Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hitachi Global Storage Netherlands, B.v.

Andrew Keith Hanlon

Ta-Chang Fu

Stanley Yen Wong

Jr-Yi Shen

Kirk Barrows Price

Andre Sirilutporn Chan

Steven Alf Hanssen

Daniel Robert Stacer

Kunihiro Shida

Tisha Jefferson

Fu-Ying Huang

Lidu Huang

Brad Vaughn Johnson

Thomas Edward Karis

David Eric Peters

Gregory Michael Frees

John Martin Burns

Holavanahally Seshachar Nagaraj

Keith Freeman Wood

M Amine Hajji

Antony Nguyen

Robert Lenicheck

Deborah Lynn Yaney

Charles E Hignite

Richard Kroeker

Eduardo Gatmaitan Canlas

Hamid Salehizadeh

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.

Disk stack assembly with spindle motor hub having improved disk-supporting flange

An apparatus and method for correcting static and dynamic imbalance with a single mass in a hard disk drive is disclosed. The method provides for determining a static imbalance of a hard disk assembly and for determining a dynamic imbalance of the hard disk assembly. A greater imbalance from the static imbalance and the dynamic imbalance is determined. A single mass is applied to the hard disk assembly to correct the greater imbalance.

Apparatus and method for correcting static and dynamic imbalance with a single mass in a hard disk drive

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

An improved disk drive system that employs a lubricant with improved charge control is provided. The disk drive system is comprised of a rotatably mounted magnetic disk. A rotor is coupled to the disk and rotatably retained by a stator. A bearing is formed that serves as an interface between the stator and the rotor. A motor coupled to the rotor rotates the magnetic disk via the rotor. Located in the bearing is a lubricant having a low relative electrical permittivity.

Disk drive system with hydrodynamic bearing lubricant having charge-control additive comprising dioctyldiphenylamine and/or oligomer thereof

A disk clamp for securing data storage disks to the hub of a spindle motor in a hard disk drive has a circumferential rib protruding from a lower surface of the disk clamp. A complementary recess is formed in the hub of the spindle motor for closely receiving the rib on the disk clamp. The inner diameter of the rib and the outer diameter of the recess are closely toleranced to provide a very precise centering feature for mounting and aligning the disk clamp with respect to the hub and spindle motor. This design reduces the complexity of the tooling and fixtures required to complete the assembly and the overall part cost is reduced.

System and method for hard disk drive with disk clamp annular rim inner wall engaging hub annular recess outer wall

A spindle motor is equipped with pre-installed adjustable balance clips on a stainless steel motor hub to facilitate better balance correction. A balance clip holder feature is formed in the hub and has grooves to hold the balance clips. The balance clip holder can be an integrally formed part of the hub, or it can be a separate piece that is assembled to the hub before the complete motor is assembled. In addition, the balance clips are provided with an improved coating to reduce friction during adjustment of the clips in the balance process. Each clip has a coating of nickel-Teflon to achieve a better coating quality and cleanliness over prior art designs. The nickel-Teflon combination yields unexpected results, such as a significantly smoother surface with more uniform coating thickness, and significantly less particle sloughing to reduce contamination.

Balance clip holder feature on a spindle motor with nickel-teflon coating on balance clips for reducing friction during clip adjustment in balance process

Hard disk drive with disk clamp inner wall engaging bearing sleeve outer wall

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

A balancing mechanism for the spindle of a computer hard disk drive uses two, substantially flat wire clips at each end of the disk pack. The clips are designed so that one clip in each pair nests concentrically inside the other clip in the pair. Each clip is provided with a substantially identical imbalance in the installed position. If the imbalance vectors of each clip at one end of the disk pack are oriented 180 degrees apart, the resulting imbalance at that end of the pack is zero. Conversely, if the imbalance vectors are oriented at the same angle, the imbalance is maximized. Thus, the resolution of the imbalance provided by the clips is theoretically infinite between these limits, up to the precision of the clips. The orientation of the imbalance vector is controlled by the angle of the pair of clips relative to an index mark on the disk pack. The magnitude of the desired counterbalance is controlled by rotating the clips in each pair relative to each other. The cross-sectional shape of each pair of clips can be varied, and include the following examples: rectangular cross-sections having a generally flat profile, cross-sections with nesting grooves and ridges, and wire that is concave on one side and convex on the other side.

Balancing apparatus and method for high speed hard disk drive spindles

A hard disk drive spindle motor has a hub, a drive shaft, and a bearing therebetween. The spindle motor also has a ferrofluid seal to prevent any incidental oil emissions from the bearing from entering the drive. A ferrofluid cap is mounted on the axial end of the spindle motor for sealing the ferrofluid seal. The cap is a flat ring and has an elastomeric pad around its outer edge. The pad seats in a recess in the bore of the hub. The cap does not touch the shaft as it rotates with the hub about the shaft. Any excess ferrofluid from the ferrofluid seal is forced radially outward away from the shaft by centrifugal force. The cap contains the excess ferrofluid within the spindle motor and prevents it from entering other areas of the disk drive.

Ferrofluid cap seal for spindle motor

Embodiments include a disk drive having a drive motor assembly including at least one component selected from the group consisting of a rotatable hub, disk spacer, disk clamp, backiron, lower bearing bushing, and lower mounting flange. At least one of the components comprises a low sulfur outgassing free machining stainless steel material. The low sulfur outgassing free machining stainless steel material may include a free machining stainless steel that outgases sulfur at a rate insufficient to cause visually observable sulfide corrosion when tested by placing a copper strip into contact with the free machining stainless steel in an environment having a temperature of 50&deg; C. and 90% relative humidity for a 7 day test period and then observing the copper strip.

Low sulfur outgassing free machining stainless steel disk drive components

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San Jose, CA, United States of America

Andrew Keith Hanlon