PURPOSE: To generate the flow of magnetic fluids with respectively different viscosity, so that lowness of torque, highness of rotational speed and longevity can be attained, by adjacently arranging a radial bearing and the first magnetic fluid seal, arranging the second magnetic fluid seal with a predetermined space provided from the first magnetic fluid seal, and providing space between the first/second magnetic fluid seals.
CONSTITUTION: A radial bearing 3a and the first magnetic fluid seal El are adjacently arranged, and the second magnetic fluid seal E2 is arranged by providing a space of a radiating ring 6 from the first magnetic fluid seal E1, to constitute a magnetic fluid bearing device by providing space (p) between the first/second magnetic fluid seals E1, E2. Consequently, magnetic fluid ×1 of low viscosity is used as lubricating liquid (o) for radial bearings 3a, 3b of large contact area with the first magnetic fluid seal E1 and a rotary shaft 1. A vaporized solvent is sealed with the second magnetic fluid seal E2, used with magnetic fluid ×2 of suitable viscosity with low volatility, to seal scattering oil to a rotary polygon mirror chamber (q).
Akiyoshi Takahashi
Toshiya Uchida
