發(fā)布時間：2018-04-11 03:34

  本文選題：接觸力學 + 凸度設計�。� 參考：《北京化工大學》2011年碩士論文

【摘要】：要加快我國石油天然氣的勘探開發(fā)速度,提高鉆井工程技術(shù)的國際競爭能力,提高鉆頭尤其是牙輪鉆頭的工作性能和工作壽命十分重要�，F(xiàn)階段應綜合應用接觸力學、潤滑理論等學科的知識,對滾子凸度設計、空心圓柱滾子及其潤滑狀態(tài)等關(guān)鍵問題進行深入研究,進而研制開發(fā)長壽命、高轉(zhuǎn)速的滾動軸承牙輪鉆頭。 本文首先針對Hertz點接觸問題的求解方法進行了研究,得到了關(guān)于點接觸問題精確高效的完全數(shù)值算法；從計算速度、計算精度和計算方便性等方面對幾種典型算法進行了對比研究,得出了各算法在不同條件下的適用情況；并將完全數(shù)值算法應用于牙輪鉆頭滾動軸承中的全圓弧凸型滾子,分析了其接觸參數(shù)在不同條件下的變化。然后,采用MSC.Marc有限元軟件對迄今常見代表性凸型滾子的應力分布規(guī)律和特點進行了分析,提出采用多段變曲率圓弧組合替代Lundberg理論對數(shù)凸型的工程化模擬技術(shù),給出了較為合理的圓弧組合數(shù)目；分析了空心圓柱滾子及其進行凹端處理后的應力分布規(guī)律。結(jié)果表明,合理的空心度可減小接觸應力的邊緣效應,但等效應力在滾子兩端的應力集中始終存在；在相同空心度下,等效應力和接觸應力隨載荷的變化規(guī)律不同；且不同載荷作用下,最佳空心度的理論值不同；空心度較大時,滾子內(nèi)壁等效應力會超過外壁成為危險區(qū)域,同時應考慮彎曲應力的影響,避免滾子內(nèi)壁發(fā)生彎曲疲勞斷裂；較之普通空心滾子,凹端空心圓柱滾子有效克服了滾子端部的應力集中現(xiàn)象。最后,采用多重網(wǎng)格法對牙輪鉆頭實心圓柱滾子和空心圓柱滾子的彈流潤滑情況進行了分析,通過對無限長滾子線接觸彈流潤滑問題的研究,揭示了實心圓柱滾子油膜壓力和膜厚隨載荷參數(shù)、速度參數(shù)和材料參數(shù)的變化規(guī)律；空心圓柱滾子空心度的變化會引起速度參數(shù)和載荷參數(shù)的變化,但并沒有引起接觸區(qū)域中部油膜厚度以及最小膜厚的明顯變化；空心度的增加可以降低油膜壓力,但合理空心度的選取應考慮其對滾子內(nèi)壁應力分布的影響。有限長線接觸彈流潤滑中最大油膜壓力和最小膜厚都位于滾子端部,故滾子端部為易破壞部位；滾子中部潤滑狀況與無限長滾子幾乎一致,可按無限長處理；空心度對滾子端部潤滑情況的影響與中部相同,由于端部油膜壓力大于中部,故二次峰值和最小油膜厚度較之中部都更靠近出口區(qū)。 本文的研究成果為國內(nèi)自主實現(xiàn)滾動軸承牙輪鉆頭的長壽命和高轉(zhuǎn)速化,乃至為工程實際中廣泛存在的重載低速滾子軸承系統(tǒng)工作性能的提高奠定了堅實基礎,同時也值得標準或通用滾子軸承、鐵路機車、冶金軋機等行業(yè)的研究人員借鑒。
[Abstract]:It is very important to speed up the exploration and development of petroleum and natural gas in China, to improve the international competitiveness of drilling engineering technology, and to improve the working performance and service life of bit, especially the cone bit.At this stage, the key problems such as roller crown design, hollow cylindrical roller and its lubrication state should be thoroughly studied by applying the knowledge of contact mechanics, lubrication theory and so on, and the long life of the roller should be researched and developed.High speed roller bit for rolling bearing.In this paper, the method of solving the point contact problem of Hertz is studied, and the exact and efficient complete numerical algorithm for the point contact problem is obtained.Several typical algorithms are compared and studied in terms of calculation accuracy and calculation convenience, and the application of each algorithm under different conditions is obtained, and the complete numerical algorithm is applied to the full arc convex roller in roller bearing of cone bit.The change of contact parameters under different conditions was analyzed.Then, the stress distribution law and characteristics of typical convex roller are analyzed by using MSC.Marc finite element software, and the engineering simulation technology is put forward to replace the logarithmic convex type of Lundberg theory with multi-segment variable curvature circular arc combination.A reasonable number of arc combinations is given and the stress distribution of hollow cylindrical rollers and their concave ends are analyzed.The results show that reasonable hollow degree can reduce the edge effect of contact stress, but the stress concentration of equivalent stress always exists at both ends of roller, and under the same hollow degree, the variation law of equivalent stress and contact stress with load is different.Under different loads, the theoretical values of the optimum hollow degree are different. When the hollow degree is large, the equivalent stress of the inner wall of the roller will exceed the outer wall and become a dangerous area. At the same time, the influence of bending stress should be considered to avoid the bending fatigue fracture of the inner wall of the roller.Compared with common hollow roller, hollow cylindrical roller at concave end overcomes the stress concentration phenomenon at the end of roller effectively.Finally, the elastohydrodynamic lubrication of solid cylindrical roller and hollow cylindrical roller of cone bit is analyzed by using multi-mesh method.The variation of oil film pressure and film thickness with load parameter, velocity parameter and material parameter are revealed, the change of hollow degree of hollow cylinder roller will cause the change of velocity parameter and load parameter.However, the oil film thickness and the minimum film thickness in the middle of the contact area are not changed obviously, and the increase of the hollow degree can reduce the oil film pressure, but the reasonable selection of the hollow degree should consider its influence on the stress distribution of the inner wall of the roller.The maximum oil film pressure and the minimum film thickness are located at the end of the roller, so the tip of the roller is easily destroyed, and the lubrication condition of the middle part of the roller is almost the same as that of the infinite length roller, which can be treated as infinite length.The effect of the hollow degree on the lubrication of the end part of the roller is the same as that of the middle part. Because the oil film pressure at the end part is larger than that in the middle part, the secondary peak value and the minimum oil film thickness are both closer to the outlet region than the middle part.The research results of this paper have laid a solid foundation for the independent realization of long life and high speed of roller bit in China, and even for the improvement of the working performance of heavy load low speed roller bearing system, which is widely existed in engineering practice.At the same time, it is also worth standard or universal roller bearings, railway locomotives, metallurgical mills and other industries for reference.
【學位授予單位】：北京化工大學
【學位級別】：碩士
【學位授予年份】：2011
【分類號】：TH133.33

【參考文獻】

相關(guān)期刊論文 前10條

1 萬長森;滾動軸承設計應用和試驗分析的有關(guān)程序(一)[J];軸承;1983年06期

2 馬家駒,徐文,劉雙表,王晨;對數(shù)滾子的工程設計[J];軸承;1997年06期

3 陳家慶 ,毛紅兵 ,張寶生;無預載荷空心圓柱滾子軸承的理論研究[J];軸承;2002年06期

4 高作斌,丁海善;滾子凸度加工技術(shù)現(xiàn)狀及發(fā)展趨勢[J];軸承;2003年08期

5 魏延剛,馬文;圓柱滾子軸承滾子凸度量的有限元分析[J];軸承;2004年04期

6 陳家慶;任偉;邱宗義;;軸承滾子凸度設計可視化軟件的開發(fā)[J];軸承;2006年06期

7 柴俊峰;賈現(xiàn)召;李濟順;;高速鐵路客車軸承滾子凸度量的有限元分析[J];哈爾濱軸承;2008年04期

8 陳曉陽;修形滾子凸型對潤滑油膜的影響[J];機械設計與研究;1996年02期

9 葛宰林,董美云,張秀娟;圓柱滾子軸承的圓柱深孔滾子受力分析[J];機械設計;2003年07期

10 魏延剛;無預負荷空心圓柱滾子軸承空心度的優(yōu)化設計[J];機械設計;2003年11期

，

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