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http://dx.doi.org/10.5050/KSNVN.2006.16.1.012

Characterization and Detection of a Free-falling State of a Mobile HDD Using the Electromechanical Analysis in a Rotating Spindle System  

Park, Sang-Jin (한양대학교 정밀기계공학과)
Jang, Gun-Hee (한양대학교 기계공학부)
Kim, Cheol-Soon (삼성종합기술원 storage Lab.)
Han, Jae-Hyuk (삼성종합기술원 storage Lab.)
Publication Information
Transactions of the Korean Society for Noise and Vibration Engineering / v.16, no.1, 2006 , pp. 12-18 More about this Journal
Abstract
This research investigates the electromechanical characteristics of a spindle motor in a free-falling mobile hard disk drive before unexpected shock. Electromechanical simulation includes a time-stepping finite element analysis of the magnetic field in a speed controlled brushless DC motor and dynamic analysis of the stationary and rotating part linked by the fluid dynamic bearing under the free-falling condition. Analysis results show that the dynamic characteristics of the rotating spindle system during free-falling state have an effect on the relative motion between the stationary and rotating part of HDD. It results from the variation of reaction force in the bearing area due to the gravity force exerted on the rotating part of HDD, and the free-falling condition can be detected by observing the signal of the spindle motor and disk-head interface without using an accelerometer.
Keywords
Brushless DC Motor; Fluid Dynamic Bearing; Free- fall; Hard Disk Drive; Rotor Dynamics; Time-Stepping Finite Element Method;
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