共查询到20条相似文献,搜索用时 140 毫秒
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针对于微硬盘驱动器斜坡加载/卸载(Load/Unload)过程,对微硬盘的磁头/盘界面及磁头悬臂与支承件接触面的摩擦学及动力学特性进行建模,对加载及卸载过程中的浮动块、悬臂的动态特性和斜坡与提升臂的接触特性进行了仿真,分析了加载与卸载速度及斜坡倾角对斜坡与提升臂的接触变形与接触力及接触面间的摩擦能耗特性的影响。研究结果表明,加载及卸载速度的增加将导致斜坡接触面上的接触力及摩擦力的增大,增大斜坡倾角将使接触面摩擦能量损耗增加。研究结果对微硬盘磁头/盘界面的改进和加载/卸载技术的进一步应用提供依据。 相似文献
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提出和发展了适用于液体(水)环境的光热微驱动技术及光热微驱动机构(OTMA).建立了水环境中OTMA膨胀臂在激光照射下的光热膨胀模型,基于有限元分析推导出膨胀臂的温升分布公式,并对长度1080μm、宽度90μm的膨胀臂在4 mW激光照射下的温升分布进行了仿真,理论研究表明了液体环境中光热微驱动技术的可行性.设计与微加工制作了一种对称型OTMA,在波长520 nm、功率可调的激光照射下,首次实现了液体环境中的光热微驱动,实验结果表明膨胀臂的光热偏转量随激光功率的增大而增加.进一步开展了在波长520 nm、有效功率4 mW、频率可调的激光脉冲照射下的光热微驱动实验,结果表明,对称型OTMA在频率0.9 Hz~16.4 Hz的激光脉冲照射下具有良好的动态响应,驱动量(偏转量)振幅在2.6μm~3.7μm之间变化,随激光脉冲频率的增大而减小.理论研究及实验曲线趋势表明,适当增大激光功率、提高激光脉冲频率,在液体环境中实现更大偏转量、更高频率的光热微驱动是完全可行的.本文研究拓展了液体环境中的光热微驱动技术,为微光机电系统及微纳米技术领域的应用提供了新的方法与途径. 相似文献
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当硬盘驱动器的磁头飞高降至5nm以下时,磁头与磁盘间的分子间作用力不能忽略.以皮米磁头和飞米磁头为模型,模拟了分子间作用力对飞高低于5nm的磁头总承载力的影响.模拟结果表明,分子间作用力改变了飞高低于5nm的磁头承载特性.分子间吸引力使总承载力减小,甚至出现负值,以致使磁头失去承载能力.当飞高进一步降低时,分子间斥力的作用显现出来.由于分子间引力和斥力的作用范围不同,磁头有一段失去承载能力的临界飞高区间.磁头的尺寸因子不同,临界飞高区间也有差别. 相似文献
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根据市场需求,提出了一套高精度 Maxtor 磁头动态性能测试系统的方案. 设计了系统的架构和硬件部分,并使用 OO、UML 和 COM 组件、NET 等技术对其软件部分进行了开发. 通过调用 Maxtor 公司提供的组件包 MACH,完成了对所设计硬件部分的底层控制电路和机械设备的控制与协调. 在系统测试阶段,通过大量的实际环境测试证明了该方案是有效的. 相似文献
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硬盘工作时,磁头滑块飞行在磁盘上方,其动态飞行特性对硬盘工作性能有重要影响。该文利用摄动法推导了磁头滑块的气膜刚度和阻尼摄动方程,且通过有限体积法进行求解,获得了初始摄动条件下的气膜刚度和阻尼矩阵。结合磁头滑块动力学方程,研究了扰动速度、扰动俯仰角和扰动侧倾角对磁头滑块动态飞行特性的影响。研究结果表明:①扰动速度会导致磁头滑块向磁盘表面作竖直方向的移动,增加了与磁盘接触碰撞的风险;②扰动俯仰角或侧倾角的增加都会导致磁头滑块振动幅度的增加,但扰动俯仰角更容易引起磁头滑块的振动。 相似文献
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针对不同电压载荷情况下介电弹性体驱动单元的动态特性,考虑材料非线性、介电常数变化和惯性效应等因素的影响,从热力学能量转化的角度得到了基于Ogden应变能函数的介电弹性体驱动单元的二阶常微分运动方程,并分析了系统的动态响应及模型几何尺寸的影响。结果表明:介电弹性体驱动单元动态响应的振幅由电场强度决定。在恒定场强下,随着电场强度幅值的增大,驱动单元的振幅将随之增大、振动频率将随之减小;在简谐场强下,随着电场强度频率的增大,驱动单元将发生共振,且共振频率将随电场强度的增大而减小。 相似文献
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A finite element model (FEM) of the ST drive from Seagate is developed in ANSYS to investigate the shock response of the hard disk drive (HDD). The FEM includes the pivot bearing, the head stack assembly (HSA) and the disk. The free state of the HSA is determined by an iterative procedure to produce the prescribed preloading force at the head–disk interface. The FE model is then verified by conducting a modal analysis over the HSA. The obtained mode shapes and resonant frequencies are compared with the modal testing results. An acceleration pulse is applied to the shaft and the whole disk surface at the same time to study the shock response of the HDD. The head slap behavior is examined at the slider–disk interface. The effect of the pulse width on the head slap behavior is studied. The duration of the acceleration pulse varies from 0.3 to 1 ms. It is found that the lift-up height of the slider reaches a peak value at different pulse widths when the amplitude of acceleration pulse changes. This is due to the nonlinear behavior introduced by the contact surfaces. 相似文献
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Wei-Hsin Liao Kwong Wah Chan 《IEEE transactions on magnetics》2008,44(4):525-532
Current dual-stage actuator design uses piezoelectric patches only, without passive damping. In this paper, we propose a dual-stage servo system using enhanced active-passive hybrid piezoelectric actuators. Because they incorporate passive damping, the proposed actuators will improve the existing dual-stage actuators, giving them higher precision and better shock resistance. We report finite-element analyses of different types of piezoelectric actuators in a disk arm assembly under external shock and vibration. We modeled the viscoelastic damping layers in the hybrid actuators with the Prony series, whose parameters we determined from the dynamic frequency data of a nomograph. In the analyses, a shock impulse (175 g, 1 ms half sine) and a vibration impulse (350 g and 1 ms full sine) are applied at one end of the base, while the other end of the base is fixed. We evaluated and compared the responses of the disk arm assembly with different configurations of the piezoelectric actuators. The simulation results show that the enhanced active-passive hybrid actuator design would reduce the residual in-plane vibration induced during the shock, resist liftoff motion, and reduce the impact damage when the head slaps. 相似文献
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Bao-Jun Shi Dong-Wei Shu Shao Wang Jun Luo Hui Meng Quock Ng Joseph H.T. Lau Razman Zambri 《International Journal of Impact Engineering》2007
This work aims to develop a method for predicting the displacement and failure of the Head Actuator Assembly (HAA) during a drop test. When a Hard Disk Drive (HDD) is dropped from a certain height, it will accelerate due to gravity until it hits the ground with a certain speed, and the head suspension system may lift off the disk and land onto it in a very short time. The impact during the head slap often leads to failure of the HAA. The pivot-bearing stiffness is a very important factor for the dynamic behavior of the HAA during a drop test. A simplified beam model with a torsional spring and a translational spring located at the end of the arm has been developed to analyze the effects of the pivot-bearing stiffness on the dynamic response of the arm in the present paper. Moreover, to further investigate a pseudo-resonance phenomenon observed by the authors in a previous work, three types of acceleration shocks different in pulse shapes (half-sine, triangular, and dual-quadratic acceleration pulses) were selected as input loadings. Dynamic analyses of the actuator arm subjected to these loadings were carried out. Numerical results show that a pseudo-resonance phenomenon occurs for the maximum relative displacement, but at different pulse widths for these different acceleration shocks. Power spectrum analyses were implemented for these different acceleration shocks. An explanation is given in terms of the acceleration power at the resonant frequency of the arm. A corollary has been derived based on a theorem developed previously by the authors. A prediction is made by the corollary and confirmed by numerical results. 相似文献
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Impact forces of an actuator arm of a hard disk drive (HDD) are measured by means of modifying the levitation mass method (LMM) whose basic concept was proposed by the first author. In the LMM, force is measured as the inertial force of a mass levitated with sufficiently small friction using an aerostatic linear bearing. The Doppler frequency shift of the laser beam reflecting from the mass is accurately calculated from the waveform recorded using a digitizer. The velocity, the position, the acceleration and the inertial force of the mass are calculated from the measured time-varying Doppler frequency shift. In the experiments, the mechanical response of an actuator arm of a HDD against an impact load and the inertial force of the actuator arm in free oscillation are measured. The importance and the problems concerning the present knowledge on the impact force of an actuator arm of a HDD are also discussed. 相似文献
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Sheng Zeng Rong-Ming Lin Li-Mei Xu 《IEEE transactions on magnetics》2001,37(3):1146-1156
Track access time is an important parameter for high-performance hard disk drives (HDDs). Presently, the resonances of the head actuator caused by the pivot-bearing stiffness are an even more urgent problem, since these resonances have become the main design factor that limits further reduction of track access time and improvement of the servo control bandwidth in HDDs. Our objective in this paper is to investigate, from a mechanics and dynamics viewpoint, the influence of the driving force waveforms on residual vibrations and to identify the characteristics of the waveform, which will lead to zero or very low residual vibrations. Using a simplified model of a head actuator assembly and finite-element simulation, we show that the residual vibration of the head actuator assembly depends strongly on the waveform and the time duration of the driving impulse force. If suitable waveform and time duration of the seeking impulse force are appropriately chosen, very low track seeking residual vibrations and quick track access can be achieved 相似文献
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《IEEE transactions on magnetics》2009,45(12):5344-5351
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Design concepts of the mechanical and servo system of a newly-developed compact disk drive are discussed. This new drive features 10 inch diameter disks with a capacity above 400 Mega-bytes. The mechanical structure, with its own closed self-circulating air system , is designed to minimize thermal offtrack and undesired vibration. A new rotary type head actuator is accommodated, and servo system design is based on an optimal control theory to achieve fast, precise positioning. 相似文献