摘要
牙轮钻头滑动轴承在不同地层中进行破岩作业时,承受重载、低速、频繁启停、高温等复杂井下工况,其接触表面可能会失稳,导致轴承失效,甚至发生钻井事故。通过建立乏油工况下微观真实表面循环加卸载接触模型,利用接触面Von Mises应力分布、弹塑性变形区域占比、实际接触面积及残余变形量等参数对接触表面稳定性进行表征,研究不同地层中破岩载荷对牙轮钻头轴承接触表面稳定性的影响,确保轴承在服役期内稳定运行。研究表明:在4种不同硬度岩石地层破岩载荷的分别作用下,超硬质岩石地层破岩载荷对轴承接触表面稳定性表征参数影响最大,接触面长时间应力集中导致弹塑性变形区域占比更高,表面理论接触面积与实际接触面积的差值最大,实际接触面积的累积量最大;卸载后最大残余变形达到了1.378μm,是软质岩石地层残余变形的133%。研究成果为在不同岩石地层工作时牙轮钻头滑动轴承表面稳定性评价提供了理论依据,并为探究轴承表面真实形貌演化规律提供了重要参考。
The sliding bearing of a tricone drill bit,while performing rock-breaking operations in various formations,endures complex downhole conditions including heavy loads,low speeds,frequent starts and stops,and high temperatures.These factors can cause instability in the contact surfaces,potentially leading to bearing failure and even drilling accidents.By establishing a cyclic loading-unloading contact model for the microscopic real surface under oil-depleted conditions,the stability of the contact surface is characterized using parameters such as the Von Mises stress distribution on the contact surface,the proportion of elastoplastic deformation regions,actual contact area,and residual deformation.The impact of rock-breaking loads from different formations on the stability of the contact surface of the tricone drill bit bearing is investigated,ensuring stable bearing operation throughout its service life.The research findings indicate that among four rock formations of varying hardness,the rock-breaking load from ultra-hard rock formations has the greatest impact on the stability parameters of the bearing contact surface.The prolonged stress concentration on the contact surface results in a higher proportion of elastoplastic deformation regions,the largest discrepancy between theoretical and actual contact area,and the maximum accumulation of actual contact area.After unloading,the maximum residual deformation reaches 1.378μm,which is 133%of the residual deformation in soft rock formations.These findings provide a theoretical basis for evaluating the surface stability of tricone drill bit sliding bearings in various rock formations and offer a valuable reference for exploring the evolution of real surface morphology on bearing surfaces.
作者
李万钟
陈泽雄
樊金龙
霍蓬勃
高磊
Li Wanzhong;Chen Zexiong;Fan Jinlong;Huo Pengbo;Gao Lei(School of Mechanical Engineering,Xi’an Shiyou University,Xi’an,Shanxi 710065,China)
出处
《机电工程技术》
2025年第3期41-46,共6页
Mechanical & Electrical Engineering Technology
基金
陕西省自然科学基础研究计划(2021JQ-606)
陕西省教育厅科研计划(19JK0659)。
关键词
滑动轴承
表面稳定性
破岩载荷
弹塑性变形
真实表面形貌
sliding bearing
surface stability
rock breaking load
elastoplastic deformation
real surface topography
