表面粗糙度对橡塑O形圈往复密封性能的影响

建立三维确定性混合润滑数值仿真模型，该模型采用统一Reynolds方程系统法，耦合了固体力学分析、流体力学分析和接触力学分析；生成非高斯粗糙表面，基于混合润滑模型研究表面粗糙度、自相关长度比值和纹理方向对橡塑O形圈往复密封摩擦力、泄漏率、平均膜厚和接触面积比等密封性能的影响规律。研究表明：低速时随着表面粗糙度的增大，润滑区接触面积比增大，引起摩擦因数增大，平均膜厚先增大后减小，临界接触面积比约为40%;在混合润滑状态时，对于横向纹理粗糙表面，存在合适的自相关长度比值使得密封的摩擦因数和接触面积比最低；当纹理方向θ=π/10时，摩擦因数最小。

Effect of Surface Roughness on Reciprocating Sealing Performance of Rubber O-ring

A three-dimensional deterministic numerical simulation model of mixed lubrication was established.The model adopted the unified Reynolds equation based on the system method and coupled the solid mechanics analysis,fluid mechanics analysis and contact mechanics analysis.Non Gaussian rough surfaces were generated,based on the mixed lubrication model,the effects of surface roughness amplitude,autocorrelation length ratio and texture direction on the sealing properties of O-ring reciprocating seal,such as friction,leakage rate,average film thickness and contact area ratio,were investigated by using the non-Gaussian rough surface.The results show that with the increase of surface roughness,the friction coefficient,average film thickness and leakage rate increase.When the Ra increases to a certain value and the contact area of the lubrication area is greater than 40%,the average film thickness and leakage rate begin to decrease.For a rough surface with transverse texture,there is an appropriate γ,which makes the comprehensive performance and lubrication state of the seal optimal.When θ =π/10,the friction coefficient reaches the minimum value.