Stator and motor

A stator, comprising:

• an iron core back, configured to be a circular ring with a center axis which extends along an up and down direction as the center;
• multiple teeth, wherein the teeth protrude from the iron core back towards the radial inner side;
• an insulating part, wherein the insulating part covers at least axial end faces of the multiple teeth;
• coil groups, wherein the coil groups are respectively wound on the multiple teeth across the insulating part;
• multiple bus bars, wherein each of the multiple bus bars is provided with a coil connecting part and an external power supply connecting part, the coil connecting part is connected with the coil group, and the external power supply connecting part is connected with the external power supply;
• and
• a bus bar retainer, configured to support the multiple bus bars,
• the stator has the following characteristics:
• the coil group is provided with a first end part, a second part, multiple coils respectively wound on the multiple teeth, and a transition line part configured to connect the multiple coils,
• the first end part is provided with a first overlapping part having the same position as at least a part of the second end part in the circumferential direction,
• the second end part is provided with a second overlapping part having the same position as the first overlapping part in the circumferential direction, and
• the coil connecting part is connected with the first overlapping part and the second overlapping part.