Numerical Analysis of a Coupled Porous Journal and Thrust Bearing System

A numerical model has been developed to analyze both static and dynamic characteristics of a coupled porous journal and thrust bearing system that is used to support a rotating shaft in a magnetic hard disk drive. The analyzed system is composed of a porous sleeve, a herringbone-grooved solid thrust plate and a flanged shaft, where the bottom end is closed to form a cantilever spindle. The inner surface and the bottom face of the porous sleeve operate as a herringbone-grooved journal and thrust bearing, respectively. The model is based on the narrow groove theory for the bearing oil film, and Darcy’s law for the internal flow in the porous sleeve. The pressure distribution, static equilibrium position of the shaft and dynamic coefficients are obtained under a given external axial load. There exists a window of permeability of the porous sleeve that presents significant advantage to prevent the creation of a sub-ambient condition and to maintain a large thrust bearing film thickness at the expense of some loss of dynamic performance.

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Analysis and Optimization of the Static and Dynamic Characteristics of Head Frame

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.418-420.2055 ◽

2011 ◽

Vol 418-420 ◽

pp. 2055-2059 ◽

Cited By ~ 1

Author(s):

Yu Lin Wang ◽

Na Jin ◽

Kai Liao ◽

Rui Jin Guo ◽

Hu Tian Feng

Keyword(s):

Machine Tool ◽

Dynamic Characteristics ◽

Maximum Stress ◽

Dynamic Performance ◽

Mode Shapes ◽

Cnc Machine ◽

Static And Dynamic Characteristics ◽

Maximum Deformation ◽

Improvement Measures ◽

Optimal Measure

The head frame is a key component which plays a supportive and accommodative role in the spindle system of CNC machine tool. Improving the static and dynamic characteristics has profound significance to the development of machine tool and product performance. The simplified finite element modal is established with ANSYS to carry out the static and modal analysis. The results showed that the maximum deformation of the head frame was 0.0066mm, the maximum stress was 3.94Mpa, the deformation of most region was no more than 0.0007mm, which all verified that the head frame had a good stiffness and deforming resistance; several improvement measures for dynamic performance were also proposed by analyzing the mode shapes, and the 1st order natural frequency increased 7.33% while the head frame mass only increased 1.58% applying the optimal measure, which improved the dynamic characteristics of the head frame effectively.

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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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VCM design to improve dynamic performance of actuator in a disk drive

APMRC 2004 Asia-Pacific Magnetic Recording Conference, 2004. ◽

10.1109/apmrc.2004.1521922 ◽

2005 ◽

Author(s):

Haeng-Soo Lee ◽

Young-Hoon Kim ◽

Tae-Yeon Hwang ◽

Cheol-Soon Kim

Keyword(s):

Dynamic Performance ◽

Disk Drive

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Analog Frontend for Tribo-Current-Based Fly-Height Sensor for Magnetic Hard Disk Drive

IEEE Transactions on Circuits and Systems I Regular Papers ◽

10.1109/tcsi.2017.2725961 ◽

2018 ◽

Vol 65 (2) ◽

pp. 556-566

Author(s):

Arup Polley ◽

Pankaj Pandey ◽

Bryan E. Bloodworth ◽

Costin Cazana

Keyword(s):

Hard Disk Drive ◽

Hard Disk ◽

Disk Drive ◽

Magnetic Hard Disk ◽

Fly Height

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Static and Dynamic Characteristics of Aerostatic Circular Porous Thrust Bearings (Effect of the Shape of the Air Supply Area)

Journal of Tribology ◽

10.1115/1.1308027 ◽

2000 ◽

Vol 123 (3) ◽

pp. 501-508 ◽

Cited By ~ 27

Author(s):

S. Yoshimoto ◽

K. Kohno

Keyword(s):

Porous Material ◽

Dynamic Characteristics ◽

Thrust Bearing ◽

Aerostatic Bearing ◽

Bearing Surface ◽

Static And Dynamic Characteristics ◽

Thrust Bearings ◽

Porous Bearing ◽

Air Supply ◽

Bearing Design

Recently, graphite porous material has been used successfully in an aerostatic bearing. In actual bearing design, it is often necessary to reduce the thickness of porous material to make the bearing smaller. However, a reduction in thickness results in a reduction in the strength of the porous material. In particular, when the diameter of porous material is large, it is difficult to supply the air through the full pad area of porous material because it deforms. Therefore, in this paper, two types of air supply method (the annular groove supply and the hole supply) in a circular aerostatic porous thrust bearing are proposed to avoid the deflection of the bearing surface. The static and dynamic characteristics of aerostatic porous bearing with these air supply methods are investigated theoretically and experimentally. In addition, the effects of a surface restricted layer on the characteristics are clarified.

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Design and testing of a novel multipath-actuation compliant manipulator

Journal of Micromechanics and Microengineering ◽

10.1088/1361-6439/ac404c ◽

2021 ◽

Vol 32 (2) ◽

pp. 025004

Author(s):

Xu Yang ◽

Lichao Ji ◽

Wule Zhu ◽

Ying Shang ◽

Shizhen Li

Keyword(s):

Dynamic Performance ◽

Large Displacement ◽

Element Analysis ◽

Static And Dynamic Characteristics ◽

Amplification Ratio ◽

Practical Applications ◽

Directional Motion ◽

Branched Chains ◽

Design And Testing ◽

The Ideal

Abstract In this paper, a novel multipath-actuation compliant manipulator (MCM) driven by piezoelectric actuators is proposed. Specifically, the monolithic MCM employs two vertically arranged compliant limbs with multipath motion transmission to actuate a symmetrically constrained planar mechanism, realizing x- and y-directional motion. For each limb, the multiple branched chains are configured in different paths but all contribute to the output motion, which results in a large displacement amplification ratio as well as a high working bandwidth. The ideal motion transmission of the proposed MCM is revealed by a specially established rigid-body kinematics model. Finite element analysis is carried out to predict the realistic static and dynamic performance of designed MCM. Moreover, a monolithic MCM prototype is fabricated, which is demonstrated to have a large displacement amplification ratio of 11.05, a high resonance frequency of 969 Hz, and a fine motion resolution of 25.48 nm. With promising static and dynamic characteristics, the proposed MCM can be widely used in practical applications.

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