斯特林机活塞杆帽式密封结构改进研究

为解决斯特林机活塞杆处介质泄漏的问题，对其帽式密封结构进行改进，并利用有限元分析软件ANSYS建立其二维轴对称模型；基于实际运行工况，分析比较改进密封结构的性能指标，并通过改变边界条件，探究介质压力、摩擦因数及活塞杆运行速度对改进密封结构性能影响规律。结果表明：改进的密封结构消除了原有结构O形圈的应力集中问题，提高了最大接触应力，且在增加有效密封面积40%的同时又将O形圈的最大等效应力降低了近50%;3个关键参数中介质压力对密封性能的影响力最大，对于改进密封结构，在介质压力为6～8.5 MPa时其密封性能最佳。

Research on Piston Rod Cap-type Seal Structure Improvement of Stirling Engine

In order to solve the problems of the Stirling machine piston rod working medium leakage,the structure of cap seal was improved,and the two-dimensional axisymmetric model of the sealing structures was established by using finite element analysis software ANSYS.Based on the actual operation condition,the performance of the improved sealing structures were analyzed.By changing the boundary conditions,the influence of working medium pressure,friction coefficient and piston rod speed on the performance of improved sealing structure was investigated.The results show that the improved sealing structure eliminates the stress concentration problem of the original O-ring structure,and the maximum contact stress is increased.The effective sealing area of the improved sealing structure is increased by 40%,and the maximum stress of O-ring is reduced by nearly 50%.Among the three key parameters,the medium pressure has the greatest influence on the sealing performance.For the improved sealing structure,the sealing performance is the best when the medium pressure is from 6 MPa to 8.5 MPa.