scholarly journals Fundamental characteristics of high-speed rotating flexible disk drive utilizing self-acting air bearing.

1987 ◽  
Vol 53 (12) ◽  
pp. 1905-1907 ◽  
Author(s):  
HIROSHI HOSAKA
Keyword(s):  
High Speed ◽  
Disk Drive ◽  
Air Bearing ◽  
Rotating Flexible Disk ◽  
Flexible Disk

Slider Air Bearing Design Enhancements for High Speed Flexible Disk Recording

2005 ◽  
Vol 127 (3) ◽  
pp. 522-529 ◽  
Author(s):  
James White
Keyword(s):  
High Speed ◽  
Numerical Solutions ◽  
Hydrodynamic Pressure ◽  
Flying Height ◽  
Air Bearing ◽  
Mechanical Shock ◽  
Current Effort ◽  
Slider Air Bearing ◽  
Flexible Disk ◽  
Air Film

The current effort was motivated largely by the fact that computing and communication platforms are becoming more portable and mobile with increased demands for both speed and disk storage. This work makes use of an asymmetric opposed slider arrangement to provide both static and dynamic improvements to the recording head air bearing interface for high speed flexible disk applications. The combination of a longitudinally slotted rail opposed by an uninterrupted rail that functions as a noncontact hydrodynamic pressure pad causes the disk to deflect at the submicron level over critical areas of the slider interface. This allows the required static minimum flying height to be focused over the recording transducer while higher clearances are positioned elsewhere, resulting in minimized exposure to contact between slider and disk. The high stiffness and low flying height of the air film at the recording element together with the low stiffness and high flying height of the opposing air film provides a noncontact air bearing interface that is especially immune to mechanical shock. A computer code called FLEXTRAN was developed that provides both static and dynamic numerical solutions of the air bearing interface composed of two opposed gimbal mounted sliders loaded against a high speed flexible disk. Simulations of the asymmetric opposed slider configuration are presented and compared with those of other slider air bearing designs.

Air Bearing Slider-Disk Interface for Single-Sided High Speed Recording on a Metal Foil Disk

2007 ◽  
Vol 129 (3) ◽  
pp. 562-569 ◽  
Author(s):  
James White
Keyword(s):  
Data Storage ◽  
High Speed ◽  
Hard Disk ◽  
Disk Drive ◽  
Flying Height ◽  
Metal Foil ◽  
Air Bearing ◽  
Recording Head ◽  
Disk Interface ◽  
Air Bearing Slider

There are disk-drive data storage applications best served by single-sided recording configurations. These include situations where (i) storage requirements can be achieved on a single side of a disk and (ii) dimensional constraints on the disk drive prohibit the presence of a recording head and its associated mounting device on each side of the disk. Even if dimensional requirements are not a concern, the most cost-effective and operationally efficient slider-disk air-bearing interface for single-sided recording is one that does not include an air-bearing slider, pressure pad, or other air-bearing structure on the nondata side of the disk. A metal foil disk offers some of the best characteristics of both the hard disk and floppy disk for digital data storage. It offers hard disk recording densities, increased shock resistance, reduced manufacturing cost, and requires less operational energy than a hard disk. However, use of a conventional recording head slider assembly without opposing air-bearing support for single-sided recording on a high-speed metal foil disk presents a fundamental problem because the air-bearing surface of the slider produces a net transverse force to the disk. This force causes the disk to deflect and can result in flying height and stability problems at the slider-disk interface. The current work describes an air-bearing interface for low flying height single-sided recording on a high-speed metal foil disk that minimizes disk deflection and instability without the presence of air-bearing components on opposing sides of the disk. The new interface utilizes a vacuum cavity-type air-bearing with little or no preload. Examples will be presented and discussed for the new interface that illustrate the flying characteristics of a picosized slider on a 1.8in. stainless steel disk with thickness of 25.4μm.

Transient Vibration of High-Speed, Lightweight Rotors Due to Sudden Imbalance

1983 ◽  
Vol 105 (3) ◽  
pp. 480-486 ◽  
Author(s):  
M. Sakata ◽  
T. Aiba ◽  
H. Ohnabe
Keyword(s):  
Transient Response ◽  
High Speed ◽  
Rotor System ◽  
Response Analysis ◽  
Transient Vibration ◽  
Flexible Shaft ◽  
Shaft System ◽  
Transient Response Analysis ◽  
Flexible Disk ◽  
Blade Loss

In the field of rotor dynamics, increased attention is being given to the transient response analysis of the rotor, since the effects of impact loading and vibrations of the rotor arising from blade loss can be studied by a time transient solution of the rotor system. As recent trends in rotating machinery have been directed towards lightweight, high-speed flexible rotors, the effect of flexibility on transient response analysis is becoming of increasing importance. In the present paper, a transient vibration analysis is carried out on a flexible-disk/flexible-shaft system or rigid-disk flexible-shaft system subjected to a sudden imbalance that is assumed to represent the effect of blade loss. To solve the basic equation governing a rotating flexible disk the Galerkin’s method is used, and the equation of motion of the rotor system is numerically solved by employing the Runge-Kutta-Gill’s method. Experiments were conducted on a model rotor having a blade loss simulator; the shaft vibrations were also measured. The validity of the anaytical results was demonstrated by comparison with the experimental results.

Vibrational response of a moving suspension-slider loading system exciting a rotating flexible disk

2012 ◽  
Vol 331 (16) ◽  
pp. 3762-3773 ◽  
Author(s):  
Yong-Chen Pei ◽  
Qing-Chang Tan ◽  
Xin Yang ◽  
Chris Chatwin
Keyword(s):  
Vibrational Response ◽  
Loading System ◽  
Rotating Flexible Disk ◽  
Flexible Disk

Axisymmetric Solution of a Flexible Disk Rotating Near a Rigid Surface

1988 ◽  
Vol 110 (4) ◽  
pp. 674-677 ◽  
Author(s):  
M. Carpino ◽  
G. A. Domoto
Keyword(s):  
Plane Stress ◽  
Asymptotic Expansions ◽  
Reynolds Equation ◽  
Flat Surface ◽  
Inertial Effects ◽  
Rigid Surface ◽  
Axisymmetric Solution ◽  
Spinning Disk ◽  
Rotating Flexible Disk ◽  
Flexible Disk

A rotating flexible disk separated from a rigid flat surface by a gas film is addressed. The gas film between the disk and the plate is represented by an incompressible Reynolds equation. Inertial effects are included. The disk is treated as a membrane where the tension is found from the plane stress solution for a spinning disk. Two different methods for the axisymmetric solution of this system are developed. The first uses the method of matched asymptotic expansions. The second method is a mixed numerical/perturbation procedure.

scholarly journals Chaotic Behaviour Investigation of a Front Opposed-Hemispherical Spiral-Grooved Air Bearing System

2017 ◽  
Vol 2017 ◽  
pp. 1-18
Author(s):  
Cheng-Chi Wang
Keyword(s):  
High Speed ◽  
Critical Speed ◽  
Large Scale ◽  
Air Bearing ◽  
Severe Damage ◽  
Design Problems ◽  
Irregular Motion ◽  
Transformation Methods ◽  
Bearing Number ◽  
Bearing System

In recent years, spiral-grooved air bearing systems have attracted much attention and are especially useful in precision instruments and machines with spindles that rotate at high speed. Load support can be multidirectional and this type of bearing can also be very rigid. Studies show that some of the design problems encountered are dynamic and include critical speed, nonlinearity, gas film pressure, unbalanced rotors, and even poor design, all of which can result in the generation of chaotic aperiodic motion and instability under certain conditions. Such irregular motion on a large scale can cause severe damage to a machine or instrument. Therefore, understanding the conditions under which aperiodic behaviour and vibration arise is crucial for prevention. In this study, numerical analysis, including the Finite Difference and Differential Transformation Methods, is used to study these effects in detail in a front opposed-hemispherical spiral-grooved air bearing system. It was found that different rotor masses and bearing number could cause undesirable behaviour including periodic, subperiodic, quasi-periodic, and chaotic motion. The results obtained in this study can be used as a basis for future bearing system design and the prevention of instability.

The Gas Bearing Interface of Opposed Recording Heads in a Disk Drive Utilizing Helium and Thin Titanium Foil Disks

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
James White
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Hard Disk ◽  
Disk Drive ◽  
Titanium Foil ◽  
Metal Foil ◽  
Mechanical Shock ◽  
Disk Interface ◽  
Recording Heads ◽  
Gas Bearing

Increased storage capacity and decreased power consumption are two key motivations in the development of hard disk drive (HDD) storage products. Two ideas that address these areas have recently received attention in the literature. These are (1) the use of helium instead of air as the working gas in the drive and (2) the incorporation of a thin metal foil as the disk substrate, replacing the much thicker aluminum or glass substrate of the hard disk (HD). The work that has been previously reported considered either the use of helium or thin foil substrates, but not both. This paper does consider both. It reports dynamic gas bearing simulation results for the helium filled interface between opposed recording heads and a disk whose substrate is a thin titanium foil. Motivation for the selection of titanium as the foil material is described in the paper. The thickness of the foil is chosen so as to achieve an optimal combination of centrifugal force and bending force that will provide required disk flatness and stability during high-speed rotation. Large-scale dynamic simulation is used to track the response of the recording head slider-foil disk interface due to mechanical shock in the vertical, pitch, and roll directions. Results are described and compared with those of the configuration that includes helium and a HD. Attention is focused on response to off-design conditions that can create head crash with the HD.

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