A stator assembly includes a strip stator core, a three-phase coil winding, and an end insulator. The strip stator core includes twelve stator core units, twelve connection parts, and twelve slots; every two adjacent stator core units are connected by one of the twelve connection parts; each slot is disposed between every two adjacent stator core units, and each stator core unit includes a yoke and a tooth protruding from one end of the yoke; every two adjacent teeth are abutted against each other to form one of the twelve slots. The three-phase coil winding includes a U-phase winding, a V-phase winding, and a W-phase winding. The end insulator includes a first end insulator and a second end insulator; the first end insulator includes a first coil-in pin, a second coil-in pin, a third coil-in pin, and a coil-out pin.