Dc motor with rotor slots closely spaced

Abstract

A direct current motor includes a substantially cylindrical rotor core and a lead wire wound around the rotor core to form a rotor coil. The rotor core has a plurality of shallower and deeper slots circumferentially and alternately disposed in the peripheral face of the rotor core at angular intervals about the center axis of the rotor core so that each of the shallower and deeper slots extends axially from the front face to the rear face of the rotor core. Each of the shallower slots includes first outer and inner radially aligned sections, each receiving a portion of the lead wire. Each of the deeper slots includes: second outer and inner radially spaced sections, each receiving a portion of the lead wire; and a neck section interposed between the second outer and inner sections. The distance between the second outer section of each deeper slot and the center axis of the rotor core is substantially equal to the distance between the center axis of the rotor core and the first outer section of each shallower slot. The distance between the second outer and inner sections of each deeper slot is longer than the distance between the first outer and inner sections of each shallower slot. The width of the neck section is substantially smaller than widths of the second outer and inner sections.