Patent ID: 7859165
Filing Date: 2010-12-28
Classification: F02M,F04D,H02K,Y10T

Abstract:
1. A fuel pump comprising: a pump portion for pumping fuel; a magnet having a plurality of magnetic poles circumferentially alternate with each other; an armature provided on a radially inside of the magnet, the armature including a rotor core provided with a coil formed of a wire, the armature being rotatable for driving the pump portion; and a commutator being in a substantially disc shape provided to an axial end of the armature for rectifying electricity supplying to the coil, wherein the pump portion includes a rotor member adapted to be driven using the armature and a case member for rotatably accommodating the rotor member, the rotor core has an axial end having an outer circumferential periphery defining a commutator-side collar portion on a side of the commutator, the commutator-side collar portion extending toward the commutator, the commutator-side collar portion being formed by bending a magnetic plate, the coil is formed by winding the wire from a gap between an outer circumferential periphery of the commutator and the commutator-side collar portion to a portion between the axial end of the rotor core on the side of the commutator and an axial end of the commutator on a side of the rotor core, the rotor core has an other axial end having an outer circumferential periphery defining a case-side collar portion on a side of the case member, the case-side collar portion extending toward the case member, the coil has an outer circumferential periphery including a radially outer portion on a side of the case member, the radially outer portion having an outer height, the coil has a radially inner portion on a side of a rotation axis of the armature on the side of the case member, the radially inner portion having an inner height, the outer height is greater than the inner height, the armature has a recess around the rotation axis on a side of the case member, and the coil is further formed by winding the wire from an inner circumferential periphery of the case-side collar portion to a portion between the axial end of the rotor core on the side of the case member and a bottom of the recess.