GB1211243A - Axial balancing arrangement in a rotodynamic pump - Google Patents

Abstract

1,211,243. Centrifugal pumps. ZABRZANSKA FABRYKA MASZYN GORNICZYCH. Nov.3, 1967 [Nov.12, 1966], No.50213/67. Heading F1C. An axial thrust balancing arrangement in a rotodynamic pump comprises a rotary balancing disc 12, Fig. 1, subjected to the pressure of oil in chambers b and c. A pressure difference is established between these chambers by a leakage gap 11 which is automatically adjusted in accordance with the axial thrust exerted on the shaft 8. A spring biased auxiliary bearing 16 prevents violent leftward movement of the pump shaft and consequent impact of the disc 12 with seating ring 13. The oil is supplied at a constant and higher pressure than that of the pumped liquid, through a passage 1 to a collector 3 and passes through tangential passages 4 on to the sliding surfaces of seal 5, 6. The oil then flows through a chamber a and pressure reducing openings 10 in a bearing 9 to the chamber b. The oil in chamber a is therefore maintained at relatively high pressure to establish a lubricating flow through the bearing 9 and avoid penetration of the pumped liquid into the balancing arrangement. Sealing liquid is supplied through a passage 18 to a chamber d associated with a helical thrower 19 which maintains a positive pressure difference between the liquid in the chamber a and the pumped liquid. In an alternative embodiment, Fig. 2 (not shown), the balancing oil is cooled by a water-cooled coil (21) in chamber (c), and thereafter passes to an annular tank (20) from where it is returned to the passage (1) by a pump (22).