CENTRIFUGAL PUMP DISCHARGE APPARATUS Russian patent published in 1999 - IPC

FIELD: pump building. SUBSTANCE: discharge apparatus has hydraulic shoe, supporting cover and discharge pipe. Hydraulic shoe has main and auxiliary rotating and fixed rings. Main rings are separated one from the other by constant space and positioned for receiving loads during change of operation mode. Fixed sleeve disposed outside hydraulic shoe defines together with movable sleeve throttle slit. Fixed sleeve is provided with annular channel faced to throttling slit, where flexible split frictional rings are positioned, so as to contact with movable sleeve. Rings are biased to movable sleeve by flexible member. Auxiliary rotating ring is positioned in bore of vertical wall of hydraulic shoe and auxiliary fixed ring is positioned in supporting cover. Suction zone of outer wheel at delivery side is in fluid communication with throttle slit. EFFECT: reduced loss through throttle slit and stable operation during transfer to other mode of operation. 3 dwg