PUMPING UNIT Russian patent published in 2002 - IPC

FIELD: pumping units for delivery of fuel to power plant of flying vehicle. SUBSTANCE: proposed pumping unit has housing with fuel supply and discharge branch pipes and drive shaft mounted in housing in radial sliding bearings. Pumping unit is also provided with axial-centrifugal low-pressure pump with working chamber and impeller mounted in this chamber. Reverse flow dampener is mounted in working chamber before axial section of impeller. Passage for recirculation of part of flow of fuel is provided in parallel with reverse flow dampener. Pumping unit has high-pressure centrifugal pump which has impeller mounted in working chamber with drive and cover disks and blades. Centrifugal pump has circular branch for fuel being handled which is opposite peripheral part of blades. Pumping unit includes also starting peripheral pump with impeller, two fixed disks mounted at spaced relation of either side of impeller and fuel flow change-over system which includes spool bypass valve fitted at peripheral pump outlet and check shut-off valve fitted at centrifugal pump outlet. Centrifugal, peripheral and axial- centrifugal pumps are mounted on common drive shaft and are provided with devices for relieving axial and radial forces acting on drive shaft. EFFECT: reduced heating of fuel of fuel. 11 cl, 15 dwg