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An electronically commutated dc motor having a dome-shaped external rotor and a stator having a double-T-shaped design with the stator consisting of one yoke stack disposed asymmetrically in relation to the longitudinal stator axis and of two pole stacks of which each is provided with an extension o

An electronically commutated dc motor having a dome-shaped external rotor and a stator having a double-T-shaped design with the stator consisting of one yoke stack disposed asymmetrically in relation to the longitudinal stator axis and of two pole stacks of which each is provided with an extension on the same side in the longitudinal direction. In the circumferential direction the extensions are provided with lugs.

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An electronically commutated direct current motor comprising, in combination: a direct current motor including a rotor having a dome-shaped body comprised of magnetizable material having a permanent magnet disposed on an inner circumference of said dome-shaped body, said rotor being a bipolar extern

An electronically commutated direct current motor comprising, in combination: a direct current motor including a rotor having a dome-shaped body comprised of magnetizable material having a permanent magnet disposed on an inner circumference of said dome-shaped body, said rotor being a bipolar external rotor; a stator located within said permanent magnet and including a yoke stack and a plurality of pole stacks and further including a longitudinal stator axis providing a longitudinal axis of symmetry through said motor; a plurality of coilforms carried by said yoke having a plurality of stator windings wound on said coilforms, said stator winding for providing an alternating current field, said stator having a double T-shaped design with said stator winding being disposed on a common leg of said double T-shaped stator, said pole stacks and said yoke stack with said stator windings wound thereon being disposed asymmetrical to said longitudinal stator axis; a plurality of stator pole stack extensions projecting in the same circumferential direction and separated from said permanent magnet by a constant air gap, said air gap located between said stator and said rotor, said stator alternating current field having a polar axis staggered parallel to said longitudinal stator axis by a fixed distance and said rotor permanent magnet having a polar axis orthogonal to a rotor neutral zone and displaced from said stator alternating current polar axis by a non-zero angle epsilon when said stator winding is currentless; a rotor shaft penetrating said dome-shaped body for turning an external load; a printed circuit board mounted adjacent to said coilform and supported by a mounting flange within said dome-shaped body, said printed circuit board having an electronic circuit for providing commutation of an input signal; and a plurality of lugs connected to said plurality of stator pole stack extensions, each of said pole stack extensions including one of said plurality of lugs for further projecting each of said pole stack extensions along a circumferential direction of said plurality of pole stacks for providing a single defined rest position for said rotor when said stator windings are currentless and wherein said plurality of lugs connected to said plurality of stator pole stack extensions provides a non-constant magnetic resistance to said rotor along the circumference of said stator creating said non-zero angle epsilon and said single defined rest position of said rotor when said stator winding is currentless for providing an optimal starting torque for said direct current motor.