Patent ID: 8520335
Filing Date: 2013-08-27
Classification: F16C,H02K

Abstract:
1. A spindle motor comprising: a stationary portion including a stator; and a rotating portion including a rotor magnet, the rotating portion being rotatably supported by the stationary portion through a lubricating oil; wherein the stationary portion includes: the rotating portion includes a sleeve portion arranged opposite to an outer circumferential surface of the shaft portion and a lower surface of the upper thrust portion; the outer circumferential surface of the shaft portion and an inner circumferential surface of the sleeve portion are arranged to have a radial dynamic pressure bearing portion defined therebetween, while the lower surface of the upper thrust portion and an upper surface of the sleeve portion are arranged to together define a thrust gap therebetween; the shaft portion includes a female screw portion recessed axially downward from an upper end thereof; an upper end of the single continuous monolithic member defined by the shaft portion and the upper thrust portion includes an upper end annular surface arranged to extend radially outward from the female screw portion perpendicularly or substantially perpendicularly to the central axis; an outside diameter of the upper end annular surface is greater than a diameter of the outer circumferential surface of the shaft portion; the upper thrust portion includes an outer annular surface and another annular surface, the outer annular surface being perpendicular or substantially perpendicular to the central axis and arranged radially outward of the upper end annular surface and at a level lower than that of the upper end annular surface; and the upper end annular surface and the outer annular surface are joined to each other through the another annular surface.