Nsk Corporation

Taisuke Maruyama

Masayuki Maeda

Suguru Sugawara

Ken Nakano

Yujiro Toda

Eri Watabe

Koichi Hachiya

Takenobu Inaba

Shunsuke Iwase

There is provided a state detection method for detecting an oil film state according to a lubricant in a device configured to lubricate a plurality of parts with the lubricant, the method including: a measurement step of measuring impedance and a phase angle of an electric circuit by applying an AC voltage to the electric circuit configured with the plurality of parts while changing a frequency; and a derivation step of deriving an oil film thickness according to the lubricant and a parameter indicating an electrical characteristic according to the oil film thickness, based on a relative dielectric constant at a high frequency limit of the lubricant defined based on a composition of the lubricant, and the impedance and the phase angle measured in the measurement step.

Oil film state detection method, state detection device, and program

A detection method for detecting a state of a bearing device including an outer member, an inner member, and a plurality of rolling elements, the detection method including: applying an alternating current voltage to an electric circuit including the outer member, the rolling element, and the inner member while a predetermined load is applied to the bearing device; measuring an impedance and a phase angle of the electric circuit applied with the alternating current voltage; and deriving an oil film thickness and a metal contact ratio between the inner member and the plurality of rolling elements or between the inner member and at least one of the plurality of rolling elements based on the impedance and the phase angle.

Detection method of state of bearing device, detection device, and program

A method for diagnosing a rolling device () including an outer member (), an inner member (), and rolling elements () includes: applying an AC voltage to an electric circuit including the outer member (), the rolling elements (), and the inner member (); measuring an impedance and a phase angle of the electric circuit when the AC voltage is applied; and measuring a dielectric constant of a lubricant at least one of between the outer member () and the rolling elements () and between the inner member () and the rolling elements () based on the measured impedance and the measured phase angle.

Method for diagnosing rolling device

The rolling bearing of the present invention is lubricated with a lubricant composition which contains a fatty acid metal salt, a metal dithiocarbamate, a phosphorous-type additive, and a basic additive, and which has a total acid value of 3.7 mgKOH/g or more. The rolling bearing makes it possible to further improve anti-fretting performance, and to reduce a decrease in fretting resistance even when used under the circumstance that fluorine-type grease penetrates into the bearing using urea-type grease.

Lubricant composition and rolling bearing having same sealed therein

A lubricant composition according to the present invention contains a fatty acid metal salt, a metal dithiocarbamate, and an additive having an effect of increasing an acid value of the lubricant composition, whereby fretting resistance performances are further improved.

Lubricant composition

A lubricant deterioration detection device of the present invention includes a gas sensor that selectively detects a carbonyl compound. The gas sensor is configured to detect the carbonyl compound from at least one of formaldehyde, acetaldehyde, propanal, butanal, pentanal, n-hexanal, n-heptanal, formic acid, and acetic acid. The detection deterioration device further includes an oil removal portion that removes an oil mist generated from the lubricant.

Lubricant deterioration detection device and lubricant deterioration state evaluation method

A method is for diagnosing a rolling device comprising an outer member, an inner member, and a rolling element. The method includes applying an alternating voltage to an electric circuit configured by the outer member, the rolling element and the inner member, measuring an impedance and a phase of the electric circuit when the alternating voltage is applied to the electric circuit, and calculating a lubrication film thickness and a metallic contact ratio between the outer member and the rolling element and/or between the inner member and the rolling element, based on a measured impedance and a measured phase.

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Fujisawa, Japan

Taisuke Maruyama