of the rotor and extending in the peripheral direction of the rotor. Each first arm portion has a first coupling portion at one end. Each second core sheet includes a plurality of second teeth laid out in a ring form on a second plane. Each second tooth has a second winding portion extending in the radial direction of the rotor and a second arm portion integrally provided at an outer end of the second winding portion in the radial direction of the rotor and extending in the peripheral direction of the rotor. Each second arm portion has a second coupling portion at one end. The first core sheets and the second core sheets are stacked in the axial direction of the rotor. Each first tooth is stacked onan associated one of the second teeth in the axial direction of the rotor. Each first tooth is coupled to that one of the second teeth which is stacked on another one of the first teeth adjoining in the peripheral direction of the rotor by coupling of the first and second coupling portions. A remaining portion of each arm portion, which excludes the associated coupling portion, is located further apart from the axis of the rotor than the associated coupling portion.
The present invention further provides a method of manufacturing a rotor of an electric motor, which comprises the steps of forming a plurality of first teeth and a plurality of second teeth by punching a metal plate, each tooth having a winding portion extending in one direction and