屈服应力对磁性液体密封启动扭矩的影响  

Influence of Yield Stress on the Starting Torque of Magnetic Fluid Seal

作　　者：何新智[1] 王志斌 李德才[2] HE Xinzhi;WANG Zhibin;LI Decai(School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China;State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China)

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044 [2]清华大学摩擦学国家重点实验室,北京100084

出　　处：《兵工学报》2022年第4期892-898,共7页Acta Armamentarii

基　　金：中央高校基本科研业务费专项项目(2019JBM047)。

摘　　要：磁性液体密封是磁性液体最成熟的应用。磁性液体密封的密封性能会随着静置时间的延长发生变化,尤其是启动扭矩随静置时间延长而增大的现象,可能会导致密封件启动困难甚至损坏。针对磁性液体密封启动扭矩发生改变的现象,实验研究启动扭矩与温度、静置时间、磁性液体注入量和磁性液体所受压力的关系,理论分析启动扭矩产生变化的原因。研究结果表明:密封装置所在环境温度降低、静置时间延长、磁性液体注入量增多、所受外界压力减小,都会造成磁性液体密封启动扭矩的增大;引起这种现象的本质是磁性液体中的磁性颗粒在磁场作用下成链,链断裂所需的屈服应力是引起磁性液体密封启动扭矩变化的原因。Magnetic fluid seal is the most mature application of magnetic fluid.The sealing performance of magnetic fluid seal changes with the extension of standing time, especially the phenomenon that the starting torque of the magnetic fluid seal increases with the extension of standing time may cause difficulty in starting the seal or even damage.In order to explore the mechanism of this phenomenon, the relations among the starting torque of magnetic fluid seal with temperature,standing time, the amount of magnetic fluid injected and the pressure exerted on the magnetic fluid are experimentally studied,and the changing reasons of the starting torque of magnetic fluid seal are theoretically analyzed.The results show that the lower the temperature is,the longer the standing timeis ,the greater the amount of magnetic fluid injected is, and/or the lower the pressure is,the greater the starting torque is.The essence of this phenomenon is thatthe particles in magnetic fluid form chain-like structures under the action of magnetic field. Yield stress needed to break chain-like structures is the cause of changing starting torque.

关 键 词：磁性液体密封 屈服应力 启动扭矩 链状结构 

分 类 号：TB43[一般工业技术]