Rotational noise reduction structure in dc motor with rotor magnets

摘要

A method and apparatus for reducing the rotational noise in dc motors with rotor magnets, comprising forming the rotor magnet so that its magnetic center plane is aligned with the geometric center plane of the stator core, thereby providing for a distribution of the air gap magnetic flux density about the magnetic center plane in an asymmetric manner and reducing the rotational noise of the motor without the need to reduce the axial dimensions of the magnet.