液压缸往复密封圈表面接触应力监测研究

在液压缸中，往复动密封圈表面接触应力是决定其密封有效性的关键，但由于在工作过程中对往复密封表面接触状态进行监测的难度很大，因此对其变化规律仍缺乏深入了解。针对这一问题，以液压缸活塞杆Y形密封圈为对象，通过有限元仿真分析密封圈内唇磨损对密封圈表面接触应力的影响，确定密封圈表面接触应力的最佳监测部位；采用光纤光栅传感器(FBG)进行密封槽表面接触应力监测试验，通过铺设于密封槽的FBG传感器采集应力数据，得出密封圈周向和轴向接触应力均随内唇磨损增加呈现先增大后减小的趋势，与仿真结果一致；接触应力对密封磨损程度变化的响应灵敏度会随密封压力的增加而增大。研究结果为液压缸实际运行过程中往复动密封状态的监测提供了依据。

Study on Surface Contact Stress Monitoring of Reciprocating Seals in Hydraulic Cylinder

In the hydraulic cylinder,the surface contact stress of reciprocating dynamic seals is the key to determine the sealing effectiveness.However,due to great difficulty in monitoring surface contact state of reciprocating seals in the working process,the change rule of contact stress of sealing structure still remains less understood.Taking the Y-ring in hydraulic cylinder as the research object,the influence of inner lip wear of Y-ring on the surface contact stress of sealing groove was analyzed and the best stress monitoring points were located based on finite element simulation.Fiber bragg grating (FBG) was applied to monitor the contact stress on outer surface of the sealing groove.Data acquired from FBG sensors laid in the sealing groove shows that with the increase of wear degree of the inner sealing lip,the radial and axial contact stresses first increase and then decrease,which is consistent with the simulation results.The response sensitivity of contact stress to the seal wear degree increases with the increase of seal pressure.This study provides basis for the condition monitoring of Y-ring in the service process of hydraulic cylinder.