“O”形橡胶密封圈(以下简称“O”形圈)是断面呈圆形的密封零件,一般安装在机械零件的沟槽里。在两个相配偶的零件(运动的或静止的)接触时,产生一定的弹性压缩而起到密封作用。同其它密封件相比,“O”形圈具有结构简单、密封性能良好、动摩擦阻力小、沟槽尺寸不大、易于加工制造和无需定期调整等优点,可用于往复运动,迥转运动或固定部位等处的液压和气压密封。目前,国内外都已有较广泛的应用;但是,由于“O”形圈的始动摩擦阻力较大,在高速下,断面易受扭曲破坏,故使用范围又受到了限制。为了探索“O”形圈在水轮机中的应用,了解、掌握 O-shaped rubber seals (hereinafter referred to as “O” ring) is a circular cross-section seal parts, usually installed in the mechanical parts of the trench. When two mating parts (moving or stationary) come in contact, a certain amount of elastic compression is produced and the seal functions. Compared with other seals, “O” ring has the advantages of simple structure, good sealing performance, small dynamic friction resistance, small groove size, easy manufacturing and no regular adjustment, etc. It can be used for reciprocating motion, Parts of the hydraulic and pneumatic seals. At present, there are more and more applications both at home and abroad. However, due to the large initial frictional resistance of the “O” ring, the cross-section is susceptible to distortion and damage at high speed, which limits its use range. In order to explore the “O” ring in turbine applications, understand and master