Patent ID: 8647082

Claim:
A fuel pump comprising: a motor section; and a pump section driven by the motor section, wherein the motor section comprises a rotor and a stator facing the rotor, the stator comprises at least two permanent magnet parts at least two magnetic material parts, and a housing, each of the permanent magnet parts being disposed along a first circumferential surface at an interval in a circumferential direction, each of the magnetic material parts being disposed between adjacent permanent magnet parts and making contact with the housing, the permanent magnet parts comprising a first permanent magnet part and a second permanent magnet part that composes a pair, a polarity of an inner surface of the first permanent magnet part being a north pole, and a polarity of an inner surface of the second permanent magnet part being a south pole, the housing being fixed to the outer surface of the permanent magnet part, the rotor comprises a first yoke facing the permanent magnet parts, the first yoke having a plurality of slots disposed along a second circumferential surface at an interval in the circumferential direction, the second circumferential surface being coaxial to the first circumferential surface, each of the inner surfaces of the permanent magnet parts is disposed on the first circumferential surface, each of the outer surfaces of the slots is disposed on the second circumferential surface, and faces the inner surface of the permanent magnet part, each of the magnetic material parts has an inner surface facing the outer surfaces of the slots, the inner facing surface including a region shifted from the first circumferential surface toward a radially outer side, at least a part of the shifted region in an axial direction being positioned in a range where the slots face the permanent magnet parts, and the shifted region in the circumferential direction being an arcuate surface and formed in an area including at least a first permanent magnet part side end of each magnetic material part, and a distance from the first circumferential surface to the shifted region is constant.