Metering fuel pump

Claim 1

A compact unit for delivering fuel to an engine at a predetermined flow rate and pressure comprising, in combination: (a) an inlet port at a first end of a substantially tubular housing for accepting input fuel; (b) a voltage controlled d.c. brushless motor, the predetermined speed of said motor being regulated to maintain said predetermined value; (c) a motor control comprising a feedback circuit located in an elongated chamber within said housing for providing a driving voltage to said motor whereby said motor is caused to operate at said predetermined speed; (d) a shaft engaged to said motor for accepting the output of said motor; (e) a two stage pump in communication with said shaft and responsive to the speed of said motor whereby the rate of flow of fuel therethrough is a function of the speed of said motor; (f) said two stage pump including a first gerotor engaged to said shaft and located between stationary inlet and outlet plates of a primary section and a second gerotor engaged to said shaft and located between stationary inlet and outlet plates of a metering section; (g) an outlet port adjacent the opposite end of said substantially tubular housing for accepting the output of said two stage pump; (h) a cyclonic fuel separator located between said gerotors, said fuel separator, said two-stage pump and said motor being coaxially aligned within said tubular housing; (i) said fuel separator including (i) an adjacent pair of plates, each including a hemispherical surface channel, said plates being arranged to form a circular bore therebetween, (ii) a fuel inlet passage within one of said plates and a fuel outlet passage within the other of said plates, said plate including a fuel outlet passage being the inlet plate of said metering section of said pump, and (iii) said inlet passage and said outlet passage are oppositely disposed with respect to said circular bore; and (j) each of the elements of said unit is contained within said substantially tubular housing.