Abstract: An embodiment rotor includes a stacked core including stacked lamination sheets. The lamination sheets include lamination segments arranged in a circle, the stacked core has an upper layer lamination segment coupled to a lower layer lamination segment with a phase difference therebetween of a first angle with respect to a center of the stacked core, the stacked lamination segments have keys arranged in a straight line on an inner surface of the stacked core so that the keys are inserted into a key way disposed in a motor shaft in an axial direction, the lamination segments have a substantially identical shape and are arranged with an interval of a second angle with respect to a center of the rotor thus having a substantially identical pattern, and the lamination segments include upper and lower layer coupling portions repeatedly disposed at intervals of the second angle in a circumferential direction.