双浮动密封橡胶O形圈接触应力分析

Contact Stress Analysis of the Rubber O-ring for Double Floating Seal

针对双浮动密封橡胶O形圈接触过程应力的变化,建立双浮动密封二维轴对称非线性接触模型;利用有限元方法对O形圈进行应力计算,分析O形圈在不同压缩率、不同浮封座和浮动环的斜面角度及不同摩擦因数下的应力变化情况。结果表明:橡胶O形圈各应力最大值随压缩率的增加呈线性增大,O形圈内高应力分布区域随压缩率的增加而增大,并由接触部位附近向其中间位置扩散;摩擦因数对O形圈各应力影响很小,而浮封座和浮动环的斜面角度对O形圈等效应力和接触压力影响较大;随着浮封座斜面角的增加,等效应力总体趋于减小,接触压力先减小后缓慢增加,而剪切应力整体变化较小;随着浮动环斜面角的增加,等效应力、接触压力呈递增趋势,剪切应力曲线上下波动,但整体变化不明显。确定双浮动密封浮封座和浮动环斜面角度最优值,为双浮动密封结构设计提供了指导。

Aimed at the variation of contact stress of rubber O-ring in double floating seal,the two-dimensional axial symmetric nonlinear model of double floating seal was built,and the stress of O-ring was calculated by finite element method.The stress variation of O-ring under different compression ratio,different inclined angles of the floating seal seat and floating seal ring and different friction coefficient was analyzed.The results show that the maximum stress of rubber O-ring increases linearly with the increase of compression ratio.The high stress distribution area of O-ring is expanded as the compression ratio increasing,and it diffuses from the contact area to the middle area of the O-ring.The friction coefficient has little effect on the stress of O-ring,while the inclined angles of the floating seal seat and floating seal ring have great influence on the equivalent stress and contact pressure of O-ring.With the increase of the inclined angles of the floating seal seat,the overall equivalent stress tends to decrease,the contact pressure first decreases and then increases slowly,while the overall change of the shear stress is small.With the increase of the inclined angles of the floating ring,the equivalent stress and contact pressure increase gradually,and the shear stress curve fluctuates up and down,but the overall change is not obvious.The optimal angles of the floating seal seat and ring of double floating seal are determined,which provides important guidance for the structure design of double floating seal.