Patent ID: 6672592
Filing Date: 2004-01-06
Classification: F16J

Abstract:
A magnetic fluid seal for sealing a circular space between a shaft and a housing, comprising:a magnetic force generating member that is arranged so that one end thereof corresponds to a north pole and the other end thereof corresponds to a south pole in a shaft extending direction; a pair of magnetic pole members that are respectively provided on both sides of said magnetic force generating member so that the magnetic force generating member is sandwiched therebetween, each of said pair of magnetic pole members includes a plurality of holding projections that extend toward a surface of said shaft and hold a magnetic fluid in a space between the holding projections and the shaft surface, a distance between the holding projections, which are nearest to the magnetic force generating member among the holding projections of the pair of magnetic pole members, is shorter than a length of the magnetic force generating member in the shaft extending direction, and an intercepting seal for intercepting a space between said magnetic force generating member and the shaft surface being provided between the holding projections that are nearest to said magnetic force generating member.