Abstract: This invention relates to a coil construction for an electric motor comprising a stator having a plurality of slots and teeth, a plurality of windings Uc, Vc and Wc of the respective phases are arranged as a plurality of coil series C.sub.1 and C.sub.2, said coil series C.sub.1 and C.sub.2 are wound independently each other, whereby it is able to procure a high redundancy of said coil series C.sub.1 and C.sub.2.

Abstract: A brushless DC motor in which a rotary axis is rotatably mounted in a bearing portion of a stator housing, a rotor yoke is fixedly mounted on an end portion of said rotary axis, a magnet member is mounted on the face of said rotor yoke, a return yoke of ring shape is mounted to one face of said stator housing, a plurality of circumferentially extending cavity portions are formed in said return yoke spaced apart from each other in the radial direction relative to the rotary axis, and a driving coil is positioned facing said rotor yoke.Therefore, core loss caused in said return yoke is reduced by said cavity portions of said return yoke, whereby it is able to obtain high stability at high speed rotation.

Abstract: A brushless d.c. motor having a stator including a stator core with a plurality of Y-shaped magnetic poles. The magnetic poles have a first portion which extend radially outwardly from a hub portion of the core, second portions which extend from an outer end of the first portion in the opposite circumferential directions and third portions that extend from a tip of the second portions to the radially outer direction. A first stator windings are wound on the first portions of the magnetic pole and serially connected to each other for each of the magnetic poles, and second windings are wound on one of the third portions and the adjacent third portion of the contiguous magnetic pole, and serially connected to each other. The phases of the stator windings are shifted relative to each other.