An external rotor motor includes: a shaft, an insulator and a core. The insulator is coupled with an outer peripheral surface of the shaft, the core is arranged on an outer periphery of the insulator, and the insulator is formed between the shaft and the core, so that no electrically conductive route can be formed between the core and the shaft. A rotor has a housing rotatably coupling with the shaft, with an inner peripheral wall of the housing having a permanent magnet module.