Abstract: A bearing apparatus includes stationary and rotating portions. The stationary portion includes a stationary shaft and a first cup portion. The rotating portion includes an annular recessed portion and first and second inner circumferential surfaces. Lubricating oil is arranged in a gap between the stationary and rotating portions. An upper surface of the lubricating oil is located between the second inner circumferential surface and an outer circumferential surface of the first cup portion. A lower surface of the lubricating oil is located between the rotating and stationary portions. The rotating portion further includes a through hole filled with the lubricating oil. One of the first cup portion and the rotating portion includes a pumping groove array arranged thereon to cause the lubricating oil to flow toward one end of the through hole during rotation of the rotating portion.

Abstract: In a bearing apparatus, a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a circular plate portion and a cylindrical portion projecting downward from an outer edge portion of the circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the cylindrical portion. Accordingly, it is possible to limit the axial dimension of the bearing apparatus while also enabling a radial dynamic pressure groove array. Additionally, one end of a through hole defined in the rotating portion is arranged to open into the annular recessed portion.

Abstract: A bearing apparatus includes a stationary shaft, a first annular member, and a rotating member. The rotating member includes a first inner circumferential surface arranged opposite to the outer circumferential surface of the stationary shaft, and a second inner circumferential surface arranged opposite to an outer circumferential surface of the first annular member. A lubricating oil is arranged in a gap between a surface of a stationary member and the rotating member. On an upper side of an upper surface of the lubricating oil, the first annular member and the rotating member are arranged radially opposite to each other with a slight gap defined therebetween, so that a labyrinth seal is defined. The labyrinth seal and a fixing range over which the stationary shaft and the first annular member are fixed to each other are arranged to overlap with each other in a radial direction.

Abstract: A bearing apparatus includes a shaft, a thrust cup including an annular potion and a cylindrical portion, a rotating member including a through hole defined therein, and a lubricating oil. A second gap defined between a lower surface of the rotating member and an upper surface of the annular portion of the thrust cup includes a first region in communication with a capillary seal portion, and a second region positioned radially inward of the first region and having an axial dimension smaller than that of the first region. A lower end portion of the through hole is open at a location radially outwardly away from a boundary between the first and second regions, so that a local circulation of the lubricating oil arises within the first region during rotation of the rotating member.

Abstract: In a bearing apparatus, a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a circular plate portion and a cylindrical portion projecting downward from an outer edge portion of the circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the cylindrical portion. Accordingly, it is possible to limit the axial dimension of the bearing apparatus while also enabling both a radial dynamic pressure groove array and a pumping groove array to have a sufficient axial dimension. Additionally, one end of a through hole defined in the rotating portion is arranged to open into the annular recessed portion, so that any air bubbles introduced into a lubricating oil by the pumping groove array can be efficiently caused to flow downward through the through hole and out of the bearing apparatus.

Abstract: A dynamic pressure bearing has a reduced axial dimension and is constructed to ensure smooth feeding of a lubricating oil. The dynamic pressure bearing includes a communicating hole and at least one tapered seal, and is constructed such that an opening angle of one of the at least one tapered seal through which oil feeding is possible is in a range of about 30 degrees inclusive to about 180 degrees exclusive, a tapered seal wall surface depth W1 of the tapered seal is about 0.3 mm or more, and a sum of distances over which the lubricating oil travels from both sides of an end portion of the communicating hole in a cross-section beyond a wall surface of the communicating hole along a wall surface opposite the end portion of the communicating hole exceeds an inside diameter of the communicating hole.

Abstract: According to the preferred embodiment of the present invention, a production method of a fluid dynamic bearing including: a shaft arranged along a center axis; an annular portion expanding radially outwards from the shaft; a sleeve having a top surface opposed to an under surface of the annular portion, for supporting the shaft and the annular portion in a relatively rotatable manner; and a lubricating fluid interposed between the shaft and annular portion and the sleeve, includes the step of preparing the annular portion having a substantially annular edge surrounding the center axis on the under surface; the step of applying a forming liquid for forming a solid lubricating film on the radially outer side of the edge of the under surface; and the step of evaporating a solvent of the forming liquid.

Abstract: A bearing apparatus includes a shaft, a thrust cup including an annular potion and a cylindrical portion, a rotating member including a through hole defined therein, and a lubricating oil. A second gap defined between a lower surface of the rotating member and an upper surface of the annular portion of the thrust cup includes a first region in communication with a capillary seal portion, and a second region positioned radially inward of the first region and having an axial dimension smaller than that of the first region. A lower end portion of the through hole is open at a location radially outwardly away from a boundary between the first and second regions, so that a local circulation of the lubricating oil arises within the first region during rotation of the rotating member.

Abstract: In a bearing apparatus, a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a circular plate portion and a cylindrical portion projecting downward from an outer edge portion of the circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the cylindrical portion. Accordingly, it is possible to limit the axial dimension of the bearing apparatus while also enabling both a radial dynamic pressure groove array and a pumping groove array to have a sufficient axial dimension. Additionally, one end of a through hole defined in the rotating portion is arranged to open into the annular recessed portion, so that any air bubbles introduced into a lubricating oil by the pumping groove array can be efficiently caused to flow downward through the through hole and out of the bearing apparatus.

Abstract: A fluid dynamic bearing device includes a shaft and a sleeve, with the shaft or the sleeve having a greater hardness being smoothed to have about 0.02 ?m or less of the arithmetical average of the surface roughness. The hardness of the shaft or the sleeve having a greater hardness is a Vickers hardness of about 100 Hv or greater at a portion that is arranged to come into contact with the other of the shaft or the sleeve. Further, the hardness of the other of the shaft or the sleeve is a Vickers hardness of about 600 HV or smaller at a portion arranged to come into contact with the shaft or the sleeve having a greater hardness. A clearance of a radial gap defined between the shaft and the sleeve S is about 1.3 ?m to about 2.5 ?m.