A bipolar-starting and unipolar-running method to drive a hard disk drive spindle motor at high speed with large starting torque

2005 ◽  
Vol 41 (2) ◽  
pp. 750-755 ◽  
Author(s):  
G. Jang ◽  
M.G. Kim
Author(s):  
Andrew Chong ◽  
Lu Yi ◽  
S. X. Chen ◽  
Q. D. Zhang

Abstract The key task for the spindle motor in a hard disk drive is to provide stable, reliable and consistent turning power for many years to allow the hard drive to function properly. As hard disks become more advanced, virtually every component in them is required to do more & perform better, and the spindle motor is no exception. Increasing the rotational speed at which the platters spin means that the data can be read off the disk faster, and also reduces rotational latency, the time that the heads must wait for the correct sector number to come under the head. For this reason, there has been a push to increase the speed of the spindle motor. Since the launching of hydro-dynamic bearing spindle technology for high speed application will not be in due course, current ball bearing technology will still be around for a couple of years provided the spindle speed does not exceed around 15 Krpm. Therefore optimizing the steel balls in the spindle system is an alternative to deal with the ever-increasing performance requirements of the hard disk drive. To accomplish this, we have to understand the failure phenomenon in the spindle, thereby set test requirements to overcome the failure mechanism. These test requirements will help us to understand the performance characteristic and robustness of the spindle motor. In this paper, the test requirements is set according to modal, load and vibration methods to quantify the hard disk drive ball bearing spindle motor.


2014 ◽  
Vol 1061-1062 ◽  
pp. 866-873
Author(s):  
Pakornwit Padtha ◽  
Kiatfa Tangchaichit

The spindle motor in a hard disk drive spins at a high rotational speed. These rotations generate air flow and thermal stress. Air flow is induced by the surface roughness of the media that is moving at a high speed through air. This air passes over the surface of many parts in the drive, including the media. Thermal stress is generated by heat in the parts, e.g. voice coil motor, pre-amplifier, slider pole tips, which are heated by electric power and by the spinning of the spindle motor. The air flow and thermal stress cause a change in the media shape called deformation.Simulation results show the trend of deformation has more bending when the slider moves outward from the media axis. The pressure acted more on the underside than on the upper side which caused the media to bend up to the top cover side of hard disk drive. The maximum deformation, 15 μm, occurred at the rim of media while the distance between the media and the slider is 30 μm; thus they did not contact each other.


Author(s):  
D. C. Han ◽  
S. H. Choi ◽  
K. B. Park ◽  
S. C. Jung

Abstract In this paper we investigate the vibration characteristics of a rotor system with flexible disks. The coupled vibration mode between rotating shaft and the flexible disk are analyzed for lateral and axial vibrations respectively. Gyro and sheer effects are considered for the modeling of lateral vibrations. An assumed mode method was used for the disk modeling considering gyro effects. For a numerical example hard disk drive is considered. The natural frequencies of the motor-spindle system with flexible disk of hard disk drive was calculated and compared to the experimental data.


2009 ◽  
Vol 45 (11) ◽  
pp. 5168-5171
Author(s):  
C. S. Soh ◽  
C. Bi ◽  
Z. H. Yong ◽  
C. P. Lim

2010 ◽  
Vol 4 (1) ◽  
pp. 70-81 ◽  
Author(s):  
Mohd Danial IBRAHIM ◽  
Tadashi NAMBA ◽  
Masayuki OCHIAI ◽  
Hiromu HASHIMOTO

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