Dynamics of a Hard Disk Drive Spindle System Due to Its Structural Design Variables and the Design Variables of Fluid Dynamic Bearings

Abstract The aim of this paper is to develop the general methodology for the optimum design of magnetic head slider for improving the spacing characteristics between head slider and disk surfaces under the static and dynamic operation conditions of hard disk drive and to present an application of the methodology to IBM 3380-type slider design. In the optimum design, the objective function is defined as the weighted sum of minimum spacing, maximum difference of spacing due to variation of radial location of head and maximum amplitude ratio of slider motion. Slider rail width, taper length, taper angle, suspension position and preload are selected as the design variables. Before the optimization of magnetic head slider, the effects of these five design variables on the objective function are examined by the parametric study, and then the optimum design variables are determined by applying the hybrid optimization technique combining the direct search method and the successive quadratic programming (SQP). From the results obtained, the effectiveness of optimum design on the spacing characteristics of magnetic head slider is clarified.

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A parametric study on rocking vibration of hard disk drive spindle motors with fluid-dynamic bearings and rotating-shaft design

Microsystem Technologies ◽

10.1007/s00542-005-0601-x ◽

2005 ◽

Vol 11 (11) ◽

pp. 1204-1213 ◽

Cited By ~ 6

Author(s):

Baekho Heo ◽

I. Y. Shen

Keyword(s):

Hard Disk Drive ◽

Parametric Study ◽

Fluid Dynamic ◽

Hard Disk ◽

Disk Drive ◽

Rotating Shaft ◽

Rocking Vibration

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Finite Element Analysis of the Coupled Journal and Thrust Bearing in a Computer Hard Disk Drive

Journal of Tribology ◽

10.1115/1.2162918 ◽

2005 ◽

Vol 128 (2) ◽

pp. 335-340 ◽

Cited By ~ 31

Author(s):

G. H. Jang ◽

S. H. Lee ◽

H. W. Kim

Keyword(s):

Finite Element ◽

Hard Disk Drive ◽

Thrust Bearing ◽

Fluid Dynamic ◽

Hard Disk ◽

Disk Drive ◽

Flying Height ◽

Separate Analysis ◽

Element Analysis ◽

Thrust Bearings

This paper proposes a method to calculate the characteristics of a coupled fluid dynamic journal and thrust bearing of a hard disk drive (HDD) spindle motor. The governing equations for the journal and thrust bearings are the two-dimensional Reynolds equations in the θz and rθ planes, respectively. The finite element method is appropriately applied to analyze the coupled bearing under the conditions of the continuity of mass and pressure at the interface between the journal and thrust bearings. The pressure in the coupled bearing was calculated by applying the Reynolds boundary condition. The validity of this application was verified by comparing the analytical results of the flying height at various rotating speeds with experimental results. The characteristics of the coupled journal and thrust bearing were also investigated due to the Reynolds and Half-Sommerfeld boundary conditions and the coupled and separate analysis. This research demonstrates that the proposed method can accurately and realistically describe the coupled fluid dynamic bearing in a HDD system.

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