Nok Corporation

Hiroshi Anzai

Yoshimi Imamoto

Takao Kanno

Hirokazu Yamamoto

Takemi Namba

A magnetic fluid seal device that increases a permissible value of eccentricity for two members to improve sealability and decreases a variation of quality by injecting a magnetic fluid before assembling of parts, that saves structural members to achieve thinning, and that is easy to produce. An annular magnetis buoyantly supported by the magnetic fluidandretained, and the space between a housingand a shaftis sealed by the annular magnetand magnetic fluidand

Magnetic fluid seal device

A high-performance magnetic fluid sealer which maintains light-shielding property even when an interval change of a gap is large and a method for easily mounting a magnetic fluid sealer. A pair of annular magnets are supported by levitation from a lens barrel by magnetic levitation force which a magnetic fluid imparts in a fitting groove in the inner peripheral face of a lens barrel. Therefore, even when the lens barrel is greatly eccentric to the lens barrel, the pair of annular magnets move radially so as to keep a constant gap from the lens barrel with the magnetic fluid.

Magnetic fluid sealer and method for mounting magnetic fluid sealer

In a housed state, a magnetic fluid is positioned in a groove and spaced from the outer circumference of a lens barrel , so that a fluorochemical surface modification film of the outer circumference of the lens barrel can be prevented from deteriorating at a position to confront the magnetic fluid in the housed state. Therefore, the deterioration of the fluorochemical surface modification film of the outer circumference of the lens barrel does not proceed earlier at a local region, so that the premature wetting of the outer circumference of the lens barrel with the magnetic fluid can be prevented to elongate the lifetime of a light shielding device

There is provided a light shielding apparatus with a light shielding seal that reduces a sliding resistance and, at the same time, improves light shielding property and realizes saving of a space. There is provided a light shielding structure that is provided between a plurality of members and , which are arranged to be able to move relatively to each other spaced a predetermined distance apart, and is capable of preventing light from entering from a gap to be formed between these plurality of members and , having magnetic force generating means and that are disposed in any one of the above-mentioned plurality of members and and magnetic fluid which is magnetically held by the magnetic force generating means and and contacts the other member and shielding a gap, which is formed between the above-mentioned plurality of members and , by the above-mentioned magnetic fluid

Light shielding structure

A magnetic fluid seal with an excellent quality for reduction of leak of magnetic fluid. Among the projections of the pole pieces, the projections, that are nearest to the permanent magnet, are placed at positions intruding into the permanent magnet sides to hold the magnetic fluid in a space between the projections and the surface of the shaft.

Growing community of inventors

Fujisawa, Japan

Hiroshi Anzai