Multi-Stage Deep Drawing Process of Thin Sheets for the Sleeve Housing Component of a Spindle Motor in HDD

2013 ◽  
Vol 389 ◽  
pp. 359-363 ◽  
Author(s):  
S.M. Yeon ◽  
S. Choi ◽  
G.A. Lee ◽  
S.J. Park ◽  
J.H. Kim ◽  
...  
Keyword(s):  
Fluid Dynamic ◽  
Thin Sheet ◽  
Disk Drive ◽  
Spindle Motor ◽  
Low Noise ◽  
Drawing Process ◽  
Forming Process ◽  
Multi Stage ◽  
Metal Forming Process ◽  
Housing Component

High-precision micro-fluid dynamic bearing is the key part in a hard disk drive, as it offers low noise levels, high speeds and high rates of accuracy with low amount of vibration. To enhance the performance, a thin sheet component called sleeve housing are newly adopted in FDB. In this paper, multi-stage sheet metal forming process is utilized to fabricate the sleeve housing component. Multi-stage drawing simulations are conducted to investigate the adequate process parameters preventing wrinkling and tearing. From the simulation result, multi-stage drawing processes are conducted with progressive die sets in order to evaluate the forming accuracy. The results reveal that it is successful to fabricate the sleeve housing component with multi-stage drawing process.

Optimization of Deep Drawing Processes Using Statistical Design of Experiments

1996 ◽  
Author(s):  
Dietrich Bauer ◽  
Regine Krebs
Keyword(s):  
Mathematical Model ◽  
Analysis Of Variance ◽  
Orthogonal Array ◽  
Deep Drawing ◽  
Metal Forming ◽  
Drawing Process ◽  
Drawing Force ◽  
Forming Process ◽  
Deep Drawing Process ◽  
Metal Forming Process

Abstract For a deep drawing process some important controllable variables (factors) upon the maximum drawing force are analyzed to find a setting adjustment for these process factors that provides a very low force for the metal forming process. For this investigation an orthogonal array L18 with three-fold replication is used. To find the optimum of the process, the experimental results are analyzed in accordance with the robust-design-method according to Taguchi (Liesegang et. al., 1990). For this purpose, so-called Signal-to-Noise-ratios are calculated. The analysis of variance for this S/N-ratios leads to a mathematical model for the deep drawing process. This model allows to find the pressumed optimal settings of the investigated factors. In the following, a confirmation experiment is carried out by using these optimal settings. The maximum drawing force of the confirmation experiment does not correspond with the confidence interval, which was calculated by analysis of variance techniques. So the predicted optimum of the process does not lead to a metal forming process with very low deep drawing force. The comparison with a full factorial plan shows that there are interactions between the investigated factors. These interactions could not be discovered by the used orthogonal array. Thus the established mathematical model does not describe the relation between the factors and deep drawing force in accordance with the practical deep drawing conditions.

Behavior of Micron-Sized Air Bubble in Operating FDBs by Using the Discrete Phase Modeling Method

2013 ◽  
Author(s):  
Y. H. Jung ◽  
G. H. Jang ◽  
K. M. Jung ◽  
C. H. Kang ◽  
H. H. Shin
Keyword(s):  
Fluid Dynamic ◽  
Disk Drive ◽  
Spindle Motor ◽  
Air Bubbles ◽  
Air Bubble ◽  
Discrete Phase Modeling ◽  
Discrete Phase ◽  
The Stability ◽  
Stiffness And Damping ◽  
Oil Injection

Fluid dynamic bearings (FDBs) have been applied to the spindle motor of a computer hard disk drive (HDD) because FDBs provide better dynamical characteristics of lower vibration and noise than ball bearings. However, one of the weaknesses of FBDs is the instability arising from the air bubble in oil lubricant of FDBs. Air bubbles are formed and trapped in oil lubricant by the inappropriate process of oil injection or the external shock. Trapped air bubbles decrease the rotational accuracy and the stability of a rotor-bearing system in such a way to generate non-repeatable run-out (NRRO) and to decrease the stiffness and damping coefficients of FDBs. It is important to predict the path of air bubbles in oil lubricant and to design FDBs in such a way to easily expel air bubbles out of operating FDBs.

Micro Pattern Forming of Spiral Grooves in a Fluid Dynamic Bearing Using Desktop Forming System

2012 ◽  
Vol 538-541 ◽  
pp. 1203-1207 ◽  
Author(s):  
Jung Han Song ◽  
Jeanho Park ◽  
Jong Sup Lee ◽  
Seo Gou Choi ◽  
Hye Jin Lee ◽  
...  
Keyword(s):  
Fluid Dynamic ◽  
Dynamic Pressure ◽  
Disk Drive ◽  
Spiral Groove ◽  
Micro Forming ◽  
Forming Process ◽  
Micro Pattern ◽  
Fluid Dynamic Bearing ◽  
Pattern Forming ◽  
Groove Pattern

This research explores the micro-forming process of spiral groove pattern on Fluid Dynamic Bearing(FDB), which is utilized in precision driving part of the hard disk drive(HDD), using micro desktop forming system. While EDM and ECM process has been widely used to engrave the precision pattern which generates dynamic pressure on FDBs, micro forming process is newly proposed in this study to increase the productivity and to reduce the product costs. At first, desktop forming system is designed for spiral groove pattern forming. FE simulations are followed in order to evaluate the feasibility of micro-forming. The simulation results show that forming loads of 1,500Kgf is required to fabricate micro patterns with the depth of 15 μm. Finally the formability test is carried out with various forming loads. Deformed shapes and forming loads obtained from the test are compared with those from the analysis. The results fully demonstrate that micro pattern forming techniques are available to fabricate micro spiral groove patterns in FDB.

Position and the Size of Drawbeads for Sheet Metal Forming with the Finite Element Method

2014 ◽  
Vol 607 ◽  
pp. 112-117
Author(s):  
Khemajit Sena ◽  
Surasith Piyasin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Drawing Process ◽  
The Finite Element Method ◽  
Forming Process ◽  
Deep Drawing Process ◽  
Metal Forming Process ◽  
Element Method

This study aims to find a solution to improve the formability in a deep drawing process. For this purpose drawbeads were used to avoid wrinkles and ruptures. The finite element method was applied to simulate the 3D metal forming process using a die and drawbead. The drawbead amount, position, size and form were studied for their affects on the formability. 3 drawbead patterns with 3 different heights were examined. The simulation was performed for each drawbead pattern and each drawbead geometrical parameter and the failure elements were counted. The best pattern chosen was the pattern that resulted in the least failure elements.

Reduction of Stages in Multi-Stage Metal Forming Process Based on Numerical Optimization in Conjunction with FE Simulation

2007 ◽  
Vol 340-341 ◽  
pp. 767-772
Author(s):  
Ryutaro Hino ◽  
Akihiko Sasaki ◽  
Fusahito Yoshida ◽  
Vassili V. Toropov
Keyword(s):  
Design Optimization ◽  
Process Design ◽  
Metal Forming ◽  
Numerical Optimization ◽  
Fe Simulation ◽  
Design Technique ◽  
Forming Process ◽  
Multi Stage ◽  
Metal Forming Process ◽  
Stage Process

In this study, a new simulation-based design technique for multi-stage metal forming process is developed with special emphasis on reduction of stages in the process. The developed design technique is an iterative design optimization, which is based on response-surface-based numerical optimization and finite element analysis of the process. The design procedure starts with the initial rough process design. To eliminate one stage in the multi-stage process, the new optimum process design is determined based on the former process design by using numerical optimization in conjunction with FE simulation. This design optimization step is repeated, reducing the stages one by one, until the possible minimum number of stages is reached. The developed design technique is applied to stage reduction of a 3-stage axisymmetric forging process of aluminum billet. We can confirm that a new 2-stage process design is determined successfully and the developed design optimization technique is effective to reduce stages in multi-stage forming process.

Multi-Stage Cold Deep Drawing of Pure Titanium Square Cup

2015 ◽  
Vol 651-653 ◽  
pp. 1072-1077 ◽  
Author(s):  
Yasunori Harada ◽  
Minoru Ueyama
Keyword(s):  
Deep Drawing ◽  
Metal Forming ◽  
Pure Titanium ◽  
Oxide Coating ◽  
Drawing Process ◽  
Forming Process ◽  
Titanium Sheet ◽  
Cold Forming ◽  
Deep Drawing Process ◽  
Multi Stage

This paper deals with the formability of pure titanium sheet in square cup deep drawing. Pure titanium has very excellent corrosion resistance. In the metal forming process, pure titanium has very good ductility in cold forming. The normal anisotropy of pure titanium is very high. Therefore, the property is suitable to the sheet metal forming, such as deep drawing process. However, the most important problem is that the occurrence of seizure becomes remarkable in severe forming operations. Many investigations on the effect of processing conditions on the seizure of titanium were carried out. In the present study, the formability of pure titanium sheet in square cup deep drawing was investigated. For the prevention, pure titanium sheets were treated by heat oxide coating. The fresh and clean titanium is not in direct contact with the die during the forming due to the existence of the oxide layer. The material was pure titanium sheets of the JIS grade 2. The initial thickness of the blank was 0.5 mm in thickness. In the deep drawing process, the sheets were employed and a flat sheet blank is formed into a square by a punch. Forming of sheet by multi-stage deep drawing was tried. Various cups were drawn by exchanging the punch and die. The die was taper without a blankholder in the subsequent stages. The effects of the intermediate annealing and tool shape on the occurrence of seizure in square cup deep drawing were also examined. The square cups were successfully drawn by heat oxide coating. The coating of titanium sheet has sufficient ability in preventing the seizure in multi-stage deep drawing operation. The results of the present study revealed that the pure titanium square cups were successfully formed by using heat oxide coating treatment.

Development of High Performance Multi-Lobe Fluid Dynamic Bearings Using a Sintered Material

2007 ◽  
Vol 534-536 ◽  
pp. 1437-1440 ◽  
Author(s):  
Hidekazu Tokushima
Keyword(s):  
High Performance ◽  
Data Transfer ◽  
Sintered Material ◽  
Fluid Dynamic ◽  
Disk Drive ◽  
Spindle Motor ◽  
High Density Recording ◽  
Bearing Stiffness ◽  
Bearing Loss ◽  
Herringbone Grooves

Recently, in spindle motors for hard disk drive (HDD) devices, fluid dynamic bearings (FDB) with herringbone grooves have come to be used instead of ball bearings due to the demand for high density recording of the devices, improvement in the speed of data transfer, and the quietness of the motor. In this study, a 5-lobe bearing with high bearing stiffness using a sintered material, as a new trial, was developed, and the bearing performance was examined by simulated calculations and experiments. As a result, it was clarified that the 5-lobe bearing had the required performance for practical use in the spindle motor for HDD by means of optimizing the bearing’s dimensions. In addition, bearing loss of the 5-lobe bearing is lower than that of the herringbone bearing, and the 5-lobe bearing showed clearly that it is effective in being used in the miniaturization of HDD spindle motors.

scholarly journals SIMULATION OF THE EFFECT OF DIE RADIUS ON DEEP DRAWING PROCESS

2012 ◽  
pp. 237-242
Author(s):  
KOPANATHI GOWTHAM ◽  
K.V.N.S. SRIKANTH ◽  
K.L.N. MURTY
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Deep Drawing ◽  
Main Process ◽  
Drawing Process ◽  
Forming Process ◽  
Element Analysis ◽  
Deep Drawing Process ◽  
Metal Forming Process ◽  
Deform 3D

This paper “SIMULATION OF THE EFFECT OF DIE RADIUS ON DRAWING PROCESS” is one of the most used Metal Forming Process within the industrial field. Different analytical, numerical, empirical and experimental methods have been developed in order to analyze it. This work reports on the initial stages of finite element analysis (FEA) of a Deep drawing process. The objective of this study is to determine the factors influencing a drawing process and analyzing the process by varying the Die radius and keeping the Friction, Punch radius and Blank Thickness as constant. In this paper Punches, blank thickness of same geometry and dies of various geometries were drawn by using CATIA software. And an effort is made to study the simulation effect of main process variant namely die radius using finite element analysis. As the FEM code, the commercially available software DEFORM-3D is used here. Aluminium alloy 6061 is used for deep drawing with initial diameter as 56mm.

Sign in / Sign up

Export Citation Format

Share Document