Abstract: A double-row ball bearing with a preload application structure including an axle and a sleeve surrounding the axle. At least two rows of bearing balls are disposed between the axle and the sleeve. An inner bearing ring is slidably mounted on the axle such that at least one of the two rows of bearing balls is set between the inner bearing ring and the sleeve. The second row of bearing balls is then set directly between the axle and the sleeve. A resilient member is connected to an external side surface of the inner bearing ring, and a preload applying member is connected to the resilient member. The preload applying member applies a preload to the inner bearing ring by increasing pressure on the resilient member. When an appropriate preload is achieved, the preload applying member is fixed to the axle.

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 motor that can prevent damages on the fluid dynamic bearing. A ball is press-fitted into the end surface of the shaft body, and the ball is disposed in such a manner that the tip portion of the ball comes to the higher position with respect to the end surface of the annular body. When the shaft is at rest, the ball abuts against the upper surface of the counter plate, and the end surface of the annular body is brought into a state of being raised from the upper surface of the counter plate, so that the situation in which the end surface of the annular body and the upper surface of the counter plate are brought into almost fully touch each other can be avoided. Therefore, when the operation is started, the circulation speed of a fluid increases and a fluid layer is quickly formed. As a consequent, the fluid circularity blocking action, which could be occurred in the relate art, is avoided, and generation of scratch caused by starting rotation in the tightly sticked state can be positively prevented.

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: There is provided a maintenance-free sleeve bearing arrangement that is light in weight, has a long service life and does not require resupply of oil during operation. The sleeve bearing arrangement is comprised mainly of a shaft and a sleeve bearing, wherein the sleeve bearing formed of CRB ceramics, and/or the shaft formed of the CRB ceramics are used.

Abstract: This low profile key switch structure provides a substantial reduction in the height or thickness of a key switch as compared to conventional and other low profile switches. Substantial height reduction in key switch structures allows the size and thickness of notebook-type personal computers and the like to be similarly reduced. One feature of this low profile key switch structure is that unlike in conventional key switch structures the membrane switch and frame structures do not over lap to cause unnecessary height in the structure. Another feature of this key switch structure is that the frames are formed to include the free motion range limiters. The frames are further formed so that they may be embedded in the reinforcing base plate in such a manner that allows the height of the key switch to be further reduced. This low profile key switch structure is also designed to eliminate unwanted key top movement that often occurs in conventional and other switches when the key top is depressed.

Abstract: A synthetic resin composition includes at least one synthetic resin and RBC or CRBC particles dispersed in the resin. A method for preparing a synthetic resin composition includes mixing RBC or CRBC particles with a synthetic resin at a temperature near the melting temperature of the synthetic resin. Preferably, the method of includes the step of kneading the mixture.

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 motor and a method of manufacturing the motor are provided for preventing undesirable deformation of the sleeve hole caused by a press fitting force during press fitting process, thus facilitating the assembly process and improving the productivity. A recess is formed on an inner peripheral wall of a center cylindrical portion at the center of a flange body. When press fitting a sleeve body into a hole (sleeve fitting hole) of a flange assembly unit for integrating both members, the annular recess of the flange assembly unit serves to reduce the contact area between the sleeve body and the flange body. The press fitting force exerted to the contact area is reduced. Therefore the deformation of the inner diameter of the sleeve body that has been press fitted is minimized, thus suppressing deformation of the inner diameter portion of the sleeve body and the flange body.

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: The method for manufacturing a spindle motor rotor hub of the present invention where a disk-shaped bulk is shaped by cutting a specified thickness of a round bar material, such as metal, perpendicular to the axial line thereof. This disk-shaped bulk is then cold forged and formed into a machining workpiece, which has approximately the shape of the rotor hub. The two ends of the machining workpiece are ground to form parallel upper and lower machining reference surfaces. The peripheral surface of the machining workpiece is then ground to form a peripheral machining reference surface. Finishing is accomplished by cutting and grinding each part of the rotor hub based on the aforementioned upper and lower machining reference surfaces and on the peripheral machining reference surface.

Abstract: A spindle motor, a fluid dynamic bearing for said spindle motor, and a method of manufacturing said bearing wherein said bearing includes a non-capillary seal fluid reservoir.

Abstract: A spindle motor, a fluid dynamic bearing for the spindle motor, and a method of manufacturing the bearing wherein the bearing does not include a capillary seal fluid reservoir.

Abstract: A spindle motor having a pivot which tip portion can easily be formed by a spherical surface having high precision, high hardness, the diameter of which can be determined as desired, the tip portion 6a of the pivot 6 is formed by cutting a steel ball used in a bearing or the like having any diameter. The pivot 6 having a spherical surface 6a is formed by fixing the pivot tip portion 6a to one side surface 6c of a substantially cylindrical shaft portion 6b. As a result, the spherical surface having a high precision, high hardness which diameter can be determined as desired can easily be formed at the tip portion 6a of the pivot 6.

Abstract: A spindle motor having a pivot which tip portion can easily be formed by a spherical surface having high precision, high hardness, the diameter of which can be determined as desired, the tip portion 6a of the pivot 6 is formed by cutting a steel ball used in a bearing or the like having any diameter. The pivot 6 having a spherical surface 6a is formed by fixing the pivot tip portion 6a to one side surface 6c of a substantially cylindrical shaft portion 6b. As a result, the spherical surface having a high precision, high hardness which diameter can be determined as desired can easily be formed at the tip portion 6a of the pivot 6.

Abstract: This low profile key switch structure provides a substantial reduction in the height or thickness of a key switch as compared to conventional and other low profile switches. Substantial height reduction in key switch structures allows the size and thickness of notebook-type personal computers and the like to be similarly reduced. One feature of this low profile key switch structure is that unlike in conventional key switch structures the membrane switch and frame structures do not over lap to cause unnecessary height in the structure. Another feature of this key switch structure is that the frames are formed to include the free motion range limiters. The frames are further formed so that they may be embedded in the reinforcing base plate in such a manner that allows the height of the key switch to be further reduced. This low profile key switch structure is also designed to eliminate unwanted key top movement that often occurs in conventional and other switches when the key top is depressed.

Abstract: According to the invention, a synthetic resin composition having a desirable a low coefficient of friction when submersed in a liquid is provided. In addition, a method of making a low friction bearing for use under liquid is provided as well as a low friction bearing or use underwater.

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 process for manufacturing miniature ball bearings that reduces material loss to improve manufacturing efficiency. The process consists of obtaining an inner and outer ring blank by cutting a first blank, forging the first blank to obtain a final blank, and separating the final blank to form an outer ring blank and an inner ring blank. The outer ring blank has an outer diameter of at most 13 mm. Cutting the first blank is performed by press cutting.

Abstract: A process for manufacturing miniature ball bearings that reduces material loss to improve manufacturing efficiency. The process consists of obtaining an inner and outer ring blank by cutting a first blank, forging the first blank to obtain a final blank, and separating the final blank to form an outer ring blank and an inner ring blank. The outer ring blank has an outer diameter of at most 13 mm. Cutting the first blank is performed by mechanically cutting and machining.