Abstract: A voice coil for a voice coil motor of a hard disk drive comprises an inner surface of the voice coil, which bounds a central space of the voice coil. A first outer surface of the voice coil is substantially parallel to a second outer surface of the voice coil. A constrained layer damper is attached to the inner surface of the voice coil by a coupler. The constrained layer damper comprises a first constraining layer coupled to a first surface of a viscoelastic damping layer. A second constraining layer is coupled to a second surface of the viscoelastic damping layer. The constrained layer damper is curved in a direction that is substantially perpendicular to the first outer surface of the voice coil and the second outer surface of the voice coil.

Abstract: A combined bulk thermal-assister and bulk eraser. The bulk thermal-assister is configured to produce a temperature in a magnetic-recording disk in a hard-disk drive when the hard-disk drive is disposed in the bulk eraser. The temperature is about equal to a second temperature greater than a first temperature of the magnetic-recording disk. The bulk eraser is configured to erase recorded information from the magnetic-recording disk at the second temperature.

Abstract: An improved disk stack assembly for a hard disk drive (HDD) includes a generally cylindrical hub with flange having a downward sloping conical flange surface. The conical flange surface is defined between a radially inner circular ridge and a radially outer circular edge. The bottom disk in the stack is in contact with the flange inner circular ridge. The disk stack assembly also includes a disk clamp with a contact surface having a contact rim that is in contact with either the radially inner portion of the top disk in the stack or a spacer ring. The clamp contact rim is located at approximately the same radial distance from the hub's central cylindrical axis as the flange circular ridge so that the clamping force is applied to the disks close to the area where the disk stack is supported on the conical flange surface.

Abstract: A method of manufacturing of a hard-disk drive using a bulk eraser for erasing recorded information on a magnetic-recording disk. The method includes providing a bulk eraser that produces magnetic-flux density in a gap sufficient to erase recorded information from a magnetic-recording disk, a hard-disk drive, a disk-stack having at least one magnetic-recording disk, and a drive motor for rotating the magnetic-recording disk. The method also includes configuring a plurality of magnets and a structure of the bulk eraser such that magnetic-flux density is oriented parallel to and in a radial direction of the magnetic-recording disk; and rotating the magnetic-recording disk. The method further includes inserting the hard-disk drive into the gap of the bulk eraser; and erasing recorded information from the magnetic-recording disk located in the gap; and removing the hard-disk drive from the gap.

Abstract: A bulk eraser for erasing recorded information on a magnetic-recording disk. The bulk eraser includes at least three magnets and a structure magnetically coupled with the at least three magnets to produce magnetic-flux density in a gap. The gap has a first portion, a second portion and a third portion, such that a first magnet and a second magnet are disposed with opposing end poles across the first portion. The at least three magnets and the structure are configured to produce a magnetic-flux density in the second portion sufficient to erase recorded information from a portion of at least one magnetic-recording disk in a disk-stack when a hard-disk drive is inserted into the second portion. In addition, the at least three magnets and the structure are configured to direct the magnetic-flux density in a substantially radial direction of the portion of the magnetic-recording disk in the second portion.

Abstract: A bulk eraser for erasing recorded information on a magnetic-recording disk. The bulk eraser includes a plurality of magnets and a structure magnetically coupled with the plurality of magnets to produce magnetic-flux density in a gap. The gap has a first portion, a second portion and a third portion. Two magnets are disposed with opposing polarity across the first portion of the gap. The plurality of magnets and the structure are configured to produce a magnetic-flux density in the second portion of the gap sufficient to erase recorded information from a portion of at least one magnetic-recording disk in a disk-stack of the hard-disk drive when the hard-disk drive is inserted into the second portion of the gap. The plurality of magnets and the structure are configured to direct the magnetic-flux density in a substantially radial direction of the portion of the magnetic-recording disk.

Abstract: A disk drive and a method for operating the disk drive compensates for rotational vibration (RV) by adaptively modifying the gains of two separate linear vibration sensors so the sensor gains are optimal under any given condition. The two sensors provide two signals S1, S2, respectively, to the disk drive's servo control processor that generates the control signal to the voice coil motor (VCM) actuator that controls the positioning of the read/write head. The processor uses S1, S2 and the head position error signal (PES) as inputs to run an adaptive RV feedforward (RVFF) algorithm. The adaptive RVFF algorithm takes the PES and sensor outputs S1 and S2 as inputs, mathematically determines the required correction to the sensor gain factors k1 and k2, respectively, and then adjusts the gain factors k1 and k2 accordingly. Each signal S1, S2 is then modified by its adjusted gain factor k1, k2, respectively.

Abstract: A flex cable assembly for a head stack assembly of a hard disk drive comprises a flex cable for conducting data signals from the head stack assembly to a connector. The flex cable has a dynamic loop section between a termination for the head stack assembly and the connector. The flex cable has a constrained layer damper for attenuating random transient vibration. The constrained layer damper has a symmetrically tapered shape for reducing stress concentration and is coupled with the dynamic loop section of the flex cable adjacent to an area of the flex cable configured for receiving a coupler for coupling the flex cable assembly with the head stack assembly.

Abstract: A method of reducing oscillation at the read write element of a hard disk drive, is described. In one embodiment, a flex cable for conducing data signals from a head stack assembly to a connector is provided. One or more weights are then coupled with the flex cable at one or more predetermined locations. The one or more predetermined locations are selected based upon mass distribution along the flex cable.

Abstract: A magnetic head is described herein. A method for manufacturing the magnetic head comprises determining a protective distance for a protective structure to extend beyond an element in a direction toward a disk, layering the protective structure, and removing material from the protective structure to obtain approximately the protective distance. The protective distance is from an element end to a protective structure end. The protective distance is determined based on a magnetic head profile. The thickness of the protective structure is based on pole-tip recession.

Abstract: A method for neutralizing the flying height sensitivity associated with thermal pole-tip protrusion (T-PTP) of an air bearing slider comprises creating head material data and air bearing surface (ABS) compensation data, based on which a head/ABS design is created. The head material data comprises at least one material property that is dependent on the manner in which the material is fabricated, such as the coefficient of thermal expansion of a material deposited using a certain deposition process. The ABS compensation data comprises data about how respective ABS features affect air bearing pressure and, therefore, ABS compensation. A protrusion profile is determined for the head/ABS design, and whether or not this protrusion profile meets particular design criteria is then determined. The head/ABS creating and determining process can be iterated if necessary to arrive at a head/ABS design which provides neutral flying height sensitivity to a range of operational temperatures.

Abstract: The present invention is directed towards a family of vibroacoustic emulators to simulate the vibroacoustic characteristics of components of an electronic device. Specific embodiments for simulating a hard disk drive comprise a housing and a vibroacoustic generator coupled to the housing. Various embodiments enable acoustic emulation through a cover side and base side, out-of-plane vibrational emulation to simulate hard disk drive during seek periods, and in-plane vibrational emulation to simulate a hard-disk drive during idle periods. Methods for using the vibroacoustic emulators to characterize system noise are also disclosed.

Abstract: An integrated flexure tongue micro-actuator is disclosed. One embodiment provides a first arm on a first side of the flexure tongue, the first arm approximately perpendicular with the flexure tongue. In addition, a second arm is provided on a second side of the flexure tongue, the second arm approximately parallel with the first arm. At least one piezoelectric device is coupled with either the first arm or the second arm and a slider is disposed between and coupled with the first am and the second arm.

Abstract: One embodiment of the invention can include a method of assembling an actuator arm system for a hard disk drive. The method can include: placing a lower bearing on a shaft; placing an actuator arm on the lower bearing; placing an upper bearing on the shaft; applying an adhesive between an inner race of the upper bearing and the shaft; applying an axial preload force to the inner race of the upper bearing; curing the adhesive; and releasing the preload force.

Abstract: A pure rotary microactuator comprising a spring assembly etched within a silicon substrate is disclosed. A first piezoelectric device is coupled with a first portion of the spring assembly and a second piezoelectric device coupled with a second portion of the spring assembly. The first piezoelectric device changes shape in response to an electrical input signal, and this change in shape provides a first push force to the first portion of the spring assembly in a first direction. The second piezoelectric device also changes shape in response to the electrical input signal, and this change in shape provides a second push force to the second portion in a second direction, which is different from the first direction. The combination of the first and the second push forces rotates the spring assembly with respect to the silicon substrate.

Abstract: A voice coil for a voice coil motor of a hard disk drive comprises an inner surface of the voice coil, which bounds a central space of the voice coil. A first outer surface of the voice coil is substantially parallel to a second outer surface of the voice coil. A constrained layer damper is attached to the inner surface of the voice coil by a coupler. The constrained layer damper comprises a first constraining layer coupled to a first surface of a viscoelastic damping layer. A second constraining layer is coupled to a second surface of the viscoelastic damping layer. The constrained layer damper is curved in a direction that is substantially perpendicular to the first outer surface of the voice coil and the second outer surface of the voice coil.

Abstract: A contoured region is disposed within a capillary buffer of a Fluid Dynamic Bearing. In one embodiment, the contoured region comprises at least one defined edge for arresting the displacement of a lubricant within the capillary buffer.

Abstract: A hard disk drive has a flexible cable and a flexible cable damper positioned adjacent to but separate from the flexible cable. The damper is a thin film loop with a damper patch that is completely independent of the flexible cable. The damper strip is a non-signal carrying substrate and has the constraint layer attached to it opposite the flexible cable. Both the damper and flexible cable extend in an arcuate configuration from the base to an integrated lead suspension tail extending from the actuator.

Abstract: An apparatus and method for damping slider-gimbal coupled vibration of a hard disk drive is disclosed. The method provides a suspension for reaching over a disk. A slider having a read/write head element on a trailing edge (TE) portion is also provided, the slider coupled with the suspension at a gimbal structure. In addition, a damping zone is provided at a stress point on the gimbal structure, the damping zone having a damping material thereon, wherein the damping material reduces vibration of the slider and the gimbal structure.

Abstract: A bearing system having variably grooved radial and thrust bearing with reduced groove angle near bearing entry is described. In an embodiment, the bearing system includes a housing. The bearing system also includes a shaft centrally located in the housing. The bearing system additionally includes a rotor portion that is adapted to be rotated about the shaft and contained within the housing. The bearing further includes a variably angled groove disposed on an internal surface of the bearing system. The variably angled groove reduces ingestion of air in the bearing system during operation of the bearing system.