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An automatic disc storage system transfers discs automatically to storage or an optical disc drive using a robotic arm. For example, an optical archive system uses an automatic disc storage system to efficiently handle a large number of discs. The automatic disc storage system commonly uses a multi-bent leaf spring (MBLS) to insert and hold a disc. In the automatic disc storage system, incomplete insertion of the disc can occur if the disc is not moved properly into storage by the robotic arm. Incomplete insertion causes several problems and therefore should be analyzed carefully. This paper examines the dynamic response of the disc during insertion. Using Castigliano's second theorem, we analyzed the relationship between deformation and the applied forces of the MBLS at the moving contact position between the MBLS and disc. The formula used to describe this relationship also provided the corresponding design parameters of the MBLS. Disc displacement was determined using a one-factor comparative design in transient analysis. An objective function was defined as a distance of the disc to ensure complete disc insertion. The number of variables was reduced based on the objective function. Interaction among variables was investigated in a 3-full-factorial design. For the MBLS design to prevent incomplete insertion, the objective function increased by 140.4%. [ABSTRACT FROM AUTHOR]

Radiation therapy system is preferred to surgery for the most cancer because it is noninvasive. In radiotherapy, respiratory motion is an obstacle of high-precision therapy. The patient support system (PSS) is a method to compensate respiratory motion without increasing treatment time. But treatment time could not be decreased dramatically with conventional PSS because it increases duty cycle of linear accelerator (LINAC). To apply multiple LINACs, the conventional PSS is not suitable as the structure of PSS interrupt workspace of LINACs. In this study, we designed a new moving bed to apply multiple LINACs as well under the bed. A force distribution method and dynamics of the bed were identified. Rigid body simulation model was made to verify that the bed can operate well as expected. And a real size model was manufactured on a basis of the simulation model. Experiments were conducted to identify that the bed can move in desired objectives. [ABSTRACT FROM AUTHOR]

This paper analyzed the effect of lubricant contact on slider dynamics under the unsteady proximity condition, which is related to the intermolecular forces between the slider and disk. To investigate the slider dynamics, an experiment was conducted with a commercial drive, and the slider dynamics were analyzed during touch-down and takeoff (TO) considering the approach and withdrawal speeds of the slider. The instability of the slider dynamics increased under the rapid withdrawal condition during TO. [ABSTRACT FROM AUTHOR]

With an increased mobility, hard disk drives (HDDs) now use ramp load/unload technology, and multiple disks are used to increase the data capacity. This can result in contact between the ramp and the disks, which negatively affects the slider dynamics under operational shock conditions. There are several types of ramp–disk contact, such as simultaneous, successive, and single contact, and these depend on the distance between the ramp and each disk in a multi-disk HDD. This paper examines the effect of ramp–disk contact on the slider dynamics using a transient shock analysis. The ramp–disk contact affects the head stack assembly bending mode and slider dynamics. The effect of irregular gaps between the disks and adjacent ramp on the slider dynamics is analyzed with the ramp–disk contact force. The simulation shows that the gap irregularity between the ramp and each disk should be as small as possible to improve the stability of the slider dynamics. [ABSTRACT FROM AUTHOR]

Operational shock (op-shock) analysis has been developed to consider the dynamics of components of a hard disk drive (HDD). Op-shock simulation uses simplified models. However, the dynamics of the components affect the head–disk interface (HDI) response, especially the disk curvature and ramp–disk contact. This paper investigated the effect of the dynamics of HDD components on the HDI response. As the HDD is more sensitive to external shock and vibration, the effects of the dynamics of HDD components need to be considered for accurate op-shock analysis. The ramp–disk contact is an important factor in an op-shock simulation, because ramp–disk contact and disk deformation occur during the shock. Therefore, this op-shock simulation modeled the ramp–disk contact and considered the disk curvature. To obtain an accurate result, a two-way coupled method was used to investigate the HDD dynamic response during op-shock. Using the op-shock model, the fluid-structure coupling effect was investigated and compared with a decoupled model that used linear springs to replace the air bearing. Then, we investigated the effect of the ramp–disk contact and disk curvature on the HDI response during a shock. [ABSTRACT FROM AUTHOR]

With the rapid adoption of mobile computing devices, it is important to analyze and predict the anti-shock performance of hard disk drive (HDD) systems accurately. This paper proposes an advanced air-bearing surface (ABS) model for analyzing the operational shock performance of a 2.5-inch HDD system, including the ramp-disk contact behavior. First, we developed a decoupled simulation method using four linear air-bearing springs using the finite element method and the Lagrange multiplier algorithm for modeling contact between the disk and ramp. With the finite element model, the effect of the linear air-bearing stiffness was investigated. We found that the air-bearing spring model affects the behavior of the slider in the HDD system with ramp-disk contact during the operational shock. Based on the numerical results, an advanced ABS model that reflects air-bearing characteristics and considers the natural frequencies and nodal lines of the ABS pitch and roll modes was proposed and evaluated. [ABSTRACT FROM AUTHOR]