Dynamic Characteristics of Hard Disk Drive Spindle Motors—Comparison Between Ball Bearings and Hydrodynamic Bearings

1996 ◽  
Vol 118 (2) ◽  
pp. 402-406 ◽  
Author(s):  
C.-P. Roger Ku
Keyword(s):  
Hard Disk Drive ◽  
Data Storage ◽  
Dynamic Characteristics ◽  
Low Frequency ◽  
Hard Disk ◽  
Axial Direction ◽  
Disk Drive ◽  
Spindle Motor ◽  
Damping Capacity ◽  
Ball Bearings

Recently, many computer hard disk drive companies and spindle motor manufacturers have been looking for a substitute for ball bearings to continue making dramatic progress in increasing the capacity of data storage systems. In this paper, the frequency-forced responses of hard disk drive spindle motors supported by both ball bearings and liquid-lubricated spiral groove hearings (SGBs) were studied experimentally. It is found that both shaft rigidity and disk flexibility have great effects on the natural frequency of the spindle motor conical (rocking) mode. The high damping capacity of the SGB is able to suppress the vibration amplitudes of both motor rocking mode and the flexible disk modes. But at a very low frequency range, the SGB motors displayed a large amplitude in the axial direction vibration test. With an adequate bearing design, the SGB motors have proven their superior dynamic characteristics.

Scanning probe-type data storage beyond hard disk drive and flash memory

MRS Bulletin ◽  
2018 ◽  
Vol 43 (5) ◽  
pp. 365-370 ◽  
Author(s):  
Yasuo Cho ◽  
Seungbum Hong
Keyword(s):  
Hard Disk Drive ◽  
Data Storage ◽  
Flash Memory ◽  
Hard Disk ◽  
Disk Drive ◽  
Scanning Probe ◽  
Probe Type ◽  
Type Data ◽  
Image Position

Abstract

Sound-Induced Vibration to Hard Disk Drive in a Data Storage Enclosure

2019 ◽  
Author(s):  
Shaomin Xiong ◽  
Toshiki Hirano
Keyword(s):  
Hard Disk Drive ◽  
Data Storage ◽  
Sound Source ◽  
Hard Disk ◽  
Disk Drive ◽  
Vibration Model ◽  
Data Center Cooling ◽  
Cooling Fans ◽  
Mechanical Components ◽  
Mechanical Disturbances

Abstract The data read and write operation in a hard disk drive (HDD) relies on precision mechanical components, such as air bearing sliders, suspension, and piezo actuators. Many of those mechanical components are sensitive to mechanical disturbances. It is found that sound a disturbance (or airborne disturbance) increases the position error signal (PES), such that the tracking, following and seeking performance is compromised. For a data storage enclosure and server in a data center, cooling fans generate strong sound noise, resulting in degradation of the performance of HDDs. In this study, we showed that the PES degrades when placing a sound source next to the HDD, indicating that the sound-induced vibration links to the mechanical components inside the HDD. It is also found that the PES is very sensitive to the location of the sound source. A vibration model was built by finite element method (FEM). The simulation results were compared to experiments on a thin plate structure to explain this dependency on the location of sound source.

Low Frequency Vibration Detection and Compensation in Hard Disk Drive

2011 ◽  
Vol 47 (7) ◽  
pp. 1964-1969 ◽  
Author(s):  
Wen-Jun Cao ◽  
JianYi Wang ◽  
MingZhong Ding ◽  
Qiang Bi ◽  
KianKeong Ooi
Keyword(s):  
Hard Disk Drive ◽  
Low Frequency ◽  
Hard Disk ◽  
Disk Drive ◽  
Vibration Detection ◽  
Low Frequency Vibration

Vibration Characteristics of a Rotor-Flexible Disk System: In Case of HDD Spindle-Motor System

1999 ◽  
Author(s):  
D. C. Han ◽  
S. H. Choi ◽  
K. B. Park ◽  
S. C. Jung
Keyword(s):  
Hard Disk Drive ◽  
Hard Disk ◽  
Disk Drive ◽  
Spindle Motor ◽  
Vibration Characteristics ◽  
Rotating Shaft ◽  
Disk System ◽  
Assumed Mode Method ◽  
Mode Method ◽  
Flexible Disk

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.

Experimental Characterization Techniques for High Performance Hard Disk Drive Ball Bearing Spindle Motors

1999 ◽  
Author(s):  
Andrew Chong ◽  
Lu Yi ◽  
S. X. Chen ◽  
Q. D. Zhang
Keyword(s):  
Hard Disk Drive ◽  
High Speed ◽  
High Performance ◽  
Ball Bearing ◽  
Hard Disk ◽  
Disk Drive ◽  
Spindle Motor ◽  
Hard Disks ◽  
Steel Balls ◽  
Test Requirements

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.

Deformation of Hard Disk Drive Media Caused by Thermal Stress and Induced Air Flow

2014 ◽  
Vol 1061-1062 ◽  
pp. 866-873
Author(s):  
Pakornwit Padtha ◽  
Kiatfa Tangchaichit
Keyword(s):  
Thermal Stress ◽  
Hard Disk Drive ◽  
High Speed ◽  
Air Flow ◽  
Voice Coil Motor ◽  
Hard Disk ◽  
Disk Drive ◽  
Spindle Motor ◽  
High Rotational Speed ◽  
The Media

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.

Contactless Measurement Method for Hard Disk Drive Spindle Motor Impedance

2009 ◽  
Vol 45 (11) ◽  
pp. 5168-5171
Author(s):  
C. S. Soh ◽  
C. Bi ◽  
Z. H. Yong ◽  
C. P. Lim
Keyword(s):  
Hard Disk Drive ◽  
Measurement Method ◽  
Hard Disk ◽  
Disk Drive ◽  
Spindle Motor ◽  
Contactless Measurement
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