背向串联式磁性液体密封聚磁结构特性分析

摘要

The magnetic field concentrating structure of magnetic fluid sealing with back-to-back polarity series has multiple annular permanent magnets and annular pole pieces which arrange alternately, and the polarity of annular permanent magnets is opposite to each other. Numerical analysis was conducted for the magnetic field concentrating behaviors of magnetic fluid sealing structures with back-to-back polarity series. The influences of such structure parameters to the field concentrating behavior as the thicknesses of annular permanent magnets, the thicknesses of annular pole pieces, the sizes of sealing gaps,and the radial width of annular laminated structures,were discussed. The results show that high density concentrated magnetic flux areas,which are separated periodically by the weak magnetic flux area,can be successfully formed along sealing paths in a relatively limited space. But there exist local dense fields in the periodic weak areas, which are harmful to compactness and the sealing ability improving.%背向串联式磁性液体密封的聚磁结构中有多个永磁环和极靴环交替相间排列,且相邻永磁环的极性彼此相反.采用ANSYS有限元软件对背向串联式磁性液体密封聚磁结构特性进行数值分析,分析永磁环厚度、极靴环厚度、密封间隙大小以及叠层环径向宽度等结构参数对密封间隙路径上的磁通密度分布特性的影响.结果表明,背向串联式磁性液体密封聚磁结构可以在相对有限的结构空间内,在其密封间隙路径上较好地形成强弱相间的周期性变化磁通密度分布；但是密封间隙路径上周期性出现的弱磁场区域内存在局部强磁场,不利于提高密封性能和结构紧凑性.