Patents by Inventor Holavanahally Seshachar Nagaraj
Holavanahally Seshachar Nagaraj has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6339515Abstract: A bearing structure for a spindle motor is disclosed. The bearing structure provides a fluid bearing seal and support structure that may simultaneously addresses the problems of preventing oil leakage, of maintaining the bearing integrity under shock, of reducing oil evaporation and of minimizing distortion of the active bearing surface. The bearing structure includes a thrust plate coupled to a shaft and a bearing plate and load plate coupled to a sleeve, wherein the load plate urges the bearing plate towards the thrust plate, and wherein an adhesive is interposed between the load plate and the thrust plate. The adhesive may be an UV epoxy. The sleeve is operatively coupled to a stator, and the stator rotates the sleeve upon receiving a drive signal. The bearing further includes a diffusion barrier disposed between the sleeve and the stator. A second diffusion barrier is disposed between the load plate and the shaft.Type: GrantFiled: May 18, 1999Date of Patent: January 15, 2002Assignee: International Business Machines CorporationInventors: Chen-Hsiung Lee, Holavanahally Seshachar Nagaraj, Neal Bertram Schirle
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Patent number: 6334616Abstract: 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.Type: GrantFiled: October 12, 1999Date of Patent: January 1, 2002Assignee: International Business Machines CorporationInventors: M. Amine Hajji, Andrew K. Hanlon, Holavanahally Seshachar Nagaraj
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Publication number: 20010053042Abstract: A bearing structure for a spindle motor is disclosed. The bearing structure provides a fluid bearing seal and support structure that may simultaneously addresses the problems of preventing oil leakage, of maintaining the bearing integrity under shock, of reducing oil evaporation and of minimizing distortion of the active bearing surface. The bearing structure includes a thrust plate coupled to a shaft and a bearing plate and load plate coupled to a sleeve, wherein the load plate urges the bearing plate towards the thrust plate, and wherein an adhesive is interposed between the load plate and the thrust plate. The adhesive may be an UV epoxy. The sleeve is operatively coupled to a stator, and the stator rotates the sleeve upon receiving a drive signal. The bearing further includes a diffusion barrier disposed between the sleeve and the stator. A second diffusion barrier is disposed between the load plate and the shaft.Type: ApplicationFiled: May 18, 1999Publication date: December 20, 2001Inventors: CHEN-HSIUNG LEE, HOLAVANAHALLY SESHACHAR NAGARAJ, NEAL BERTRAM SCHIRLE
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Publication number: 20010045702Abstract: 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.Type: ApplicationFiled: July 17, 2001Publication date: November 29, 2001Applicant: International Business Machines Corp.Inventors: M. Amine Hajji, Andrew K. Hanlon, Holavanahally Seshachar Nagaraj
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Patent number: 6280094Abstract: 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.Type: GrantFiled: June 27, 2000Date of Patent: August 28, 2001Assignee: International Business Machines CorporationInventors: Larry Joe Gilliland, Holavanahally Seshachar Nagaraj, Daniel Stacer
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Patent number: 6179472Abstract: 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.Type: GrantFiled: October 13, 1998Date of Patent: January 30, 2001Assignee: International Business Machines CorporationInventors: Larry Joe Gilliland, Holavanahally Seshachar Nagaraj, Daniel Stacer
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Patent number: 6051169Abstract: A method of degassing a disk drive component including heating the drive component to a temperature ranging from about 70.degree. C. to 250.degree. C.; subjecting the drive component to vacuum pressure during heating, the vacuum pressure having a first pressure and a second pressure; and monitoring the vacuum pressure to determine the level of degassing of the disk drive component.Type: GrantFiled: August 27, 1997Date of Patent: April 18, 2000Assignee: International Business Machines CorporationInventors: Charles Allan Brown, John Martin Burns, Holavanahally Seshachar Nagaraj, James Joseph O'Neill, Muhammad Inayet Ullah, Leo Volpe, Herman Russell Wendt
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Patent number: 5957589Abstract: A bearing structure for a spindle motor is disclosed. The bearing structure provides a fluid bearing seal and support structure that may simultaneously addresses the problems of preventing oil leakage, of maintaining the bearing integrity under shock, of reducing oil evaporation and of minimizing distortion of the active bearing surface. The bearing structure includes a thrust plate coupled to a shaft and a bearing plate and load plate coupled to a sleeve, wherein the load plate urges the bearing plate towards the thrust plate, and wherein an adhesive is interposed between the load plate and the thrust plate. The adhesive may be an UV epoxy. The sleeve is operatively coupled to a stator, and the stator rotates the sleeve upon receiving a drive signal. The bearing further includes a diffusion barrier disposed between the sleeve and the stator. A second diffusion barrier is disposed between the load plate and the shaft.Type: GrantFiled: December 10, 1997Date of Patent: September 28, 1999Assignee: International Business Machine CorporationInventors: Chen-Hsiung Lee, Holavanahally Seshachar Nagaraj, Neal Bertram Schirle
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Patent number: 5940247Abstract: A magnetic recording data storage device includes a magnetic recording disk, a spindle motor, a head supported on an air bearing carrier and an actuator connected to the head carrier for moving the head across the rotating disk. The spindle motor has lubricant covered ball bearings where the lubricant includes an alkali hydroxystearate, an ester oil, a dialkyldiphenylamine and a dialkyldithiocarbamate.Type: GrantFiled: March 26, 1997Date of Patent: August 17, 1999Assignee: International Business Machines CorporationInventors: Thomas Edward Karis, Holavanahally Seshachar Nagaraj