Motor stator and phase coil preform

A phase coil preform used for a stator of a motor, wherein the stator of the motor has a stator core having a plurality of teeth forming slots between any two adjacent teeth, wherein a plurality of phase coils formed by wave winding are provided in the slots, wherein the phase coil preform forming the phase coil is made of a continuous wire, wherein

• the phase coil preform comprising:
• a first wave winding bundle preform, wherein the first wave winding bundle preform including:
• a plurality of first convex portions, the respective first convex portion being convexed in a radial direction of the first wave winding bundle preform;
• a plurality of first concave portions, the respective first concave portion being concaved in a radial direction of the first wave winding bundle preform;
• and
• a plurality of first slot passing portions provided between any first convex portion and its adjacent first concave portion;
• wherein the first phase coil preform is of an annular shape having the first convex portion and the first concave portion arranged alternately, and
• a second wave winding bundle preform, wherein the second wave winding bundle preform including:
• the same number of second convex portions as the first convex portions, the respective second convex portion being convexed in a radial direction of the second wave winding bundle preform;
• the same number of second concave portions as the first concave portions, the respective second concave portion being concaved in a radial direction of the second wave winding bundle preform;
• and
• the same number of second slot passing portions as the first slot passing portions provided between any second convex portion and its adjacent second concave portion;
• wherein the second phase coil preform is of an annular shape having the second convex portion and the second concave portion arranged alternately, wherein the second slot passing portion is located inward of the first slot passing portion.