PUMP ASSEMBLY OF TURBO-PUMP UNIT, AND AUTOMATIC AXIAL ROTOR UNLOADING MECHANISM OF TURBO-PUMP UNIT Russian patent published in 2014 - IPC F04D13/04 F04D29/22 F04D29/41 

FIELD: engines and pumps.

SUBSTANCE: pump housing includes pumped medium inlet and outlet housings and a projection-shaped rear annular element, which together form a flow cavity for arrangement of a screw centrifugal impeller of a closed type and an automatic rotor axial unloading mechanism. Blades of the impeller are of different length and variable height as to length, which decreases towards the impeller outlet with observance of a quasiequality condition of the cross sectional area at an interblade channel inlet. Number of blades at the outlet is divisible and exceeds at least by two times the number of blades at the impeller inlet. Active volume of dynamic filling of a set of interblade channels of impeller is provided with possibility of releasing to flow part of (4.7÷45)×10^-5 m³/rpm of pumped liquid per revolution of impeller. The automatic axial unloading mechanism includes adjacent annular shoe and belt, which form an end slot seal. The seal provides a self-adjustable flow of the pumped medium from the high pressure zone to the low pressure zone through overflow openings in the main disc and creates pulsating change of axial rotor unloading force.

EFFECT: increasing service life, improving reliability, compactness and operating efficiency of a pump assembly and an automatic axial unloading mechanism at simultaneous reduction of material consumption.

12 cl, 2 dwg