International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Other

Hgst Netherlands, B.v.

Neal Bertram Schirle

Chen-Hsiung Lee

James William Berberich

Holavanahally Seshachar Nagaraj

Kirk Barrows Price

Thomas Edward Karis

Steven Alf Hanssen

Daniel Robert Stacer

Kunihiro Shida

Huey M Tzeng

Scott Edwin Heeren

John C Kan

A fluid dynamic bearing with an immiscible fluid barrier deposited on the bearing oil is disclosed. One embodiment provides the fluid dynamic bearing having a seal gap to define a seal cavity. The seal cavity is filled with the bearing oil for lubricating the fluid dynamic bearing. The immiscible fluid is disposed on the bearing oil to prevent the bearing oil from evaporating from the seal cavity. In one embodiment, the immiscible fluid is insoluble in the bearing oil.

Fluid dynamic bearing with an immiscible fluid barrier

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.

Method for assembly level disk erase

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.

System and apparatus for assembly level disk erase

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. The milliactuator of the target head can also be used to sense the phase and amplitude of the dominant arm sway mode to enable the deceleration control signal to be applied with a phase relation that suppresses the arm sway mode that was excited upon application of seek servo actuator control.

Secondary actuator system for mode compensation

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.

Motor shaft having an integral heat pipe

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. The bearing structure may also include an O-ring disposed above the bearing plate for sealing a gap between the bearing plate and the sleeve.

Fluid bearing seal and support structure

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.

Head suspension lift cam adjustment apparatus

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.

Head suspension lift cam adjustment

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.

Disk drive motor spin-up control

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.

Thermally conductive spindle support shaft

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.

Adjustable head suspension load/unload lift cam assembly

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.

Disk drive start-up failure detection under disparate conditions

A data storage device for a computer system, such as a hard disk drive (HDD), provides means for channeling air flow from the spinning disks to other components within the HDD enclosure that require cooling, particularly a voice coil motor having a coil which is used to move an actuator assembly. Channeling may be provided by forming a slot or gap in the disk cavity wall, or by providing an insert part which has a channel formed therein that directs air flow to the VCM coil.

Disk drive having an insert with a channel for directing air flow to a

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.

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Morgan Hill, CA, United States of America

Neal Bertram Schirle