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博碩士論文 etd-0912112-130547 詳細資訊
Title page for etd-0912112-130547
論文名稱
Title
潤滑油缺乏之預測與其對潤滑特性之影響
Prediction of lubrication starvation and its effect on the lubricating characteristics
系所名稱
Department
畢業學年期
Year, semester
語文別
Language
學位類別
Degree
頁數
Number of pages
77
研究生
Author
指導教授
Advisor
召集委員
Convenor
口試委員
Advisory Committee
口試日期
Date of Exam
2012-07-28
繳交日期
Date of Submission
2012-09-12
關鍵字
Keywords
液體凹凸面、缺油、過浸沒、供油量、表面張力
starved, meniscus, over-flooded, supply flow rate, surface tension
統計
Statistics
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The thesis/dissertation has been browsed 5644 times, has been downloaded 910 times.
中文摘要
  潤滑油流經赫茲接觸區後,會回到軌道進口端與側面當作儲油,藉由表面張力及固體表面速度驅動進入供油區而形成黏附層油膜,在自由表面流動下此黏附層油膜將維持與固體表面一樣之流速,因此亦可視為固定流量條件。在缺油與固定流量條件下,油膜流入赫茲接觸壓力區之前,因受到表面張力作用而使油膜產生向上攀升之幾何形狀,即俗稱液體凹凸面,此凹凸面內部之壓力略小於大氣壓力。
  藉由理論分析並與實驗結果比較,推導出一黏附層油膜厚度之經驗公式,其與供油區進口端之油膜厚度以及潤滑油與空氣界面間之表面張力成正比,與潤滑油之黏度和固體表面速度成反比。此外,藉由理論分析建立缺油區、完全浸沒區與過浸沒區之模型,結果發現在缺油與固定流量條件下,持續增加供油量,流入壓力區之潤滑油膜逐漸增加,而赫茲接觸壓力區進口油池範圍逐漸變大且往上游移動。因此缺油與否,與供油流量率是否超過完全浸沒區之流量率有關,而供油流量率則與操作條件有關。當供油流量率超過完全浸沒區之流量率的98%,壓力區中央油膜厚度隨供油流量率增加而趨近於飽和值,稱為完全浸沒。當供油流量率超過完全浸沒區之流量率,將無法提升壓力區中央油膜厚度,多餘的流量率將堆積於壓力區進口端,隨時間之增加,壓力區進口端油膜厚度亦逐漸增加,稱為過浸沒。
Abstract
Excess lubricant can be found as reservoirs on the sides of the rolling tracks when the oil flows through the Hertzian contact and the side leakage. Uniform lubricant layers adhered to both rolling surfaces can flow into the supply region by the action of surface tension. Uniform lubricant layers are separated by air so that they move with the surfaces the surface tension of the liquid-air interface and the velocity of the roller. Hence, it can be considered as the fixed flow rate conditions. Under the lubricant starvation and the fixed flow rate conditions, the meniscus in the film inlet is formed due to the action of the surface tension of the oil-air interface, where the fluid pressure in the oil layer is smaller than the ambient pressure.
An empirical formula to predict the thickness of the oil layer is derived based on the theoretical analysis and the experimental results of Cann et al. [10]. Results show that this thickness increases the amount of oil in the track and the surface tension of the liquid-air interface, but it decreases with the surface velocity and the oil viscosity. Moreover, the starved, fully flooded, over-flooded regimes are established based on the theoretical analysis. Under the lubricant starvation and the fixed flow rate conditions, the central film thickness in the pressure region increases with increasing the supply flow rate, so that the location of the meniscus moves to upstream. When the supply flow rate is more than 98% flow rate of fully flooded condition, the central film thickness achieves a saturated value. Hence, when the supply flow rate is between 98% and 100% flow rate of fully flooded condition, it is called the fully flooded regime. When the supply flow rate is more than the flow rate of fully flooded condition, the central film thickness remains constant, and the excess oil accumulates in the inlet region, so that the film thickness in the inlet region increases with time. When the supply flow rate is larger than the flow rate of fully flooded condition, it is called the over-flooded region.
目次 Table of Contents
論文審定書 i
誌謝 ii
中文摘要 iii
英文摘要 iv
目錄 vi
圖次 viii
表次 xi
符號說明 xii
第一章 緒論 1
1.1 研究動機 1
1.2 文獻回顧 2
1.3 論文架構 9
第二章 理論分析與數值方法 10
2.1 供油區薄油膜流動之理論模型-固定流量率 10
2.2 供油區數值方法 14
2.3 供油區進口端為固定高度之理論模型與數值方法 16
2.4 壓力區理論模型與數值方法 22
第三章 結果與討論 24
3.1 供油區薄膜油流動之不同供油量影響 24
3.2 供油區薄油膜流動之不同表面張力影響 29
3.3 供油區進口端為固定高度之不同參數影響 31
3.4 黏附層厚度之預測公式 37
3.5 壓力區點接觸進口端位置之影響 39
3.6 壓力區點接觸不同參數之影響 42
第四章 結論與未來展望 47
參考文獻 49
附錄 51
1. 線接觸之壓力區理論分析 51
2. 線接觸之壓力區數值方法 54
3. 點接觸之壓力區理論分析 57
4. 點接觸之壓力區數值方法 60
參考文獻 References
[1] Wedeven, L.D., Evans, D., Cameron, A., Optical analysis of ball bearing starvation, Trans. ASME, J. Lub. Tech. 93 (1972) 199-210.

[2] Chiu, Y.P., An analysis and prediction of lubricant film starvation in rolling contact systems, Trans. ASLE 17 (1974) 22-35.

[3] Hamrock, B. J., Dowson, D., Isothermal elastohydrodynamic lubrication of point contacts, Part I, Theoretical Formulation, ASME J. Lubr. Technol. 98 (1976) 223-229.

[4] Bayada, G., Chambat, M., El Alaoui, M., Variational formulations and finite element algorithms for cavitation problems, ASME J. Tribol. 112 (1990) 398-403.

[5] Elrod, H.G., A cavitation algorithm, ASME J. Lubr. Technol. 103 (1981) 350- 354.

[6] Chevalier, F., Lubrecht, A.A., Cann, P.M.E., Colin, F., Dalmaz, G., Film thickness in starved EHL point contacts, ASME J. Tribol. 120 (1998) 234-242.

[7] Venner, C.H., Berger, G. and Lugt, P.M., Waviness deformation in starved EHL circular contacts, Trans. ASME, J. of Tribol. 126 (2004) 248-257.

[8] Dumont, M. L., Lugt, P. M., and Tripp, J. H., Surface feature effects in starved circular EHL contacts, ASME J. Tribol. in press, (2002).

[9] Wijnant ,Y.H.,Contact dynamics in the field of elastohydrodynamic lubriction, Univ. of Twente , Ph.D-thesis, Enschede , the Netherlands,(1998).

[10] Cann, P.M.E., Damiens, B., Lubrecht, A.A.,The transition between fully flooded and starved regimes in EHL. Tribol. Int.37 (2004) 859–864.

[11] 鄞 茂 捷,“線接觸彈液動潤滑之潤滑油膜缺乏預測模型研究”,國立中山 大學機械與機電工程研究所碩士論文(2011).

[12] Hayes , M., O'Brien , S. B.G., Lammers,J.H., Green's function for steady flow over a small two-dimensional topography,Phys.Fluids,12 (2000) 845-2858.

[13] Wilson,S.D.R.,The drag-out problem in film coating theory, J.Engg.Math. 16 (1982) 209-221.

[14] Schlichting ,H., Boundary-Layer Theory,狀元出版社, 1979, 廖燦景, 90-91.

[15] 許昭和,“高等複層法解熱彈液動潤滑問題”, 國立中山大學機械與機電工 程研究所碩士論文 (1994) .

[16] Gao , C., Tian , X., Bhushan , B., A meniscus model for optimization of texturing and lubrication of magenetic thin-film rigid disks, 38 (1995) 201-212.
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