GB277165A - Improvements in or relating to centrifugal bore hole pumps - Google Patents

Abstract

277,165. Pulsometer Engineering Co., Ltd., and Bjornstad, J. Aug. 28, 1926. Pumping-machines, for use in deep wells; leakage-preventing devices.-In a centrifugal bore-hole pump, clean filtered water is supplied to the hollow shaft and passes through holes in the wall of the shaft to the various clearance spaces and working surfaces, subsequently becoming mixed with the water being pumped. The upper portion 1 of the shaft is enclosed in a tube 3 and has a number of holes 6, while the lower portion 2 carries the impellers 5, and has a number of holes 2<a> communicating through holes in sleeves 7 and bearing bushes 8 with chambers 12 above each impeller. These chambers 12 communicate by passages 13 with the annular spaces 15 between the pump impellers above them and the casing; and they communicate by passages 14 with the annular spaces 17 in perforated slip rings between impellers below them and the casing. Clean water is supplied to the tube 3; it passes through the holes 6 into the hollow shaft, then passes outwards again through the holes 2<a>, between the bearing surfaces, and through the clearances to join the stream of pumped water from the impellers which passes upwards through the pipe 10. Bv these means sand, grit and the like are prevented from entering between the working parts. The parts of the footstep bearing may be kept clean in the same way. A pipe 22 may convey additional clean water under pressure to the lower end of the shaft.