Ntn Corporation

Hideyuki Tsutsui

Kouya Oohira

Masakazu Hirata

Masaki Egami

Yoji Sato

Masashi Kitai

Naoko Ito

Tomoya Sakaguchi

Eiichirou Shimazu

Kenji Tamada

Naoaki Tsuji

Masaki Nakanishi

Sadatoshi Inagaki

Takumi Shimokusuzono

Kouma Katou

Miki Arihana

Kohei Kamiya

An abnormality diagnosis device according to the present invention detects damage to a bearing device based on vibration data on acceleration of the bearing device. The abnormality diagnosis device includes a first filter, a second filter, and a diagnosis unit. The first filter is configured to extract a first vibration waveform belonging to a frequency band from the vibration data. The second filter is configured to extract a second vibration waveform belonging to a second frequency band higher than the first frequency band from the vibration data. The diagnosis unit is configured to diagnose that there is damage to the bearing device when an evaluation value calculated by dividing a first amplitude of the vibration waveform by a second amplitude of a second vibration waveform at a time at which the first amplitude has occurred exceeds a determination value, the first amplitude exceeding a reference value.

Abnormality diagnosis device and abnormality diagnosis method

A state monitoring method and a state monitoring apparatus which achieve a lower error rate are provided. Rather than collectively processing whole measurement data, the state monitoring apparatus divides the whole measurement data into a plurality of segments and processes each segment. From the measurement data, training data and test data to which an anomaly detection approach is to be applied is randomly selected. By repeatedly calculating an anomaly ratio and averaging the anomaly ratios, a result of discrimination is stabilized.

State monitoring method and state monitoring apparatus

A state monitoring system for monitoring state of a gear device having a plurality of gear pairs has a meshing frequency determination device. The meshing frequency determination device includes a maximum-peak-amplitude calculation unit that calculates a maximum peak amplitude from a detected meshing vibration, in estimated frequency ranges and a set harmonic region, and selects such estimated frequencies that a difference in maximum peak amplitude between a plurality of estimated frequency ranges, is less than or equal to a predetermined multiple, and a meshing frequency determination unit that determines an estimated frequency having a total value of maximum peak amplitudes calculated in the plurality of estimated frequency ranges, within a predetermined time, being the k-th (k is a natural number) greatest among the selected estimated frequencies, as a meshing frequency of a gear pair having the k-th highest tooth surface speed.

State monitoring system of gear device and state monitoring method

A vibration analysis method includes the steps of: inputting damage data of a rolling bearing; calculating, by a dynamics analysis program, a history of an exciting force occurring to the rolling bearing due to damage when a rotational shaft of the rolling bearing is rotated; calculating, by a mode analysis program, a vibration characteristics model of the bearing device; and calculating a vibration waveform at a predetermined position on the bearing device by applying to the vibration characteristics model the history of the exciting force calculated in the step of calculating a history of an exciting force.

Bearing device vibration analysis method, bearing device vibration analyzer, and rolling bearing condition monitoring system

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

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

Reliability of a mechanical part including two parts fixed to each other by an anaerobic adhesive is improved, at least one of the two parts being made of a resin material. After UV treatment is performed on an adhesive surface () with respect to a bracket () of an outer peripheral surface () of a housing () made of the resin material, the housing () is fixed to the bracket () by the anaerobic adhesive, whereby an adhesive strength per unit area of 8 N/mmor more is obtained for both parts. The UV treatment is performed by irradiating an electromagnetic wave, of an electromagnetic wave irradiated from a light source (), transmitted through an infrared cut filter () having a transmittance of 50% or more and 80% or less in an electromagnetic wave having a wavelength of 254 nm, onto the adhesive surface () of the housing ().

Mechanical part and manufacturing method for the same

A retainer for a rolling bearing, which is used for a food machine or a vacuum apparatus, containing an increased amount of a lubricating oil and enhancing a use efficiency of the lubricating oil and rolling bearing is described. The retainer consists of a molding, of a synthetic resin composition, which holds a rolling element of a rolling bearing. The molding is composed of a resinous porous article having an interconnected hole porosity not less than 30% and a lubricating oil which impregnates the resinous porous article. The resinous porous article has an interconnected hole are formed by molding a resin containing a pore-forming substance having a melting point higher than that of the resin and can be used as a food material, and by extracting said pore-forming substance from the molding with a solvent which dissolves the pore-forming substance and does not dissolve the resin.

Retainer for roller bearing, and rolling bearing

The present invention provides a porous resinous oil-retaining article, containing lubricating oil, which is excellent in the utilization efficiency of the lubricating oil, has a high mechanical strength, and further allows the resin and the lubricating oil to be combined with each other according to a use and a specification. The present invention also provides a method of producing the resinous oil-retaining article. The resinous oil-retaining article comprises a resinous porous article having interconnected holes which are open to a surface of the resinous porous article; and an oil impregnated into the resinous porous article. The interconnected holes are formed by molding a resin containing a pore-forming substance into a molding and extracting a part of the pore-forming substance from the molding with a solvent which dissolves the pore-forming substance and does not dissolve the resin. An interconnected hole porosity of the resinous porous article is not more than 30%.

Resinous oil-retaining article and method for production thereof

In a thrust needle bearing employing lubricating oil and having rollers held by a cage and rolling on races, the value of the arithmetic average roughness Ra of roller is 0.03 to 0.15 &#x3bc;m. Even when the bearing is used under the conditions where lubrication is lean or lubrication characteristics are wrong, the rolls can be prevented from being worn at the contact parts thereof with the pocket guide face of the cage and the life of the rollers and races can be increased.

Thrust needle bearing

The present invention provides a resinous porous article having a high interconnected hole porosity and capable of retaining a large amount of a lubricating oil and does not rust iron and steel, even though an unextracted portion of a pore-forming substance bleeds out when the resinous porous article is used as parts which contact a metal portion or the like and a method of producing the resinous porous article. The resinous porous article is formed by a producing method of molding a resin containing the pore-forming substance into a molding, and extracting the pore-forming substance from the molding with a solvent which does not dissolve the resin therein. The resinous porous article has an interconnected hole porosity not less than 30%. The pore-forming substance consists of an alkali compound.

Resinous porous article and method for production thereof

Retainer for rolling bearing, and rolling bearing

A sliding material including a resinous porous article having an interconnected hole porosity of not less than 30% and a lubricating oil which impregnates the resinous porous article is disclosed. The resinous porous article has an interconnected hole formed by molding a resin mixed with a pore-forming substance into said resin, and extracting said pore-forming substance from said molded article with a solvent which dissolves said pore-forming substance and does not dissolve said resin. A sliding bearing composed of a sliding material having a sliding surface which slides on a mating member and a lubricating oil supply layer which supports the sliding material and supplies the sliding surface with the lubricating oil.

Growing community of inventors

Kuwana, Japan

Hideyuki Tsutsui