旋转冲击载荷下组合密封的敏感参数研究

Research on Sensitive Parameters of Combined Seal under Rotating Impact Load

在高温、三维复合运动耦合作用下冲击螺杆钻具传动轴总成密封极易失效,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,定义轴与滑环形成的接触面为主密封面,O形密封圈与槽底面形成的接触面为次密封面,基于主密封面接触压力,对影响冲击螺杆钻具传动轴组合圈密封特性的相关参数进行数值仿真模拟,研究摩擦因数、O形圈直径、碳纤维含量和往复速度等参数对组合圈密封性能的影响规律。研究表明:摩擦因数增大,预压缩状态主密封面、次密封面接触压力及Mises应力增大,静密封状态主密封面及次密封面接触压力减小,滑环Mises应力增大;动密封状态下,当左、右行程摩擦因数为0.01、0.02、0.03时,接触压力波动幅度较小,当摩擦因数为0.04时波动幅度较大,推荐摩擦因数小于0.04较为合理。O形圈直径增大、碳纤维含量增大,预压缩状态主密封面、次密封面接触压力及O形圈、滑环Mises应力增大,静、动密封状态主密封面、次密封面接触压力和Mises应力增大。随往复速度的增大,右行程主密封面、次密封面接触压力平均值比左行程大,左行程接触压力呈减小趋势,而右行程相反,左、右行程接触压力均值及应力差值增大。研究结果为以后冲击螺杆钻具密封圈的选型及使用提供指导和参考。

The sealing of the drive shaft assembly of the impact screw drilling tool is very easy to fail under the coupling of high temperature and 3-D compound motion,which limits the popularization and application of the impact screw drilling tool.In order to study the sealing characteristics and parameter sensitivity of the drive shaft assembly under the coupling effect of high temperature,high speed and reciprocating motion,the contact surface formed by the shaft and the slip ring was defined as the main sealing surface,and the contact surface formed by the O-ring and the groove bottom was defined as the secondary sealing surface.Based on the contact pressure of the main sealing surface,numerical simulation was performed on the relevant parameters that affect the sealing characteristics of the combined ring,and the influence of friction coefficient,O-ring diameter,carbon fiber content and reciprocating speed on the sealing performance of the combined ring was studied.Studies have shown that with the increase of friction coefficient,the contact pressure and Mises stress of the primary and secondary sealing surfaces in the pre-compression state increase,the contact pressure of the primary and secondary sealing surfaces in the static seal state decreases,and the Mises stress of the slip ring increases.In the dynamic seal state,when the friction coefficient of left and right stroke is 0.01,0.02,0.03,the contact pressure fluctuation range is small.When the friction coefficient is 0.04,the contact pressure fluctuation range is larger.It is reasonable to recommend that the friction coefficient is less than 0.04.As the diameter of the O-ring and the carbon fiber content increase,the contact pressure of the primary and secondary sealing surfaces and the Mises stress of the O-ring and slip ring in the precompression state increase,and the contact pressure and Mises stress of the primary and secondary sealing surfaces in the static and dynamic sealing states increase.With the increase of reciprocating speed,the average contact pressure of the primary and secondary sealing surfaces in the right stroke is larger than that in the left stroke.The contact pressure of the left stroke shows a decreasing trend;on the contrary,the average value of the contact pressure and the stress difference between the left and right strokes increase.The research results provide guidance and reference for the selection and use of sealing rings of impact screw drilling tools in the future.