Disclosed are a soft bistable magnetic actuator, a fabrication method thereof, a fatigue testing device, and an auto underwater vehicle. The method for fabricating the soft bistable magnetic actuator includes the following operations: casting a soft precursor by injection molding, wherein the soft precursor consists of a soft deformable portion and a soft peripheral portion surrounded, the soft deformable portion is made of magnetic particles and polymer, and the soft peripheral portion is made of a magnetic particle, a mixture of organic liquid, and polymer; and extracting the organic liquid by an organic solvent shrinks the soft peripheral portion, buckles the soft deformable portion towards one side.

Provided is a method for a magnetic encoder having a magnetic body comprised of a magnetic rubber molded article, comprising a mixing step of mixing and then kneading a nitrile rubber (A), a ferrite magnetic powder (B) and a vulcanizing agent (C) to provide a magnetic rubber composition; and a molding step of molding and vulcanizing the magnetic rubber composition in a mold to which a magnetic field is applied to provide the magnetic rubber molded article, wherein a content of the ferrite magnetic powder (B) is 700 to 1500 parts by mass based on 100 parts by mass of the nitrile rubber (A); and a compressed density of the ferrite magnetic powder (B) is 3.5 g/cm.sup.3 or more. According to this method, a magnetic encoder having a magnetic body with high coercivity and residual magnetic flux density can be produced by vulcanizing a magnetic rubber composition having favorable moldability.

The magnetic encoder is constituted by integrally bonding a magnet portion obtainable by forming a magnetic material containing a magnetic powder and a binder for the magnetic powder in a circular ring shape to a slinger. The binder contains at least a thermoplastic resin and an impact resistance-improving agent.

The magnetic encoder is constituted by integrally bonding a magnet portion obtainable by forming a magnetic material containing a magnetic powder and a binder for the magnetic powder in a circular ring shape to a slinger. The binder contains at least a thermoplastic resin and an impact resistance-improving agent.

There is provided a magnetic rubber composition comprising a rubber (A), a thermosetting resin (B) and a magnetic powder (C), wherein a mass ratio (A/B) of the rubber (A) to the thermosetting resin (B) is 0.2 to 5, and a mass ratio [C/(A+B)] of the magnetic powder (C) to the total mass of the rubber (A) and the thermosetting resin (B) is 0.5 to 20. It gives a magnetic rubber molded article excellent in flexibility and abrasion resistance, and a magnetic encoder produced therewith.

There is provided a magnetic rubber composition comprising a rubber (A), a thermosetting resin (B) and a magnetic powder (C), wherein a mass ratio (A/B) of the rubber (A) to the thermosetting resin (B) is 0.2 to 5, and a mass ratio [C/(A+B)] of the magnetic powder (C) to the total mass of the rubber (A) and the thermosetting resin (B) is 0.5 to 20. It gives a magnetic rubber molded article excellent in flexibility and abrasion resistance, and a magnetic encoder produced therewith.

A noise reduction tool includes a magnetic body that can be wound around, more than one turn around an axis of an electric wire or an electric wire bundle, the electric wire or the electric wire bundle and a fixing member that fixes, to each other, overlapping sections of a stacked portion in the magnetic body having a winding shape wound around the electric wire or the electric wire bundle and fixes the magnetic body to the electric wire or the electric wire bundle while keeping the winding shape of the magnetic body. The magnetic body is capable of changing a winding diameter according to an electric wire diameter of the electric wire or an electric wire bundle diameter of the electric wire bundle, and the fixing member fixes, to each other, the overlapping sections corresponding to a winding diameter of the magnetic body irrespective of the winding diameter.

A noise reduction tool includes a magnetic body that can be wound around, more than one turn around an axis of an electric wire or an electric wire bundle, the electric wire or the electric wire bundle and a fixing member that fixes, to each other, overlapping sections of a stacked portion in the magnetic body having a winding shape wound around the electric wire or the electric wire bundle and fixes the magnetic body to the electric wire or the electric wire bundle while keeping the winding shape of the magnetic body. The magnetic body is capable of changing a winding diameter according to an electric wire diameter of the electric wire or an electric wire bundle diameter of the electric wire bundle, and the fixing member fixes, to each other, the overlapping sections corresponding to a winding diameter of the magnetic body irrespective of the winding diameter.