Wear Characteristics of Padded Air Bearing Sliders During a Contact Take-Off Process

1999 ◽  
Vol 122 (3) ◽  
pp. 628-632 ◽  
Author(s):  
Yong Hu

The pressing and challenging demand for resolving the stiction/glide-height conflict, driven by today’s ever decreasing head/disk spacing, forces us to constantly search for new technologies. One of them is padding the slider’s air bearing surface. Although the padded air bearing sliders can significantly reduce the stiction, the wear of these landing pads becomes a central issue. This paper attempts to analytically predict the wear characteristics of the landing pads during a contact take-off process. A wear factor derived from the adhesive wear law is employed to measure the wear extent of the landing pads. The contact force profile and wear factor of each pad are calculated through the partial contact air bearing simulation of a slider’s take-off process. It is found that the rear pad wears an order magnitude more than the leading pads. The wear volume of the rear pad increases exponentially with pad height, interface roughness and altitude. Raising the leading pads alone slightly reduces the wear of the rear pad. Placing the rear pad away from the slider’s trailing edge, however, substantially alleviates the wear of the rear pad. Finally, a lightly textured pad/disk interface decreases the pads’ wear to a minimum value for a given padded air bearing design. [S0742-4787(00)01903-2]

1999 ◽  
Vol 121 (4) ◽  
pp. 948-954 ◽  
Author(s):  
Yong Hu

A partial contact air bearing model and Archard’s wear law are used to investigate the air bearing and wear characteristics of proximity recording sliders during a take-off process. The air bearing pitch torque, pitch and contact force are used to characterize the contact take-off process. In addition, the wear factor derived from the Archard’s wear law is employed to measure the take-off performance. The results indicate the existence of two distinct take-off stages: a period of rapidly increasing pitch preceding a relatively steady take-off event. The proper range of taper angle and step height, which produce a rapid initial pitch increase and steady subsequent take-off as well as less wear in the head/disk interface, are determined through simulation. While the simulation results demonstrate the negligible effect of crown height on the rate of the initial pitch increase, larger crown values are shown to yield higher pitch and smaller wear in the head/disk interface during the take-off process. In summary, the partial contact air bearing simulation and the wear factor calculation of the take-off process, developed in this study, offers a fast and accurate analytical tool to optimize ABS design for the fast take-off performance.


Author(s):  
Bo Liu ◽  
MingSheng Zhang ◽  
Yijun Man ◽  
Shengkai Yu ◽  
Gonzaga Leonard ◽  
...  

2007 ◽  
Vol 43 (2) ◽  
pp. 715-720 ◽  
Author(s):  
Bo Liu ◽  
Shengkai Yu ◽  
Mingsheng Zhang ◽  
Leonard Gonzaga ◽  
Hui Li ◽  
...  

Author(s):  
Du Chen ◽  
David B. Bogy

A new partial contact head disk interface (HDI) with thermal protrusion is proposed for magnetic recording with densities of 1 Tbit/in2 and above. This HDI has the advantage of maintaining light contact between the slider and the disk, so that both the bouncing vibration amplitude and the contact force are small compared with a traditional partial contact HDI. The slider’s dynamic simulations are carried out to analyze the effect of various factors within the HDI on the slider’s dynamic performance, including the friction and adhesion between the slider and the disk, the track profile morphology of the disk and the air bearing design. It is found that the bouncing vibration amplitude can be reduced to the level of the flying height modulation (FHM) of a non-contact air bearing slider without thermal protrusion.


Author(s):  
Du Chen ◽  
David D. Bogy

A nonlinear dynamic model is developed to analyze the bouncing vibration of a partial contact air bearing slider, which is designed for the areal recording density in hard disk drives of 1 Tbit/in2 or even higher. In this model the air bearing with contact is modeled using the generalized Reynolds equation modified with the Fukui-Kaneko slip correction and a new second order slip correction for the contact situation [1]. The adhesion, contact and friction between the slider and the disk are also considered in the model. It is found that the disk surface roughness, which moves into the head disk interface (HDI) as the disk rotates, excites the bouncing vibrations of the partial contact slider. The frequency spectra of the slider’s bouncing vibration have high frequency components that correspond to the slider-disk contact.


Author(s):  
Eric M. Jayson ◽  
Frank E. Talke

Hard disk drives must be designed to withstand shock during operation. Large movements of the slider during shock impulse can cause reading and writing errors, track misregistration, or in extreme cases, damage to the magnetic material and loss of data. The design of the air bearing contour determines the steady state flying conditions of the slider as well as dynamic flying conditions, including shock response. In this paper a finite element model of the hard disk drive mechanical components was developed to determine the time dependent forces and moments applied to the slider during a shock event. The time dependent forces and moments are applied as external loads in a solution of the dynamic Reynolds equation to determine the slider response to a shock event. The genetic algorithm was then used to optimize the air bearing contour for optimum shock response while keeping the steady flying conditions constant. The results show substantial differences in the spacing modulation of the head/disk interface after a shock as a function of the design of the air bearing contour.


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