Y形活塞杆密封动静态性能分析及结构优化

为提高液压缸活塞杆用Y形密封的可靠性，研究其在动、静密封状态下的密封特性。通过有限元分析，研究Y形密封在不同工况下的受力、变形及主密封面接触压力分布规律。根据液压往复密封原理，研究不同介质压力下活塞杆密封在往复行程中的泄漏量的变化趋势。结果表明：Y形密封在安装工况下抵抗压力冲击的能力较弱；随着介质压力增大，Y形密封在静密封状态下的密封性能指数、动密封状态下的净泵回量均有所下降，防止泄漏的能力降低；高压工况下，Y形密封抗挤出能力降低，根部被挤入密封间隙，将出现咬伤现象导致密封系统失效。针对Y形密封工作过程中出现的咬伤问题，使用根部倒角的方法进行结构优化；利用中心设计方法建立以单个往复行程中的泄漏量为目标函数的响应面模型，对Y形密封进行结构优化。优化后的Y形密封在动、静密封状态下的密封性能得到提高，磨损速度、被咬伤的风险降低，提高了Y形密封的可靠性。

Dynamic and Static Performance Analysis and Structural Optimization of Y-shaped Piston Rod Seal

In order to improve the reliability of the Y-seal for the piston rod of the hydraulic cylinder,the sealing characteristics of the Y-seal in the state of dynamic and static seal were studied.Through finite element analysis,the stress,deformation and contact pressure distribution of Y-shaped seal under different working conditions were studied.According to the principle of hydraulic reciprocating seal,the changing trend of the leakage of piston rod seal in reciprocating stroke under different media pressure was studied.The results show that the Y-shaped seal has weak resistant ability against fluid pressure under installation condition.With the increase of the medium pressure,the sealing performance index of the Y-shaped seal under static sealing state and the net amount of flow back of Y-shaped seal under dynamic sealing state decrease,and the ability to prevent leakage decreases.Under high pressure condition,the anti extrusion ability of Y-shaped seal is reduced,and the root is squeezed into the seal gap,which will cause bite and lead to seal system failure.Aimed at the bite problem of the Y-shaped seal,the root chamfering method was used to optimize the structure.A response surface model was established using the central design method to optimize the Y-shaped seal by taking the leakage as the objective function.The sealing performances of the optimized Y-seal under dynamic and static seal conditions are improved,the wear speed and the risk of being bitten are reduced,and the reliability of Y-seal is improved.