| 摘要 |
A spindle motor includes a flat stator, a rotor magnet arranged above the stator, and a magnetic portion made of a ferromagnetic material. The magnetic portion is positioned lower than the stator and the magnetic portion are axially overlapped with coils. A magnetic attraction force is generated between the magnetic portion and the rotor magnet. Since the magnetic portion is positioned lower than the stator, it is possible to cause magnetic fluxes to efficiently flow between the rotor magnet and the stator. Further, the stator includes a protrusion protruded radially outward beyond an outer circumferential portion of a rotor hub. Accordingly, in a plan view, the stator is positioned radially outward of the rotor hub. |
