DESCRIZIONE
A magnetic seal device that includes a magnetic sleeve having a cylindrical body that and fits on an outer peripheral surface of a rotatable shaft, a ring shaped magnet being arranged radially outwardly from an outer peripheral surface of the magnetic sleeve with a gap, and a magnetic circuit formed between the outer peripheral surface of the magnetic sleeve and the ring shaped magnet. A magnetic fluid is maintained at the gap. The magnetic sleeve includes a groove arranged circumferentially around the outer peripheral surface of the magnetic sleeve, and a flange extending radially outwardly from and circumferentially around the outer peripheral surface of the magnetic sleeve. The flange has a diameter that is larger than a diameter of the outer peripheral surface of the magnetic sleeve.