A stator for an electric machine is disclosed herein. In at least one embodiment, the stator comprises a stator core including a plurality of teeth with slots formed between the teeth. A winding arrangement is positioned on the stator core and includes a plurality of conductors forming a multi-phase winding. Each phase of the multi-phase winding includes a plurality of parallel paths arranged in the slots with the winding defined by at least four slots-per-pole-per-phase. The plurality of parallel paths include a first plurality of adjacent paths and a second plurality of adjacent paths, wherein the winding is weaveless and void of any weave between the first plurality of adjacent paths and the second plurality of adjacent paths. Start leads and finish leads for the plurality of parallel paths are all positioned on a same half of the stator core.

A method for the making of a stator for electric motors, comprising: providing two jigs, each having a circular opening inside the jig and a series of teeth inside the circular opening extending towards a central axis, the teeth defining a series of slots; arranging the two jigs coaxially spaced along a central axis; winding, between the teeth, a plurality of wires to form a plurality of windings, so the wires of each winding occupy a plurality of the slots of both jigs, the windings including linear wire portions extending between the two jigs; inserting, from the inside, a plurality of first stator portions between the linear wire portions; and inserting, from the outside, a plurality of second stator portions complementary to the first stator portions between the linear wire portions, to form a stator body.

A compound winding motor stator includes a stator core and a coil winding structure. The stator core has a yoke, and a plurality of winding portions formed toward the center of the yoke in an equally distanced manner. The winding portions are defined as a plurality of first winding portions and a plurality of second winding portions. The first winding portions and the second winding portions are arranged in a staggered manner. The coil winding structure has first windings configured as rectangular windings and disposed on the first winding portions, and second windings configured as trapezoid windings and disposed on the second winding portions. Accordingly, the rectangular windings and the trapezoid windings are arranged in a staggered manner, that improves the slot fill factor of the motor stator, thereby increasing the efficiency of the motor.

A compound winding motor stator includes a stator core and a coil winding structure. The stator core has a yoke, and a plurality of winding portions formed toward the center of the yoke in an equally distanced manner. The winding portions are defined as a plurality of first winding portions and a plurality of second winding portions. The first winding portions and the second winding portions are arranged in a staggered manner. The coil winding structure has first windings configured as rectangular windings and disposed on the first winding portions, and second windings configured as trapezoid windings and disposed on the second winding portions. Accordingly, the rectangular windings and the trapezoid windings are arranged in a staggered manner, that improves the slot fill factor of the motor stator, thereby increasing the efficiency of the motor.

A coil insertion device includes coil diameter expanders, the coil diameter expanders being configured to insert a coil assembly in a wound state into slots of a stator core by expanding the coil assembly in diameter from inside of the stator core, each of the coil diameter expanders includes: a coil presser that is arranged inside the coil assembly and presses coil end portions of the coil assembly outward from inside to expand the coil end portions in diameter; and a restrictor that is arranged outside the coil assembly, restricts outward movement of the coil end portions expanded in diameter by the coil presser, and sandwiches the coil end portions of the coil assembly inserted in the slots with the coil presser.

A coil insertion device includes coil diameter expanders, the coil diameter expanders being configured to insert a coil assembly in a wound state into slots of a stator core by expanding the coil assembly in diameter from inside of the stator core, each of the coil diameter expanders includes: a coil presser that is arranged inside the coil assembly and presses coil end portions of the coil assembly outward from inside to expand the coil end portions in diameter; and a restrictor that is arranged outside the coil assembly, restricts outward movement of the coil end portions expanded in diameter by the coil presser, and sandwiches the coil end portions of the coil assembly inserted in the slots with the coil presser.