Turbine fuel pump

Abstract

An electric motor turbine-type fuel pump having a pair of substantially separate fuel pumping channels on opposed faces of an impeller which has a plurality of circumferentially spaced vanes disposed about the periphery of the impeller. The tip portion of each vane is generally arcuate or curved such that a radially outermost edge of the tip is forward or leads the corresponding radially innermost edge of its base relative to the direction of rotation of the impeller. Preferably, each vane is defined between a pair of radially, axially, and circumferentially extending pockets formed in the impeller, with one set of vanes opening to each of a pair of opposed side faces of the impeller. An axially centered, circumferentially extending rib extends to the radially outermost portion of the vanes and separates the vanes on one face of the impeller from the vanes on the opposed face of the impeller. The center rib communicates with a complementary rib of a guide ring in which the impeller is received in assembly of the fuel pump to also separate the pair of fuel pumping channels from each other. The orientation of the vanes within the split or separated fuel pumping channels dramatically increases the efficiency of the fuel pump, especially during the condition of low fuel pump motor speeds and low fuel flow rate conditions in the fuel pump. Desirably, this will, for example, improve the cold starting of an engine utilizing the fuel pump.