International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Daniel Robert Stacer

Kirk Barrows Price

Brad Vaughn Johnson

Ta-Chang Fu

Stanley Yen Wong

Gregory Michael Frees

Andrew Keith Hanlon

Holavanahally Seshachar Nagaraj

Ungtae Kim

Larry Joe Gilliland

Sattar Malek

Gregory Allen Lyons

Don E De Leo

John Beck

Peter E Brooks

David Eric Peters

Neal Bertram Schirle

Michael R Hatchett

Scott Edwin Heeren

Daniel L Good

A method of redefining nodal points of rotation comprises providing an actuator assembly with a comb, a pivot having an axis of rotation, comb legs on one side of the pivot, a voice coil motor, an arm, and a head gimbal assembly mounted to the arm with a head opposite the arm; defining a first nodal point of rotation for the actuator at a position that is on the arm between the pivot and the head; defining a second nodal point of rotation for the actuator at a position adjacent to the pivot and the coil; moving the first nodal point in a radial direction away from the axis toward the head; and moving the second nodal point in a radial direction away from the pivot to a geometric center of active legs of the coil.

Method for reducing off-track gain for a disk drive actuator

A top pole piece of a voice coil motor (VCM) is attached to a hard disk drive cover without screw fasteners and with minimal loss of VCM magnetic flux capacity. A pair of leaf springs are supported at both ends, rather than by cantilever, to more uniformly distribute mechanical stress throughout the springs so that less space is required to achieve the same transverse load as a cantilevered spring of the same profile. The smaller space envelope required by this design minimizes the loss of magnetic flux capacity of the VCM. Each leaf spring has two integral legs, central portions of which are rigidly fastened to the drive cover. The end of each leg opposite the central portion applies a force against the cover in the assembled disk drive.

System, method, and apparatus for attaching top pole piece of a voice coil motor to a hard disk drive enclosure

A mounting interface for a spindle motor allows the optimization of the spindle dynamics. The mounting interface provides a steadfast relationship between a motor and a baseplate, wherein the mounting interface includes at least three surface points forming a single plane acting as a common boundary between the motor and the baseplate. The three surface points may be pads, and the pads may be coupled to the baseplate or to the mount flange. The three surface points provide reduced contact area between the mount flange and the baseplate, and the reduced contact area lowers the rigidity of the mount flange and the resonant frequencies. The surface area of the pads and the material of the pads is chosen to reduce acoustical noise. In addition, a damping ring may be provided for dissipating distortion energy between the motor, baseplate and/or mount flange.

Mounting interface for a spindle motor

The dynamics of a disk drive actuator are enhanced by redistributing the mass and stiffness of the structure. The two nodal points of the second primary bending mode of the actuator are relocated to positions that are both radially outboard of their original positions. One nodal point is positioned as close to the read-write head as possible at one end of the actuator, and the other nodal point is positioned at the center of the active legs of the VCM coil at the other end of the actuator. This is done to reduce the off-track displacement associated with this fundamental resonance to near zero, allowing higher track densities to be supported.

System and apparatus for reducing off-track gain for a disk drive actuator

A hard disk drive has a motor mounting bracket with mounting screws that attach from outside the drive and external to the seal with a screw bolt pattern diameter that is larger than an outer diameter of the motor hub. This configuration greatly reduces contamination inside the disk drive since all contaminants due to the screws are sealed from entering the disk drive. Consequently, the bottom of the mounting bracket is extended to the form factor limit to increase the internal space that is provided for the stator/winding of the motor. In relatively high platter count disk drives, the bottom disk is positioned very close to the motor bracket with this approach, which normally would cause the air drag to increase drastically and thereby impede the performance of the disk drive. Bosses may be used on the bracket to accommodate blind tap hole depths from the external surface of the bracket.

Screw attachment from exterior of disk drive enclosure for motors with mount bracket screw bolt pattern diameter larger than the motor hub outside diameter

A lubricant retention design for a fluid dynamic bearing design in a spindle motor utilizes a labyrinth gap that is formed between the sleeve and the shaft of the bearing. The gap is used in conjunction with a barrier film to impede the flow of lubricant into the lateral and axial vent holes during non-operational vibration, such as shipping and handling of the end product. In another version, a plug is located in the lateral vent hole. The plug has a very small passage that permits air to pass therethrough for atmospheric pressure equalization, but prevents the escape of lubricant into the vent holes. Alternatively, the plug may be formed from a non-wettable material such as porous foam or sintered material and provided with a larger opening. Yet another solution utilizes a combination of both the labyrinth and plug designs.

Lubricant retention design for disk drive fluid dynamic bearing spindle motor

A cordless compression motor connector connects a spindle motor inside a hard disk drive enclosure to a printed circuit board (PCB) mounted outside the disk enclosure. The disk enclosure includes a base casting formed with a lipped aperture. The connector includes a rigid, cantilever-like insulating body having conductors supported therein. The conductors terminate at the resilient spring contacts located at both ends of the connector body. One end of the connector body is secured to the PCB with a screw such that the resilient contacts on one end are compression connected to contacts on the PCB. The other end of the connector body passes through the aperture and reacts against the lip in the base casting. Contacts formed on the spindle motor are compression connected to the electrical contacts on the other end of the connector body.

Cordless compression motor connector for a hard disk drive

Improved shield designs for ball bearing based spindle motors that exhibit improved containment of grease and the base oil within the bearings at accelerated conditions of temperature and speed is disclosed. Improved shield designs are provided at the shield OD contact area, the use of an impervious shield material, the use of barrier films, shield/bearing designs that use tortuous paths and labyrinth schemes for reducing the oil and grease loss from the shield ID gap of DASD spindle ball bearings, and improved stainless steel shield designs.

Ball bearing oil/grease loss containment shield

Shield designs for ball bearing based spindle motors that exhibit containment of grease and the base oil within the bearings at accelerated conditions of temperature and speed are provided at the shield OD contact area, the use of an impervious shield material, the use of barrier films, shield/bearing designs that use tortuous paths and labyrinth schemes for reducing the oil and grease loss from the shield ID gap of DASD spindle ball bearings, and stainless steel shield designs.

Ball bearing oil/grease loss containment method

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 spindle motor shaft having variable geometrical features for adjusting the torsion mode frequency of the shaft/stator assembly. The variable geometric features allow the torsion mode frequency to be tuned away from the driving force frequency of the motor. Variable geometrical features for the shaft may include circumferential grooves, radial slots cut through the shaft, or transverse holes disposed along the axis of the shaft. The radial slots have a longitudinal axis that is parallel to the axis of the shaft. Where circumferential grooves are used, the circumferential grooves may be designed to form a locator region along the shaft axis to promote axial alignment of the shaft and stator. Thermal track-misregistration (TMR) or screw torque problems are not introduced in the process of reducing or eliminating the acoustic problem thereby establishing a torsion mode frequency which is not subject to change due to temperature or time. Further, the removal of material from the shaft reduces the torsional stiffness of the shaft and lowers the torsion mode frequency of the shaft. Finally, the use of circumferential grooves prevents the wicking of excess epoxy up the shaft by the movement of the stator during the assembly/manufacturing process, which may lead to an undesirable increase in the stiffness.

Stepped spindle motor shaft to reduce disk drive acoustic noise

A cartridge filter for an enclosed magnetic disk drive is disclosed which includes a dual media drum type filter element in a recirculating filter assembly that surrounds the breather filter and delivers air from the periphery of the disk stack to the axial entry of the ventilated disk spindle assembly. The cartridge provides an extended media surface within a compact space for frequent cycling of the enclosed air volume through the filter.

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Morgan Hill, CA, United States of America

Daniel Robert Stacer