Stator assembly with teeth having different cross-sectional profiles with stem and head portions

A rotary synchronous motor comprising:

• a stator assembly comprising:
• a stator having a plurality of teeth which are distributed around a circumference of the stator and point toward a central axis of the stator, the teeth alternately having a first cross-sectional profile and a second cross-sectional profile, a plurality of slots being formed between the teeth;
• and
• a plurality of coils which are disposed around the teeth having the first cross-sectional profile;
• wherein the second cross-sectional profile has a parallel-sided stem portion and an adjoining tapered head portion, and wherein a height of the stem portion of the second cross-sectional profile is less than a height of a respective one of the coils that is disposed around an adjacent one of the teeth having the first cross-sectional profile,
• wherein the head portion of the second cross-sectional profile is tapered in such a way that a smallest width of the head portion is in a range from 80% to 95% of a width of the stem portion of the second cross-sectional profile, and
• wherein the first cross-sectional profile has a parallel-sided portion along the height of the respective one of the coils, and wherein the teeth are arranged and the head portion of the second cross-sectional profile is tapered in such a way that an outer surface of the head portion of the second cross-sectional profile is oriented parallel to an outer surface of the parallel-sided portion of the respective one of the teeth having the first cross-sectional profile that is adjacent to a same respective one of the slots;
• and
• at least one rotor disposed in the stator assembly and adapted to rotate about the central axis of the stator assembly during operation of the rotary synchronous motor.