Operational shock response of ultrathin hard disk drives

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

Operational shock is one of key challenges for designing the ultrathin mobile hard disk drives (HDDs) due to the reduced thickness of mechanical components and their stiffness. Some simplifications in the conventional methods for operational shock simulation are not valid. In this paper, a method for system level modelling and simulation of operational shock response of HDDs has been proposed by coupling the structural finite element model of the HDD and the air bearing model. The dynamic shock response of the head-disk system in a 5 mm ultrathin HDD design is investigated. The effects of drive base stiffness, disk-ramp contact, disk spinning and disk distortion have been studied. The results reveal that the drive base deformation and ramp contact are critical for the operational shock resistance performance of ultrathin drives.


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.


2011 ◽  
Vol 47 (7) ◽  
pp. 1874-1877 ◽  
Author(s):  
Dongwei Shu ◽  
Fook Fah Yap ◽  
Bin Gu ◽  
Baojun Shi ◽  
Djati Wibowo Djamari

2006 ◽  
Vol 12 (12) ◽  
pp. 1109-1116 ◽  
Author(s):  
Aravind N. Murthy ◽  
Bert Feliss ◽  
Donald Gillis ◽  
Frank E. Talke

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

Most hard disk drives manufactured in the last few years have Load/Unload (L/UL) technology. As opposed to the Contact Start/Stop (CSS) technology, L/UL technology has the advantage of improved areal density because of more disk space availability and better shock performance. The latter characteristic has significant benefits during the non-operational state of the hard disk drive since head/disk interactions are eliminated and the head is parked on a ramp adjacent to the disk. However, even if head/disk interactions are absent, other failure modes may occur such as lift-tab damage and dimple separation leading to flexure damage. A number of investigations have been made to study the response of the head disk interface with respect to shock when the head is parked on the disk ([1], [2]). In this paper, we address the effect of non-operational shock for L/UL disk drives.


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