工况自适应机械密封端面结构设计与试验

机械密封在工况易变的装置或工况调节过程中 ,极易发生摩擦副整体位移或端面分离的失效现象。就密封结构进行分析 ,如果作用在摩擦副上的大气压力与弹簧力方向相反 ,并且存在大气压力大于弹簧力时 ,就可能推开摩擦副的浮动环或推动摩擦副整体位移 ;摩擦副的密封面设计有宽度 ,液体在泄漏方向上有压力差 ,温度升高 ,造成液膜汽化 ,密封面间出现汽液混相或全汽相 ,膜压增大推开密封面。为防止密封面整体分离和位移提出了波纹管机械密封的设计结构 ,给出了密封面刃边形的设计方法

Design and Test of End Face Structure of Mechanical Seal Self-Adaptive to Operation Condition

In the equipment which operating condition varies easily or when adjusting operating condition, the fault that friction pairs of mechanical seal are moved or separated from end face will happen. The structure of seal was analyzed. The results show that if the atmosphere pressure acting on the friction pairs directs opposite to the spring force, and when the atmosphere pressure is greater than the spring force, the force will push floating ring of friction pairs away or the friction pairs are moved in whole. When there exists width in seal face of friction pairs there will exist pressure drop in the liquid leaking direction. When the temperature rises liquid film will be gasified. The gas-liquid phase or pure gas will exist between the seal faces. The enlarged film pressure can push the seal face away. To prevent the seal face moving in whole or separating from each other, a mechanical seal design structure of bellows was proposed. A design method for knife-edge seal face was also given.