不同沟槽棱圆角半径对带挡环的O形圈密封的影响

Influence of Different Fillet Radius of Groove Edge on O-ring Seal with Retaining Ring

O形圈密封沟槽棱圆角有利于O形圈和挡环的安装,防止O形圈或挡环被锐边划伤而影响密封可靠性,且沟槽棱圆角半径对O形圈密封性能也有较大影响。以沟槽棱圆角半径为变量,利用有限元分析软件建立有、无挡环配合使用2种O形圈密封结构的二维轴对称模型,分析在35 MPa介质压力下静密封和动密封2种密封状态下O形圈密封性能,比较不同半径下2种密封结构O形圈和挡环的von Mises应力、接触压力和挤出情况。结果表明:在35 MPa介质压力作用下,带挡环的O形圈密封能达到密封要求,挡环与O形圈配合使用能有效降低沟槽棱圆角半径对O形圈密封性能的影响;挤出处应力随着沟槽棱圆角半径的增大而增大,沟槽棱圆角半径越大,挤出处应力增幅越大,因此在涉及到动密封时,为了保证O形圈和挡环不被沟槽棱划伤,且挡环在挤出处受到较小应力,沟槽棱圆角半径取值不能太大,该结论将对带挡环O形圈密封沟槽设计起到一定的参考作用。

The groove fillet of O-ring seal is beneficial to the installation of the O-ring and the retaining ring,which can prevent the O-ring or retaining ring from being scratched by the sharp edge to affect the reliability of the seal.The groove fillet radius also has a great influence on the sealing performance of the O-ring.Taking the fillet radius of groove edge as a variable,a two-dimensional axisymmetric model of O-ring seal structure with and without retaining ring was established by using the finite element analysis software.The sealing performance of O-ring under static seal and dynamic seal under 35 MPa medium pressure was analyzed.The von Mises stress,contact pressure and extrusion of O-ring and retaining ring with different radius were compared.The results show that the O-ring seal with retaining ring can meet the sealing requirements under the action of 35 MPa medium pressure,and the combined use of retaining ring and O-ring can effectively reduce the influence of groove fillet radius on O-ring sealing performance.The stress at the extrusion position increases with the increase of the fillet radius of the groove edge.The larger the fillet radius of the groove edge,the greater the stress increase at the extrusion point.Therefore,when it comes to dynamic seal,in order to ensure that the O-ring and retaining ring are not scratched by groove edges and that the retaining ring is subject to small stress at the extrusion point,the fillet radius of groove edge should not be too large.The conclusion can be used as a reference for the design of O-ring sealing groove with retaining ring.