徐氏密封理论与矩形和O形环密封

XU′s Sealing Theory and Rectangular & O-Shaped Ring Seals

密封元的至密封和持密封的难度是由其密封难至系数m1(接触层的弹性模量Ec/接触层基体的弹性模量Es)决定的。因此,在理论上,密封元的密封接触层应软而无弹性并安装至充分屈服变形,以提供1个弹性模量Ec值低的接触层;密封元的接触层基体应强而富弹性并安装至充分弹性变形,以提供1个弹性模量Es值高的接触层基体。橡胶密封元因其Ec≡Es而最难至密封,金属密封元因可通过设计和涂镀确保安装至其Ec<Es而远比橡胶易至密封。

The difficulty for a sealing element to create and maintain a leak-free joint is determined by its sealing difficulty coefficient m1 [ elastic modulus （Ec） of its sealing contact layer/elastic modulus （Es） of its sealing contact layer substrate]. Therefore, ideally the contact layer of a sealing element shall be soft ＆ inelastic and assembled up to its fully yielded deformation to provide a contact layer with a lower value of elastic modulus （Ec）, and the contact layer substrate shall be strong ＆ elastic and assembled up to its fully elastic deformation to provide a contact layer substrate with a higher value of elastic modulus （Es）. It is the most difficult for a rubber sealing elenmnt to create a leak-free joint because its Ec≡Es, and it is far easier for a metal sealing element than for a rubber sealing element because the metal sealing element can be designed and coated to cause its Ec〈Es.