Patent ID: 7456540
Filing Date: 2008-11-25
Classification: H02K

Abstract:
1. A motor comprising: a cylindrical rotor magnet centered on a center axis and having a circular cross section perpendicular to the center axis; a plurality of magnetic pole teeth formed by a first core and a second core stacked in an axial direction parallel to the center axis, each of the first core and the second core having a radially extending portion which extends in a radial direction perpendicular to the center axis and a radial end which faces the rotor magnet and is curved when viewed along the center axis, wherein a first radius of curvature of the radial end of the first core is different from a second radius of curvature of the radial end of the second core; coil windings respectively arranged around the magnetic pole teeth; a rotor operable to hold the rotor magnet; and a bearing mechanism operable to support the rotor in a rotatable manner relative to the magnetic pole teeth.