Patent ID: 8264113
Filing Date: 2012-09-11
Classification: H02K

Abstract:
1. A brushless motor comprising a stator including a plurality of teeth around which coils are wound, and a rotor, which is rotatable with respect to the teeth and includes a plurality of magnetic pole portions that face the teeth, wherein the rotor includes a plurality of magnet accommodating portions arranged at equal angular intervals along the circumferential direction of the rotor, permanent magnets forming the magnetic pole portions are accommodated in the magnet accommodating portions, and the permanent magnets face the teeth and have magnetic pole surfaces of the same polarities, wherein the rotor includes gaps that function as magnetic resistance at circumferential ends of each of the magnetic pole portions so that an iron core portion is formed between circumferentially adjacent magnetic pole portions, and magnetic flux of the magnetic pole portions passes through the iron core portion along the radial direction, wherein a magnetic member is arranged in each magnet accommodating portion to fill the gap between the magnetic pole surface of the associated permanent magnet and the inner surface of the magnet accommodating portion facing the magnetic pole surface, wherein the rotor is rotatably arranged radially inward of the stator, and wherein each magnetic member is arranged in the associated magnet accommodating portion to abut against only the radially inner magnetic pole surface of the corresponding permanent magnet.