Hitachi Powdered Metals Co., Ltd.

Hitachi Industrial Equipment Systems Co., Ltd.

Japan Servo Co.,ltd.

Denso Corporation

Hitachi Chemical Company, Ltd.

Kobe Steel, Ltd.

Resonac Corporation

Other

Hitachi, Ltd.

Hitachi Metals, Ltd.

Nidec Servo Corporation

Kabushiki Kaisha Kobe Seiko Sho

Chio Ishihara

Kazuo Asaka

Yuji Enomoto

Motoya Ito

Ryoso Masaki

Shoji Ohiwa

Takashi Inagaki

Yasuaki Motegi

Masashi Kitamura

Tsuyoshi Akao

Katsuyuki Yamazaki

Kohei Muramatsu

Akio Takahashi

Kenji Miyata

Yuichi Satsu

Hiroaki Miyata

Noboru Baba

Hideaki Katayama

Kei Ishii

Hiroyuki Mitani

Yuzo Ito

Nobuaki Akagi

Kazuhiro Satou

Kouki Isozaki

Isao Makino

Chikara Tanaka

Hirofumi Houjou

Makoto Iwakiri

Tamio Takada

Hirotake Hamamatsu

Tadashi Sato

Sohei Yamada

Kazumasa Takeuchi

Noriyuki Nakayama

Fumio Tajima

Shigeru Kakugawa

Haruo Koharagi

Masahiro Mita

Hideo Maeda

Masahiko Osaka

Ryozo Masaki

Akeshi Takahashi

Jiro Shima

Kosuke Urashima

Katsuyuki Yamasaki

Yasukumi Mochimizo

Masahide Yamazaki

Masaki Yanaka

Yasukuni Mochimizo

Kazumasa Ide

Teruo Itoh

Arisa Taira

Hiroaki Kondo

Motoya Hitachi Ltd Ito

Ryozo Hitachi Ind Equip Syst Co Ltd Masaki

Yuji Hitachi Ltd Enomoto

A compound for dust core includes a metal powder including iron, a resin composition, and a metal salt, in which the metal salt is represented by RM, R represents a saturated fatty acid group having 6 or more and 12 or less carbon atoms, and M represents at least one metal element between Ca and Ba.

Dust core compound, molded body, and dust core

A compound comprises a resin composition containing an epoxy resin, a phenol resin, a wax, and an imidazole compound, and a metal element-containing powder, wherein the epoxy resin comprises a crystalline epoxy resin, the wax comprises a montanic acid ester, and the content of the metal element-containing powder is 90 mass % or more based on the total mass of the compound.

Compound and tablet

Provided is a powder magnetic core for a reactor, whose electromagnetic properties are difficult to change with time, even when applied to a reactor used in a state that the core is exposed without being potted. The powder magnetic core for a reactor consists essentially of a compact composed of an insulation-coated iron-based soft magnetic powder that an insulating film is formed on the surface of an iron-based soft magnetic powder, and which has such a change with time of 500 hours at 180&#xb0; C. that a ratio of decrease in effective magnetic permeability being 1% or less. In the compact, the content of gapping between two adjacent particles of the insulation-coated iron-based soft magnetic powder is 2 vol % or less.

Powder magnetic core for reactor

The powder magnetic core of the present invention can exhibit reliable superposition property in which variance rate of inductance value is small even if superposed current is varied, and can reduce the number of cores used in a reactor. The powder magnetic core comprises: soft magnetic powder particles, and gaps between the soft magnetic powder particles, in which the powder magnetic core has a density ratio of 90 to 95%, and when observing a cross section thereof, layered gaps having thicknesses of 1 to 3 &#x3bc;m and widths of 20 to 200 &#x3bc;m are formed inside of the powder magnetic core. It is desirable that the layered gaps be not less than 50% of all the gaps in a cross sectional area ratio.

Powder magnetic core and reactor using the same

The compact for a magnetic core is manufactured by filling a soft magnetic powder in the die hole, pressing it to form a compact at a density ratio of the soft magnetic powder being 91% or more, and extruding it from the die hole. Before filling the soft magnetic powder to the die hole, a lubricating coating containing lubricating oil and molybdenum disulfide particles is formed on the inner surface of the die hole. It is more effective when further containing insulating ceramic particles. On the extrusion-sliding surface, the compact has a surface layer of the structure that molybdenum disulfide particles and the insulating ceramic particles are interposed between the soft magnetic powder particles, and insulation of soft magnetic powder particles in the surface layer is not destroyed by extrusion. This provides a powder magnetic core suitable for high frequency application.

Powder magnetic core, method of manufacturing powder compact for magnetic core, die and die assembly for manufacturing powder magnetic core, and die lubricating composition for manufacturing powder magnetic core

The present invention provides a powder magnetic core which has a low iron loss and an excellent constancy of magnetic permeability and is suitably used as a core for a reactor mounted on a vehicle. The powder magnetic core is a compact of a mixed powder containing an iron-based soft magnetic powder having an electrical insulating coating formed on its surface and a powder of a low magnetic permeability material having a heat-resistant temperature of 700&#xb0; C. or higher than 700&#xb0; C. and a relative magnetic permeability of not more than 1.0000004. The density of the compact is 6.7 Mg/mor more, and the low magnetic permeability material exists in the gap among the soft magnetic powder particles in the green compact.

Powder magnetic core and method for producing the same

An iron-based magnetic powder for dust cores has layers of phosphoric acid-based film and silicone resin film sequentially formed on the surface thereof. The phosphoric acid-based film contains at least one element selected from the group consisting of Co, Na, S, Si, and W. The iron-based powder effectively keeps insulation among iron powder particles, excels in mechanical strength even though the amount of insulating material is reduced due to achieve high-density forming, and exhibits good thermal stability necessary for electrical insulating properties even after high-temperature heat treatment.

Iron-based soft magnetic powder for dust core, method for production thereof, and dust core

A powder mixture, which contains a soft magnetic powder and an insulating powder lubricant in an amount of 0.1% by mass or more relative to the soft magnetic powder, is formed by compacting at a compacting pressure of 800 MPa or less, thereby obtaining a powder compact that has a space factor of the soft magnetic powder of 93% or more. The powder compact can be used as a soft magnetic powdered core. The soft magnetic powdered core has a specific resistance or 10,000 &#x3bc;&#x3a9;cm or more. A powder of a metal soap such as barium stearate or lithium stearate is used as the insulating powder lubricant.

Soft magnetic powdered core and method for producing same

The present invention relates to an iron-base powder for a powder core, wherein when cross-sections of at least 50 iron-base powders are observed and a crystal grain size distribution containing at least a maximum crystal grain size is determined by measuring a crystal grain size of each iron-base powder, 70% or more of the measured crystal grains are a crystal grain having a crystal grain size of 50 &#x3bc;m or more. According to the iron-base powder of the invention, a coercivity of the powder core can be made small and a hysteresis loss can be reduced.

Powder core and iron-base powder for powder core

A method for producing a soft magnetic powdered core includes preparing a mixture of a soft magnetic powder and a resin powder, compacting the mixture into a predetermined shape so as to obtain a compact, and heating the compact. The resin powder has a median size of not more than 30 &#x3bc;m, a maximum particle size of not more than 100 &#x3bc;m, and a specific surface area of not less than 1.0 m/cm, and the additive amount thereof is 0.005 to 2 vol %.

Method for producing soft magnetic powdered core

A method for producing a soft magnetic powdered core comprises a mixing step for forming a raw powder by adding a thermoplastic resin powder to a soft magnetic powder and mixing them, a compacting step for forming a compact by compacting the raw powder into a predetermined shape, a melting and setting step for the resin in which the resin of the compact is melted by heating to at least the melting point of the thermoplastic resin and the melted resin is set by cooling to a room temperature, and a crystallizing step for the resin in which the set resin is heated to not less than the exothermic onset temperature and not more than the endothermic onset temperature, which are measured by DSC analysis of the thermoplastic resin, and is cooled to a room temperature.

A claw pole type motor includes first and second claw poles opposed to each other and each including a radial yoke portion having an inner diameter side and an outer diameter side, a plurality of pole portions arranged on the inner diameter side, and axially extended, and an outer peripheral side yoke portion extending on the outer diameter side. A stator core is provided having an inner diameter side, and is formed so as to cause the pole portions of the first claw pole to be meshed with the pole portions of the second claw pole. A rotor is arranged on the inner diameter side of the stator core with a circumferential gap being defined therebetween. In order to provide high efficiency while simplifying manufacturing, the first and second claw poles are formed by compacting of magnetic powder.

Multiple phase claw pole type motor

A multiphase claw-pole type electric rotary machine has two or more phases-stator units. The stator units are arranged phase by phase in an axial direction of the electric rotary machine. Each phase stator unit comprises a pair of complementary-opposed claw pole core blocks and a ring-shaped stator coil sandwiched therebetween. The stator units have structures rotatably adjustable independent of each other in their phase positional relations while maintaining concentricity of them after assembly of the rotary machine before being secured.

Multiphase claw-pole type electric rotary machine, cogging torque adjustment system of the same, generator system, and motor system

To realize reduction in vibration and noise while utilizing reluctance torque, a rotating electrical machine includes: a rotor having permanent magnets disposed in a cylindrical surface coaxial with a rotary shaft; and a stator having an annular stator core disposed coaxially with the rotary shaft, and a annular coil for magnetizing the stator core. The stator core has an annular part covering the annular coil, claws disposed at equal intervals in an inner radius surface of the annular part and extending axially, and magnetic gaps formed between neighboring claws. The number of claws is equal to the number of permanent magnets, and magnet flux in a direction orthogonal to a center axis of the magnetic pole of the permanent magnet at right angles in electric angle is larger than magnetic flux in the center axis direction generated between neighboring permanent magnets. Metal interpoles are provided between neighboring permanent magnets.

Claw-teeth-type rotating electrical machine

In a multiple phase claw pole type motor which includes: a plurality of claw poles including a claw portion extending in an axial direction and having a magnetic pole surface facing a rotor in a state of being separated from the rotor by a small gap, a radial yoke portion extending radially outwardly from this claw portion, and an outer peripheral yoke extending from this radial yoke portion in the same direction as the direction of extension of the claw portion; a stator core formed by alternately placing the claw poles in a circumferential direction so that a distal end of each claw portion faces the outer peripheral yoke of an adjacent one of the claw poles; and a stator constructed by sandwiching an annular coil with the adjacent claw poles of this stator core, a multiple phase claw pole type motor characterized in that the claw poles are formed by compacting a magnetic powder and are formed of a magnetic compact having a DC magnetizing property of its flux density becoming 1.7 teslas or more when 10000 A/m of magnetic field is applied.

Growing community of inventors

Tokyo, Japan

Chio Ishihara