Patent ID: 6982513

Claim:
A recording disk drive motor employed in a recording disk drive that supports and rotates a replaceable recording disk that is 30 mm or less in diameter, the recording disk drive motor comprising: a stationary member which comprises: a stator core which comprises: a core back having a port formed in the core back by omitting a portion of the core back, and an arc shaped inner surface; and a plurality of stator teeth that are disposed so as to be equally spaced apart with each other and extend inward in the radial direction from the arc shaped inner surface of the core back; a base member on which the stator core is mounted; and polyphase windings that are wound around the stator teeth; a rotor which comprises: a rotor magnet that is disposed inside the arc shaped inner surface of the core back and which faces the stator teeth in a radial direction; and a recording disk mounting portion for supporting the recording disk; and a sliding bearing that is cylindrical in shape, has a through hole formed along a rotational axis of the rotor, and rotatably supports rotation of the rotor in the radial direction; wherein the sliding bearing is concentric with the arc shaped inner surface of the core back, and the rotor is magnetically attracted in the opposite direction of the port of the core back; and one end surface of the core back is disposed on each side of the port, and a distance between each end surface of the core back is equal to a distance on the arc shaped inner surface of the core back on which at least one stator tooth from each phase are disposed.