US Patent 7497669 Wesco type fuel pump

To make a Wesco type fuel pump to supply pressure-increased fuel toward a fuel injection valve with no time delay at a time of restarting an engine, an impeller (8) which is rotated by an electric motor (M) arranged within a motor chamber (9) is arranged within a pump chamber (7), a fuel inflow passage (6) which communicates with the outside and a discharge hole (5) which communicates with the motor chamber (9) are open to the pump chamber (7), and the discharge hole (5) is provided with a fuel holding function which inhibits air from flowing into the motor chamber (9) from the pump chamber (7) at a time when the engine stops.