高压下浇注型聚氨酯弹性体密封圈挡环性能研究

Performance Study of Casting Polyurethane Elastomer Retaining Ring of O-ring under High Pressure

为探讨某新型的浇注型聚氨酯弹性体(CPU)作为O形圈挡环材料的性能,使用有限元分析软件构建O形圈和挡环的二维对称模型,分析35MPa介质压力下动、静密封状态下CPU挡环的性能,并与聚四氟乙烯(PTFE)、热塑性聚酯弹性体(TPEE)挡环进行对比。结果表明:CPU材料挡环配合的O形圈的在接触应力、与缸体和活塞接触处的密封长度都略优于其他2种材料,能够很好地实现密封效果;CPU材料挡环静、动密封最大变形程度最小,其承受的最大von Mises应力相较于其他材料小,具有较高的可靠性和较长的使用周期,可有效防止O形圈在高压下的挤出、咬伤等失效情况的发生。台架试验结果表明,CPU挡环的挤出高度远小于TPFE和TPEE挡环,从而验证了有限元分析结果的正确性。研究表明,新型CPU挡环可以用于和O形圈配合实现液压缸的动静密封。

In order to investigate the properties of a new type of cast polyurethane elastomer(CPU)as O-ring retaining ring material,a two-dimensional symmetrical model of O-ring and retaining ring was constructed by using finite element analysis software.The performance of CPU material retaining ring in dynamic and static sealing state under 35 MPa dielectric pressure was analyzed,and was compared with that of polytetrafluoroethylene(PTFE)and thermoplastic polyester elastomer(TPEE)material retaining rings.The results show that the contact stress and sealing length of O-ring matched with CPU material retaining ring are slightly better than those of the other two material retaining rings,which can achieve better sealing effect.The maximum deformation of CPU material retaining ring in static and dynamic sealing state is the smallest,and the maximum von Mises stress of CPU material retaining ring is lower than that of the other two material retaining rings.The CPU material retaining ring has higher reliability and longer service life,which can effectively prevent the failure of O-ring such as extrusion and bite under high pressure.The bench test results show that the extrusion height of CPU retaining ring is much smaller than that of TPFE and TPEE retaining rings,which verifies the correctness of the finite element analysis results.It can be concluded that the new CPU retaining ring matched with O-ring can realize the dynamic and static sealing of hydraulic cylinder.