臺灣博碩士論文加值系統

近年來流體潤滑軸承在旋轉機構中的使用越來越廣泛，不過流體動壓軸承在運作過程中必會產生不穩定現象，如油漩、油顫等等，這些現象會造成軸承之間的碰撞與摩擦，使機台損壞壽命降低等後果。因此本研究將針對流體動壓軸承的不穩定現象提供最佳化方法，以磁流體代替傳統潤滑液並在外部設置海爾貝克陣列磁場，藉由磁流體在磁場下的特性提高油膜不穩定發生的頻率，使旋轉機構能避免在共振區下做運轉。
在本論文中，將成功建立一組流體動壓軸承轉子測試平台，其中以磁流體作為軸承潤滑液，並在外部設置一般環形排列磁鐵以及海爾貝克陣列磁鐵，藉由磁路和磁力大小分析觀察此兩種對於油軸承油旋、油顫等實驗之影響比較。最後由油軸承全頻譜串聯圖中觀察軸承發生油漩的穩定門檻轉速可得知，因為磁場可改變磁流體黏滯係數並提高軸承潤滑液剛度，進而提高油旋、油顫等不穩定現象發生頻率。實驗結果顯示，海爾貝克陣列磁場的效果最好，可有效將原始的油漩、油顫不穩定門檻每分鐘2940轉提高到4140轉。

Nowadays,the fluid-lubricated bearing applying in the rotating machines are very widespread. However some instability phenomenas ,such as oil whip and oil whirl, will appear when the fluid-lubricated bearing is working. These phenomenas will make bearing vibrating and decrease life of machine. Against to solve this problem, the research propose a solution to optimization the instability phenomenas. We use ferrofluid replace used lubrication,and set Halbach array magnetic field to change ferrofluid characteristic to increase the frequencies of fluid-induced self-excited vibrations. So that the rotor system can prevent working in resonance frequencies.
First, this research will build a fluid-dynamic bearing rotor test platform. Using ferrofluid as lubrication ,and set a general annular array magnetic and a Halbach array magnetic outside. Second, through observed different magnetic directions effect on oil whip and oil whirl. Finally, we can found the oil whip and oil whirl appear frequencies obviously increase by full spectrum cascade plots with Halbach array magnetic. The speed of fluid-induced self-excited vibrations is increased from 2940rpm to 4140rpm.

目錄
摘要 I
Abstract II
目錄 III
圖目錄 VI
表目錄 VIII
第一章 緒論 1
1-1前言 1
1.2研究目的 3
1.3研究重要性 3
1.4文獻回顧 4
第二章 流體動壓軸承原理及公式推導 7
2-1動壓軸承介紹 7
2.2動壓軸承基本方程式 10
2.3軸承潤滑液之雷諾方程式 14
2.3-1雷諾方程式 14
2.3-2 非牛頓流體雷諾方程式 18
2.4動壓軸承轉子不穩定 19
2.4-1 轉子不穩定簡介 19
2.4-2油漩和油顫 20
2.4-3 油軸承不穩定門檻 21
第三章 磁流體分析 25
3.1磁流體 25
3.2磁流體黏滯系數 26
3.2-1 磁力矩 L 26
3.2-2黏性力矩Lτ 26
3.2-3 磁力矩Lm 27
3.2-3合力矩 L 29
3.2-4 等速渦漩下鐵磁流體磁化強度 29
3.2-5 磁流體在磁場下之黏滯系數ηH 33
3.3 磁流體運動方程式 34
3.4磁流體的磁化方程 38
3.5 軸承內磁流體潤滑液 40
第四章 實驗平台與磁場分析 42
4.1 實驗平台架構 42
4.1-1 Bently-Nevada ADRE 108 Data Acquisition Instrument 43
4.1-2 FW-BELL 5180高斯計 44
4.1-3 油軸承設計 45
4.2 海爾貝克陣列與永久磁鐵介紹 50
4.3 分析軟體 52
4.4磁路分析結果 52
第五章 實驗數據與結論 56
5.1未加磁場軸承之觀察 56
5.2實驗結果－一般陣列磁場對對磁流體軸承之影響 58
5.3實驗結果－海爾貝克環狀磁場對對磁流體軸承之影響 60
5-3結論 62
參考文獻 64


圖目錄
圖2.1 動壓軸承作動示意圖 (a)靜止模式 (b)作動模式 10
圖2.2軸頸軸承偏心示意圖 11
圖2.3 (a)流體動壓軸承壓力分佈示意圖 (b)軸承橫向示意圖 12
圖2.4軸承內示意圖 14
圖2.5微元體壓力分析 15
圖2.6壓力曲線分布圖(沿x軸) 17
圖2.7 註解: 油漩與系統自然頻率會隨著轉子轉速上升而增加，而油顫則不會隨自然頻率而增加。 20
圖2.7 旋轉座標系統(ζ,η)與固定座標系統(X,Y) 22
圖3.1 圓柱形內磁模型(a) 靜止磁流體微型圓柱(b)具有渦漩運動磁流體微型圓柱 28
圖3.2磁流體潤滑液 41
圖4.1實驗平台示意圖 42
圖4.2 ADRE 108Data Acquisition Instrument 43
圖4.3 FW-BELL 5180高斯計 44
圖4.4 軸承頭部分工程圖 46
圖4.5 軸承中工程圖 46
圖4.6加壓薄片工程圖 47
圖4.7軸承尾部分工程圖 47
圖4.8軸承中柱工程圖 48
圖4.9軸承蓋板工程圖 48
圖4.10軸承頗面示意圖 49
圖4.11實際設計圖 49
圖4.12 海爾貝克磁場示意圖 51
圖4.13實驗磁鐵實際圖(三種不同磁力方向磁鐵) 51
圖4.14 (a)海爾貝克陣列磁鐵實際圖(b)安裝在軸承內實際圖 52
圖4.15一般形排列磁通量分布(Magnetic flux density vector) 53
圖4.16一般排列磁力線分布 54
圖14.17 海爾貝克環狀排列磁通量大小分布以及磁極方向 55
圖14.18海爾貝克環狀排列磁力線分布 55
圖5.1未加入磁場時油膜軸承之全頻串聯圖 57
圖5.2未加入磁場的油軸承頻譜圖(Spectrum Plots) 58
圖5.3一般環狀陣列磁鐵油軸承全頻串聯圖(Full Spectrum Cascade Plots) 59
圖5.4一般環狀磁場下的油軸承頻譜圖(Spectrum Plots) 60
圖5.5海爾貝克環狀陣列磁鐵油軸承 60
圖5.6海爾貝克環狀磁場下的油軸承頻譜圖(Spectrum Plots) 61
表目錄
表2.1 壓力曲線圖分析 17
表3-1 油基磁流體性質 40
表4-1 此為FW-BELL 5180高斯計規格表 44
表5-1不同環狀磁場影響油軸承之數值 61

參考文獻
[1]Oscar, Pinkus, “The Reynolds centennial: a brief history of the theory of hydrodynamic lubrication” Transactions of the ASME, Journal of Tribology, Vol.109, pp.2-20, 1987.
[2]Sami Naïmi, Mnaouar Chouchane &; Jean-Louis Ligier “Steady state analysis of a hydrodynamic short bearing supplied with a circumferential groove” Comptes Rendus Mécanique , Vol.338, Issue 6, pp.338-349, June 2010.
[3]J. H. Vohr &; C. Y. Chow, “Characteristics of Herringbone-Grooved Gas-Lubrication Journal Bearings” Transactions of the ASME: Journal of Basic Engineering Technology, pp.568-578, 1965.
[4]Nobuy shi Kawabata, Yasumi Ozawa, Shuji Kamaya and Yutaka Miyake, “Static Characteristics of the Regular and Reversible Rotation Type Herringbone Grooved Journal Bearing” Transactions of the ASME：Journal of Tribology, Vol.111, pp.484-490, 1989.
[5]哈爾濱理工大學 機械設計http://jpk.hrbust.edu.cn/jxsj/第十七章%20%20滑動軸承1.htm
[6]磁流體應用http://www.iaa.ncku.edu.tw/~cywen/labs/sciedu/ferrofluid/application.html
[7]M.I. Shliomis, “Magnetic fluids” Soviet Phys Uspekhi, 17 (2) (1974) 153– 169.
[8]B. U. Felderhof, “Magnet to viscosity and relaxation in ferrofuids” Physical review, Vol.62, No.3, 2000.
[9]Joseph L. Neuringer &; Ronald E. Rosensweig, “Ferro hydrodynamics” Phys. Fluids 7, 1927 (1964)
[10]Ferrohydrodynamics (1985), Ronald. E. Rosensweig. The usual starting reference for learning the details of ferrofluids
[11]A. Muszynska, “Rotor dynamics” CRC Taylor &; Francis Group, 2005.
[12]D.E. Bently, “The death of whirl and whip” Bently Nevada Corporation ORBIT, pp.42–46, 2001.
[13]D.E. Bently, C.T. Hatch, R. Jesse and J. Whiteley, “Dynamic stiffness inwhirl and whip” Bently Nevada Corporation ORBIT, pp.4–9, 1998.
[14]D.E. Bently and C.T. Hatch, “Fundamentals of Rotating Machinery Diagnostics” Bently Pressurized Bearing Company, 2002.
[15]Petchenve A.,Goldman P, Muszynska A., “Torque And Power Loss in a Cylindrical Fulid- Lubricated earing/Rotor System” 96-GT-408,IGTI/ASME TURBO EXPO, Birmingham, UK, pp.1-6, 1996.
[16]Petchenve ,A., Bently, D.E., Goldman, P., Muszynska, A. “Analytical Study on the Fulid Journal Bearing/Seal/Rotor System” The Joint ASME &; JSME Fulids Engineering Annual Conference, Hilton Head Isl.SC, FED-Vol.207, p33-38, 1995.
[17]Chi Changqing“Ferrofluid Lubricated Journal Bearing in Uniform Magnetic Field” Journal of Aerospace Power, 15(2), pp.174-178, 2000
[18]Chi Changqing, “On performance of Ferrofluid Lubrica-ted Plane Slider in Uniform Magnetic Field” Journal of Beijing University of Aeronautics and Astronautics, 27(1), pp.93-96, 2001.
[19]Chi Changqing, “Non-Newtonian Effects on Ferrofluid Lubrication” Journal of Beijing University of Aeronautics and Astronautics, 27(1), pp.88-92, 2001．
[20]C.C. Fan and M.C. Pan, “Fluid-induced instability elimination frotor-bearing system with an electromagnetic exciter” International Journal of Mechanical Sciences, Vol.52, pp.581-589, 2010.
[21]C.C. Fan and M.C. Pan, “Experimental study on the whip elimination of rotor-bearing systems with electromagnetic exciters” Mechanism and Machine Theory, Vol.46, pp.290-304, 2011.
[22]陳廷宇 Magnetic Field Analysis and Stability of a Hydrodynamic Journal Bearing System Lubricated with Ferrofluid中原大學碩士論文 2014
[23]K. Halbach (1980). "Design of permanent multipole magnets with oriented rare earth cobalt material". Nuclear Instruments and Methods 169 (1): 1–10.
[24]Sarwar, A. Nemirovski and B. Shapiro (2012). "Optimal Halbach permanent magnet designs for maximally pulling and pushing nanoparticles". Journal of Magnetism and Magnetic Materials 324 (5): 742–754.
[25]電工技術學報(Transactions of China Electrotechnical Society) 2014年11月第29卷第11期Halbach永磁陣列磁場解析求解及推力建模 宋玉晶 張鳴 朱煜