Abstract: A spindle motor includes a stationary portion and a rotating portion. The stationary portion preferably includes a shaft portion, an upper thrust portion, and an outer tubular portion. The rotating portion preferably includes an inner tubular portion, a flange portion, an upper hub annular portion, and a lower hub annular portion. The flange portion includes a communicating hole. An upper surface of a lubricating oil is located in a fifth gap defined between an upper thrust portion and an upper hub annular portion, while a lower surface of the lubricating oil is located in a sixth gap defined between an outer tubular portion and a lower hub annular portion. The communicating hole and a space extending from the fifth gap to the sixth gap through a fourth gap, a first gap, a second gap, and a third gap are continuously filled with the lubricating oil.

Abstract: A fluid dynamic bearing includes an auxiliary bearing portion, a first radial bearing portion and a second radial bearing portion arranged along an axial direction of the fluid dynamic bearing, wherein the auxiliary groove formed in the auxiliary bearing portion is shallower in depth than the radial dynamic pressure groove formed in the first radial bearing portion, and wherein a gap size in the auxiliary bearing portion is set to be equal to or larger than a gap size in the radial bearing portions.

Abstract: A fluid dynamic bearing mechanism includes a stationary shaft, a sleeve portion arranged to rotate with respect to the shaft, and a thrust portion including an upper end surface arranged oppose to a lower end surface of the sleeve portion. An inside surface of the thrust portion includes an inside surface contact portion arranged in contact with an outside surface of the shaft, and an inside surface lower non-contact portion spaced away from the outside surface of the shaft, and arranged to extend downward from a lower end of the inside surface contact portion. An outside surface of the thrust portion includes an outside surface inclined portion arranged in contact with an interface of a lubricating oil. The lower end of the inside surface contact portion is arranged at a level axially higher than that of a lower end of the outside surface inclined portion.

Abstract: A bearing mechanism includes a shaft, a sleeve portion, a thrust portion, and a cover portion. Lubricating oil is arranged in a communicating channel in the sleeve portion, a thrust gap between the sleeve portion and the thrust portion, and a tapered gap between an outside surface of the thrust portion and the cover portion. A lower end opening of the communicating channel is defined in an outer circumferential portion of a lower surface of the sleeve portion radially outward of the thrust gap. A radially outermost portion of the thrust portion is arranged either tangent to a wall surface of the communicating channel or closer to a central axis than the wall surface. The tapered gap is arranged closer to the central axis than a radially outermost point of the wall surface. The outer circumferential portion and the cover portion define a guide gap therebetween.

Abstract: A rotary head drum apparatus includes a stator drum. A rotary drum is provided with a plurality of magnetic heads and rotates the magnetic heads. The rotary drum is mounted for rotational movement with respect to the stator drum. A rotary transformer includes a stator-side rotary transformer provided on the stator drum and a rotating-side rotary transformer fixed to the rotary drum. The stator-side rotary transformer and the rotating-side rotary transformer are adapted to send and receive signals to each other. An adhesive providing gap is disposed between the rotating-side rotary transformer and the rotary drum for receiving an adhesive for bonding the rotating-side rotary transformer to the rotary drum. An adhesive splashing prevention part is provided on the rotating-side rotary transformer and receives adhesive splashing from the adhesive providing gap.