Nsk Corporation

Kyodo Yushi Co., Ltd.

Suguru Sugawara

Taisuke Maruyama

Masayuki Maeda

Yujiro Toda

Eri Watabe

Kazuki Isa

Masatoshi Ijima

Yuki Takeyama

A grease composition for vehicular hub unit bearings is provided, in which a base oil is a synthetic hydrocarbon oil having a kinematic viscosity at 40° C. of 25-50 mm/s, a thickener is an alicyclic aliphatic diurea compound, based on a total mass of the composition, 0.1-5% by mass of a carboxylic acid-based corrosion inhibitor, 0.1-5% by mass of a carboxylic acid salt-based corrosion inhibitor, and 0.1-3% by mass of an amine salt of a fatty acid are contained, and a worked penetration is 220-270.

Grease composition for vehicular hub unit bearings

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

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.

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Fujisawa, Japan

Suguru Sugawara