Patent ID: 7667361

Claim:
An electric motor comprising: a rotor having a permanent magnet that is substantially cylindrical in shape, the rotor having an axial through-hole and an end portion formed with a first recessed portion, a bottom portion of the first recessed portion being formed with a second recessed portion having an inner diameter smaller than that of the first recessed portion and larger than that of the axial through-hole; a rotational shaft extending through the axial through-hole and mounted to the rotor along a center of rotation of the rotor for rotation therewith; a stator that covers an outer peripheral portion of the rotor and that forms a magnetic field that interacts with a magnetic field of the permanent magnet to generate a torque around the rotational shaft to thereby rotate the rotational shaft and the rotor; a bearing for rotatably supporting the rotational shaft, the bearing being entirely spaced-apart from the end portion of the rotor; a slider that is substantially plate-like in shape and that is slidably mounted around the rotational shaft and supports rotation of the rotational shaft about a rotational axis thereof, the slider being interposed between the bearing and the end portion of the rotor and having a portion that extends into the first recessed portion of the rotor in an axis line direction of the rotational shaft so as to contact the bottom portion of the first recessed portion and not extend into the second recessed portion formed in the bottom portion of the first recessed portion, the second recessed portion forming a space between the rotor and the portion of the slider to thereby reduce a contact area between the slider and the rotor; and a lubricant stored in the second recessed portion formed in the bottom portion of the first recessed portion and filled between the rotor and the portion of the slider that extends into the first recessed portion.