摘要 |
A shaft seal containing magnetic liquid, for pump shafts or the like, consists of a permanent magnet which surrounds the shaft and is a distance away and one or more pole pieces connected to the said magnet. The pole piece, together with the shaft surface, forms an air gap in which the magnetic liquid is held by the magnetic field, so that a liquid sealing ring is produced. A volume of gas located between the magnetic liquid seal and the shaft channel to the medium prevents the magnetic liquid from coming into contact with the medium. |