Hitachi, Ltd.

Takashi Shimaguchi

Tatsuo Natori

Toshihiro Yamada

Akihide Watanabe

Hideo Nakae

Syogo Morimoto

Toshinori Ozaki

Junji Sakai

Susumu Hioki

Keiichi Koike

Kazuaki Yokoi

Akihisa Okada

Hiroshi Misumi

Kazunori Nakane

Kensuke Kanekatsu

A magnet pump has a magnet coupling for magnetically coupling an inner ring yoke and an outer ring yoke so as to magnetically transmit a torque from driving part to driven part of the pump to rotate the driven part. The magnet pump comprises magnetized magnet pieces bonded to the outer peripheral surface of the inner ring yoke and magnetized magnet pieces bonded to the inner peripheral surface of the outer ring yoke; non-magnetic cylindrical covers covering the surface of the inner ring yoke carrying the magnet pieces and the surface of the outer ring yoke carrying the magnet pieces, respectively; and mold resin parts filling the gap between the surface of the inner ring yoke and the associated non-magnetic cylindrical cover and the gap between the surface of the outer yoke ring and the associated non-magnetic cylindrical cover. Also disclosed are a method of producing the magnet pump in which the non-magnetic cylindrical covers are used as molds, and a nuclear reactor equipment in which the magnet pump is used as a coolant circulation pump.

Magnetically coupled pump and nuclear reactor incorporating said pump

In a method for forming a cast article by slip casting through casting of a slip of powders of ceramics, etc. as disporsed in a solvent such as water, etc. into a solvent-absorbable, porous casting mold of gypsum, etc., the casting mold as made is heated to considerably lower the strength of the casting mold in a shape-maintainable range, the slip is cast into the cavity of the casting mold and after solidification of the slip into a green body the casting mold is removed to obtain a defect-free green body. The casting mold can be removed with much ease.

Method for forming cast article by slip casting

In a casting method comprising casting a slip containing water or an organic solvent as the medium into a mold and removing the mold after solidification of the slip, use of a mold formed with an organic binder soluble in the medium of the slip allows the slip to quickly solidify and afford a green body due to absorption of the medium in the slip by the mold. In this case, the mold softens with loss of the binding power thereof simultaneously with the absorption of the medium. Therefore, no cracks appear at all in the green body, and removal of the mold is very easy.

Slip casting method

A cast article having a complicated shape of the appearance and the hollow can be obtained by forming a coating film on the surface of a pattern from a solvent-insoluble material to prepare a mold pattern, filling and hardening a molding material around the mold pattern, dissolving the pattern with a solvent, and removing the residue of dissolution and the coating film outside the mold.

Process for preparing mold

A mold forming method in which a pattern is made of an organic material such as foamed polystyrene and at least a portion of the outer or inner surface of the mold pattern is covered by a thin coating, and surrounded with a mold material. The pattern is then dissolved by a solvent, leaving the coating undissolved. The coating is finally removed by a solvent contained in a slip which is poured into the cavity provided with the coating.

Method of producing mold for slip casting and method of molding slip

In a forming method and a mold wherein a slip is cast into the mold and wherein the mold is removed after hardening of the slip, the mold is patterned by the use of a water-soluble binder. The mold absorbs a water content in the slip to soften and to become easy of removal, while the slip has the water content absorbed to harden promptly. Therefore, the forming method and the mold are especially suited to produce a cast article of complicated shape.

Slip casting forming method and mold

A slip casting mold consisting essentially of a gypsum mold, which contains a water-insoluble organic material, more particularly, a water-insoluble vegetable material such as cellulose, or which further contains glue in addition to the water-insoluble organic material. Since the strength of the casting mold is reduced markedly by heating, a cast article requiring a core (or master mold) having complex shape can be obtained extremely easily.

Slip casting mold

A method of producing a vibration attenuating material having the steps of forming a multiplicity of grooves in the surface of a ductile raw material and subjecting the raw material to a drawing or rolling work to form a multiplicity of minute friction interfaces in the surface region of the vibration attenuating material. An improved vibration attenuating performance is ensured by a suitable selection of numerical values of factors such as relationship between the maximum depth of the friction interface and the thickness of the vibration attenuating material, pitch of the friction interfaces and so forth.

Method of producing vibration attenuating metallic material

Particulate material for forming molds produced by mixing particulate refractory material with one material selected from the group consisting of colloidal silica, colloidal alumina, colloidal zirconia and ethyl silicate, drying the mixture and allowing same to set, and crushing the dried mixture into particulate form again. The particulate material includes refractory particles provided with a coat of silica or alumina or zirconia on the surface and increases the strength and surface precision of a mold.

Particulate material for forming molds and method for producing same

One or a plurality of layers of a metallic raw material in plate form and one or a plurality of layers of wire netting are placed one over another in vertically stacked relation and then subjected to rolling to produce vibration absorbing metallic material. The metallic material produced in this way exhibits an excellent vibration damping performance.

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Ibaraki, Japan

Takashi Shimaguchi