Fluid dynamic bearing device, spindle motor, and hard disk drive device

A fluid dynamic bearing device comprising:

• a fixing portion having a shaft and two conical bearing members fixed to the shaft,
• a rotating portion supported relatively rotatably with respect to the fixing portion,
• two dynamic bearing portions formed by conical bearing surfaces arranged on the two conical bearing members and two rotor side conical surfaces which are inner circumferential surfaces of the rotating portion facing the conical bearing surfaces, and
• a lubricating oil arranged in the two dynamic bearing portions,
• wherein the lubricating oil is arranged being separated by a separator portion, the separator portion holds an air layer and is arranged between the two conical bearing members,
• two primary tapered seal portions are respectively connected to each axial end of the separator portion,
• widths in a radial direction of the two primary tapered seal portions are shortened approaching toward the two conical bearing members,
• a gas-liquid interface of the lubricating oil is located at each of the two primary tapered seal portions,
• an oleophobic agent blocking portion is arranged at each axial end of the separator portion,
• a separator central portion is arranged between each oleophobic agent blocking portion of the separator portion, and
• an oleophobic coating is formed at least at the separator central portion of the separator portion.