Patent ID: 6847144

Claim:
A permanent magnet rotor assembly for a brushless electric motor, comprising: at least two main magnetic poles, disposed on a periphery of a rotor, each of said at least two main magnetic poles having a mechanical opening angle A which covers N/2 times an angle of a stator segment, with N being an odd number that is greater than or equal to 3, so as to yield a closest value smaller than 360/P degrees, with P being the number of said at least two main magnetic poles, with each of said at least two main magnetic poles having a central section R 1 and two end sections R 2 , with R 1 having an opening angle A 1 which covers N/2 times said angle of each of said stator sections, with N being an odd number greater or equal to 3, and A 1 being smaller than said opening angle A; wherein each of said at least two main magnetic poles has a permanent magnet composed of two plates with two ends located in central positions and protruding outward.