旋冲载荷下传动轴组合密封沟槽敏感参数研究*

随着勘探深度的增加,地层压力升高和岩石硬度增加,螺杆钻具经常发生横向涡动、纵向跳动、扭向振动及黏滑现象,限制了冲击螺杆钻具的推广应用。为研究高温、高转速和往复运动耦合作用下传动轴总成密封特性及参数敏感性具,对比相同工况下星形圈、O形圈和组合圈密封特性,得到不同密封圈在静密封、动密封状态下接触压力分布,根据主密封面接触压力判定方法得到最佳密封圈结构。根据该结构研究沟槽敏感参数,并讨论沟槽形状、位置、数目和宽度等对组合圈密封特性的影响。结果表明:组合圈密封效果远远优于O形圈及星形圈;沟槽形状采用等腰三角形、沟槽数目为3时密封性能最优,沟槽位置于中间最合理;静、动密封状态下,主密封面接触压力随沟槽宽度增大而增大,而静密封状态下次接触面接触压力及O形圈应力几乎不变。

Study on Parameters Sensitivity of Combined Seal Groove of Drive Shaft Under Rotary Impulse Load

With the increase of exploration depth,formation pressure rises and rock hardness increases,screw drilling tools often experience lateral whirl,longitudinal bounce,torsional vibration and stick-slip phenomena,which limit the popularization and application of impact screw drilling tools.In order to study the sealing characteristics and parameter sensitivity of the transmission shaft assembly under the coupling effect of high temperature,high speed and reciprocating motion,the sealing characteristics of star rings,O-rings and combined rings under the same working conditions were compared,and the contact pressure distribution of different sealing rings in static and dynamic sealing states was obtained.The best sealing ring structure was determined according to the method of determining the contact pressure of the main sealing surface.Based on this structure,the sensitive parameters of the groove were studied,and the influence of the groove shape,position,number and width on the sealing characteristics of the combined ring was discussed.The results show that the sealing effect of the combined ring is far better than that of the O-ring and the star ring.When the groove shape is isosceles triangle and the number of grooves is 3,the sealing performance is the best,and the groove position in the middle is the most reasonable.In the static and dynamic sealing state,the contact pressure of main sealing surface increases with the increase of the groove width,while the contact pressure of secondary sealing surface in the static sealing state and the stress of O-ring is almost unchanged.