PUMPING UNIT Russian patent published in 1997 - IPC

FIELD: pumping viscous fire hazardous liquids out of reservoirs. SUBSTANCE: pumping section A and drive section B are located in one housing 1 and have common drive shaft 7. They are made in form of similar three-screw hydraulic machines whose chambers are separated by means of separating device which has two bushes 12 and 13. Bush 13 is secured on shaft 7 and has helical thread on its outer surface; bush 12 is fixed in bore of housing 1. Labyrinth seal 16 is provided between flat end surfaces of engageable bushes 12 and 13. Helical lines of drive rotors 8 and 9 have similar direction. Axial force of rotors is transmitted to bush 12 through bush 13. Bush 12 performs the function of supporting member. EFFECT: enhanced reliability. 2 cl, 1 dwg