Abstract: An anti-frictional bearing which is reduced in its asynchronous rotational run out so that the cumbersome analyzing operation of the raceway surface and selecting operation of inner and/or outer races are not required. The bearing will contribute for the high packaging density and high speed operation of the hard disk device. An anti-frictional bearing including an inner raceway is formed on an outer peripheral surface of an inner race 1, an outer raceway 2a formed on an inner peripheral surface of an outer race 2, and a plurality of rotating bodies 3 interposed between the raceways and retained by retainers 4 in a predetermined distance with each other, wherein an out of roundness of a raceway surface 1a, 2a of at least one of said inner and outer races 1, 2 is equal to or less than 0.05 &mgr;m.

Abstract: A motor of long life and high precision in its rotation wherein the variation on the rotation and the noises generated thereby are suppressed by maintaining the radial clearance between the components of the bearing device constantly in an appropriate value even if the thermal expansion of the components is caused by rising the temperature thereof.

Abstract: A motor of long life and high precision in its rotation wherein the variation on the rotation and the noises generated thereby are suppressed by maintaining the radial clearance between the components of the bearing device even if the thermal expansion of the components is caused by rising the temperature thereof.

Abstract: A motor of high precision in its rotation wherein the variation of the resonant frequency or the rotational run out due to thermal expansion of the component of the bearing device through the increasing temperature thereof is difficult to occur.

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: An anti-frictional bearing which is reduced in its asynchronous rotational run out so that the cumbersome analyzing operation of the raceway surface and selecting operation of inner and/or outer races are not required. The bearing will contribute for the high packaging density and high speed operation of the hard disk device.

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 blower includes a durable and quiet bearing structure which eliminates or reduces rotational run out, and a bearing wherein the number of essential components and cost for manufacturing is reduced, and the diameter of the shaft can be increased. The blower has an impeller adapted to be rotated upon energizing the blower. The blower has a bearing apparatus which supports the rotational center portion of the impeller, in which the bearing apparatus has a sleeve, and a stepped shaft including a larger diameter portion and a reduced diameter portion provided at one end thereof. A first rolling contact groove is formed at an appropriate position on the outer peripheral surface of the larger diameter portion. A second rolling contact groove is formed on an inner peripheral surface of the sleeve so as to correspond with the first rolling contact groove.

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: An anti-frictional bearing which is reduced in its asynchronous rotational run out so that the cumbersome analyzing operation of the raceway surface and selecting operation of inner and/or outer races are not required. The bearing will contribute for the high packaging density and high speed operation of the hard disk device.

Abstract: A single-piece outer race ring 3, a sleeve-like spacer 11, a plurality of first balls 4, a conventional ball bearing unit 7, a stepped-diameter shaft 1 and the like are assembled into a compound bearing assembly by a bearing maker with high accuracy to enable a user to be free from a cumbersome assembling work of rotating portions or cylindrical rotary shaft and its bearing means of a computer and its peripheral devices. In use, the compound bearing assembly is coaxially mounted in the cylindrical rotary shaft and the like at the user's end to rotatably support the cylindrical rotary shaft and the like in the computer and its peripheral devices.

Abstract: A spindle motor including a bearing means which is not seized under the high speed rotational operation and with reduced fretting wear. Consequently, the densification of the hard disk drive device can be achieved.

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.

Abstract: A bearing apparatus including inner and outer rings and balls interposed therebetween, the apparatus being characterized in that it comprises:

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: The object of the present invention is to provide a motor, or spindle motor in which only an assembling operation of a completed compound bearing with the motor may be effected on the side of motor maker, the number of steps required for assembling can be reduced because the assembling operation of the bearing is not necessary, the precision of the rotation of the motor is high, the cost for fabrication can be reduced, the resistance against impact and/or resonance is high since the diameter of the shaft can be enlarged.

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: The object of the present invention is to provide a spindle motor of high accuracy of rotation irrespective of the temperature differential for driving the hard disk or disks of the hard disk drive device. A spindle motor including a shaft secured on a base to extend vertically therefrom, and a rotor hub journalled rotatably around the shaft through a plurality of anti-friction bearings each of which has outer and inner races and rotational bodies disposed between races, characterized in that a cylindrical sleeve having a through bore is disposed between outer peripheral surface of each anti-friction bearing and an inner peripheral surface of a central bore provided through the rotor hub, the sleeve and the outer races of the anti-friction bearings are made of the ferrous metal material of substantially the same coefficient of expansion, and the inner races of anti-friction bearings and the shaft are also made of the ferrous metal material of substantially the same coefficient of expansion.

Abstract: A compound bearing assembly for a swing arm is disclosed, which comprises a stepped shaft 1 having a large-diameter portion 1a and a small-diameter portion 1b, the large-diameter portion 1a having an inner raceway groove 2a directly formed in the inner periphery, a sleeve-like outer race ring 5 surrounding the stepped shaft 1 and having a distinct-member outer race ring 3 provided adjacent one end and also having an outer raceway groove directly formed in the inner periphery of a portion adjacent the outer end, a plurality of balls 4 provided between the inner raceway groove 2a directly formed in the large-diameter portion 1a and an outer raceway groove 2a formed in the distinct-member outer race ring 3, and a plurality of other balls 8a provided between an inner raceway groove formed in an inner race ring 7a fitted on the small-diameter portion 1b of the stepped shaft 1 and the outer raceway groove 2b directly formed in the inner periphery of the sleeve-like outer race ring 5.

Abstract: A spindle motor including a double row bearing apparatus 2 for supporting a rotor hub 9 rotatably on a base 1. A labyrinth seal mechanism is incorporated into the bearing apparatus. The double row bearing apparatus includes a two-stepped shaft 3 and a pair of rows of rotating bodies 5a and 5b interposed between the shaft and a sleeve outer race 4 surrounding the shaft. A pair of inner and outer sealing plates 13a and 13b are provided between the spacing defined between the sleeve outer race and the inner race fitted around the reduced diameter portion of the shaft to form a labyrinth seal. A pair of inner and outer sealing plates 14a and 14b are also provided between the sleeve outer race and the inner race fitted around the enlarged diameter shaft portion to form a labyrinth seal. Thus, there is no necessity for the manufacturer of the motor to incorporate the additional sealing mechanism into the motor.