MAGNETIC FLUID SEAL Russian patent published in 2003 - IPC

FIELD: mechanical engineering. SUBSTANCE: invention can be used for sealing shafts of machines in different industries. Proposed seal contains housing, shaft installed on two bearings, pole attachments made in form of bushing with two or more ring grooves on outer surface. Permanent magnets are installed in grooves. Said magnets consists of separate simple-shape magnets and are uniformly spaced over circumference in one or more rows. Clearance between bushing and shaft is filled with magnetic fluid forming ring barriers on each magnetic field concentrator. If shaft is made of nonmagnetic material, magnetically conductive cylindrical attachment is installed on shaft under bushing, with magnetic field concentrators provided on outer surface of attachment, or hollow cylinder is installed on bearings in housing. Said cylinder accommodates bushing hermetically connected with shaft and enclosing magnetically conductive cylindrical attachment hermetically fitted in housing coaxially with bushing. Invention improves reliability of sealing by increasing value of critical pressure differential and provision of higher uniformity of working clearance over circumference and makes unnecessary installation of gaskets on each pole attachment for sealing static clearances between attachments and housing. EFFECT: improved reliability of sealing. 3 cl, 3 dwg