Patent ID: 8366116

Claim:
A shaft-sealing device comprising, in combination: a shaft sleeve adapted to receive a rotary shaft to rotate jointly with the rotary shaft; an outer ring mounted around the shaft sleeve, with the outer ring including first and second ends spaced along an axis, with the outer ring further including inner and outer peripheral surfaces spaced in the radial direction, with the outer ring further including a through-hole extending from the inner peripheral surface through the outer peripheral surface; a magnetic-field generating unit mounted around the shaft sleeve, with the magnetic-field generating unit including inner and outer magnetic rings spaced in a radial direction perpendicular to the axis, with the inner magnetic ring including inner and outer peripheries spaced in the radial direction, with the inner periphery of the inner magnetic ring mounted around and abutting the shaft sleeve, with the outer magnetic ring mounted in the outer ring and between the outer ring and the inner magnetic ring in the radial direction, with the outer magnetic ring including an inner periphery facing the outer periphery of the inner magnetic ring, with a gap defined between the inner periphery of the outer magnetic ring and the outer periphery of the inner magnetic ring, with the gap adapted to be filled with a magnetic liquid, with the outer magnetic ring further including a hole in communication with the through-hole, with one of the inner and outer magnetic rings being a magnet for creating a magnetic field providing magnetic force to retain the magnetic liquid in the gap, with the magnetic liquid adapted to be filled in the gap through the hole and the through-hole; and a first seal ring mounted in the outer ring and located between the outer magnetic ring and the first end of the outer ring, with the first seal ring including inner and outer peripheries spaced in the radial direction, with the shaft sleeve extending through the first seal ring, with the first seal ring further including a first lip extending from the inner periphery of the first seal ring toward the first end of the outer ring, with the first lip of the first seal ring at a non-parallel angle to the radial direction of the first seal ring to form a first seal around the shaft sleeve.