Axial gap-type electric motor equipped with coreless stator, and water pump using same

A water pump comprising:

• a pump housing having a space in a sealing state on one side thereof, in which, on the other side thereof, an inlet through which a fluid is introduced and an outlet through which the introduced fluid is discharged are connected through a fluid flow passage;
• a rotor rotatably supported on the fluid flow passage;
• an impeller integrally formed with the rotor on an upper side of the rotor;
• a stator arranged in the lower space to generate a rotating magnetic field to rotatably drive the rotor;
• and
• a partition wall arranged inside the pump housing to separate the rotor from the stator, wherein
• the rotor and the stator form an axial gap-type electric motor, and
• the stator comprises:
• 3-phase (U, V, W) coils split and wound in advance in a fan shape and having a through-hole therein in coreless and bobbinless structures;
• and an auxiliary printed circuit board (PCB) on which the split and wound 3-phase (U, V, W) coils are mounted spaced apart on the same circumference and a plurality of conductive patterns for establishing 3-phase Y-connections of the 3-phase (U, V, W) coils are formed, wherein
• start lines of the 3-phase (U, V, W) coils are respectively connected to 3-phase (U, V, W) output terminals of an inverter circuit, and end lines of the 3-phase (U, V, W) coils are commonly connected to each other to form a Y-connection neutral point (COM).