Ntn Corporation

National Institute of Advanced Industrial Science and Technology

Kouya Oohira

Hideyuki Tsutsui

Tatsuo Nakajima

Kazutoyo Murakami

Arito Matsui

Masaki Egami

Yoji Sato

Masaki Nakanishi

Naoki Yashiro

Naoko Ito

Eiichirou Shimazu

Yoshinobu Akamatsu

Naoaki Tsuji

Takahiro Okuno

Yosuke Taguchi

Yoshihide Himeno

Miki Arihana

Setsuo Nakao

Philippe Blondel

Shinya Matsuno

Noritaka Kako

Sylvain Benet

Provided is a method of manufacturing a machine part having a radial crushing strength of 120 MPa or more, including: a compression molding step of compressing raw material powder including, as a main component, metal powder that is capable of forming an oxide coating and has a pure iron powder content ratio of 95 mass % or more, to thereby obtain a green compact () having a predetermined shape; and a coating forming step of causing the metal powder to react with an oxidizing gas while heating the green compact () at a temperature lower than a sintering temperature of the metal powder in an oxidizing gas atmosphere, to thereby obtain a reinforced green compact () in which the oxide coating () is formed between particles of the metal powder.

Method for producing machine component

A sintered compact having a density of 7.5 g/cmor more is formed by mixed powder. The mixed powder is obtained by mixing graphite powder having an average particle diameter of 8 &#x3bc;m or less and diffusion alloyed steel powder. The ratio of the graphite powder is from 0.05 wt % to 0.35 wt % with respect to 100 wt % of the diffusion alloyed steel powder. Or, the mixed powder is obtained by mixing the graphite powder and completely alloyed steel powder. The ratio of the graphite powder is from 0.15 wt % to 0.35 wt % with respect to 100 wt % of the completely alloyed steel powder.

Sintered machine part and method of manufacturing the same

The present invention provides a highly dielectric elastomer molded body which is inexpensive and excellent in its dielectric property, shock resistance, flexibility, and processability and can be used at a UHF band having 800 to 960 MHz and an electronic component material for a high frequency use. The highly dielectric elastomer molded body is formed by molding a highly dielectric elastomer composition comprising an elastomer and dielectric ceramic powder added thereto. The molded body has a tensile elongation not less than 250% and a hardness not more than 70. In measurement at a frequency of 950 MHz, a dielectric constant of the highly dielectric elastomer molded body is 4 to 10, and a dielectric dissipation factor thereof is not more than 0.02. An electronic component material for a high frequency use is made of the highly dielectric elastomer molded body.

Highly dielectric elastomer molded body and electronic component material for high frequency use

The present invention provides a hard film which has high wear resistance and excellent peeling resistance and can be prevented from peeling off a base material over a long period of time and a hard film formed body on which the hard film is formed. A hard film () has a structure composed of a first mixed layer (), consisting mainly of Cr and WC, which is formed directly on a raceway surface () of an inner ring () (base material) of a rolling bearing, a second mixed layer (), consisting mainly of WC and DLC, which is formed on the first mixed layer (), and a surface layer (), consisting mainly of DLC, which is formed on the second mixed layer (). In the first mixed layer (), a content rate of the Cr becomes continuously or stepwise lower and that of the DLC becomes continuously or stepwise higher from a side of the base material toward a side of the second mixed layer (). In the second mixed layer (), a content rate of the WC becomes continuously or stepwise lower and that of the DLC becomes continuously or stepwise higher from a side of the first mixed layer () toward a side of the surface layer (). A content of hydrogen in the second mixed layer () is set to 10 to 45 atomic percent.

Hard film, hard film formed body, and rolling bearing

The present invention provides a film formation method capable of forming a favorable amorphous carbon film under a low vacuum by using a bipolar-type PBII apparatus and the amorphous carbon film to be produced by the film formation method. The film formation method is carried out to form the amorphous carbon film under a low vacuum (1000 to 30000 Pa) by using a power source for the bipolar-type PBII apparatus. There are provided inside a chamber () a power source side electrode () connected to a power source () for the PBII apparatus and a grounding side electrode () opposed to the power source side electrode (). A base material () is disposed on one of the power source side electrode () and the grounding side electrode (). Plasma of a noble gas and that of a hydrocarbon-based gas are generated between the base material () and the electrode where the base material () is not disposed to form the amorphous carbon film on a surface of the base material ().

Amorphous carbon film and method for forming same

A rolling bearing which is capable of preventing the rolling elements from dropping out from between the inner and the outer rings even when the separators have been worn to an advanced stage. A rolling bearing includes: a plurality of rolling elements arranged between an inner and an outer rings; and a plurality of prismatic separators disposed in a circumferential direction between the rolling elements. The separator includes integrally therewith a metal band on at least one of its outer surfaces including those which face the inner or the outer ring, or at least one of its axial side surfaces, excluding however, surfaces which face the circumferential direction and make contact with the rolling elements. The metal band has a narrower width than a width of the separator in the circumferential direction, and prevents wear of the separator from advancing beyond a certain extent.

Roller bearing

The present invention provides a rolling bearing in which the peeling resistances of a DLC film formed on raceway of inner and outer rings and a sliding surface of a cage are improved to allow the intrinsic properties of the DLC film to be displayed so that the rolling bearing is excellent in its resistance to seizing, wear, and corrosion. A rolling bearing () has an inner ring (), an outer ring (), a plurality of rolling elements (), and a cage (). A hard film () is formed on a curved surface such as a raceway () of the inner ring (), a raceway () of the outer ring (), and the like. The hard film () is composed of a foundation layer, composed mainly of Cr, which is formed directly on the curved surface.

Rolling bearing

The present invention provides a hard multilayer film formed body which has an intermediate layer excellent in its adhesion to a base material and a DLC film which is a surface layer excellent in its wear resistance, prevents peeling from occurring between the DLC film and the intermediate layer, and is excellent in its wear resistance and a method for producing the same. A hard multilayer film formed bodyconsists of a multilayer film formed on a surface of a base materialconsisting of a cemented carbide material or a ferrous material. The multilayer film has (1) a film, composed mainly of DLC, which is formed as a surface layerof the multilayer film; (2) an intermediate layer, composed mainly of a metallic material, which is formed between the surface layerand the base material; and (3) a stress relaxation layer, composed mainly of carbon, which is formed between the intermediate layerand the surface layer. The stress relaxation layeris a graded layer whose hardness increases continuously or stepwise from a side of the intermediate layertoward a side of the surface layer

Hard multilayer film formed body and method for manufacturing same

The present invention provides a member, for a resin-made rolling bearing, which has a low extent of a moisture absorption-caused change in its dimension and mechanical properties, keeps sufficiently high mechanical properties after the member absorbs moisture, and is excellent in its resistance to hydrolysis, grease deterioration, and heat and also provides the rolling bearing in which the member for the rolling bearing is used. A rolling bearing () has an inner ring (), an outer ring (), a plurality of rolling elements () interposed between the inner ring () and the outer ring (), a crown-shaped cage () for retaining the rolling elements (), and a seal () covering an opening disposed at a gap between the inner ring () and the outer ring (). The cage () and the seal () are moldings of a resin composed of polyphthalamide resin.

Member for rolling bearing and rolling bearing

It is an object of the present invention to provide a dielectric elastomer composition which has a sufficient dielectric property as a high-frequency electronic component material and to which an excellent flame retardance can be imparted as necessary in consideration of an influence on environment and the high-frequency electronic component material formed by molding the dielectric elastomer composition. The dielectric elastomer composition of the present invention comprises an elastomer to which (A) carbon black and (B) at least one powder selected from among magnesium hydroxide powder and dielectric ceramic powder is added. An average particle diameter of the carbon black is 50 to 200 nm, and 5 to 40 parts by weight thereof is added to 100 parts by weight of the elastomer. In the magnesium hydroxide powder, a content of ferric oxide is not more than 0.02 wt %. In at least one measuring condition selected from among a measuring condition (1) in which a frequency is 400 MHz and a temperature is 30&#xb0; C. and a measuring condition (2) in which a frequency is 5 GHz and a temperature is 25&#xb0; C., a dielectric constant is not less than three, and a dielectric dissipation factor is not more than 0.01.

Dielectric elastomer composition and high-frequency electronic component material

The present invention provides a dielectric elastomer composition which has been improved to have an excellent flame-retardant property in consideration of influence on environment and a satisfactory dielectric characteristic as a material for an antenna; and a member for the antenna formed by molding the dielectric elastomer composition. The dielectric elastomer composition contains 50 to 400 parts by weight of a metal hydroxide such as aluminum hydroxide powder, magnesium hydroxide powder and 10 to 200 parts by weight of a brominated flame retardant except polybromodiphenyl ether and polybromobiphenyl for 100 parts by weight of an elastomer such as ethylene propylene rubber. At a frequency of 1 GHz and a temperature of 30&#xb0; C., a dielectric constant of the dielectric elastomer composition is not less than 3, and a dielectric loss tangent thereof is not more than 0.02. The member for the antenna is formed by molding the dielectric elastomer composition.

Dielectric elastomer composition and antenna member

A rolling bearing is provided that includes an inner ring, an outer ring, and a plurality of rolling elements provided between a raceway surface of the inner ring and that of the outer ring and has a ceramic film formed on at least one surface selected from among an inner peripheral surface of the inner ring and a peripheral surface of the outer ring. The ceramic film is formed by using an aerosol deposition method in which alumina fine particles or the like is used as a material of aerosol. The ceramic film is formed with an aerosol injection nozzle kept stationary and the inner ring or the outer ring being rotated by using a motor for rotating an object, the inner ring or the outer ring is moved axially by using a positioning XY table.

Rolling bearing with a ceramic coating and method for manufacturing the same

The present invention provides a highly dielectric elastomer composition which shows a high dielectric constant in a wide temperature range from low to high temperature and has a low dielectric loss tangent, and a dielectric antenna composed of the highly dielectric elastomer composition. A dielectric antenna including a molding of a highly dielectric elastomer composition composed of an elastomer and a highly dielectric ceramic powder mixed with the elastomer and an electrode formed on the molding. The highly dielectric ceramic powder of barium titanate.neodymium ceramic has a temperature coefficient &#x3b1;(unit: 1/&#xb0; C.) of a dielectric constant of the ceramic powder on 25&#xb0; C. standard ranging from &#x2212;200&#xd7;10to 100&#xd7;10over a temperature range from &#x2212;40&#xb0; C. to 100&#xb0; C. The dielectric constant of the highly dielectric elastomer composition is &#x2267;7 and a dielectric loss tangent thereof is &#x2266;0.01.

Highly dielectric elastomer composition and dielectric antenna

A magnetic encoder includes a multipolar magnet, having magnetic poles formed therein so as to alternate with each other in a direction circumferentially thereof, and a core metal supporting the multipolar magnet. The multipolar magnet is prepared from a sintered element formed by sintering a powdery mixture of a magnetic powder and a non-magnetic metallic powder. This multipolar magnet is fixed to the core metal to form a unitary component made up of the sintered element and the core metal. The unitary component is subjected to a surface treatment for anticorrosion.

Magnetic encoder and wheel support bearing assembly using the same

To provide a magnetic encoder which can be assembled having a thin-walled structure while securing an excellent detection sensitivity and which can provide an excellent moldability by suitably selecting materials, the magnetic encoder is provided which includes a multi-pole magnethaving a plurality of opposite magnetic poles alternating in a direction circumferentially thereof, and a core metalfor supporting the multi-pole magnet. The multi-pole magnetcontains a powdery magnetic material mixed in an amount within the range of 20 to 90 vol. % relative to the total volume of the multi-pole magnet. The multi-pole magnetmay be a sintered magnet.

Growing community of inventors

Mie, Japan

Kouya Oohira