关于对油缸活塞杆动密封外泄漏的设计改进

该文通过理论计算,借助仿真分析和台架实验与整机实验,对某机型工程机械油缸外泄漏的失效原因进行分析,认识到在杆密封方案选型合理及工艺加工符合图纸要求的前提下,油液从杆动密封处外泄漏的原因除了油液里面的杂质损坏杆动密封之外,杆动密封处的外泄漏一般是以“油环”状形式间歇的向外泄漏。通过在静止状态下对油缸杆串联动密封各密封圈间的压力测试及在往复运动过程中对油缸串联杆密封各密封圈间收集的油膜油液“泵回吸”回油缸内腔的动态分析。得出除了杂质导致油液外泄外,合理设置各密封圈与活塞杆之间的间隙S和密封圈唇口前间隙为S的相对表面长度L,是降低油缸杆密封外泄漏的关键核心因子。

Design Improvement of Cylinder Rod Seal for External Leakage

Through theoretical calculation,this paper analyzes the failure causes of the external leakage for a certain type of engineering machinery according to simulation analysis,bench test and machine experiment.It is recognized that under the premise of reasonable selection of rod seal scheme and meeting the requirements of drawing,the reason for oil leakage from rod dynamic seal is that the impurities in oil damage the seal of rod,and the leakage is usually intermittent in the form of“ring”.In the static state,the pressure between the series seal of the cylinder piston rod is measured,and the dynamic analysis of the oil film in the cylinder chamber during the reciprocating motion is carried out.It is concluded that besides the oil leakage caused by impurities,the key factor to reduce the leakage of cylinder rod seal is to reasonably set the clearance S between each seal ring and the relative length L before the lip of seal ring clearance S.