-in volume ratio of the machine. The valve contains a cylindrical valve member 11 displaceable in an axial boring 13 and an actuating piston 12 in a cylinder 14. The boring 13 extends between the working space 24 of the machine and said cylinder 14. Through channels 20, 21, 22 pressure fluid is supplied to the cylinder 14 whereby the actuating piston 12 affects the valve member 11 to take an open or a closed position. By making the actuating means as a unit separate from the valve member 11 the manufacture is facilitated. |
