FUEL PUMP APPARATUS

摘要

A fuel pump apparatus (20) for maintaining fuel flow when the surface of the fuel in a fuel tank (l0) is below a minimum level. The fuel pump apparatus includes a reservoir (54) in the fuel tank and a pump (60) in the reservoir. A motor in the pump drives a first pump (78) which draws fuel from a secondary chamber (l29) of the pump and discharges it to the engine. The motor also drives a second pump (76) which draws fuel from the tank through a primary chamber (l36) and discharges it to the secondary chamber. The excess of fuel discharged by the second pump over the first pump is discharged through a flow orifice (l32) in the pump to the reservoir. At fuel levels below the minimum, a float (l48) controlled solenoid (l56) closes an inlet port (l42) to the primary chamber causing fuel to back-flow through the flow orifice to the secondary chamber to supply the first pump.