Abstract: A method of erasing information on one or more disks in a disk drive uses a high strength magnetic field to erase the disks while the disks are in the HDD assembly. The design of the head disk enclosure provides a reduced thickness in a localized region over the disks. This allows a narrower working magnetic gap of the HDD level disk erase apparatus. The localized region of the HDD may be a formed indentation on the top cover, elimination of flange, and reduced floor thickness of the HDD base.

Abstract: A disk erase apparatus for erasing information on one or more disks in a disk drive uses a high strength magnetic field to erase the disks while the disks are in the HDD assembly. The design of the head disk enclosure provides a reduced thickness in a localized region over the disks. This allows a narrower working magnetic gap of the HDD level disk erase apparatus. The localized region of the HDD may be a formed indentation on the top cover, elimination of flange, and reduced floor thickness of the HDD base.

Abstract: A secondary servo actuator system for use in disk drives comprising a controller and two PZT transducers mounted on each suspension load beam in an arm assembly. When a seek operation is initiated the acceleration of the arms generates vibration modes. The PZT transducers on a suspension adjacent to the target head/suspension sense the vibration motion and provide output signals to the controller. The controller filters the signal and generates a control signal for the PZTs mounted on the target arm/suspension. The deformation of the PZTs in turn rotates the arm load beam and thereby adjusts the position of the target head to compensate for arm motion caused by the vibration modes. The secondary actuator system can be used during the deceleration trajectory of a target head to suppress lower order arm sway frequencies.

Abstract: A spindle motor assembly having a shaft with an integral heat pipe. The shaft with the integral heat pipe improves the thermal conductivity of the shaft and the spindle motor assembly. The shaft includes an elongated portion and a sealing structure. For one embodiment, the sealing structure includes a cap and a gasket that are joined to the shaft by a brazing process.

Abstract: A bearing structure for a spindle motor is disclosed. The bearing structure provides a fluid bearing seal and support structure that may simultaneously addresses the problems of preventing oil leakage, of maintaining the bearing integrity under shock, of reducing oil evaporation and of minimizing distortion of the active bearing surface. The bearing structure includes a thrust plate coupled to a shaft and a bearing plate and load plate coupled to a sleeve, wherein the load plate urges the bearing plate towards the thrust plate, and wherein an adhesive is interposed between the load plate and the thrust plate. The adhesive may be an UV epoxy. The sleeve is operatively coupled to a stator, and the stator rotates the sleeve upon receiving a drive signal. The bearing further includes a diffusion barrier disposed between the sleeve and the stator. A second diffusion barrier is disposed between the load plate and the shaft.

Abstract: A bearing structure for a spindle motor is disclosed. The bearing structure provides a fluid bearing seal and support structure that may simultaneously addresses the problems of preventing oil leakage, of maintaining the bearing integrity under shock, of reducing oil evaporation and of minimizing distortion of the active bearing surface. The bearing structure includes a thrust plate coupled to a shaft and a bearing plate and load plate coupled to a sleeve, wherein the load plate urges the bearing plate towards the thrust plate, and wherein an adhesive is interposed between the load plate and the thrust plate. The adhesive may be an UV epoxy. The sleeve is operatively coupled to a stator, and the stator rotates the sleeve upon receiving a drive signal. The bearing further includes a diffusion barrier disposed between the sleeve and the stator. A second diffusion barrier is disposed between the load plate and the shaft.

Abstract: A method, apparatus, and a disk file for adjusting the height of a set of load/unload lift cams with respect to the axial height of an associated stack of disks. The method steps comprise supporting load/unload lift cams with an adjustment tool, measuring the relative height of the load/unload lift cams with respect to the stack of disks in the axial direction with a non-contact transducer, and fixing the load/unload lift cams at a registered height with respect to the stack of disks.

Abstract: A method and apparatus for adjusting the height of a set of load/unload lift cams with respect to the axial height of an associated stack of disks. The method steps comprise supporting load/unload lift cams with an adjustment tool, measuring the relative height of the load/unload lift cams with respect to the stack of disks in the axial direction with a non-contact transducer, and fixing the load/unload lift cams at a registered height with respect to the stack of disks.

Abstract: A motor control processor controls motor spin-up in a disk drive by detecting environmental temperature at the spindle motor of the disk drive, controlling commutation phase advance to generate substantially maximum torque if the detected environmental temperature indicates that maximum torque is needed, and adjusts the commutation phase advance for optimal efficiency after the maximum torque is no longer needed. Following motor start and reaching operational speed, the motor is operated in a steady-state maximum operating efficiency mode unless sensed environmental temperature indicates that maximum torque, rather than maximum efficiency, is needed. The system determines that the need for maximum torque has passed either when a predetermined time interval after motor start expires or by repeatedly polling motor temperature information.

Abstract: A highly thermally conductive spindle support shaft is composed of a metal matrix composite of aluminum (Al) and silicon carbide (SiC) of substantially 53% to 63% silicon carbide by volume. The spindle support shaft supports a magnetic disk file spindle by means of rotatable bearings, replacing a steel shaft. The spindle support shaft increases the heat transfer from, and reduces the temperature of, the rotatable bearing, and matches the coefficient of thermal expansion of a conventional steel shaft, thereby maintaining the bearing preload through a range of temperatures.

Abstract: A method, apparatus, and a disk file for adjusting the height of a set of load/unload lift cams with respect to the axial height of an associated stack of disks. The method steps provide supporting load/unload lift cams with an adjustment tool, measuring the relative height of the load/unload lift cams with respect to the stack of disks in the axial direction with a non-contact transducer, and fixing the load/unload lift cams at a registered height with respect to the stack of disks.

Abstract: Disclosed are a method and apparatus for detecting disk drive start-up failure under disparate temperature conditions by employing a temperature sensor to measure the temperature of the disk drive at start-up. A controller selects, in response to the measured temperature, a start-up failure timing corresponding to that measured temperature. The controller then detects whether the disk drive reaches operational speed within the selected start-up failure timing. Preferably, the temperature sensor is digital. The temperature sensor may be mounted on the drive electronics card, or on electronics in the disk enclosure. The controller may have a stored lookup table relating various temperatures to start-up failure timings for selecting a start-up failure timing corresponding to the measured temperature. This method allows selection of a motor torque constant that does not compromise normal operating performance based on cold start conditions.

Abstract: A bearing structure for a spindle motor is disclosed. The bearing structure provides a fluid bearing seal and support structure that may simultaneously addresses the problems of preventing oil leakage, of maintaining the bearing integrity under shock, of reducing oil evaporation and of minimizing distortion of the active bearing surface. The bearing structure includes a thrust plate coupled to a shaft and a bearing plate and load plate coupled to a sleeve, wherein the load plate urges the bearing plate towards the thrust plate, and wherein an adhesive is interposed between the load plate and the thrust plate. The adhesive may be an UV epoxy. The sleeve is operatively coupled to a stator, and the stator rotates the sleeve upon receiving a drive signal. The bearing further includes a diffusion barrier disposed between the sleeve and the stator. A second diffusion barrier is disposed between the load plate and the shaft.

Abstract: A vent is disclosed for a screw mounted support shaft of a fluid dynamic bearing for a spindle of a magnetic disk file. The support shaft for mounting a spindle bushing has an axial hollow center internally threaded at one end, and has upper and lower bearing journals for rotatably mounting the spindle bushing with a fluid lubricant. The bearing journals are separated by a recess having a vent passage between the recess and hollow center. A screw is threaded through the base plate or cover into the threaded end of the support shaft, mounting the support shaft to the base plate or cover. An air vent passage, such as a slit is provided axially either in the threaded end of the hollow center of the support shaft or in the screw, and radially across the end of the support shaft so the air bleed passage extends from the hollow center externally of the support shaft.

Abstract: A head load/unload and airflow control apparatus for a disk stack is disclosed. Load/unload cams protrude into the OD of the disk stack for guiding the heads away from the corresponding disks during unloading and ramping the heads toward the corresponding disk during loading. Airflow vanes, each in the same plane and radially proximate to the outer edges of the corresponding disks are provided to limit airflow turbulence at the edge of the disks. Each airflow vane supports corresponding load/unload cams. A shroud supports the vanes and extends axially of the disk stack to limit airflow from the disks. The load/unload cams, airflow vanes and shroud may comprise a single element.

Abstract: An extender frame is disposed between the enclosure and the circuit board of a high speed hard disk drive having a 1.0" form factor height, to improve cooling of the disk drive by directing air flow between the enclosure and card. After the extender frame is installed, the profile of the assembly is a 1.6" form factor height. To engage the frame with the drive, the circuit board is unfastened from the enclosure, the extender frame positioned between the card and enclosure, and then relatively longer fasteners are reinstalled through the enclosure, frame, and circuit board to hold the assembly together.

Abstract: A hard disk drive head actuator includes a plurality of arms for holding the heads over the disks. Each arm is formed with one or more cutouts, to reduce the rotational inertia of the actuator. To prevent increased viscous dissipation, or windage losses, that would otherwise be caused by the cutouts, the cutouts are filled with lightweight plastic inserts. Advantageously, filling the cutouts improves structural damping of an arm and enhances the dynamic response of an actuator assembly that incorporates one or more such arms.