Sep 30, 1997
"Through vertical integration and the work performed in our Advanced Concepts Labs, Seagate is in a unique position to develop and manufacture leading-edge fluid dynamic spindle motors," said Tom Porter, executive vice president and Chief Technical Officer for Seagate's Storage Products Group. "These partnerships are indicative of Seagate's commitment to the advancement of information storage technology, and the Company's ability to develop products that improve the way people live and work."
"Fluid dynamic bearing motors have been used in gyroscopes and high-accuracy machine tools for many years," said Gunter Heine, vice president, Motor Development, who initiated Seagate's fluid dynamic motor program in January 1994. "But making this technology applicable to disc drives was a significant challenge with regard to performance, robustness, component life and cost. Forming partnerships with world-class companies enables Seagate to achieve excellence in high-precision machining and volume manufacturing, making these advanced motors a reality today."
Fluid dynamic bearing motors utilize a viscous oil or air rather than metal ball bearings, and are superior to conventional ball-bearing motors in several distinct ways:
Lower Nonrepeatable Runout
Ball bearing motors typically use between 8 and 12 metal balls. Any imperfections in the balls' roundness or in the raceways in which the balls roll can cause higher nonrepeatable runout when the motor rotates. This severely limits the tracks per inch (TPI) on the disc and consequently reduces the disc drive capacity.
In a fluid dynamic bearing motor, the working parts of the motor are separated by a film of oil, which acts like a shock absorber and prevents damage to the bearing surfaces. While typical ball bearing motors can withstand up to 150 Gs of shock, fluid dynamic bearing motors have been tested up to 1,200 Gs.
As drive spindle speed continues to increase, noise from the contact of the ball bearings in the raceway increases. Fluid dynamic bearings produce very little noise because they have no metal-to-metal contact.
Fatigue life is the calculated number of hours the motor can survive before metal fatigue, from the constant rolling of the balls over the raceway, causes the bearings to fail. With no metal-to-metal contact, fluid bearing motors have, theoretically, an infinite fatigue-life.
A well-designed fluid bearing can quickly dampen any oscillation generated externally or internally. Dampening in bearings is important for a disc drive to correctly write to or retrieve the data from the disc.
About Sankyo Seiki Manufacturing Co., Ltd.
Sankyo Seiki Manufacturing Co., Ltd. was established in 1946 in Japan as a precision parts manufacturer. The Company is a world leading manufacturer of micro motors, optical pick-up units, magnetic card readers, time switches and musical movements. Sankyo Seiki is also a leading manufacturer of industrial robots.
About Seiko Instruments Inc. (SII)
SII was established in Japan as a watch manufacturing company for the Seiko group of companies sixty years ago. SII, with its 75 manufacturing sites/sales and marketing offices around the globe, not only manufacture and market wrist watches, but information devices, electronic parts, scientific instruments, high-precision machine tools and factory automation devices and systems.
About Taylor Hobson Pneumo
Founded 110 years ago with headquarters in Leicester, UK, Taylor Hobson Pneumo develops and manufactures ultra precision inspection instruments and machining systems, traditionally selling to industries such as automotive, machine tool, aerospace and general engineering worldwide. Used by leading multinational and smaller companies alike, Taylor Hobson Pneumo is truly international with manufacturing, research and sales facilities in England and a comprehensive network of technical sales and service offices worldwide.
Seagate Technology, Inc. (NYSE:SEG) is a leading provider of technology and products enabling people to store, access, and manage information. Seagate is committed to providing best-in-class products to help people get their information when, where and how they need it. Seagate is the worlds largest manufacturer of disc drives, magnetic discs and read-write heads, a market leader in tape drives, and a leading developer of software for information availability, access and analysis. With nearly $9 billion in revenues for its 1997 fiscal year, Seagate can be found around the globe and on the World Wide Web at http://www.seagate.com.
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