Numerical simulation of shock response of disk-suspension-slider air bearing systems in hard disk drives

2002 ◽  
Vol 8 (4-5) ◽  
pp. 289-296 ◽  
Author(s):  
Q. H. Zeng ◽  
D. B. Bogy
1990 ◽  
Vol 112 (4) ◽  
pp. 593-602 ◽  
Author(s):  
O. J. Ruiz ◽  
D. B. Bogy

In previous papers the dynamics of air bearing sliders used to carry the read/write transducers in magnetic hard disk files has been studied. These studies are useful in evaluating the steady flying and stability of sliders subjected to various disturbances. They are particularly useful in finding the natural frequencies of the air bearings. However, in hard disk drives the sliders are attached to suspensions, which are highly specialized structures that connect the sliders to the positioning actuators. These suspensions have to be relatively stiff in lateral translation, but very flexible in pitch and roll. This latter feature is accomplished by the gimbal or flexure that connects the slider to the end of the suspension. The suspension-gimbal structure has its own natural frequencies, which can be excited by disturbances such as track seeking and impacting the actuator against the crash stop. In order to study the effect of these structures on the head-disk spacing it is necessary to include them in the numerical simulator. In this two part study such a simulator is developed. In Part I the component parts and their interfaces are modeled. In Part II the numerical simulation of the coupled system is accomplished and the numerical results of several sample simulations are presented and discussed.


2006 ◽  
Vol 129 (1) ◽  
pp. 153-160 ◽  
Author(s):  
P. Bhargava ◽  
D. B. Bogy

As nontraditional applications of hard disk drives emerge, their mechanical robustness during the operating state is of greater concern. Over the past few years, there has been an increasing application of small form factor (1in. and smaller) hard disk drives in portable consumer appliances and gadgets. A procedure for simulating the operational shock response of a disk-suspension-slider air bearing system is proposed in this paper. A coupled structural-fluid model is presented which can be used to obtain the dynamic response of the slider-suspension-disk system. A commercial program, ANSYS, is used for the finite element models of the suspension and the disk, while the CML dynamic air bearing code is used to concurrently solve the air bearing equations of the system. We obtain not only the responses of the structural components, but also the responses of the air bearing slider. The procedure is convenient for practical application as well as being highly accurate, since it implicitly solves the structural and air bearing problems simultaneously. It is used to simulate the shock response of a 1in. drive. The air bearing has different responses for upward and downward shocks (which are referred to as positive and negative shocks, respectively). For negative shocks, slider-disk contacts are observed to occur when a strong shock is applied, however, the air bearing does not collapse. For positive shocks, we observe a collapse of the air bearing when the shock is sufficiently strong, which is followed by severe contacts between the slider and the disk due to the “head-slap” phenomenon.


1993 ◽  
Vol 115 (3) ◽  
pp. 370-375 ◽  
Author(s):  
T. G. Jeong ◽  
D. B. Bogy

The dynamic loading process in hard disk drives is simulated numerically. The effects of the slider’s loading velocity and initial pitch and roll on its dynamics during loading, as well as on slider-disk contacts, are studied by using the dynamic loading simulator. The air bearing forces due to the squeezing and shearing flows are calculated and their contributions to the dynamics of the slider during loading are investigated. Slider-disk contacts are considered in the numerical simulation through generalized impulse-momentum equations. Slider-disk contact criteria are obtained from the numerical simulation, and they are compared with those obtained from a previous experimental parameter study.


Author(s):  
Wending Fang ◽  
Yujuan Wang ◽  
Yunfei Chen

Hard disk drives continue to increase the data storage density. The parameters of the head slider flying attitude must satisfy very strict performance goals. This paper focuses on the topic of the simulated annealing algorithm when it is applied to the problem of slider air bearing design in hard disk drives. The objective is to minimize the static flying height, to keep the pitch angle within a reasonable range, and to minimize the roll angle. The design variables include recess depth and geometry configuration of the slider air bearing surface. A typical tri-pad slider was taken as the physical model to demonstrate the validity of the optimal algorithm. Results show that simulated annealing is efficient for the optimization of the slider air bearing design. The static air bearing characteristics were enhanced significantly.


2015 ◽  
Vol 21 (12) ◽  
pp. 2573-2579 ◽  
Author(s):  
Shengkai Yu ◽  
Jianqiang Mou ◽  
Wei Hua ◽  
Weidong Zhou ◽  
Chye Chin Tan

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