Seagate Technology Incorporated

Seagate Technologies, Inc.

Gregory I Rudd

Karl H Scheppers

Raquib Uddin Khan

Hans L Leuthold

Gunter Karl Heine

Norbert Steven Parsoneault

David John Jennings

Michael David Kennedy

Donald James Macleod

Arnold George Slezak

Robin Francis Dorulla

Gregg P Stevens

Karl Scheppers

Louis Borelis

Thaveesin Vasavakul

Dirk Anthony Krieger

Larry Liu

Paul Weidler

Thomas Patrick McDonnell

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 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.

A contaminant reduction system comprises an assembly of appropriate size and shape for mounting within a sealed or semi-sealed hard disk drive (HDD). The system comprises a photocatalytic surface mounted in close proximity or in contact with a light source which may be utilized as a means for activation. The photocatalytic surface is preferably titanium dioxide (TiO ); it may be other metal oxide catalyss that can be photochemically activated such as zinc oxide (ZnO). The activation is achieved utilizing a lamp which illuminates the photocatalyst and has an output below 100 nm.

Photocatalytic device for disk drive contamination reduction

A very thin lubricating coating on one or both of the facing surfaces defining the gap of the hydrodynamic bearing. The lubricant film would need to be 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 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 esther could be used. Particularly with this type of coating, the material could be quenched in the phosphate esther, providing the desired thin surface coating. 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 surface as well as on the surface with hard coating. The use of coating allows for the usage of free machining or soft material which itself is vulnerable to wear degradation; the use of thin film safeguards the hard coating from wear failure.

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

Disc drive spindle motor having hydro bearing with optimized lubricant

Method and apparatus for collecting a large number of outgas samples at the same time. Specimens to be tested for outgassing are placed in throw-away widemouth bottles, and the bottles are placed in cups provide in a heating block. A custom made cap is fastened to each bottle using an O-ring. Each cap is provided with an outgassing sample collecting tube. A source of pure gas such as nitrogen or helium is connected by way of a pressure regulator and a hydrocarbon filter to a manifold. Each of the caps on each bottle is coupled to the manifold by way of a metering valve. An adsorbent is placed in each collecting tube. The gas pressure is set to between 10 and 15 psi. The flow through each collecting tube is set to a predetermined level by adjusting its metering valve and measuring the flow at the exit of the collecting tube using a flowmeter. The heating block is heated by means of a thermal tape used in conjunction with a power supply and a thermocouple inserted into a hole in the heating block. The samples are heated and held at an elevated temperature for a predetermined length of time. After the outgassing test is completed, the collecting tubes are desorbed and analyzed with the appropriate instrumentation.

Sample container for multisample dynamic headspace sampler

Disc drive spindle motor having hydro bearing with lubricant optimized

Multisample dynamic headspace sampler

Calibration method for multisample dynamic headspace sampler

Method and apparatus for collecting a large number of outgas samples at the same time. Specimens to be tested for outgassing are placed in throw-away widemouth bottles, and the bottles are placed in cups provide in a heating block. A custom made cap is fastened to each bottle using an O-ring. Each cap is provided with an outgassing sample collecting tube. A source of pure gas such as nitrogen or helium is connected by way of a pressure regulator and a hydrocarbon filter to a manifold. Each of the caps on each bottle is coupled to the manifold by way of a metering valve. An adsorbent is placed in each collecting tube. The gas pressure is set to between 10 and 15 psi. The flow through each collecting tube is set to a predetermined level by adjusting its metering valve and measuring the flow at the exit of the collecting tube using a flowmeter. The healing block is heated by means of a thermal tape used in conjunction with a power supply and a thermocouple inserted into a hole in the heating block. The samples are heated and held at an elevated temperature for a predetermined length of time. After the outgassing test is completed, the collecting tubes are desorbed and analyzed with the appropriate instrumentation.

The hydrodynamic bearing arrangement comprises a journal sleeve defining a journal bore and a journal thrust surface. A shaft is mounted in the journal bore by means of a hydrodynamic journal bearing which permits rotation of the shaft and the journal sleeve relative to one another. A thrust plate extends transversely from the shaft and defines two hydrodynamic thrust bearings in combination with the journal thrust surface and a counterplate which is mounted adjacent to the thrust plate. A porous lubricant reservoir is mounted adjacent to the thrust plate. The porous lubricant reservoir serves to remove wear particles from the lubricant in the bearing arrangement, and provides a supply of lubricant to the hydrodynamic journal and thrust bearings should they become depleted of lubricant.

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Aptos, CA, United States of America

Gregory I Rudd