Seagate Technology Incorporated

Donald James Macleod

Norbert Steven Parsoneault

Tan Hung Pham

Anthony Joseph Aiello

Klaus Dieter Kloeppel

Gunter Karl Heine

Troy Michael Herndon

Robert Michael Pelstring

Jeffry Arnold LeBlanc

Lynn Bich-Quy Le

Gregory I Rudd

Ramgopal Battu

Sanjoy Ghose

Arnold George Slezak

Karl H Scheppers

Efim Bronshvatch

James Sidney Lee

Robin Francis Dorulla

Marten Fredrick Byl

Gregg P Stevens

Miles L Peterson

Michael James Whittome

Robert Alan Notingham

Thaveesin Vasavakul

Dirk Anthony Krieger

Larry Liu

Paul Weidler

Thomas Patrick McDonnell

Bernhard M Seeger

Enrique J Klein

Oswald Kuwert

Charles G Nowark, Jr

The present invention provides methods for laser sealing of disk drive housings. In addition, laser sealed housings are provided. Laser sealing of hard drives, allows for the disk drive assembly to be maintained in an inert gas environment.

Method and apparatus for a laser-welded disk drive housing

An apparatus and method are provided for sealing an outer surfaceof a shaftto an inner surfaceof a hubThe seal includes a magnetwith top and bottom pole piecesand a ferrofluidmagnetically held in a gapbetween the pole piecesand the hubor the shaftThe top pole piecehas a cross-section that is L-shaped, with a horizontal portionparallel to the magnetand a shorter vertical portionfacing the shaftIn one version, the vertical portionor the portion of the shaftfacing it is contoured to provide a flux gradient that axially concentrates the ferrofluidin the gapIn another aspect, a catcheris provided to reduce loss of ferrofluidwhen the ferrofluidic sealused to form an outside seal. In yet another aspect, a stationary ferrofluidic sealis provided for sealing a stationary shaftto a rotating hub

Apparatus and method for forming a rotatable ferrofluidic seal between a shaft and a hub

Hard disk drive track density is increased by selectively increasing the stiffness of a fluid dynamic bearing (FDB) motor during servo write. Applying a load to the shaft of a fixed shaft FDB motor to close the bearing gaps increases stiffness. Alternatively, the disk drive is cooled to increase bearing fluid viscosity or the motor is operated at an increased rotational velocity.

Selectively stiff FDB bearing for better servo write

A data access assembly with a load arm formed from an Mn&#x2014;Cu alloy is disclosed. The load arm may be supported by and actuator arm formed from a common Mn&#x2014;Cu damping alloy, which has a composition (X)Fe&#x2014;(A)Mn&#x2014;(B)Cu&#x2014;(C)Ni. In one embodiment, X is substantially 73, A is substantially 20, B is substantially 5 and C is substantially 2, wherein A, B, C and X represent the weight percent of the respective elements in the composition.

Data storage device with damped load arm formed from Mn-Cu alloy composition

The counterplate and/or sleeve are modified to reduce or eliminate distortion in the counterplate in a laser welded fluid bearing design. It is known to directly weld the counterplate which lies across the end of the shaft and the thrust plate to a wall or shoulder of the sleeve in which the counterplate is fit. The radial stiffness of the sleeve is weakened by cutting grooves or the like at or near the interface between the sleeve wall and the counterplate, or on the outer diameter of the sleeve wall to essentially weaken the sleeve wall. This weakening of the sleeve wall prevents bowing or distortion of the counterplate being imposed by the sleeve.

Distortion free laser welded fluid bearing design

The tooth saturation level is improved and electromagnetic harmonics reduced by reducing the path cross-section of area in the tooth with a geometrical means such as punched holes through the stator laminations. The punched holes alter the magnetic flux pattern by forcing the flux to go around the holes, providing a greater concentration of the flux within regions of the teeth, as well as, depending on the position of the hole along the long axis of the tooth, redistributing the flux density in the air gap. This redistributed flux density will also reduce the harmonics to improve the electromechanical device electromagnetic performance.

Tooth saturation for reduced electromagnetic harmonics

The smallest shaft diameter while retaining rigidity is achieved using either ceramic or tungsten carbide. However, to maintain the stiffness of the shaft of the surrounding sleeve and supported therefrom by a hydrodynamic bearing, the gap must also be adjusted and diminished. According to this method, the shaft thickness and bearing gaps are optimized by first setting a ceramic shaft thickness, then modifying the gaps in relation to that thickness.

Design methods for highly efficient high speed fluid dynamic bearing motors

A system for cleaning disc drive components includes a rotary support member for receiving an assembled disc drive component. A rotary drive motor is coupled to the rotary support member for rotating the rotary support member and disc drive motor supported thereon together at a rotation speed to impart a centrifugal force on any excess lubricant contained by the disc drive motor of sufficient magnitude to draw the excess lubricant from the disc drive motor. The system may also or alternatively include an enclosure defining an interior having an oxygen-containing environment. A support platform is disposed within the oxygen-containing environment of the interior of the enclosure, for supporting a disc drive component within the oxygen-containing environment of the enclosure, for example, after the component is removed from the rotary support member. An ozone source is disposed within the enclosure, for providing sufficient ozone in the vicinity of the disc drive component to oxidize organic material on the disc drive component and convert the organic material to water vapor and carbon dioxide. The enclosure includes a vent for venting the carbon dioxide and any remaining ozone from the enclosure.

Cleaning process for disc drive components

A low-profile spindle motor for a disc drive data storage device includes a cylindrical sleeve which is used to mount the motor to a housing base using press-fitting or adhesive bonding, thus eliminating the vertical height required by screws, bolts or other prior art mounting mechanisms. The same cylindrical sleeve is used to mount the stator stack of the motor, and, on the inner surface of the cylindrical sleeve, to mount the ball bearing assemblies used to allow rotation of a central shaft and attached disc-mounting hub. In another aspect of the invention, ball bearing assemblies having a sealing element on only one side are used to allow greater separation between the ball bearing assemblies, while maintaining a low-profile motor. In yet another aspect of the invention, signals to drive the motor are directed to the stator windings via a printed circuit cable whose termination pads are disposed in the vertical space between adjacent stator windings.

Low profile spindle motor

In a disc drive with an integrated casting comprising the housing for the stepper and spindle motors, the transducer is mounted on a normal bearing pivot assembly lightweight actuator arm and biasing strip spring. One end of the strip spring is mounted to a block and the effective force of the spring is aligned with the actuator arm running toward the stepper motor. The other, or head end of the actuator arm contains a gear sector having gear teeth on its face which mesh with a pinion on a motor shaft so rotation of the motor shaft across the face of the gear sector causes movement of the head mounting arm. The actuator arm is formed of a self-lubricating polymer or other lightweight self-lubricating material. This way, wear on the gear is reduced; and as the teeth are worn, the gear is still tightly biased against the pinion to maintain accurate movement of the actuator arm with rotation of the pinion.

Rotary actuator

A spindle motor for use in a disc drive including a base casting for the drive, the motor comprising a shaft extending through the base casting and carrying a hub supporting one or more discs for rotation, the shaft being supported for rotation in the casting by one or more bearings, rotation of the shaft being controlled by an axial air gap motor comprising a flat rotor connected to the shaft and extending axially parallel to the base casting of the housing, the rotor comprising a magnet supported by a rotor support plate carried on an end of the shaft, a single printed board is supported so as to have first and second surfaces essentially out of contact with the base casting and the rotor support plate for supporting on one surface thereof a plurality of axially oriented coils in a toroidal path around the shaft and in a plane parallel to the magnet, and on the other of the surfaces a toroidal magnetic return path element mounted on the opposite side of the axially oriented coils from the rotor, the magnetic return path being formed of a wound coil of thinly sliced sheet steel, thereby forming a magnetic path comprising the magnet, the coils and the return path element, whereby a low profile spindle motor is achieved.

Spindle motor for a disc drive

Growing community of inventors

Santa Cruz, CA, United States of America

Donald James Macleod