Abstract: A pivot bearing assembly comprises a shaft having a main body portion and a reduced portion integrally and coaxially formed therewith, an outer ring-sleeve member coaxially surrounding the shaft, a first bearing arranged between the reduced portion of the shaft and the outer ring-sleeve member, a second bearing arranged between the main body portion of the shaft and the outer ring-sleeve member and a tolerance ring mounted on the outer peripheral surface of the outer ring-sleeve member. The inner ring of the second bearing is a part of the main body portion of the shaft. The outer ring-sleeve member can comprise an outer ring and a sleeve tightly mounted on the outer ring or an outer ring portion and a sleeve portion surrounding the outer ring and integrally formed therewith.

Abstract: To provided a pivot bearing assembly that can be easily assembled without deformation, featuring lower amount of outgas and thermal compensation of bond strength. Further, with the pivot bearing assembly, between a bearing inner ring and a shaft, between a bearing outer ring and a housing are slidingly fitted, bonded and secured to each other with an ultraviolet curing type anaerobic adhesive having a high vitrification temperature, respectively.

Abstract: A pivot assembly for sustaining a magnetic head, a head suspension and an actuator block pivotally parallel to magnetic disks oscillates slowly. Hence the invention has been made in light of examining a sealing structure for retaining sufficient capability of preventing a leakage of lubricant and retaining sufficient capability of preventing a contamination of lubricant, characterized in that retaining required sealing capabilities, an annular shield plate is secured to the shaft, achieving pivot assembly manufacturing cost by reducing machining process and a number of sealing members.

Abstract: A shaft 2 of a spindle motor is composed of a steel material including 0.20 wt % of C, 0.35 wt % of Si, 8.00 wt % of Mn, higher than 0 and equal to or less than 0.05 wt % of P, 0.15 wt % of S, higher than 0 and equal to or less than 2.00 wt % of Ni and 14.00 wt % of Cr and the remainder substantially being Fe. The steel material has corrosion resistance with no plating requirement and wear resistance with no need for a heat treatment and/or a soft nitriding. Further, when considering a conventionally employed stainless steel, Pb has been frequently added thereto in order to improve machinability. On the contrary, the steel material according to the embodiments of the present invention is Pb-free material. Since the shaft of the spindle motor is manufactured by a material high in its wear resistance, corrosion resistance and workability and in which the generation of the out gas of sulfur and sulfur compounds is suppressed low, the qualities of electronic devices and communication devices, etc.

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 pivot bearing of the present invention comprises inner rings, outer rings surrounding the inner rings and rollable balls arranged between the inner and outer rings. This pivot bearing does not have a sleeve which is provided on the outer rings of a conventional pivot bearing. Each of the outer rings is made thicker substantially by the thickness of the sleeve of the conventional pivot bearing than the outer rings of the conventional pivot. The other components of the pivot bearing according to the present invention than the outer bearings use commercially available components or standardized components manufactured in the ordinary manufacturing line at ball bearing manufacturers' factories. Thus, a simple, inexpensive and precise pivot bearing can be manufactured.

Abstract: A hard disk drive is made small in size, large in storage capacity and high in data reading/writing speed. Two actuator blocks (3) are fixed to a sleeve 16A of a first pivot and sleeve (16B) of a second pivot, respectively. Position of magnetic heads to be accessed to different magnetic disks are controlled independently by the actuator block 3 basis. Therefore, it is possible to distribute the reading/writing processing to the plurality of magnetic disks and perform these processing in parallel, to thereby increase the data reading/writing speed while increasing the storage capacity.

Abstract: A swing arm assembly reduced in the number of the component parts, facilitated in its assembly, and can be expected in the reduction of the manufacturing cost thereof and thus providing a hard disk drive device of lower cost.

Abstract: The closed end 11b of the Sleeve 11 and the shaft end 12b are made to be point-contacted through the ball 14. By this point contact, while allowing the sleeve 11 and the shaft 12 to rotate, the pressurization in the axial direction between the sleeve and the shaft can be received. Further, by giving this pressurization, the inner ring 13a of the bearing 13 is displaced toward the axial direction (downward in FIG. 1) interposing the ball 13b to absorb the play of the bearing 13. Accordingly, even though merely one bearing 13 is used, the sleeve 11 and the shaft 12 are prevented from being deflected, to obtain the pivot assembly 10 having a necessary rotation precision.

Abstract: A shaft 2 of a spindle motor is composed of a steel material including 0.20 wt % of C, 0.35 wt % of Si, 8.00 wt % of Mn, higher than 0 and equal to or less than 0.05 wt % of P, 0.15 wt % of S, higher than 0 and equal to or less than 2.00 wt % of Ni and 14.00 wt % of Cr and the remainder substantially being Fe. The steel material has corrosion resistance with no plating requirement and wear resistance with no need for a heat treatment and/or a soft nitriding. Further, when considering a conventionally employed stainless steel, Pb has been frequently added thereto in order to improve machinability. On the contrary, the steel material according to the embodiments of the present invention is Pb-free material.

Abstract: The freedom of the resilient deformation of the claws 3 is controlled by changing the configuration (diameter and depth) of the cylindrical cut out portion 7 of the bearing retainer 6. And, the necessary force to push and widen the claws 3 is optimized, thereby, it is avoided to damage the ball 11 at the time of setting the ball in the pocket 2.

Abstract: In order to facilitate fixing a pivot assembly to an actuator block and to obtain the stable coaxiality, a screw hole passing from the outside is provided towards a fitting hole into which the pivot assembly is inserted. Moreover, a set screw is screwed into a screw hole to press a sleeve of the pivot assembly, which has been inserted into the fitting hole with an end portion of the set screw. The sleeve pressed at a pressure F1 with the set screw is clamped and fixed by a inside wall surface of the fitting hole and the end portion of the set screw revealing in the inner side of the fitting hole.

Abstract: A pivot bearing assembly comprises a shaft having a main body portion and a reduced portion integrally and coaxially formed therewith, an outer ring-sleeve member coaxially surrounding the shaft, a first bearing arranged between the reduced portion of the shaft and the outer ring-sleeve member, a second bearing arranged between the main body portion of the shaft and the outer ring-sleeve member and a tolerance ring mounted on the outer peripheral surface of the outer ring-sleeve member. The inner ring of the second bearing is a part of the main body portion of the shaft. The outer ring-sleeve member can comprise an outer ring and a sleeve tightly mounted on the outer ring or an outer ring portion and a sleeve portion surrounding the outer ring and integrally formed therewith.

Abstract: A magnetic recording disk device achieving higher speed, larger capacity and higher reliability. The disk device includes two or more actuator blocks that are individually and rotatably supported, and a device driver that causes a magnetic head of each of the actuator blocks to access its associated magnetic disk to arbitrarily perform read/write operations. The device driver is provided with a logic for driving, at an arbitrary RAID level, the magnetic heads of the respective actuator blocks and the magnetic disks accessed by the magnetic heads. By handling the magnetic head of each actuator block and the magnetic disk accessed by the magnetic head as one unit to implement a necessary function, a single magnetic disk device can be used as a simplified version equivalent to a RAID system.

Abstract: There is provided a pivot assembly for a magnetic disk storage which is improved in its rotating accuracy and reduced in manufacturing cost. A pivot assembly includes a pair of ball bearings each having an outer ring, and the outer ring is fitted directly into an axial bore of an actuator block. This arrangement requires no sleeve to be interposed between the pair of ball bearings and the actuator block, thus enabling to reduce its manufacturing cost. No need to interpose any sleeve allows to increase the thickness of the outer ring of the ball bearing and thus the rigidity thereof, thereby improving the rotating accuracy of the pivot assembly.