US Patent 11060461 Fuel systems having reduced bypass flow

A fuel system for an engine can include a fuel circuit and a primary fuel pump in fluid communication with the fuel circuit and configured to pump fuel to the engine as a function of engine speed. The primary fuel pump is configured to pump insufficient fuel flow to the engine during at least one engine speed or speed range. The system also includes a supplemental fuel pump in fluid communication with the fuel circuit configured to selectively pump fuel to the engine at least during the at least one engine speed or speed range to supplement fuel flow from the primary fuel pump to provide sufficient total fuel flow to the engine during all engine speeds.