Patent ID: 6931652

Claim:
A spindle motor for a disk drive, which is used for a disk player, comprising: a deck plate; a shaft rotatably disposed on the deck plate; a stator composed of a metal baring disposed on the outer peripheral surface of the shaft, a holder disposed on an outer side of the metal bearing and a core having coils disposed on the outer peripheral surface of the holder; a pulling magnet which is provided at the upper part of the stator and generates a magnetic force; a cap type rotor which is coupled to the upper end of the shaft integrally with the shaft so as to be located at the upper part of the pulling magnet and the stator and is provided on the upper part with a track having a different height from another; a magnet which is disposed on the inner peripheral surface of the rotor so that it can be opposed to the core of the stator with an air gap therebetween; and a turntable which is disposed on the upper surface of the rotor integrally with the rotor and is composed of a disk chuck on which a disk is centered and mounted, a jaw which is disposed on the disk chuck and fixes the mounted disk and a disk seat which supports the mounted disk from a lower side; wherein the track is formed of three horizontal portions; wherein the horizontal portions have an upward staircase structure in which they become gradually elevated in the outward direction from the shaft coupled to the center of the rotor.