PUMP

摘要

Disclosed is a pump provided with a rotor and a stator. The rotor rotates as a result of a magnetic field generated by the stator. The rotor has an impeller and a permanent magnet. The rotor has an axial direction, a circumferential direction, and a radial direction. The rotor has a through-hole along the axial direction. The permanent magnet is a bonded magnet, and thus has a weld line going from the inside to the outside in the radial direction. The permanent magnet also has a plurality of magnetic poles arranged along the circumferential direction. There are boundary planes between adjacent magnetic poles. The through-hole is offset in the circumferential direction from the weld line and the boundary planes.