Study On The Application Of Magnetic Fluid Seals For Special Environment

The technology of Magnetic Fluid Seals has the natural advantage,such as non-pollution,friction-free,long-life and so on,which made it application widely under the engineering environment of demanding.Because of the sealed medium is corrosive sea water,this paper selected stainless steel,which was in corrosion resistance and low permeability,as the magnetic poles and shaft materials.The reserch improved the bearing capacity of magnetic fluid sealing by opimizing sealing structure and improving the performance of magnetic fluid,and solved the sealing problem of the ship pumps.At the same time,according to the demand of the magnetic fluid sealing sea water,the magnetic fluid interface stability were researched,and in order to increase the sealing ability of unit length along the axial shaft,the gear adding sealing structure were designed?The experiment of preparing cobalt powder adopts the method of homogeneous precipitation,urea as precipitant in this paper.The oleic acid modified zinc phosphate nanoparticles were synthesized by chemical co-deposition method.Adding a small amount of cobalt particles larger than the saturation magnetization microns into the traditional magnetic fluid,it would form"flexible magnetic poles"over the seal pole gear.Through research,this article came to the following conclusion:1.Magnetic fluid seal with the sealing gap increaseing,the sealing pressure drastically decreased;with the increasing in the number of adding-gear,sealing ability of magnetic fluid seal continued to increase.With the magnetic particles in magnetic fluid increasing,sealing ability continued to increase.With the rotating shaft speed increasing,the pressure value constantly reduced;each gear width,there was an optimum value of the gear gap which led pressure value to reaching maximum value.With the magnetic particles of Fe₃O₄ in magnetic fluid increasing,sealing ability continued to increase.With the rotating shaft speed reduced,the pressure value constantly increasing;2.The interface stability of magnetic fluid was characterized by the amount of water infiltration.With the volume fraction of reduces,the water intered into the magnetic fluid increased,and the magnetic fluid interface stability decreased.Compared with the water environment,the salt water environment promoted the amount of water infiltration.But as the time of scouring extended,the infiltration rate gradually reduced.The interface stability of Fe₃O₄ magnetic fluid was characterized by the amount of water infiltration.3.Adding a small amount of cobalt particles larger than the saturation magnetization microns into the traditional Fe₃O₄ magnetic fluid,it would form"flexible magnetic poles"over the seal pole gear.The forming of"flexible magnetic poles"improve the magnetic fluid sealing ability markedly.