高速牙轮钻头密封研究
摘要
牙轮钻头在井底破岩中起着主导作用，它的使用寿命几乎直接取决于钻头轴承的寿命，而轴承的寿命在很大程度上有依赖密封的寿命。牙轮钻头目前的发展趋势是实现高速化，随着钻头转速的不断提高，在恶劣环境下工作的普通轴承密封这一环节的薄弱性将显得越来越突出。因此，在研究钻头的同时，决不可忽视对轴承寿命的研究和改进。
为了提高牙轮钻头轴承密封的可靠性，本文设计采用端面-径向组合密封结构，即在一只钻头中同时布置端面和径向密封，采用非线性有限元方法对密封结构进行分析和优化。碟形密封圈属于端面密封元件，依靠一定的轴向压缩量进行密封，由于端面内压力分布、温度分布不均，端面内的摩擦状况也不是处处相同。为改善碟形圈外径与牙轮的摩擦工况，更好地防止泥浆等有害物质的侵入，可将其外径略向上弯曲，弯边的长度及开口数可由实际工况的模拟来确定。改进的碟形密封圈不但具有端面密封能力，而且将具有一定的径向密封和擦拭功能。
最常用的钻头轴承密封圈是单个O形圈，主要以丁腈橡胶制作。它与低速密封轴承钻头已基本匹配，但其失效不可避免。为此，普通矩形槽密封被尝试着改为具有一定弧度的弧形槽，当径向密封作用的O形圈被置于设计合理的弧形槽内，其受力、变形和摩擦状况均得到改善，有助于
密封寿命的提;锐
有限元法对结构的分析和设计具有指导意义。通过矩形槽和弧形槽
的对比研究发现，矩形槽O形圈在密封过程中出现两个高应力区，磨损
发生在内径、外径两个表面_匕，弧形槽O形圈的高应力区仅出现在牙爪
轴邻近的局部区域内，应力分布较前者更为均匀，磨损进发生在内径表面
，其受力变形状况的改善将使密封寿命进一步提高。
本文的研究表明，在伟l]约钻头寿命的轴承密封润滑系统中，采用端
面一径向组合密封结构能够在一定程度上适应牙轮钻头转速提高的发展趋
The service life of cone bits which play an important role in breaking rock of the bottom of a well is almost directly decided by the life of bit bearing, which depends a large extent to the life of their seals. The recent development trend of cone bits is to realize their high speed. Faster the speed of bit is, the more weak of common bearing seals worked under the rough environment is. Therefore, we should not neglect the study and improvement for the service life of bearing while researching cone bits.
To enhance the reliability of bearing seal of cone bit, this paper plans to adopt face-radial combination sealing structures; that is to say, end-face and radial seal are arranged in one bit simultaneously. The nonlinear finite element method is applied to analyze and optimize the design of sealing structures. The dishing ring seals belong the end face sealing parts, and act as sealing by some axial compression. Because of different distribution of internal pressure and temperature, the friction inside the end-face is also different at all area. In order to improve the friction between the outer diameter of dishing ring and cone, and prevent any contaminant, such as slurry and ect. from coming, the outside diameter may be curved upward. The length and open of the curved may be determined by the analogue to the actual condition. The innovative dishing ring not only possesses end -face sealing capacity, but also has some radial seal and clean function.
The most common sealing ring of bit bearing is single O-ring, which is made of rubber. It has basically matched with low speed sealing bearing bit, but it cannot avoid its fault. Therefore, the common rectangular groove seals are often be changed into the curved groove with some arc degree. When the O-ring acted as sealing function is placed in the curve groove with suitable design, its stress, strain and friction are all improved so as to lengthen the service life of sealing.
The finite element method has guide meaning to analyze and design of structure. By comparing between the rectangular groove and curved groove, we find that two high stress area of rectangular groove O-ring occurs during the sealing period, and the wearing on the both inside and outside diameter surfaces; the high stress area only happens at the part area of cone shaft, and the distribution of stress is more even than the former, and the wearing is on the inside diameter surface, the improvement of its distortions makes the service life of sealing lengthen.
According to achievements in research, using face-radial sealing structures can adapt to the developing trend of increasing rotary speed of cone bit to a certain extent in lubricating system of bearing seal, which is cramp to bit service life.
为了提高牙轮钻头轴承密封的可靠性，本文设计采用端面-径向组合密封结构，即在一只钻头中同时布置端面和径向密封，采用非线性有限元方法对密封结构进行分析和优化。碟形密封圈属于端面密封元件，依靠一定的轴向压缩量进行密封，由于端面内压力分布、温度分布不均，端面内的摩擦状况也不是处处相同。为改善碟形圈外径与牙轮的摩擦工况，更好地防止泥浆等有害物质的侵入，可将其外径略向上弯曲，弯边的长度及开口数可由实际工况的模拟来确定。改进的碟形密封圈不但具有端面密封能力，而且将具有一定的径向密封和擦拭功能。
最常用的钻头轴承密封圈是单个O形圈，主要以丁腈橡胶制作。它与低速密封轴承钻头已基本匹配，但其失效不可避免。为此，普通矩形槽密封被尝试着改为具有一定弧度的弧形槽，当径向密封作用的O形圈被置于设计合理的弧形槽内，其受力、变形和摩擦状况均得到改善，有助于
密封寿命的提;锐
有限元法对结构的分析和设计具有指导意义。通过矩形槽和弧形槽
的对比研究发现，矩形槽O形圈在密封过程中出现两个高应力区，磨损
发生在内径、外径两个表面_匕，弧形槽O形圈的高应力区仅出现在牙爪
轴邻近的局部区域内，应力分布较前者更为均匀，磨损进发生在内径表面
，其受力变形状况的改善将使密封寿命进一步提高。
本文的研究表明，在伟l]约钻头寿命的轴承密封润滑系统中，采用端
面一径向组合密封结构能够在一定程度上适应牙轮钻头转速提高的发展趋
The service life of cone bits which play an important role in breaking rock of the bottom of a well is almost directly decided by the life of bit bearing, which depends a large extent to the life of their seals. The recent development trend of cone bits is to realize their high speed. Faster the speed of bit is, the more weak of common bearing seals worked under the rough environment is. Therefore, we should not neglect the study and improvement for the service life of bearing while researching cone bits.
To enhance the reliability of bearing seal of cone bit, this paper plans to adopt face-radial combination sealing structures; that is to say, end-face and radial seal are arranged in one bit simultaneously. The nonlinear finite element method is applied to analyze and optimize the design of sealing structures. The dishing ring seals belong the end face sealing parts, and act as sealing by some axial compression. Because of different distribution of internal pressure and temperature, the friction inside the end-face is also different at all area. In order to improve the friction between the outer diameter of dishing ring and cone, and prevent any contaminant, such as slurry and ect. from coming, the outside diameter may be curved upward. The length and open of the curved may be determined by the analogue to the actual condition. The innovative dishing ring not only possesses end -face sealing capacity, but also has some radial seal and clean function.
The most common sealing ring of bit bearing is single O-ring, which is made of rubber. It has basically matched with low speed sealing bearing bit, but it cannot avoid its fault. Therefore, the common rectangular groove seals are often be changed into the curved groove with some arc degree. When the O-ring acted as sealing function is placed in the curve groove with suitable design, its stress, strain and friction are all improved so as to lengthen the service life of sealing.
The finite element method has guide meaning to analyze and design of structure. By comparing between the rectangular groove and curved groove, we find that two high stress area of rectangular groove O-ring occurs during the sealing period, and the wearing on the both inside and outside diameter surfaces; the high stress area only happens at the part area of cone shaft, and the distribution of stress is more even than the former, and the wearing is on the inside diameter surface, the improvement of its distortions makes the service life of sealing lengthen.
According to achievements in research, using face-radial sealing structures can adapt to the developing trend of increasing rotary speed of cone bit to a certain extent in lubricating system of bearing seal, which is cramp to bit service life.
引文
[1] 广廷洪，汪德涛．密封件使用手册．机械工业出版社．1994．12．
[2] 徐灏．新编机械设计师手册(上)．机械工业出版社．1995．3．
[3] 马德坤．牙轮钻头工作力学．石油工业出版社．1994．2．
[4] 四川石油管理局总机修厂钻头研究所，西南石油学院钻头研究室；三牙轮钻头使用手册．四川石油管理局科技处．1978．12．
[5] 顾永泉．流体动密封．石油大学出版社．1990．8．
[6] B．S．纳乌．国际流体密封会议文集．机械工业出版社．1991．3．
[7] 谢贻权，何福保．弹性和塑性力学中的有限单元法．机械工业出版社．
[8] 谢呜明．在磨粒及冲击条件下的橡胶磨损试验研究及其数据库．西南石油学院硕士论文．1991。
[9] 黄志强．牙轮钻头轴承密封研究．西南石油学院硕士论文．1992．
[10] 陈家庆．牙轮钻头轴承径向密封的研究．石油钻采机械．
[11] J.W. Langford, M.S.Kalsi: Field Performance of a Hydrodynamically lubricated Bearing seal for Rock Bits. SPE Drilling Engineering, March 1992.
[12] M.J. Fear, J.L. Thorogood: Uptimization of Rock-Bit Life Based on Bearing Failure Criteria, SPE Drilling Engineering September 1992.
[13] 荒井芳男．油封的密封理论．润滑与密封．1983．
[14] 王子瑜．牙轮钻头轴承系统失效分析．西南石油学院学报．1987．
[15] 周锡容，王子瑜．牙轮钻头轴承密封的典型结构与失效．
[16] U.S. pat. No. 4.610,319 Sep 9.1980
[17] U.S. pat. No. 4,484,753 Nov 27,1984.
[18] 陈家庆，罗纬．牙轮钻头流体动压密封圈的实验研究．石油矿场机械．1995．
[19] 谭春飞，王镇泉．新型高速牙轮钻头滑动轴承的试验研究．石油机械．1996．
[20] 陈家庆，罗纬．牙轮钻头流体动压密封的结构构想和参数确定．石油矿场机械．1995．
[21] 罗纬，何其翔．牙轮钻头金属浮动密封研究及设计，石油机械，1994．
[22] Burr, B.H. Marshek, K.M.:An Equation for the Abrasive Wear of Elastomeric O-Ring Materials Wear(1982)81.
[23] Kalsi, M.S. :Elastohydrodynamic Lubrication of Offset O-Ring Rotary Seal, Lubrication Tech (July 1981).
[24] Hendrickson, R.R.:Seals for Geothermal Roller Drill Bits. Pessure Vessel Tech (Nov. 1977).
[25] 任韶然，李春山．陈家庆。石油大学硕士论文．
[26] 板金冲压工艺手册编委会．板金冲压工艺手册．国防工业出版社．1989．9．
[27] 温诗铸，杨沛然．弹性流体动力润滑．清华大学出版社．19992．9．
[28] 机械工程手、电机工程手册编辑委员会．机械工程手册(第五卷)．机械工业出版社．1982．3．
[29] MARC Analysis Research Coporation:Mentat Ⅱ User's Guide
[30] MARC Analysis Research Corporation:Volume A.B.C.D.E.F.
[31] 中国科学技术情报研究所重庆分所．国外机械密封．科学技术文献出版社重庆分社．1977．4．
[32] 陈德才，崔德容．机械密封设计制造与使用．机械工业出版社．1993．4．
[33] H．体戈．布赫特．工业密封技术．化学工业出版社．1988．5．
[34] 近森德重．O 形密封圈．机械工业出版社．1976．6．
[35] 刘希圣．钻井工艺原理．石油工业出版社．1988．9．
[36] 周锡容，杨启明．摩擦磨损与润滑．石油工业出版社．1997．12．
[2] 徐灏．新编机械设计师手册(上)．机械工业出版社．1995．3．
[3] 马德坤．牙轮钻头工作力学．石油工业出版社．1994．2．
[4] 四川石油管理局总机修厂钻头研究所，西南石油学院钻头研究室；三牙轮钻头使用手册．四川石油管理局科技处．1978．12．
[5] 顾永泉．流体动密封．石油大学出版社．1990．8．
[6] B．S．纳乌．国际流体密封会议文集．机械工业出版社．1991．3．
[7] 谢贻权，何福保．弹性和塑性力学中的有限单元法．机械工业出版社．
[8] 谢呜明．在磨粒及冲击条件下的橡胶磨损试验研究及其数据库．西南石油学院硕士论文．1991。
[9] 黄志强．牙轮钻头轴承密封研究．西南石油学院硕士论文．1992．
[10] 陈家庆．牙轮钻头轴承径向密封的研究．石油钻采机械．
[11] J.W. Langford, M.S.Kalsi: Field Performance of a Hydrodynamically lubricated Bearing seal for Rock Bits. SPE Drilling Engineering, March 1992.
[12] M.J. Fear, J.L. Thorogood: Uptimization of Rock-Bit Life Based on Bearing Failure Criteria, SPE Drilling Engineering September 1992.
[13] 荒井芳男．油封的密封理论．润滑与密封．1983．
[14] 王子瑜．牙轮钻头轴承系统失效分析．西南石油学院学报．1987．
[15] 周锡容，王子瑜．牙轮钻头轴承密封的典型结构与失效．
[16] U.S. pat. No. 4.610,319 Sep 9.1980
[17] U.S. pat. No. 4,484,753 Nov 27,1984.
[18] 陈家庆，罗纬．牙轮钻头流体动压密封圈的实验研究．石油矿场机械．1995．
[19] 谭春飞，王镇泉．新型高速牙轮钻头滑动轴承的试验研究．石油机械．1996．
[20] 陈家庆，罗纬．牙轮钻头流体动压密封的结构构想和参数确定．石油矿场机械．1995．
[21] 罗纬，何其翔．牙轮钻头金属浮动密封研究及设计，石油机械，1994．
[22] Burr, B.H. Marshek, K.M.:An Equation for the Abrasive Wear of Elastomeric O-Ring Materials Wear(1982)81.
[23] Kalsi, M.S. :Elastohydrodynamic Lubrication of Offset O-Ring Rotary Seal, Lubrication Tech (July 1981).
[24] Hendrickson, R.R.:Seals for Geothermal Roller Drill Bits. Pessure Vessel Tech (Nov. 1977).
[25] 任韶然，李春山．陈家庆。石油大学硕士论文．
[26] 板金冲压工艺手册编委会．板金冲压工艺手册．国防工业出版社．1989．9．
[27] 温诗铸，杨沛然．弹性流体动力润滑．清华大学出版社．19992．9．
[28] 机械工程手、电机工程手册编辑委员会．机械工程手册(第五卷)．机械工业出版社．1982．3．
[29] MARC Analysis Research Coporation:Mentat Ⅱ User's Guide
[30] MARC Analysis Research Corporation:Volume A.B.C.D.E.F.
[31] 中国科学技术情报研究所重庆分所．国外机械密封．科学技术文献出版社重庆分社．1977．4．
[32] 陈德才，崔德容．机械密封设计制造与使用．机械工业出版社．1993．4．
[33] H．体戈．布赫特．工业密封技术．化学工业出版社．1988．5．
[34] 近森德重．O 形密封圈．机械工业出版社．1976．6．
[35] 刘希圣．钻井工艺原理．石油工业出版社．1988．9．
[36] 周锡容，杨启明．摩擦磨损与润滑．石油工业出版社．1997．12．