MAGNETIC FLUID SEAL Russian patent published in 2018 - IPC F16J15/43 

FIELD: machine engineering.

SUBSTANCE: magnetic fluid seal comprises a body 1, bearings 3, 4, a movable shaft 2 and a magnetic system 5 with movable 7 and stationary 8 magnetic cores and with permanent magnets 6. At least one of the magnetic cores has ring grooves 12, in which the permanent magnets are installed, slots divide magnetic circuits into areas of pole shoes 14 and areas of tightly interconnected pole tips of thin jumpers. The mutually facing surfaces of the movable and stationary magnetic cores are spaced from each other at certain distances - gaps. Circular teeth for concentration of magnetic field are made on at least one of the surfaces of the magnetic cores, the vertices of the circular teeth are in the area of pole faces. The minimum distances between the vertices of the teeth and the opposite surface or vertices of the circular teeth of another magnetic core form a working gap δ_z. On the circular teeth, there is a magnetic liquid in the form of circular liquid plugs. Said jumpers have variable thickness at their length. Additional circular teeth are introduced under the jumpers, the vertices of which are spaced at a distance δ_pz from the jumper surface located opposite, magnetic fluid forming additional circular plugs is also placed on said additional circular teeth.

EFFECT: increase of retained pressure with reduction of friction torque and start-up moment.

5 dwg