scholarly journals A computational analysis for thin air film lubrication of magnetic recording disk memory. (1st Report).

1989 ◽  
Vol 55 (513) ◽  
pp. 1351-1356
Author(s):  
Ryuii FUJINUMA ◽  
Teruo NAKAMURA
Keyword(s):  
Magnetic Recording ◽  
Computational Analysis ◽  
Air Film ◽  
Film Lubrication ◽  
Disk Memory

Design of Negative Pressure Slider for Magnetic Recording Disks

1983 ◽  
Vol 105 (3) ◽  
pp. 496-502 ◽  
Author(s):  
K. Kogure ◽  
S. Fukui ◽  
Y. Mitsuya ◽  
R. Kaneko
Keyword(s):  
Dynamic Characteristics ◽  
Magnetic Recording ◽  
Negative Pressure ◽  
Dynamic Pressure ◽  
Slip Flow ◽  
Pressure Distributions ◽  
Light Load ◽  
Flow Effects ◽  
Film Stiffness ◽  
Air Film

This paper reports on investigations of static and dynamic characteristics of a negative pressure slider for magnetic recording disks. The negative pressure slider is composed of two narrow pressure pads, as on a cylindrical slider, separated by a rather large reverse step region. Through a modified Reynolds equation, which considers slip flow effects, the static and dynamic pressure distributions are calculated by divergence formulation and a finite difference method. Using the calculated results, the optimum reverse step depth is clarified in terms of both dynamic characteristics and wear caused by starting and stopping in contact with the disk. With a 4.6 mm length, 3.2 mm total pad width and 4 μm reverse step depth, the negative pressure slider has six times the air film stiffness of a conventional light load slider. Experimental data concerning spacing versus reverse step depth and take-off characteristics for the negative pressure slider in submicron spacing region are in good agreement with the calculated results.

Simulation of Tape Floating Behavior in VTR

1993 ◽  
Vol 115 (4) ◽  
pp. 561-565 ◽  
Author(s):  
Jun Itoh ◽  
Takeshi Ebihara ◽  
Yuji Kubota ◽  
Atsushi Takahashi
Keyword(s):  
Interface Problem ◽  
The Finite Element Method ◽  
Height Control ◽  
Rotary Drum ◽  
Twist Effect ◽  
Air Film ◽  
Raphson Method ◽  
Method Show ◽  
Film Lubrication ◽  
Good Agreement

An efficient method for numerical simulation of tape floating behavior in VTR has been developed. Parameter survey examples for tape floating height control in some drum-guide tape systems have been shown. The spacing between a drum and a tape is one of the most important topics regarding the tape/head interface problem for a VTR. The spacing is caused by air film lubrication and can be determined by using the Reynolds equation for air and the elastic equation for a tape. Each equation is discretized, using the finite element method, and solved by the Newton-Raphson method. The results, calculated by the present method, show good agreement with experimental results. The authors also investigated tape floating behavior for several drum-guide tape systems, which are intended to decrease tape/drum spacing, especially in the head entrance region, as follows; (1) Guidepost twist effect; (2) Difference between a rotary drum configuration and a rotary center drum configuration; (3) A new groove location for tape floating height equalization.

Thermo-molecular gas-film lubrication (t-MGL) analysis for heat-assisted magnetic recording head sliders

2014 ◽  
Vol 20 (8-9) ◽  
pp. 1447-1454 ◽  
Author(s):  
Shigehisa Fukui ◽  
Naoya Kitagawa ◽  
Ryo Wakabayashi ◽  
Kiyomi Yamane ◽  
Hiroshige Matsuoka
Keyword(s):  
Magnetic Recording ◽  
Molecular Gas ◽  
Recording Head ◽  
Heat Assisted Magnetic Recording ◽  
Magnetic Recording Head ◽  
Molecular Gas Film Lubrication ◽  
Film Lubrication

scholarly journals The Air Lubrication Behavior of a Kingsbury Thrust Bearing Demonstration

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Wanjun Xu ◽  
Jiangang Yang
Keyword(s):  
Thin Film ◽  
Thrust Bearing ◽  
Surface Irregularity ◽  
Middle Region ◽  
Thin Film Lubrication ◽  
Working Surface ◽  
Mass Load ◽  
Air Lubrication ◽  
Air Film ◽  
Film Lubrication

In order to understand the air lubrication behavior of Kingsbury thrust bearing demonstration, an experimental and theoretical investigation on a simulated Kingsbury thrust bearing was presented. The motions of the thrust disk and tilting pads were measured by eddy current sensors for three mass load cases. A simplified theoretical model governing the motion of the thrust disk was established. The bearing successfully passed the examination of lamp extinction and maintained the maximum rotation time of 16 s. The effective hydrodynamic film with a thickness of about 5 μm was concentrated on the middle region of the working surface under a flatness of 0.010 mm. The adverse effect of the three surface bumps was minimized by the swing motion of tilting pads. Moreover, about 1/3 air film thickness was shown to be wasted due to the surface irregularity. However, the requirements of surface quality and misalignment were appropriately relaxed through the design of the centrally pivoted tilting pads. This design is conducive to thin-film lubrication and is a potential application for microturbines.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

4-dimensional, high-resolution imaging of living cells

1992 ◽  
Vol 50 (1) ◽  
pp. 416-417
Author(s):  
Shinya Inoué
Keyword(s):  
Light Microscope ◽  
Living Cells ◽  
Live Cells ◽  
Video Tape ◽  
Active Living ◽  
High Resolution Imaging ◽  
3 Dimensional ◽  
Dynamic Architecture ◽  
Resolution Imaging ◽  
Disk Memory

This paper reports progress of our effort to rapidly capture, and display in time-lapsed mode, the 3-dimensional dynamic architecture of active living cells and developing embryos at the highest resolution of the light microscope. Our approach entails: (A) real-time video tape recording of through-focal, ultrathin optical sections of live cells at the highest resolution of the light microscope; (B) repeat of A at time-lapsed intervals; (C) once each time-lapsed interval, an image at home focus is recorded onto Optical Disk Memory Recorder (OMDR); (D) periods of interest are selected using the OMDR and video tape records; (E) selected stacks of optical sections are converted into plane projections representing different view angles (±4 degrees for stereo view, additional angles when revolving stereos are desired); (F) analysis using A - D.

High-resolution scanning electron microscopy of thin-film magnetic media of magnetic recording disk

1992 ◽  
Vol 50 (2) ◽  
pp. 1334-1335
Author(s):  
K. Ogura ◽  
H. Nishioka ◽  
N. Ikeo ◽  
T. Kanazawa ◽  
J. Teshima
Keyword(s):  
Thin Film ◽  
Fine Structure ◽  
High Resolution ◽  
Magnetic Recording ◽  
High Performance ◽  
Magnetic Hysteresis ◽  
Grain Structure ◽  
Magnetic Media ◽  
Cross Sectional ◽  
Resolution Observation

Structural appraisal of thin film magnetic media is very important because their magnetic characters such as magnetic hysteresis and recording behaviors are drastically altered by the grain structure of the film. However, in general, the surface of thin film magnetic media of magnetic recording disk which is process completed is protected by several-nm thick sputtered carbon. Therefore, high-resolution observation of a cross-sectional plane of a disk is strongly required to see the fine structure of the thin film magnetic media. Additionally, observation of the top protection film is also very important in this field.Recently, several different process-completed magnetic disks were examined with a UHR-SEM, the JEOL JSM 890, which consisted of a field emission gun and a high-performance immerse lens. The disks were cut into approximately 10-mm squares, the bottom of these pieces were carved into more than half of the total thickness of the disks, and they were bent. There were many cracks on the bent disks. When these disks were observed with the UHR-SEM, it was very difficult to observe the fine structure of thin film magnetic media which appeared on the cracks, because of a very heavy contamination on the observing area.

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