A motor assembly includes a stator including a stator core, a stator coil, and an insulator, and a rotor. The stator core includes a yoke, a plurality of teeth, and a shoe. The insulator includes an insulator body wrapping and insulating an outer surface of the shoe so that an inner end of the shoe is exposed to outside, and a creepage distance extension portion extending a creepage distance between the stator coil and the inner end of the shoe. The creepage distance extension portion includes an inner extension section extending from the end of the shoe along the circumferential direction, and an outer extension section extending outwardly from the inner extension section. Accordingly, the creepage distances between the stator coil and the stator core in the circumferential direction and the radial direction may be increased, respectively, without increasing the size of the stator in the radial direction.