笔记本电脑的硬盘及扬声器装置的减振优化设计及应用
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2. Analysis of structurally transmitted
HDD vibrations in Notebook PC
Fig. 3 FE model of the notebook PC
Fig. 4 FE model of the internal components
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2. Analysis of structurally transmitted
HDD vibrations in Notebook PC
c. HDD vibrations induced by CD-ROM in Notebook PC
Fig. 14 Simulated HDD vibration excited by CD-ROM in the notebook PC
The first dominant response is at the frequency of speaker excitation, and the amplitudes of the responses of chassis and HDD are decreased gradually due to the vibration energy dissipation along the transmission routes.
Fig. 6 The experimental out of plane vibration frequency response at the speaker rim
The experimental out-of-plane vibration frequency response at the speaker rim, subjected to a sweep sinusoidal current i=i0sin(2πft), is used as the excitation input in the FEM vibration analysis.
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目录
1. 序言 2. 笔记本电脑结构振动模型及分析 a. 扬声器引起的硬盘振动 b. CPU冷却风扇引起的硬盘振动 c. 光驱引起的硬盘振动 3. 笔记本电脑振动传播路径及阻尼分析 4. 机架结构设计及部件装置方法 5. 不同装置下硬盘性能试验结果 6. 结论 7. 参考文献
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结论
1) 本文应用有限元方法和理论模型研究了笔记本电脑中的内置振动源 包括扬声器,CPU冷却风扇和光驱引起的硬盘振动特性, 以及笔记 本电脑中的结构振动传播特性。研究发现,当频率大于1000赫兹时, 硬盘振动主要是由扬声器引起来的。 2) 良好的硬盘伺服系统设计可消减硬盘的低频区振动,但是高频振动 很难通过伺服控制来减少。为消减大于1000赫兹的高频振动对硬盘 性能的不利影响,通过适当的机架结构和装置设计来降低由内置振 动源引起的激励显得尤为重要。 3) 应用本文所示的柔性扬声器装置和柔性硬盘装置可以有效地消减扬 声器引起来的大于500赫兹的硬盘振动。 4) 低刚度高阻尼的机架设计以及将扬声器远离硬盘的装置有利于减少 大于1000赫兹的硬盘振动。但是,柔性装置和低刚度机架设计可能 引起低频振动增加。相反,过高刚度的机架设计,在大于1000赫兹 的振动区,可能有相反的效果。 5) 柔性硬盘装置的共振频率应该远离风扇和光驱的谐波频率,特别是 在频率低于200赫兹的tructurally transmitted
HDD vibrations in Notebook PC
c. HDD vibrations induced by CD-ROM in Notebook PC
Measurement for CD-ROM Drive (Hitachi-LG GT33N)
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2. Analysis of structurally transmitted
HDD vibrations in Notebook PC
a. HDD vibrations induced by speakers in Notebook PC
Fig. 7 Simulated displacement responses of speaker, chassis and HDD excited by speaker A
Fig. 13 The experimental out of plane vibration frequency response at the CD-ROM drive Fig. 12 Experimental setup of the vibrations measurements of CD-ROM drive using LDV
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1. Introduction
The Hard Disk Drive (HDD) [1~3] in notebook PCs [4~5] are expected to be robust enough to ensure the diversification of the operating environment. Oscillating force induced by the built-in components such as speakers, fans and CD-ROM in notebook PC, could be transmitted to the HDD via chassis, and therefore cause position error signal (PES) of HDD. Previous Study: 1. S. Lim et al. (2006, rubber mounts in notebook , analysis & experimental) [6]; 2. Y. Matsuda et al. (2009, design, flexible support mechanism for HDDs mounted in PC, fabrication & evaluation)[7]; 3. T. Semba, et al. (2009, adaptive cancellation method for vibrations of soft mounting HDDs in notebook PC)[8]; 4. Y. Y. Hu et al. and our team , (2009, built-in speaker induced structuralacoustic vibration of hard disk drives in Notebook PCs, analysis & testing )[10]; Comprehensive study on reduction of HDD vibration by good chassis design and components mounting has yet to be reported.
1. 2. The first dominant response of HDD vibration is at the frequency 76 Hz corresponding to the rotational speed of fan. The HDD vibration is mainly attributed to the low order harmonics of the fan vibration at frequencies below 1000 Hz.
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2. Analysis of structurally transmitted
HDD vibrations in Notebook PC
Fig. 1 Interior view of a notebook PC
Fig. 2 CAD model of the notebook PC
CAD model of a commercial notebook PC is developed and imported into the ANSYS software.
笔记本电脑的硬盘及扬声器装置的 减振优化设计及应用
(HDD & Speaker Mounting Optimization for Vibration Reduction in Notebook Computers)
Oct. 2012
数据存储研究院(新加坡)
A*Star Data Storage Institute (Singapore)
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2. Analysis of structurally transmitted
HDD vibrations in Notebook PC
a. HDD vibrations induced by speakers in Notebook PC
Fig. 8 Simulated HDD vibration excited by speaker A and B respectively
A finite-element-method (FEM) model of a commercial notebook PC is developed, consisting of the chassis, HDD, built-in speakers , fans, CD-ROM and other key components. The FEM model has been validated in [10] by comparing simulation results with experimental results.
HDD vibrations in Notebook PC
b. HDD vibrations induced by fans in Notebook PC
Measurement for fan (ADDA AD06705HX)
Fig. 10 The experimental out-of-plane vibration frequency response of cooling fan Fig. 9 Experimental setup of the vibrations measurements of fan using LDV