A stator core (30) of a motor arrangement (13) includes six cores (32), which are arranged one after another in a circumferential direction. A bobbin (40), which is made of dielectric resin, is fitted to each core (32). Each coil (42) is formed such that a winding is wound around the bobbin (40) through a concentrated winding technique. Dielectric resin (46) is filled between each circumferentially adjacent two teeth (33) to cover each coil (42). Furthermore, the dielectric resin (46) is molded to form clearances (204), each of which is formed between the corresponding circumferentially adjacent two teeth (33) on a rotor (50) side. Fuel, which is pressurized by a pump arrangement (12), passes an interior of the motor arrangement (13) through a fuel passage (202), which is a gap between aninner peripheral surface of the stator core (30) and an outer peripheral surface of the rotor (50), and also through the clearances (204).