Motor stator winding structure

A motor stator winding structure comprising:

• a ring-shaped stator core defining a rotor accommodation space at a center of the stator core, wherein the stator core comprises an insertion side and an extension side allowing a plurality of hairpin wires inserted from the insertion side and extended out from the extension side;
• a plurality of slot-positions disposed on the stator core and surrounding the rotor accommodation space circumferentially, the slot-positions forming a plurality of radially-adjacent slot-position layers, the stator core comprising a plurality of polar regions, each polar region comprising a plurality of phases, each phase comprising a plurality of phase slots,
• wherein the hairpin wires are configured to be disposed into the slot-positions of the phase slots of the same phases of the polar regions, the hairpin wires are connected to form a plurality of parallel windings, the windings comprise:
• at least one first phase winding comprising a plurality of first hairpin wires of the hairpin wires inserted from an entry phase slot-position of a first phase, and comprising a plurality of first phase return connection wires;
• at least one second phase winding comprising a plurality of second hairpin wires of the hairpin wires inserted from an entry phase slot-position of a second phase, and comprising a plurality of second phase return connection wires;
• and
• at least one third phase winding comprising a plurality of third hairpin wires of the hairpin wires inserted from an entry phase slot-position of a third phase, and comprising a plurality of third phase return connection wires,
• wherein the entry phase slot-position of the first phase, the entry phase slot-position of the second phase and the entry phase slot-position of the third phase are located in three different polar regions respectively,
• wherein the first phase return connection wires, the second phase return connection wires and the third phase return connection wires have respective portions that protrude from the insertion side of the stator core and are not overlapped with each other in an axial direction of the stator core.