GB159785A - Improvements in centrifugal pumps - Google Patents

Abstract

159,785. Fleming & Ferguson, Ltd., and Dunlop, E. May 27, 1920. Leakage-preventing devices; balancing moving parts.-A centrifugal pump has rings 4, subject to the action of springs 5 or to the pump pressure, arranged to prevent the pumped liquid from passing back from the discharge side to the bearings. In the single suction pump shown in Figs. 1 and 4, the rings are fitted in a recess 6 in the casing with a spring the pressure of which may be varied by the screw pin 10. The face of each ring is held against the facing 12 on the impeller 3; the ring face has a lubricating-space 8, and packing 7 prevents the passage of liquid into the recess 6. In a modification, the ring is provided with a lip 15, Fig. 6, exposed to the pump pressure to hold the ring against the impeller. A light spring is provided to hold the ring in position when the pump is not working. The ring may be carried by the impeller and pressed against a facing on the casing. In another modification, Fig. 8, the ring is divided and packing 7 placed between the parts. The spring 5 that holds the ring against the face 12 also presses the packing against the sides of the recess 6. The rings may be placed so that liquid under pressure at the back of the impeller balances the axial thrust.