给水泵油封装置O形密封圈的有限元非线性分析

Finite Element Nonlinear Analysis of O-ring for Boiler Feed Pump Oil Seal Device

为解决给水泵油封装置中O形圈因密封失效而引起泄漏的问题,利用有限元法对密封圈的大变形、超弹性进行非线性接触分析。首先建立密封圈与转动环沟槽之间的轴对称模型,分析O形圈在不同压缩率、不同轴向压力下的应力分布规律,进而对油封装置结构改进,最后利用试验台位测试油封的密封性能。结果表明:O形密封圈压缩率越大主接触面峰值应力越大,侧接触面应力基本不变;密封圈轴向压力的增加,接触应力也急剧上升,侧面接触应变较大,但工况内无胶料"挤出"发生;改进后双密封O形圈动环结构密封可靠性、安全性更高,在不同工况下进行密封性能试验,油封装置无泄漏,为油封密封圈选型以及避免给水泵实际运行中出现"滴、漏"现象具有一定的指导意义。

In order to solve leakage problem caused by O-ring in a boiler feed pump oil sealing device, nonlinear contact analysis of large deformation and super elasticity is carried out by the finite element method. Firstly, an axisymmetric model between seal ring and moving ring groove is established. The stress and strain distribution rules of the O-ring under different compression ratios and different axial pressures are analyzed. Then the structure of oil seal device is optimized. Finally, a test bench is used to test sealing performance. The research shows that the higher the compression rate of O-ring seal, the greater the peak stress of main contact surface, and the stress of side contact surface is basically unchanged. With the increase of axial pressure of sealing ring, the contact stress also increases sharply, and the lateral contact strain is larger, but there is no “extrusion” of glue material in working condition. The double-sealed O-ring dynamic ring structural seal has higher reliability and safety after optimization, and the test oil seal device has no leakage under different working conditions, which is of the guiding significance for selecting O-ring and avoiding the phenomenon of “dripping and leaking” in actual operation of boiler feed pump.