磁性液体大间隙旋转密封装置的设计及实验研究

Theoretical and Experimental Research on Ferrofluid Rotary Sealing of Large Dimension and Large Gap

针对大型船舶装备中大功率电机冷却蒸发介质的密封问题,设计一种五级九齿大间隙磁性液体与磁性润滑脂组合旋转密封装置,该装置适用于大型船舶高横摇性、高腐蚀性的环境场合。通过耐压公式的理论推导,得到密封耐压能力随磁性液体的饱和磁化强度、磁性润滑脂的屈服应力和密封间隙内磁场梯度的增大而增大的结论。采用ANSYS对该装置间隙内的磁场分布进行有限元分析。在密封实验台上对该装置进行密封耐压实验,结果表明:在最大间隙0.7 mm时,其单级耐压能力仍能达到18 kPa,密封能力随转速的递增保持稳定。理论和实验表明,设计的该密封适合具有腐蚀性环境下的大功率电机或其他高振动装备的大间隙密封场合。

A combination large gap ferrofluid rotation sealing device of magnetic fluid and magnetic lubricating grease was designed for the sealing of the cooling medium of high power electric motor of large vessels equipment,which has five stage and nine tooth,and is suitable for large ships with high rolling and corrosive environment.The pressure formula of the ferrofluid rotation sealing device were derived theoretically.It is concluded that the pressure capacity is related with saturation magnetization of the ferrofluid,the yield stress of the magnetic grease,the magnetic field gradients in the sealing gap and other factors.The magnetic field distribution within sealing gap for the designed ferrofluid rotation sealing device was analyzed by using ANSYS.The pressure experiments were carried out on the sealing bench.The experimental results show that when the maximum gap is 0.7 mm,the single-stage pressure capacity can still reach 18 kPa,and the sealing ability keeps stable with the increase of rotational speed.The theoretical and experimental results show that the designed seal is suitable for large clearance sealing of high-power motor or other high-vibration equipment in corrosive environment.