VACUUM PUMP OR COMPRESSOR

摘要

1,257,345. Liquid-ring pumps. NASH ENG. CO. Jan.27, 1969 [May 17, 1968], No.4522/69. Heading F1C. A liquid-ring pump has passages 78, 80, Fig. 2, through which liquid from the ring passes to annular chambers 72, 74. By suitably selecting the angular location of the passages, a specific pressure is set up in the chambers. The liquid in the chamber 74 cools the shaft seal 44 and passes through a passage 82 into a central chamber 58 where it seals the running clearance 59. The chamber 72 communicates with the pump discharge 22 via a passage 76 and a reservoir chamber 26. The arrangement may be such that the pressure in the chamber 72 exceeds the pump discharge pressure at low compression ratios to cause some of the sealant liquid to be delivered to the various running clearances and some to be exhausted to the pump discharge, and is less than the pump discharge pressure at high compression ratios to cause an increase in the sealant liquid delivered to the running clearances. A one-way valve may be installed to prevent sealant liquid flowing from the chambers 72, 74 to the ring during high compression ratio operation. The pressures in chambers 72, 74, 58 are substantially equalized to balance axial thrust. The width of the rotor chamber can be varied by shims 18. Sealant liquid is delivered through conduit 28 to inlet part 70. In an alternative embodiment, Fig. 4 (not shown), the sealant liquid is delivered through a conduit (281) coaxial with the shaft and communicating directly with the central chamber (581).