球面浮动套轴承在牙轮钻头中的应用研究

发布时间：2018-12-09 15:30

【摘要】：牙轮钻头是钻井领域中最重要的破岩工具之一,它的寿命直接影响着钻井的效率和成本。众所周知,牙轮钻头轴承失效是影响牙轮钻头寿命的最关键因素之一,其主要形式为粘着磨损,而浮动套轴承就能改善轴承粘着磨损现象。但是在实际的工作中,浮动套轴线会发生偏转,这样就造成了浮动套的边缘发生应力集中现象,降低了浮动套轴承的使用寿命。本文将浮动套的外表面设计成球面,这样使浮动套在实际工作中,接触的表面积增大,降低了接触应力,提高了浮动套轴承的寿命,进而提高牙轮钻头的寿命。论文开展的主要工作如下： 1)设计了一种球面浮动套轴承结构,并通过理论分析和有限元模拟分析,发现相同条件下球面浮动套在应力上均小于普通浮动套,能够有效地改善普通浮动套的应力集中现象； 2)本文选取18CrNiMo7-6钢作为球面浮动套的基体材料,制定了合适的热处理工艺并对其进行数值模拟。在经过数值模拟后,发现热处理后的球面浮动套提高了耐磨性能和抗冲击的能力,较好地满足牙轮钻头的实际工况； 3)为了进一步提高球面浮动套的摩擦性能,本文将TiN涂层技术应用于牙轮钻头轴承系统中。测试TiN涂层一系列参数,发现TiN涂层能够有效地降低摩擦副间的摩擦系数,并且提高其表面硬度,增加了耐磨性能,说明TiN涂层技术能够有效地提高牙轮钻头的寿命。
[Abstract]:Cone bit is one of the most important rock breaking tools in drilling field. Its service life directly affects the efficiency and cost of drilling. It is well known that the failure of roller bit bearing is one of the most important factors affecting the life of cone bit. The main form of bearing is adhesive wear, and floating sleeve bearing can improve the phenomenon of bearing adhesion wear. But in the actual work, the axis of the floating sleeve will deflect, thus causing the stress concentration on the edge of the floating sleeve and reducing the service life of the floating sleeve bearing. In this paper, the outer surface of the floating sleeve is designed as a spherical surface, so that the surface area of the contact is increased, the contact stress is reduced, the life of the floating sleeve bearing is increased, and the life of the cone bit is increased. The main work of this paper is as follows: 1) A spherical floating sleeve bearing structure is designed. Through theoretical analysis and finite element simulation analysis, it is found that the stress of spherical floating sleeve is smaller than that of ordinary floating sleeve under the same conditions. It can effectively improve the stress concentration phenomenon of ordinary floating sleeve. 2) in this paper, 18CrNiMo7-6 steel is chosen as the base material of spherical floating sleeve, and the appropriate heat treatment process is established and numerically simulated. After numerical simulation, it is found that the spherical floating sleeve after heat treatment can improve the wear resistance and impact resistance, and better meet the actual working conditions of the cone bit. 3) in order to improve the friction performance of spherical floating sleeve, TiN coating technology is applied to roller bit bearing system. By testing a series of parameters of TiN coating, it is found that TiN coating can effectively reduce the friction coefficient between friction pairs, improve the surface hardness and increase the wear resistance. It shows that the TiN coating technology can effectively improve the life of cone bit.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE921.1

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