Patent ID: 8008819

Claim:
A spindle motor comprising: a rotor unit; and a stator unit arranged to rotatably support the rotor unit about a central axis through a fluid dynamic pressure generated in a lubricant held within a bearing gap between the rotor unit and the stator unit; wherein the bearing gap has an annular opening substantially coaxial with the central axis; the lubricant is arranged to define a capillary seal near the annular opening within the bearing gap; an oil buffer is provided between the rotor unit and the stator unit, the oil buffer is arranged to continuously expand in an outward direction from the annular opening of the bearing gap and to temporarily store the lubricant when the lubricant is filled into the bearing gap; an oleophobic material is arranged on a surface of the rotor unit and a surface of the stator unit adjacent the oil buffer; and at least one recess is provided on at least one of the surface of the rotor unit and the surface of the stator unit adjacent the oil buffer at a position closer to the bearing gap than the oleophobic material, the at least one recess being defined by a radially recessed surface which extends in a direction parallel or substantially parallel to the central axis.