Patent ID: 6768242
Filing Date: 2004-07-27
Classification: H02K

Abstract:
A motor structure having an inner rotor assembly, the motor structure comprising:a stator including annular stator yokes each having a plurality of pole teeth located along an inner circumference thereof and coils arranged inside said stator yokes, each coil being constructed by winding a magnet wire; and a yoke-less rotor rotatably disposed with a small gap from said pole teeth of said annular yokes and having a permanent magnet arranged opposite to said pole teeth, wherein said permanent magnet comprises a sleeve fitted to a rotor shaft and a rare earth magnet further comprising a plurality of discrete segment magnets which are arranged apart from each other on an outer surface of the rotor with a thermoplastic material that fills a space between the rotor shaft and each segment magnet and a space between adjacent segment magnets.