Fuel metering unit

摘要

A fuel metering unit (10) including a pump (12) having a rotor (36) with a plurality of slots. The pump (12) also includes a pivotally movable cam ring (40) coaxially arranged with respect to the rotor (36). Vanes (38) are slideably disposed in the slots for maintaining contact with the cam ring (40) during movement thereof. A servovalve (14) has a motor (100) and nozzles (90,92) operatively connected to the pump (12) such that increased flow through the first nozzle (92) pivots the ring of the pump toward maximum while increased flow through the second nozzle (90) pivots the ring toward minimum. An arm (94) extends between the nozzles (90, 92) for varying fluid flow therethrough. The arm (94) couples to the motor (100) such that the motor (100) moves the arm (94). A flow meter (16) connects to the pump (12) and an end of the arm (96) for applying a force against the arm (94) to assist in maintaining position of the arm (94).