MULTIPLE-STAGE ELECTRIC PUMPING UNIT Russian patent published in 2001 - IPC

FIELD: machine-building hydraulics. SUBSTANCE: pumping unit may be used as a part of temperature-control system of aviation and rocket engineering articles. Pumping unit has a body accommodating cylindrical yoke. Electric motor and n (n=2,3, etc.) working impellers are positioned in yoke recess. External surface of yoke is provided with n-1 by-pass channels communicating with surface of recess at places of outlet of every preceding impeller and inlet of every subsequent working impeller. Yoke recess is made eccentric relative to external cylindrical surface of yoke, and by-pass channels are made in shape of grooves of constant cross-sectional area and constant depth h with respect to external cylindrical surface of yoke. Eccentricity is calculated by formula and it depends on geometric sizes of yoke. EFFECT: reduced radial dimensions and mass. 3 dwg