某空气涡轮起动机动密封泄漏分析

针对某型航空用空气涡轮起动机在设计研发过程中出现的动密封滑油泄漏问题,对机械密封结构进行分解分析,初步判定泄漏的滑油来源于摩擦副中静环与动环的贴合端面。根据动密封的结构特点及空气涡轮起动机使用环境编制故障树,对动密封处介质温度和摩擦副温度场开展试验研究和仿真计算,对摩擦副端面进行检测分析,对动密封所需的轴向压紧力以及弹簧提供的压紧力进行校核计算,结果发现动密封滑油泄漏的主要原因是辅助胶圈在高温滑油中体积胀大从而引起摩擦阻力增加,导致弹性元件无法提供摩擦副贴合所需的足够压紧力。根据研究结果增加了该动密封波形弹簧的预紧力,并通过试验验证了改进后动密封的密封效果。

Analysis on Leakage of Dynamic Seal for Air Turbine Starter

Aimed at the problem of oil leakage of the dynamic seal of an aviation air turbine starter in the process of design and development,the mechanical seal structure was decomposed and analyzed,and it was preliminarily determined that the leakage oil comes from the end face of the static ring and the dynamic ring of the friction pair.A detailed fault tree was compiled based on the structural characteristics of the dynamic seal and the service environment of the air turbine starter.The experimental research and simulation calculation of the medium temperature and friction pair temperature field of the dynamic seal were carried out,the end face of the friction pair was detected and analyzed,and the axial compression force required by the dynamic seal and the compression force provided by the spring were checked and calculated.It was concluded that the main reason for the oil leakage was the expansion of the auxiliary rubber ring in the high temperature oil,which leaded the increase of friction resistance.As a result,the elastic element could not provide enough pressing force for the friction pair.According to the research result,the preload of the dynamic seal wave spring was increased,and the sealing effect of the improved dynamic seal was verified by experiments.