Development of a miniature axial-field spindle motor

This paper presents the development of a miniature axial-field spindle motor. Such a spindle motor could play a very important role in modern storage devices, which demand increasingly large storage capacity under limited physical space, especially for the miniature hard-disk drive or small-form-factor optical (SFFO) storage drive developments. In the present paper, an axial-field motor structure was employed to facilitate the design of a miniature spindle motor of a low profile height. In addition, the axial spoolless coil windings, which eliminate the cogging torque due to slot, serve as the electromagnetic exciting source.