Abstract: A pivot bearing includes a stepped shaft having an enlarged diameter shaft portion and a reduced diameter shaft portion; a plurality of balls of a lower row are interposed between the enlarged diameter shaft portion and a sleeve outer ring surrounding the enlarged diameter shaft portion; a ball bearing including inner and outer rings and a plurality of balls interposed therebetween is provided around the reduced diameter shaft portion so that the inner ring is secured around the reduced diameter shaft portion while applying an appropriate pre-load on the upper end surface of the inner ring, and the outer ring is urged to contact the lower surface thereof intimately onto the upper surface of the sleeve outer ring. The pivot bearing has a reduced number of parts, is facilitated in incorporation into a swing arm, and is expected to be manufactured at a reduced cost.

Abstract: The object of the present invention is to provide a blower in which electrical components such as printed circuit board or electronic parts are isolated from the wind flowing through the blower to protect these components from moisture, dirt, dusts, or other harmful gas or substance contained in the wind, and to prevent the degradation of the insulating property such as the electric insulation or dielectric strength.

Abstract: A spindle motor of the present invention is capable of keeping its ball (5a, 5b)'s pre-load constant, because a sleeve (6) is capable of being resiliently deformed due to its resiliency, and therefore capable of constantly keeping a pre-load applied to the balls (5a, 5b) from inner and inner ring raceways of inner and outer rings (3a, 4a, 3b, 4b) of ball bearings (3, 4). In this motor, a rotor hub (7) has an axial center bore (8). This bore (8) is provided with: a large-diameter bore portions in its opposite axial ends; and, a small-diameter bore portion (8a) axially interposed between the large-diameter bore portions. An inner diameter of the small-diameter bore portion (8a) is smaller than an outer diameter of the sleeve (6).

Abstract: A spindle motor comprising a double row bearing device including a shaft, a sleeve surrounding the shaft, and a pair of upper and lower rows of balls, a cylindrical bearing holder extending upwardly from a base of the spindle motor for accommodating the sleeve within a vertical bore of the holder, and a rotor hub mounted on the shaft for journaling the rotor hub rotatably on the base, the spindle motor is characterized in that a reduced inner diameter portion of an inner diameter smaller than the outer diameter of the sleeve is formed on the inner surface of the bore of the bearing holder between the upper and lower larger inner diameter portions to urge the sleeve inwardly by the reduced inner diameter portion to deform it elastically to form a squeezed portion protruding inwardly of the sleeve between the upper and lower rows of balls.

Abstract: A retainer for a ball bearing being characterized in that each pocket includes upper halves following the entrance, a pair of lower halves following the upper halves, and a bottom portion disposed between lower halves, wherein an inner peripheral surface of each upper half presents a curved surface of a radius of curvature slightly larger than that of the ball to be retained therein in both peripheral and width directions of the pocket, an inner peripheral surface of each lower half descending inwardly, the inner peripheral surface of each lower half and an inner surface of the bottom portion each presents a configuration which has a shape of curved surface in the width direction of the pocket and of a straight shape in the peripheral direction of the pocket so as to contact tangentially with the ball so as to contact tangentially with the ball to be retained.

Abstract: The object of the present invention is to provide a compound bearing apparatus having arrangements for preventing the lubricant present around the rotating bodies from leaking out to the outside as well as the interior space between two rows of rotating bodies of the bearing apparatus. This is effected for the purpose of providing the compound bearing apparatus and a spindle motor and a swing arm assembly for a hard disk drive device including such bearing apparatus in which the sufficient amount of lubricant can be retained around the rotating bodies to obtain long life feature and having substantially no noise or vibration due to the loss of lubricant.

Abstract: A double seal bearing includes a labyrinth seal mechanism. The double seal bearing is provided with a pair of annular inner and outer sealing plates having respective central openings with a remaining slight clearance between each respective sealing plate and one of the inner and outer races, respectively, so as to assure the labyrinth seal function.

Abstract: A bearing apparatus including inner and outer rings and balls interposed therebetween, the apparatus being characterized in that it comprises: a low expansion ring press fit around the outer periphery of the outer ring, wherein the low expansion ring is made of a material with lower factor of linear thermal expansion than the outer ring material.

Abstract: A compound bearing apparatus including a shaft, a cylindrical outer ring member surrounding the shaft, and a plurality of balls of the first and the second rows interposed between the shaft and the outer ring member is provided. The bearing apparatus of the present invention is characterized in that: the outer ring member includes upper and lower portions and a central portion therebetween, two rows of outer raceways for the first and the second row of balls are formed on the inner peripheral surface of the upper and lower portions of the outer ring member, a squeeze ring of the same material as that used in making the outer ring member or of any other material of substantially the same factor of linear thermal expansion as that of the outer ring member is press fit around the outer periphery of the central portion of the outer ring member to elastically deform the outer ring member inwardly to form an inwardly protruding squeezed portion.

Abstract: The object of the present invention is to provide a compound bearing apparatus having arrangements for preventing the lubricant present around the rotating bodies from leaking out to the outside as well as the interior space between two rows of rotating bodies of the bearing apparatus. This is effected for the purpose of providing the compound bearing apparatus and a spindle motor and a swing arm assembly for a hard disk drive device including such bearing apparatus in which the sufficient amount of lubricant can be retained around the rotating bodies to obtain long life feature and having substantially no noise or vibration due to the loss of lubricant.

Abstract: A spindle motor of the present invention is capable of keeping its ball (5a, 5b)'s pre-load constant, because a sleeve (6) is capable of being resiliently deformed due to its resiliency, and therefore capable of constantly keeping a pre-load applied to the balls (5a, 5b) from inner and inner ring raceways of inner and outer rings (3a, 4a, 3b, 4b) of ball bearings (3, 4). In this motor, a rotor hub (7) has an axial center bore (8). This bore (8) is provided with: a large-diameter bore portions in its opposite axial ends; and, a small-diameter bore portion (8a) axially interposed between the large-diameter bore portions. An inner diameter of the small-diameter bore portion (8a) is smaller than an outer diameter of the sleeve (6).

Abstract: In a method for manufacturing outer and inner rings of a bearing, the method being characterized in that it comprises the steps of: cutting a cylindrical bar material to form a circular plate work of a predetermined width, forming on both plain sides surface of the work through cold forging operation a central circular recess provided around the axis of the work and an annular groove provided concentrically with respect to the recess, forming a central circular aperture by punching out the recess remaining material in the axial direction, punching out the groove remaining material in the axial direction to form an outer work for the outer ring and an inner work for the inner ring, and machining each work respectively through cutting, grinding and/or polishing operations to form ring raceways or to finish the surface thereof for manufacturing the outer and inner rings.

Abstract: A spindle motor comprising a double row bearing device including a shaft, a sleeve surrounding the shaft, and a pair of upper and lower rows of balls, a cylindrical bearing holder extending upwardly from a base of the spindle motor for accommodating the sleeve within a vertical bore of the holder, and a rotor hub mounted on the shaft for journaling the rotor hub rotatably on the base, the spindle motor is characterized in that a reduced inner diameter portion of an inner diameter smaller than the outer diameter of the sleeve is formed on the inner surface of the bore of the bearing holder between the upper and lower larger inner diameter portions to urge the sleeve inwardly by the reduced inner diameter portion to deform it elastically to form a squeezed portion protruding inwardly of the sleeve between the upper and lower rows of balls.

Abstract: The object of the present invention is to provide a hard disk drive device having a bearing device of larger size and sufficient strength, improved impact resistance, high accuracy of rotation, and high reliability.

Abstract: A plurality of toroidal sealing plates 16a, 16b, and 16c spaced axially by slight gaps S1 and S2 are disposed between spindle 3 and vertical bore 6 of the rotor hub at above and/or below the bearing apparatus such that the outer or inner peripheral portion of each plate is secured to the inner peripheral portion of the bore of the rotor hub or the outer peripheral portion of the spindle so as to leave slight radial gaps &agr;1, &agr;2 and &agr;3 between the inner or outer peripheral portion of each plate and the outer peripheral portion of the spindle or the inner peripheral portion of the bore of the rotor hub to make each sealing plate uncontacted with the spindle or the bore, wherein the radial gaps are positioned alternately on the side of the spindle or on the side of the bore of the rotor hub.

Abstract: A pivot bearing includes a stepped shaft including an enlarged and a reduced diameter shaft portions; a plurality of balls of the lower row are interposed between the enlarged diameter shaft portion and a sleeve outer ring surrounding the enlarged diameter shaft portion; a ball bearing including inner and outer rings and a plurality of balls interposed therebetween is provided around the reduced diameter shaft portion so that the inner ring is secured around the reduced diameter shaft portion with applying an appropriate pre-load on the upper end surface of the inner ring, and the outer ring is urged to contact the lower surface thereof intimately onto the upper surface of the sleeve outer ring. The pivot bearing is reduced in the number of elements, facilitated in incorporating a bearing with the swing arm, and expected to reduce the manufacturing cost.

Abstract: A grinding operation is effected by rotating the motor hub in high speed around the central axis thereof, and urging the outer peripheral surface of a grinding wheel rotated in high speed around the central axis against the upper surface of the outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk. The surface of the flange can be worked in high precision. Thus, a compact, large capacity, and reliable hard disk drive apparatus is to be provided by reducing the rotational runout of the magnetic disk incorporated within the hard disk drive apparatus.

Abstract: The object of the present invention is to provide a blower including a bearing structure wherein the number of components is reduced, the cost for manufacturing can be reduced, and the diameter of the shaft can be increased. The bearing structure is good at its durability, eliminates or reduces the rotational run out, and provides superior quietness.

Abstract: A spindle motor of the present invention is capable of keeping its ball (5a, 5b)'s pre-load constant, because a sleeve (6) is capable of being resiliently deformed due to its resiliency, and therefore capable of constantly keeping a pre-load applied to the balls (5a, 5b) from inner and inner ring raceways of inner and outer rings (3a, 4a, 3b, 4b) of ball bearings (3, 4). In this motor, a rotor hub (7) has an axial center bore (8). This bore (8) is provided with: a large-diameter bore portions in its opposite axial ends; and, a small-diameter bore portion (8a) axially interposed between the large-diameter bore portions. An inner diameter of the small-diameter bore portion (8a) is smaller than an outer diameter of the sleeve (6).

Abstract: A retainer for a ball bearing being characterized in that each pocket includes upper halves following the entrance, a pair of lower halves following the upper halves, and a bottom portion disposed between lower halves, wherein an inner peripheral surface of each upper half presents a curved surface of a radius of curvature slightly larger than that of the ball to be retained therein in both peripheral and width directions of the pocket, an inner peripheral surface of each lower half descending inwardly, the inner peripheral surface of each lower half and an inner surface of the bottom portion each presents a configuration which has a shape of curved surface in the width direction of the pocket and of a straight shape in the peripheral direction of the pocket so as to contact tangentially with the ball so as to contact tangentially with the ball to be retained.