International Business Machines Corporation

Thomas S Larson

Christopher Guild Keller

Thomas A Gregory

Zine-Eddine Boutaghou

David F Glaess

Patricia Joanne Wadkins

Randall Mason Bates

Hal Hjalmar Ottesen

Dallas W Meyer

Lowell James Berg

Jerry Lee Neubauer

Jaquelin K Spong

Jay Michael Mosbrucker

Donald C Buettner

Disclosed is a disk drive having a spindle motor, a disk that is rotated by the spindle motor, and a movable actuator arm that carries a read/write head. The head physically engages a parked, or home, position at the Inner Diameter (ID) of the disk when the spindle motor is not energized and the disk is stationary. The electrical energization that must be applied to the spindle motor in order to breakaway the head from the disk (i.e., the breakaway current), and the energization that is necessary to cause the motor to achieve a stable spinning state (i.e., the spin current) are monitored. Possible future failure of the disk drive is predicted as a function of any changes in these two-electrical parameters, as these parameters may change over a period of time; i.e., may change over a number of disk drive stop/start events.

Method and apparatus for predicting failure of a disk drive

A rotating magnetic storage device is shown wherein the transducer and media are separated during operation by a thin film of low viscosity liquid lubricant that is recirculated from a reservoir within the head-media enclosure. Lubricant recirculation can be effected by capillary action using a wick, mechanical pumping and metering or distillation techniques. As compared to devices using air bearing separation, the transducer carrying slider has very small bearing surfaces which may be in the form of narrow rails or small depending foot elements. This enables fly heights. of 2 microinches using a film of one micron thickness.

Apparatus and method for near contact magnetic recording

A rotating magnetic storage device is shown wherein the transducer and media are separated during operation by a thin film of low viscosity liquid lubricant that is recirculated from a reservoir within the head-media enclosure. Lubricant recirculation can be effected by capillary action using a wick, mechanical pumping and metering or distillation techniques. As compared to devices using air bearing separation, the transducer carrying slider has very small bearing surfaces which may be in the form of narrow rails or small depending foot elements. This enables fly heights of 2 microinches using a film of one micron thickness.

Near contact magnetic recording using a liquid lubricant bearing to

A load/unload device to remove the slider from the proximity of the magnetic recording surface of a disk in a disk drive whenever the disk is to be stopped. The load/unload device is a ramp-like wedge which extends generally radially from the center of the magnetic disk and to the magnetic recording surface of the magnetic disk. When the slider is moved toward the center of the disk by an actuator mechanism, the end of the load arm supporting the slider, referred to as a tang, will engage the inclined plane of the wedge and lift the slider from the surface of the magnetic disk as the slider is translated closer to the center of the disk. Once the slider has been removed from close proximity of the disk, the tang may engage a trough-like surface on the structure supporting the wedge and will effectively detent the position of the slider through the forces exerted on the tang by the load beam of the actuator. Thus the disk will be protected from undesirable and damaging impacts of the slider against the magnetic recording surface of the disk thereby prolonging disk utility.

Inner diameter disk drive head/slider load/unload device

Disclosed is a disk drive having a spindle motor, a disk that is rotated by the spindle motor, and a movable actuator arm that carries a read/write head. The head physically engages a parked, or home, position at the Inner Diameter (ID) of the disk when the spindle motor is not energized and the disk is stationary. The electrical energization that must be applied to the spindle motor in order to breakaway the head from the disk (i.e., the breakaway current), and the energization that is necessary to cause the motor to achieve a stable spinning state (i.e., the spin current) are monitored. Possible future failure of the disk drive is predicted as a function of any changes in these two electrical parameters, as these parameters may change over a period of time; i.e., may change over a number of disk drive stop/start events.

A starting sequence is provided for a rotating disk data storage device by providing a low level sensing current to the spindle motor which is able to initiate rotation of the disk spindle assembly when, absent stiction between head and confronting disk surface, it is only necessary to overcome disk assembly inertia and head drag. A sensing device is provided to sense a back electromotive force (EMF) in the spindle motor windings which indicates the start of disk rotation when any stiction condition has been terminated. A sequence of alternating current pulse bursts are applied to the actuator motor to impart a dithering action to the heads which induces axial vibration of the disks to break the stiction between the heads and confronting disk surfaces. The initial burst is of low amplitude pulses and each succeeding burst is of progressively greater amplitude and the pulses of each burst are of constant or progressively varying frequency to afford some consecutive pulses approaching the resonant frequency of the disk modes of vibration to enhance the stiction breaking force. The sensing of a back EMF (indicating disk rotation and the termination of any stuck head condition) is used to terminate the start sequence and switch the spindle and actuator motors to the normal operational control of the drive.

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Altura, MN, United States of America

Thomas S Larson