Hub motor

A hub motor comprising:

• a housing as a power output;
• a supporting shaft disposed through the housing;
• an electric motor in the housing and the electric motor including a stator secured to the supporting shaft, and a rotor surrounding the stator and driven by the stator;
• and
• a planetary gear train surrounding the rotor and including a plurality of planet gear assemblies, a stationary ring gear at one end of the planet gear assemblies, and a driving ring gear at another end of the planet gear assemblies;
• wherein the driving ring gear is configured to rotate the housing, the planet gear assemblies and the rotor form an annular rotor, the planet gear assemblies are equally spaced apart around the rotor, each planet gear assembly includes a first planet gear and a second planet gear coaxial with and co-rotated with the first planet gear, the first planet gear meshes with the stationary ring gear, the second planet gear meshes with the driving ring gear, a number of teeth of the first planet gear is equal to that of teeth of the second planet gear, a number of teeth of the stationary ring gear is different from that of teeth of the driving ring gear, and a difference between the number of the teeth of the stationary ring gear and that of the teeth of the driving ring gear is a multiple of the number of the planet gear assemblies.