Spindle motor

A spindle motor comprising:

• a base member having a stator core fixedly installed therein;
• a sleeve fixedly installed on the base member;
• a shaft inserted into the sleeve and rotating;
• and
• a rotor hub fixedly installed on the shaft and including a body having a disk shape, a magnet mounting part extended from an edge of the body in a downward axial direction and having a driving magnet installed on an inner surface thereof, and a disk supporting part extended from the magnet mounting part in an outer diameter direction,
• wherein the driving magnet is installed on the magnet mounting part so that the magnetic center thereof in an axial direction is disposed in a position higher than that of the magnetic center of the stator core in the axial direction in order to generate force directed in a downward axial direction by interaction with the stator core, and
• the stator core is formed of a soft magnetic material and includes protrusion parts formed at a front end portion thereof disposed to face the driving magnet and extended therefrom in the axial direction.