Analysis of Off-Track Slider Vibrations in a Laptop Hard Disk Drive

2011 ◽  
Author(s):  
Rahul Rai ◽  
David B. Bogy
Keyword(s):  
Vibration Isolation ◽  
Fluid Dynamic ◽  
Current Model ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Spindle Motor ◽  
Working Environment ◽  
Air Bearing ◽  
Detailed Model ◽  
Vibration Performance

Over the past decade there has been a significant increase the demand of hard disk drives (HDD) for the mobile platforms. In such applications, a mobile HDD is often subjected to harsh working environment. For example, components like DVD drive and built-in speakers present in a laptop can excite its HDD and hence can degrade its read/write (R/W) performance. In this study, we develope a complete model for a mobile HDD to analyze and characterize its vibration performance due to external disturbances. The current model includes a spinning disk, a fluid dynamic bearing (FDB) based spindle motor, a base plate, an actuator assembly (E-block and suspension) and a detailed model for the air bearing slider. Prediction of slider dynamics during an excitation essentially requires the solution of coupled fluid-structure problem in which head gimbal assembly (HGA) is coupled with the disk-support system through the air bearing. Off-track displacement of the slider is used to quantify the vibration performance of the HDD for excitation of different frequencies and orientations. It is observed that during an excitation, the sway modes of the actuator assembly provide the most significant contribution to the off-track vibration. This knowledge about the vibration characteristics of mobile drive can be used to design better a vibration isolation system for mounting a HDD in a laptop.

Analysis of the oil injection process in fluid dynamic bearings of the spindle motor of computer hard disk drives

2013 ◽  
Vol 19 (9-10) ◽  
pp. 1465-1474 ◽  
Author(s):  
Yeonha Jung ◽  
Gunhee Jang ◽  
Kyungmoon Jung ◽  
Hokyung Jang
Keyword(s):  
Fluid Dynamic ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Spindle Motor ◽  
Disk Drives ◽  
Injection Process ◽  
Oil Injection

Air Bearing Spindle Motor for Hard Disk Drives

2005 ◽  
Vol 48 (4) ◽  
pp. 468-473 ◽  
Author(s):  
QIDE ZHANG ◽  
GUOXIAO GUO ◽  
CHAO BI
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Spindle Motor ◽  
Air Bearing ◽  
Disk Drives

Air Bearing Slider Simulation and Modeling for Hard Disk Drives with Ultra-Low Flying Heights

2007 ◽  
pp. 314-314
Author(s):  
B. J. Shi ◽  
D. W. Shu ◽  
B. Gu ◽  
M. R. Parlapalli ◽  
C. N. Delia ◽  
...  
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Air Bearing ◽  
Disk Drives ◽  
Simulation And Modeling ◽  
Air Bearing Slider

Optimization of Air Bearing Contours for Shock Performance of a Hard Disk Drive

2003 ◽  
Author(s):  
Eric M. Jayson ◽  
Frank E. Talke
Keyword(s):  
Hard Disk Drive ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Element Model ◽  
Time Dependent ◽  
Air Bearing ◽  
Disk Interface ◽  
Shock Response ◽  
Shock Event

Hard disk drives must be designed to withstand shock during operation. Large movements of the slider during shock impulse can cause reading and writing errors, track misregistration, or in extreme cases, damage to the magnetic material and loss of data. The design of the air bearing contour determines the steady state flying conditions of the slider as well as dynamic flying conditions, including shock response. In this paper a finite element model of the hard disk drive mechanical components was developed to determine the time dependent forces and moments applied to the slider during a shock event. The time dependent forces and moments are applied as external loads in a solution of the dynamic Reynolds equation to determine the slider response to a shock event. The genetic algorithm was then used to optimize the air bearing contour for optimum shock response while keeping the steady flying conditions constant. The results show substantial differences in the spacing modulation of the head/disk interface after a shock as a function of the design of the air bearing contour.

Design and Dynamics of Flying Height Control Slider With Piezoelectric Nanoactuator in Hard Disk Drives

2006 ◽  
Vol 129 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Jia-Yang Juang ◽  
David B. Bogy ◽  
C. Singh Bhatia
Keyword(s):  
Numerical Study ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Areal Density ◽  
Flying Height ◽  
Air Bearing ◽  
Disk Drives ◽  
Adhesion Forces ◽  
Surface Design ◽  
Ultrahigh Density

To achieve the areal density goal in hard disk drives of 1Tbit∕in.2 the minimum physical spacing or flying height (FH) between the read/write element and disk must be reduced to ∼2nm. A brief review of several FH adjustment schemes is first presented and discussed. Previous research showed that the actuation efficiency (defined as the ratio of the FH reduction to the stroke) was low due to the significant air bearing coupling. In this paper, an air bearing surface design, Slider B, for a FH control slider with a piezoelectric nanoactuator is proposed to achieve virtually 100% efficiency and to increase dynamics stability by minimizing the nanoscale adhesion forces. A numerical study was conducted to investigate both the static and dynamic performances of the Slider B, such as uniformity of gap FH with near-zero roll over the entire disk, ultrahigh roll stiffness and damping, low nanoscale adhesion forces, uniform FH track-seeking motion, dynamic load/unload, and FH modulation. Slider B was found to exhibit an overall enhancement in performance, stability, and reliability in ultrahigh density magnetic recording.

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