Seagate Technology Incorporated

Other

Raquib Uddin Khan

Hans L Leuthold

Gunter Karl Heine

Mohamed Mizanur Rahman

Mohammad Mahbubul Ameen

David John Jennings

Gregory I Rudd

Norbert Steven Parsoneault

Wesley R Clark

Klaus Dieter Kloeppel

Lakshman Nagarathnam

Anthony Joseph Aiello

Paco Gregor Flores

Alan Lydon Grantz

Michael David Kennedy

Samnathan Murthy

Matt L Shumway

Coda H Pan

Guenther Heine

Troy Michael Herndon

Alan Lyndon Grantz

Robert Michael Pelstring

Jeffry Arnold LeBlanc

Dean Albert Tarrant

Steve G Gonzalez

Marten Fredrick Byl

Etoli Wolff

Susan Feng Fan

Greg Rudd

Louis Borelis

An electrostatic discharge apparatus for use with a hub and spindle assembly for a disc drive storage system comprising a spindle; a hub rotatably mounted on the spindle; a capsule formed at least in part from an electrically conductive material that can be placed in electrical communication with the hub and defining a chamber configured to hold an electrically conductive fluid and defining at least one capillary channel in fluid communication with an opening formed in the capsule, the opening configured to permit rotation about the spindle, and to permit a meniscus formed by the conductive fluid proximate to the opening to electrically contact the spindle during rotation of the hub about the spindle.

Electrostatic discharge apparatus for hub and spindle assemblies

For motors having a journal with one or more groove regions and a shaft for relative rotation in the journal, aspects include providing a dual tapered shaft. The shaft may be tapered by the application of a wear resistant coating at least opposite the groove regions. The coating introduces a shaft taper from near a top end and from near a bottom end towards the shaft middle. The shaft taper may provide for improved pumping efficiency. The coating may be applied in various processes such as chemical vapor deposition or physical vapor deposition to establish a thickness gradient of coating material from near the top end and near the bottom end towards the shaft middle. In one example, the coating includes a DLC coating. Additionally, shaft portions may be shielded to prevent coatings thereon.

FDB motor with tapered shaft for improved pumping efficiency

A seal with a primary axis lying in the radial direction so that the fluid bearing is primarily extending in the axial direction between the rotating shaft and surrounding sleeve is disclosed. The capillary seal is positioned with an opening adjacent an end of the fluid bearing gap, and comprises two walls which diverge as they extend radially away from the fluid bearing so that the fluid held in the radial capillary seal is maintained adjacent an end of the gap, while the size of the reservoir defined by the diverging walls provides a large reservoir volume. The seal uses an additional capillary defined by a narrow annulus between the rotating shaft and a seal wall end. The narrow annulus establishes very high shock resistance preventing fluid loss past the outer axial wall of the radially capillary seal, and defines a small surface area from which evaporation can occur.

Radial capillary seal for fluid dynamic bearing motors

A system and means is provided for preserving bearing surfaces and maintaining bearing life, for use with spindle motors. In an aspect, adhesive and abrasive wear is minimized, corrosion is reduced, and bearing dynamic performance and fluid purity is maintained. In an aspect, a silicon containing copper alloy is utilized for one bearing surface and a stainless steel is utilized for an adjacent surface. The present invention also satisfies considerations including hardness, thermal expansion, thermal conductivity and use with grooved surfaces.

Fluid dynamic bearing with wear resilient surface

A disc drive storage system including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member is described. A hydrodynamic bearing interconnects the stationary member and the rotatable member and includes at least one working surface comprising a low-friction wear resistant coating.

Disk drive spindle motor having hydrodynamic bearing working surface with low friction layer formed on wear resistant layer

A method and system is provided for achieving good dynamic performance and negligible wear to spindle motor components. In an aspect, a disc drive storage system is provided having a hydro bearing surface coating for meeting bearing gap tolerance design specifications. In an aspect, the surface coating is a non-reactive coating of diamond like carbon (DLC), applied with physical vapor deposition (PVD). In an aspect, the surface coating nullifies any taper of an opposing surface coating. In an aspect, the hydro bearing, with an applied coating, defines a uniform gap between 0.5 microns and 6 microns.

Refinement of spindle motor bearing gap

A method and apparatus is provided for allowing a molecularly thin film to be established on a surface of the gas fluid dynamic bearing. The film can be controllably replenished so that the problem of liquid lubricant starvation is overcome. A suitable non-sludging lubricant of low surface tension is held in a porous reservoir within the stationary portion of the bearing. This fluid migrates out of the reservoir to coat the contiguous bearing surfaces. Alternatively, the lubricant may be held in a porous reservoir within the rotating portion of the bearing; due to centrifugal force, as the rotating portion spins, the fluid is spun out and coats the opposite non-rotating surface. The reservoir may be replaced by a singular reservoir such as a simple hole, depression, cavity or groove filled with lubricant. The liquid may also migrate by capillary force through natural surface asperities or roughness by texturing the surface to promote capillary migration; or the distribution of the lubricant is accomplished by evaporation and condensation. The reservoir may be located in a region of the bearing that reaches a relatively higher operating temperature than the wear surfaces of the bearing. The transport of the lubricant then occurs by evaporation at the wanner reservoir, and condensation at the cooler bearing surface.

Lubricant reservoir for gas bearing

A disc drive storage system including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member. A hydro bearing interconnects the stationary member and the rotatable member and includes a lubricating fluid having a base fluid and an additive and/or a combination of additives or base fluids for reducing the temperature dependency of the viscosity of the lubricating fluid.

Hydrodynamic fluid bearing containing lubricants with reduced temperature sensitivity for disk drive application

A disc drive data storage system includes a hydrodynamic bearing including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member. A hydrodynamic bearing interconnects the stationary member and the rotatable member. At least a portion of a surface of one or more of the hydrodynamic bearing components has a tilt-limiting layer formed thereon to restrict the tilting distance between the working surfaces in the disc drive data storage system.

Dynamic tilt limiter for fluid dynamic bearings

A very thin lubricant coating is applied to one or both of the facing surfaces defining the gap of a hydrodynamic bearing to prevent wear of these surfaces. The lubricant film is necessarily very thin, in the range of about 10 &angst; to 1000 &angst;, so that the film is thin enough that it does not materially affect the performance of the hydrodynamic bearing gap which is about typically 1-10 &mgr;m. The thin lubricant film could be a perfluoropolyether (PFPE) or a mixture of PFPE or a phosphazine derivative. To improve the adhesion and lubricating performance, functional PFPE can be used. For pure metallic surface like steel, phosphate esters can also be used because of its affinity with the metallic surface, e.g., ferrous. For example, the film could be PFPE, or a mixture of PFPE and a phosphazine derivative. The lubricant should be chosen to be thermally stable, and non-reactive with the typical ambient environment. The lubricants also have to have very low vapor pressure so that it lasts for the life of the bearing, as it will be applied only once during the manufacturing process. As an alternative, particularly if one of the surfaces of the bearing gap is ferrous, a phosphate ester could be used. Particularly with this type of coating, the surface of the hydrodynamic bearing could be quenched in the phosphate ester to provide the desired thin lubricant coating thereon. A thin film of phosphate esters without quenching can also be a effective wear protective coating. The thin lubricant film can be applied to both metallic surfaces as well as surfaces with hard coatings. The use of a hard coating allows for the usage of free machining or soft material which itself is vulnerable to wear degradation; the use of a thin lubricant film safeguards the hard coating from wear failure.

Antiwear lubrication coating for bearing surfaces for hydrodynamic fluid bearings

A method and apparatus is provided for allowing a molecularly thin film to be established on a surface of the gas fluid dynamic bearing. The film can be controllably replenished so that the problem of liquid lubricant starvation is overcome. A suitable non-sludging lubricant of low surface tension is held in a porous reservoir within the stationary portion of the bearing. This fluid migrates out of the reservoir to coat the contiguous bearing surfaces. Alternatively, the lubricant may be held in a porous reservoir within the rotating portion of the bearing; due to centrifugal force, as the rotating portion spins, the fluid is spun out and coats the opposite non-rotating surface. The reservoir may be replaced by a singular reservoir such as a simple hole, depression, cavity or groove filled with lubricant. The liquid may also migrate by capillary force through natural surface asperities or roughness by texturing the surface to promote capillary migration; or the distribution of the lubricant is accomplished by evaporation and condensation. The reservoir may be located in a region of the bearing that reaches a relatively higher operating temperature than the wear surfaces of the bearing. The transport of the lubricant then occurs by evaporation at the warmer reservoir, and condensation at the cooler bearing surface.

Motor with stationary shaft and high speed capillary seal

A disc drive storage system includes a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member. A hydro bearing interconnects the stationary member and the rotatable member and includes a lubricating fluid having a base fluid and an additive for reducing the tendency of bubble formation in the lubricating fluid.

Hydrodynamic fluid bearing containing lubricants with reduced bubble forming tendency for disk drive application

A disc drive storage system including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member is described. A hydrodynamic bearing interconnects the stationary member and the rotatable member and includes at least one working surface comprising a wear resistant coating.

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Pleasanton, CA, United States of America

Raquib Uddin Khan