Spindle motor

Abstract

A spindle motor including a rotor hub which is rotationally driven by a magnetic action of a rotational magnetic field generated when a current is applied to a wire wound around teeth of a stator core and a magnetic field of a magnet provided on a rotor. Herein, the stator core formed by laminating magnetic steel plates is mounted to an outer periphery of a supporting part of a rotation support shaft of the rotor hub, and the supporting part is made of sintered metal containing a ferromagnetic material. This spindle motor can suppress generation of vibration and noise even when it is reduced in size.

1 . (canceled) 
   
   
       2 . (canceled) 
   
   
       3 . A spindle motor comprising:
 a stator comprising a stator core having teeth;   a wire wound around the teeth of the stator core; and   a rotor comprising a rotation support shaft, a rotor hubs and a magnet,   the rotor capable of being rotationally driven by a magnetic action of a rotational magnetic field created when a current is applied to the wire wherein   a support part of the rotation support shaft and the stator core are respectively made of sintered metal containing a ferromagnetic material, and   a hydrodynamic bearing comprising an operating fluid between the rotation support shaft and the supporting part, and   at least a portion of the supporting part of the rotation support shaft which comes into contact with the operating fluid is pore-sealed.   
   
   
       4 . (canceled) 
   
   
       5 . (canceled) 
   
   
       6 . (canceled) 
   
   
       7 . The spindle motor according to  claim 3 , wherein the ferromagnetic material comprises at least one of iron, nickel, cobalt, and an alloy thereof. 
   
   
       8 . The spindle motor according to  claim 3 , wherein the portion of the supporting part of the rotation support shaft is impregnated with a pore-sealing resin. 
   
   
       9 . The spindle motor according to  claim 8 , wherein the portion of the supporting part of the rotation support shaft is further plated. 
   
   
       10 . The spindle motor according to  claim 3 , comprising a shoulder on a lower part of an outer periphery of the supporting part, and the stator core is mounted on the shoulder of the supporting part.