旋转导向工具心轴弯曲对悬臂轴承影响的研究

The effect of the bending of the rotary shaft of the rotary steerable drilling tool on cantilever bearing

指向式旋转导向工具利用心轴的弯曲变形达到导向钻进的目的,在轴承受力分析的基础上,选择滚针轴承达到心轴上部的悬臂轴承限制心轴弯曲的目的,但是心轴的弯曲会影响滚针轴承的工作及寿命。通过对心轴弯曲变形的力学分析,建立了心轴在静态偏置状态下的挠曲线方程,得出在滚针轴承处心轴的挠度值与偏置力之间的关系曲线,利用试验验证了力学分析的合理性;并通过试验研究了在静态和动态2种工作条件下心轴弯曲对滚针轴承工作的影响。结果表明,心轴的弯曲变形是滚针轴承失效的主要原因;采用组合轴承或硬质合金轴承可以改变轴承的受力状态以延长轴承的工作寿命。

The directional rotary steerable drilling tool makes use of the bending deformation to achieve the purpose of navigational drilling.On the basis of bearing force analysis,the needle bearing was chosen to achieve the purpose of using the cantilever bearing in the upper part of the rotary shaft to restrict the bending of the shaft.However,the bending of the shaft will affect the operation and service life of the needle bearing.Through dynamic analysis of the bending deformation of the rotary,the deflection curve equation of the shaft in its static biasing condition was established to obtain the relation curve between the deflection value and the bias force concerning the shaft in needle bearing.The experiment was carried out to verify the rationality of the dynamic analysis.Through the experiment,the effect of the shaft bending on the operation of needle bearing in static and dynamic operating conditions was studied.The result indicates that the bending deformation of the shaft is the major reason for the failure of needle bearing.Adoption of combined bearing or cemented carbide bearing can change the force condition of the bearing so as to lengthen its service life.