Abstract: The present invention generally relates to a head comb for use in a hard disk drive. In one embodiment, the head comb comprises a core body having a bore formed therethrough. The bore is bound by walls having a top extension extending into the opening and a bottom extension extending into the opening. The top extension has a first height, and the bottom extension has a second height that is different than the first height.

Abstract: A thin film piezoelectric element of the present invention includes a substrate and a piezoelectric thin film stack formed on the substrate. The piezoelectric thin film stack includes a top electrode layer, a bottom electrode layer and a piezoelectric layer sandwiched between the top electrode layer and the bottom electrode layer, wherein the piezoelectric layer includes a first piezoelectric layer and a second piezoelectric layer whose compositions have different phase structures. The present invention can obtain high piezoelectric constants, enhanced coercive field strength, thereby enabling larger applied field strength without depolarization and achieving a large stroke for its applied device.

Abstract: A magnetic recording head includes a main magnetic pole generating a recording magnetic field, a trailing shield, a recording coil generating a magnetic field and a high frequency oscillator. The trailing shield includes a magnetic region including a gap side end surface facing a write gap and a nonmagnetic film arranged in the vicinity of the write gap in the trailing shield, and within a plane including track width direction centers of the main magnetic pole and the high frequency oscillator and being perpendicular to a recording layer of a recording medium, a film thickness of the nonmagnetic film along a track moving direction is substantially equivalent to or more than a half of a distance from the gap side end surface to the nonmagnetic film.

Abstract: According to one embodiment, a perpendicular magnetic recording medium including a soft magnetic under layer, a nonmagnetic seed layer consisting of AgGe, a nonmagnetic interlayer made of Ru or an Ru alloy, and a perpendicular magnetic recording layer, laminated on the nonmagnetic substrate is provided. The nonmagnetic seed layer is an layer containing Ag grains having an fcc structure and an amorphous Ge grain boundary, and the Ag grain surface is higher than the Ge grain boundary surface.

Abstract: According to one embodiment, a disk drive includes a case including a base with a bottom wall, a drive motor on the bottom wall of the base, a plurality of disk recording mediums rotatable by the drive motor, a magnetic head configured to perform data processing on the recording mediums, a carriage on the bottom wall of the base, configured to support the magnetic head for movement relative to the recording mediums, a drive section including a yoke and a magnet on the bottom wall of the base and configured to drive the carriage, and a spoiler including a main body, which includes a magnetic shield member between the yoke and the recording mediums, and a baffle plate extending from the main body and between the adjacent disk recording mediums.

Abstract: A perpendicular magnetic recording medium according to an embodiment includes a substrate and perpendicular magnetic recording layer. The perpendicular magnetic recording layer includes a recording portion and non-recording portion. The recording portion has patterns regularly arranged in the longitudinal direction, and includes magnetic layers containing Fe or Co and Pt as main components, and at least one additive component selected from Ti, Si, Al, and W. The non-recording portion includes oxide layers formed by oxidizing the side surfaces of the magnetic layers, and nonmagnetic layers formed between the oxide layers.

Abstract: A magnetic-recording head with touch-down detector incorporating a carbon nano-tube (CNT). The magnetic-recording head includes a write element, a read element and a touch-down detector. The write element is configured to write data to a magnetic-recording disk. The read element is configured to read data from the magnetic-recording disk. The touch-down detector includes a thermal sensor, and a CNT portion. The thermal sensor is configured to convert heat to a voltage signal. The CNT portion is configured to touch down on the magnetic-recording disk. The CNT portion is also coupled to the thermal sensor, and is configured to transfer heat generated by contact between the CNT portion and the magnetic-recording disk to the thermal sensor. A hard-disk drive (HDD) including the magnetic-recording head with touch-down detector incorporating a CNT, and a method for detecting contact between the magnetic-recording head and a recording surface of a magnetic-recording disk are also provided.

Abstract: There is provided a base assembly including: a bracket device connected to a head assembly in order to drive the head assembly for reading information from a disk and including an elastic member provided on one surface thereof, the elastic member having a terminal disposed in an inner portion thereof and connected to a main circuit board; and a press base formed by press processing and having an opening part into which the elastic member is inserted, wherein the press base includes an elastic support part forming the opening part and extended in a direction into which the bracket device is inserted to thereby increase a contact area with the elastic member.

Abstract: There is provided a spindle motor. The spindle motor includes a fixed member; and a rotating member rotating relatively to the fixed member, and having oil filling a bearing clearance formed between the fixed member and the rotating member, wherein the fixed member and the rotating member are provided with an oil diffusion path communicating an air/oil interface formed at a boundary between the oil filled in the bearing clearance and air with the outside, and at least one of the fixed member and the rotating member is provided with at least one dummy oil groove opened to the oil diffusion path and having oil filled in at least a portion of the inside thereof.

Abstract: A damping material to increase a damping ratio is disclosed. In one embodiment, an actuator arm assembly of a hard-disk drive (HDD) comprises an actuator arm. A viscoelastic layer is coupled with the actuator arm. A constraining layer is coupled with the viscoelastic layer on a side of the viscoelastic layer opposite the actuator arm. The coupling of the actuator arm, the viscoelastic layer, and the constraining layer occurs over an area which is a fraction of the area between the constraining layer and the actuator arm.

Abstract: A disk drive is disclosed comprising a disk, a spindle motor operable to rotate the disk, a head actuated over the disk, an interface operable to receive a host supply voltage, and a capacitor. The host supply voltage is used to charge the capacitor to a capacitor voltage higher than the host supply voltage. During a power failure, the host supply voltage stops charging the capacitor, and a motor supply voltage is generated from the spindle motor. The capacitor voltage is used to operate control circuitry, and when the capacitor voltage decays below the motor supply voltage, the motor supply voltage charges the capacitor.

Abstract: There is provided a hard disk drive including: a bottom plate including a disk rotating by a motor; and a cover having a first wall member formed thereon, the first wall member inducing an airflow generated at the time of rotation of the disk.

Abstract: There is provided a base assembly for a motor, the base assembly including: a base body having a disk disposed thereon; an outer wall part defining an outer side of the base body; one or more ribs depressed from one surface of the base body and protruded toward the other surface thereof to thereby improve rigidity of the base body; and one or more blocking parts provided in the ribs to thereby block abnormal air flow due to the ribs at a time of rotation of the disk.

Abstract: A motor includes a shaft portion, an upper plate cylindrical portion, a lower plate cylindrical portion, and a sleeve portion disposed between an upper plate portion and a lower plate portion. The sleeve portion includes an inner sleeve cylindrical portion and an outer sleeve cylindrical portion. An upper seal portion is arranged between the outer circumferential surface of the upper plate cylindrical portion and the inner circumferential surface of the outer sleeve cylindrical portion. A lower seal portion is arranged between the outer circumferential surface of the outer sleeve cylindrical portion and the inner circumferential surface of the lower plate cylindrical portion. At least a portion of the upper seal portion and at least a portion of the lower seal portion radially overlap with a radial gap between the outer circumferential surface of the shaft portion and the inner circumferential surface of the inner sleeve cylindrical portion.

Abstract: A motor includes a shaft component, an upper plate portion, a lower plate portion, and a sleeve portion. The shaft component includes an inner shaft portion and an outer shaft portion. The upper plate portion defines a single monolithic member with one of the inner shaft portion and the outer shaft portion. The lower plate portion defines a single monolithic member with the other of the inner shaft portion and the outer shaft portion. The sleeve portion is disposed between the upper plate portion and the lower plate portion. A radial gap is defined between the sleeve portion and the outer shaft portion. A fixing range in which the outer shaft portion and the inner shaft portion radially overlap is arranged. At least a portion in an axial direction of the fixing range radially overlaps with an existing range in the axial direction of the radial gap.

Abstract: A suspension includes a flexure and a plurality of electrical traces formed on the flexure. Each electrical trace has a trace body and a bonding pad arranged for connecting with a slider, and the bonding pad is a free end before connecting with the slider and is capable of bending to the trace body flexibly, and the bonding pad includes a trace body layer and a solder layer formed on the trace body layer, thereby the bonding pads of the electrical traces connecting with the slider by reflowing the solder layer. The present invention uses no extra solder balls, so as to reduce the manufacturing cost and the corresponding apparatus cost. The invention also discloses a manufacturing method of a suspension, and a connecting method for a suspension and a slider.

Abstract: A head-gimbal assembly (HGA) with a suspension-lead pad having a form that is configured to inhibit formation of an inter-pad solder bridge. The HGA includes a gimbal, a head-slider and a plurality of suspension-lead pads. The head-slider is coupled with the gimbal, and includes a plurality of head-slider pads. The plurality of suspension-lead pads is coupled with the plurality of head-slider pads by a plurality of solder bonds. A suspension-lead pad comprises a first lateral side, a second lateral side, a proximal side, disposed in proximity to a respective head-slider pad, and a distal side. A first width of the suspension-lead pad closer to the proximal side is substantially larger than a second width of the suspension-lead pad further from the proximal side than the first width. A disk drive including the HGA, and a head-slider with a head-slider pad having similar form to the suspension-lead pad are also provided.

Abstract: There is provided a rotor assembly for a motor and a motor including the same, the rotor assembly including: a hub including a magnet electromagnetically interacting with a coil to generate rotational driving force; and a disk mounting part included in the hub and having a disk mounted thereon, wherein contact surfaces of the disk and a contact part that contacts the disk are formed of the same material, have the same roughness, and are coupled to each other.

Abstract: A spindle motor includes a stationary portion, and a rotating portion supported rotatably with respect to the stationary portion. The stationary portion includes a base portion, a ring-shaped core back, a plurality of teeth, and a coil. The rotating portion includes a magnet radially opposite to a radially inner end surface of the teeth and a hub arranged to hold the magnet. The teeth include an outer core portion arranged radially outward from an outer circumference of the hub, and an inner core portion arranged radially inward from the outer core portion. The inner core portion includes a positioning portion which is positioned radially outward from the outer circumference of the hub, and arranged radially inward from the coil, and the width of the positioning portion in a circumferential direction is larger than the width of the outer core portion in the circumferential direction.

Abstract: A stator includes a stator core and a plurality of coils. The stator core includes a core-back and a plurality of teeth portions. Each of the teeth portions includes a coil winding portion, a tip end portion, and an increased width portion. The tip end portion has a circumferential width larger than a smallest width of the coil winding portion. The increased width portion has a circumferential width larger than the smallest width of the coil winding portion. The increased width portion includes a slanted portion extending radially outward and upward. An axial position of a magnetic center of the rotor magnet positioned radially outward of the stator overlaps with an axially extending range of the tip end portion. A thickness of the slanted portion in a direction perpendicular to an upper surface of the slanted portion is smaller than an axial thickness of the coil winding portion.

Abstract: A motor includes a stationary unit and a rotary unit. The stationary unit includes a stator, a base portion having at least one hole extending in the up-down direction, and a flexible wiring substrate. The flexible wiring substrate reaches a position higher than a lower surface of the base portion through at least one hole and is arranged to supply electric power to the stator. The flexible wiring substrate includes a connection portion arranged higher than the lower surface of the base portion and connected to the stator. The connection portion includes a solder portion arranged on a lower surface thereof to cover a portion of a lead wire extending from a coil of the stator. At least a portion of the solder portion is positioned within the hole.

Abstract: A spindle motor includes a stator unit and a rotor unit supported to be rotatable with respect to the stator unit. The stator unit includes a stator, a base portion including a through hole, and a circuit board. The circuit board includes a connection portion to which a conductive wire from the stator is connected after passing through the through hole. A lower surface of the base portion includes a central region, a peripheral region, a recess portion, and a protrusion. A position of a distal portion of the protrusion is provided at a level higher than a level of a lowermost surface region of the central region and lower than a level of a bottom surface of the recess portion in a direction parallel or substantially parallel to a central axis.

Abstract: A spindle motor includes a base portion, a rotor hub, a stator, and a circuit board. The base portion preferably includes a through hole and is arranged to spread out radially around a central axis. The rotor hub is arranged above the base portion to rotate about the central axis. The stator is arranged above the base portion, and includes coils each including at least one lead wire. The circuit board is arranged radially outward of the through hole, and arranged on a lower surface of the base portion. The base portion includes a communicating groove arranged to join the through hole and the circuit board to each other. The at least one lead wire of the coils is arranged to pass inside the through hole and the communicating groove to be electrically connected to the circuit board. The through hole is sealed with a sealant.

Abstract: According to one embodiment, a recording head includes a main pole, a trailing shield including a first connecting portion and a second connecting portion, and configured to form together with the main pole a first magnetic core, a leading shield including a first connecting portion connected to the main pole through a magnetic material and an end portion opposing to the end portion of the main pole through a non-magnetic material, and configured to form together with the main pole a second magnetic core, and first and second coils wound around the first and second magnetic cores, and a connection terminal configured to flow a current through the main pole, non-magnetic conductive layer, and trailing shield.

Abstract: An optical disc driving device having a metallic exterior casing composed of a first casing and a second casing and an internal unit to be housed in the exterior casing, the internal unit including an optical pickup unit having an optical pickup part that moves in radial directions of an optical disc to perform recording or reproduction of information signals on the optical disc, wherein at a portion, which the optical pickup part moved radially outward of the optical disc makes a closest approach to, in either one of the first casing or the second casing opposed to the first casting, a protrusion for electrically connecting the first casing and the second casing to each other is provided.

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 method of manufacturing a bearing mechanism of a motor includes steps a)-e). In step a), a bearing assembly is assembled. In step b), an upper seal gap between an upper thrust portion and an upper hub annular portion is arranged to face downward to increase the width of a gap between an outer tubular portion and a flange portion, or a lower seal gap between the outer tubular portion and a lower hub annular portion is arranged to face downward to increase the width of a gap between the upper thrust portion and the flange portion. In step c), pressure in all gaps is reduced. In step d), lubricating oil is injected into the upper or lower seal gap which faces upward, and a predetermined time or longer is allowed to pass. In step e), pressure is returned to atmospheric pressure.

Abstract: A voice coil motor for a disk drive unit includes an external magnet and an actuator coil movably located above the external magnet. The external magnet has a main body with a magnetic north pole, a magnetic south pole and a transition surface therebetween, and further has a protrusion extending from the center part of the main body for increasing torque force, thereby improving the performance of the voice coil motor. The invention also discloses a disk drive unit including the same.

Abstract: A reader sensor comprises a first shielding layer, a second shielding layer, a read element formed therebetween, and a pair of permanent magnet layer respectively placed on two sides of the read element; and it further comprises a magnetic field generating means formed beside the read element and arranged for providing a magnetic field with a direction perpendicular to the first shielding layer and the second shielding layer, thereby stabilizing the reading performance of the reader sensor. The invention can stabilize the reading performance, ameliorate the unstable defective reader sensor, and decrease the waste and the manufacturing cost. The present invention also discloses a magnetic head, a HGA and a disk drive unit.

Abstract: A hard disk drive of the invention comprises: a housing comprising a base and a cover; an insert positioned on an interior surface of the base of the housing for stabilization of one or more components within the hard disk drive during operation of the hard disk drive, wherein the insert is relatively stiff as compared to stiffness of the base; and the at least one of the one or more components mounted on the insert. Methods for forming such hard disk drives and hard disk drive rack assemblies comprising the hard disk drives are also disclosed.

Abstract: According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field perpendicular to a recording medium, a trailing-shield pole opposed to the main pole with a recording gap therebetween, a high-frequency oscillator between the main pole and the trailing-shield pole in the recording gap, configured to produce a high-frequency magnetic field, a magnetic seed layer between the main pole and the high-frequency oscillator and in contact with the main pole, and a highly oriented magnetic layer of a soft magnetic material superposed on the magnetic seed layer between the main pole and the high-frequency oscillator and in contact with the high-frequency oscillator.

Abstract: A motor includes a stationary portion and a rotating portion. The rotating portion includes a sleeve portion including one communicating hole arranged to extend completely there through from an upper surface to a lower surface thereof, and a cover portion including a hole portion. The axial extension range of the hole portion is arranged to overlap with the axial extension range of the communicating hole in a radial direction. A center of the hole portion is arranged on a plane including a central axis and a center of the communicating hole. The communicating hole and the hole portion are arranged on opposite sides of the central axis. The following inequality is satisfied: V2<(?1/?2)·V1, where ?1 is the density of the sleeve portion, V1 is the volume of the communicating hole, ?2 is the density of the cover portion, and V2 is the volume of the hole portion.

Abstract: A housing member for use in a disk drive apparatus includes a rectangular bottom portion and a side wall portion arranged to extend upward from an outer circumferential portion of the bottom portion. The side wall portion includes four outside surfaces including a first outside surface and a second outside surface perpendicular or substantially perpendicular to the first outside surface. The first outside surface includes a first cutting base region. The second outside surface includes a second cutting base region. The bottom portion includes a bearing fixing portion arranged to fix a bearing mechanism of a motor arranged to rotate a disk.

Abstract: According to one embodiment, a spindle motor includes: a bearing portion fixed to a base and configured to have a cylindrical outer shape; a stator provided with a core serving as a magnetic pole, and fixed to the base outside the bearing portion; a hub provided with a magnet facing the core, and rotatably supported by the bearing portion; and a shielding structure including: a shielding plate configured to shield airflow between the stator and the hub; a first elastic member configured to attach the shielding plate closely to the bearing portion at a top end of a cylindrical outer shape of the bearing portion; and a second elastic member configured to attach the shielding plate closely to the base at the region spreading outwardly from an outer end of the hub.

Abstract: In a spindle motor, a lead wire extending from a coil includes a first solder portion coated with a first solder. The lead wire is arranged to extend downward through a base hole portion and a board hole portion. The first solder portion is soldered to a circuit board through a second solder portion. An upper end portion of the first solder portion is arranged above an upper surface of the circuit board such that d1>(d2?d3)/2 is satisfied, where d1 denotes the axial distance between the upper end portion of the first solder portion and the upper surface of the circuit board, d2 denotes an opening width of the board hole portion, and d3 denotes the diameter of the lead wire.

Abstract: A data storage apparatus and method. The apparatus comprises a mounting structure, a motor mechanically attached to mounting structure, and a data storage platter mechanically attached to the motor. The apparatus additionally comprises a single actuator arm comprising a first and second read/write data head or multiple radial movement mechanisms each comprising a read/write data head. The single actuator arm is configured to move axially along an arc and across a top surface of the data storage platter such that the first read/write data head has access to a first section and a second section of the data storage platter and the second read/write data head only has access to the second section of data storage platter. Each radial movement mechanism moves a different read/write data head radially all along a radius of the data storage platter and over and across different sections of the data storage platter.

Abstract: A rotating machine includes: a coil that is provided on the first surface side of a base and formed with a wire; an insulation sheet that has a sheet hole formed at the position aligned with the position of a guide hole in the base; and a wiring that is provided on the second surface and electrically connected to the coil. The wire forming the coil has a guide wire that is guided on the second surface side through the guide hole and the sheet hole to be connected to the wiring. The insulation sheet has an extending portion that protrudes from the sheet hole and covers at least part of the circumferential surface of the guide hole. The extending portion is placed between part of the circumferential surface of the guide hole and the guide wire.

Abstract: According to one embodiment, a recording head includes a main pole, a trailing core, a first coil wound around the trailing core, a leading core, and a second coil wound around the leading core. The trailing core includes a return pole opposed to a trailing side of the main pole with a write gap therebetween, and side shields arranged individually on opposite sides of the main pole transversely relative to tracks and magnetically separated from the main pole at a distance not more than double a track pitch of the recording medium. The leading core includes a junction opposed to a leading side of the main pole with a gap therebetween and joined to the side shields with a width of 20 ?m or less transversely relative to the tracks and a connecting portion joined to the main pole in a position off the recording medium.

Abstract: A suspension for a HGA comprises a flexure having a suspension tongue arranged for supporting a slider, which comprising a stainless steel layer and a dielectric layer formed thereon. The dielectric layer has a top surface and bottom surface, a plurality of bonding pads are formed on the top surface at a leading portion of the suspension tongue and arranged for connecting with the slider, and at least two separate supporting pieces are formed on the bottom surface and located at a corresponding position with the bonding pads, thereby releasing stress generated on the bonding pads. The invention also discloses a HGA and a disk drive unit with the same. The invention can release the stress generated on the bonding pads of the suspension, reduce the temperature impact to the suspension, and in turn, reduce thermal crown change of the slider, thereby improving the reading and writing performance.

Abstract: The invention relates to a spindle motor, preferably for driving a hard disk drive, having a stationary motor component and a rotatable motor component that is rotatably supported with respect to the stationary motor component and that is driven by an electromagnetic drive system, at least one storage disk being fixed to the rotatable motor component using some means of mounting and fastening. According to the invention, at least parts of the rotatable motor component and at least parts of the means of mounting and fastening have a wear resistant surface coating or are subjected to a wear resistant surface treatment.

Abstract: According to one embodiment, a head gimbal assembly includes a suspension, a head, and a conductor trace on the suspension, including one end portion electrically connected to the head and the other end portion includes a terminal area. The conductor trace includes a thin metal plate, a base insulating layer on the thin metal plate, a trace pattern on the base insulating layer, including a plurality of conductors and a plurality of first and second connection terminals continuous with the conductors, and a cover insulating layer on the base insulating layer, configured to cover the trace pattern. The terminal area includes an opening including two opposite side edges, the first connection terminals extend into the opening from one of the side edges thereof, and the second connection terminals extend into the opening from the other side edge thereof.

Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field, a return pole opposed to a trailing side of the main pole across a write gap and configured to return magnetic flux from the main pole, a coil configured to excite magnetic flux in the main pole, a spin-torque oscillator located between respective facing surfaces of the return pole and an end portion of the main pole on the recording-medium side and configured to produce a high-frequency magnetic field, a current source configured to apply current to the spin-torque oscillator through the return and main poles, and a nonmagnetic layer provided in at least one of the poles and extending from a facing surface of the at least one of the poles, which faces the spin-torque oscillator, in a direction across the facing surface.

Abstract: There is provided a motor allowing for an increase in the rigidity of a hydrodynamic bearing by controlling a gap between a shaft and a sleeve as well as minimizing power consumption and a recording disk derive device including the motor. The motor includes a sleeve having a cylindrical shape and including a hole whose inner circumferential surface has at least one dynamic pressure groove therein; and a shaft rotatably inserted into the hole of the sleeve and having at least one rigidity reinforcing portion protruding in an outer diameter direction from an outer circumferential surface thereof corresponding to the dynamic pressure groove.

Abstract: A motor unit for use in a disk drive apparatus includes a motor portion, a housing member including a through hole defined therein, and a circuit board. The motor portion includes a rotating portion, a base portion, and a stator fixed to the base portion. The circuit board is arranged to extend from an outside of the motor portion to an inside of the stator through a gap defined between the stator and the base portion. The circuit board includes a connection portion arranged radially inward of the stator. A plurality of lead wires of the stator is connected to the connection portion.

Abstract: An optical disc drive is provided to comprise a main circuit board; an optical pickup head, electrically connected to the main circuit board for reading data from an optical disc and for writing a label side of the optical disc; an spindle motor module, electrically connected to the main circuit board through a first flexible flat cable for supporting and rotating the optical; and a spoke detecting module, electrically connected to the main circuit board through a second flexible flat cable for detecting a spoke pattern formed on inner radius of the label side of the optical disc.

Abstract: According to one embodiment, a magnetic head includes a magnetic core including a main pole, and a return pole opposed to the main pole with a magnetic gap therebetween, and configured to return magnetic flux from the main pole and form a magnetic circuit in conjunction with the main pole, a coil configured to excite magnetic flux in the magnetic circuit, and a nonmagnetic electrically conductive layer formed by disposing only a nonmagnetic material in the magnetic gap between the return pole and an end portion of the main pole on the recording medium side, and configured to electrically connect the main pole and the return pole. The main pole, the nonmagnetic electrically conductive layer, and the return pole are configured to constitute a series electrical circuit.

Abstract: According to one embodiment, a magnetic recording medium includes a substrate, and a magnetic recording layer formed on the substrate. The magnetic recording layer includes recording portions having patterns regularly arranged in an longitudinal direction and containing cobalt and platinum, and non recording portions formed between the recording portions and containing boron and at least one light rare earth metal selected from the group consisting of yttrium, lanthanum, and cerium.

Abstract: A fluid dynamic pressure bearing device includes a shaft, an annular member, and a rotating member. The annular member is fixed to or seamlessly defined with the shaft and is radially opposed to the rotating member. The annular member and the rotating member are covered with a seal member. A first gap is defined between the seal member and the annular member. A second gap is defined between the rotating member and the seal member. A third gap is defined between the annular member and the rotating member. The first gap preferably has a width smaller than that of the second gap but greater than that of the third gap.

Abstract: According to one embodiment, in a method of manufacturing a magnetic recording medium which is configured such that a ferromagnetic recording part is formed on a substrate in a desired track pattern or a desired bit pattern, a ferromagnetic film is formed on the substrate, and then a mask is formed on the ferromagnetic film, the mask having an opening above a region for isolating the ferromagnetic film between tracks or bits. Subsequently, a B-based gas is radiated on the region of the ferromagnetic film through the opening of the mask, thereby increasing a B content of the region to nonmagnetize the region.

Abstract: A clamping device for coupling a rotatable component of a machine with a shaft, including a balance hole configured to confine a counterweight. The clamping device includes a circular plate. The circular plate includes at least one fastener hole configured to accept a fastener, and at least one balance hole. The fastener is configured to fasten the clamping device to couple the component with the shaft. The balance hole includes a cavity configured to accept a counterweight. The counterweight is configured to balance the rotational motion of at least the circular plate when the shaft is rotated. Moreover, the cavity is configured to confine the counterweight to an end of the cavity by effects of rotation of the shaft on the counterweight when the shaft is rotated.