Ntn Corporation

Kyodo Yushi Co., Ltd.

Takayuki Kawamura

Hidenobu Mikami

Kenji Ito

Masaki Egami

Toshiaki Endo

Makoto Muramatsu

Tomoya Sakaguchi

Mitsunari Asao

Ryouta Kondou

Mika Kohara

Kenji Tamada

Motohiro Ito

Takuya Ishii

Eiichirou Shimazu

Tomoyoshi Izutsu

Mitsuo Kawamura

Yosuke Taguchi

Makoto Seki

Masaharu Inoue

Takahiro Koremoto

Kazuhiro Watanabe

Eiichiro Shimazu

Koya Ohira

Hikaru Ishida

Tomoaki Goto

Norihide Sato

Minoru Hasegawa

Noriaki Miwa

Mari Kataoka

Susumu Yamaji

Hiroyuki Amari

Yuji Oonuki

Yoshinori Sugisaki

Kouhei Nakano

Kunio Takemura

Hidenobu Mikaki

Motohiro Itou

To provide an axle bearing having a low torque property and superior bearing lifetime. A hub bearingis configured to rotatably support a wheel of a vehicle, and has a grease compositionsealed in an inner space thereof. The grease compositioncontains a base oil and a thickener. The shear stress of the grease composition at the shear rate of 1,000-10,000 sat 25° C. is 3,000 Pa or less. The viscosity of the grease composition is 1 Pas or less. The yield stress of the grease composition at 25° C. measured by a dynamic viscoelasticity analysis method using a rheometer is 1,300-3,000 Pa.

Axle bearing, grease composition and rolling ball bearing

To provide a grease composition for a tapered roller bearing having superior bearing lifetime under a condition of high temperature and a condition of high load, and a tapered roller bearing in which the grease composition for the tapered roller bearing is filled. A tapered roller bearingincludes an inner ringhaving a raceway surface, an outer ringhaving a raceway surfaceand a plurality of tapered rollers, and a flange part of the inner ringgets into sliding contact with the tapered rollers. Greaseis filled around the tapered rollers. The greaseincludes a base oil, a thickener and an additive. A frequency in which a storage modulus, which varies depending on frequency, of the greasebecomes minimum is equal to 7 Hz or more.

Grease composition for tapered roller bearing and tapered roller bearing

Provided is a grease composition which can be used as a lubricant for roller bearings, exhibits excellent high temperature durability and rust preventive property, and can prevent premature flaking on the rolling surface due to hydrogen embrittlement. A roller bearingis obtained by sealing a grease compositionin the periphery of a rolling element, this grease compositionis composed of a base oil excluding an ester-based synthetic oil, a thickener, and an additive, the additive contains (a) an alkanolamine and (b) 2,2,4-trimethyl-1,2-dihydroquinoline or a polymer thereof but does not contain an organic sulfonate, and (a) and (b) are contained at from 0.1 to 10 parts by weight with respect to 100 parts by weight of a total amount of the base oil and the thickener, respectively.

Grease composition and grease-sealed roller bearing

It is an object of the present invention to provide a grease composition, for an outer ring rotation type rolling bearing, which is capable of satisfying all of high-temperature durability, low-temperature property, peeling resistance, and rust-preventive property. A grease composition () to be enclosed in the outer rig rotation type rolling bearing for use in automotive electric auxiliary machines contains base oil, a thickener, a peeling-resistant additive, a wear-resistant additive, and a rust-preventive agent. The base oil is mixed oil of trimellitic acid ester oil and synthetic hydrocarbon oil mixed therewith in a mass ratio of (70:30) to (90:10). The thickener consists of a diurea compound shown by a formula (1).R&#x2014;NHCONH&#x2014;R&#x2014;NHCONH&#x2014;R&#x2003;&#x2003;(1)wherein a reference symbol Rdenotes a divalent aromatic hydrocarbon group having a carbon number of 6 to 15, and a reference symbol Rdenotes a cyclohexyl group.

Grease composition

The present invention provides a grease composition or a lubricating oil composition which is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface of a rolling bearing, is excellent in durability in a high temperature and speed operation, and can be used for a long time. A grease-packed bearing () has an inner ring (), an outer ring (), and a plurality of rolling elements (). A sealing member () for sealing a grease composition () is provided at openings () and () disposed at both axial ends of the inner ring () and the outer ring (). The grease composition () includes a base grease composed of a base oil and a thickener and an additive added to the base grease. The additive contains at least one compound selected from among plant-derived polyphenolic compounds and compounds formed by decomposition thereof. The above-described compounds include tannin, gallic acid, ellagic acid, chlorogenic acid, caffeic acid, curcumin, quercetin, and quinic acid.

Grease composition, grease-packed bearing, universal joint for propeller shaft, lubricating oil composition, and oil-impregnated sintered bearing

A rolling bearing that can prevent peeling on a surface of an iron-based metal member by hydrogen brittleness even under a severe environment is provided. The rolling bearinghas plural bearing elements formed of an iron-based metal, and a lubricant compositionthat lubricates metal contact surfaces of the respective bearing elements, the lubricant compositionis a grease containing a base oil and alkanolamine and being free of alkali metal salts and alkaline earth metal salts of inorganic acids, the base oil is at least one oil selected from alkyl diphenyl ether oils, poly-&#x3b1;-olefin oils and ester oils, and the alkanolamine is contained by 0.1 to 10 parts by weight with respect to 100 parts by weight of the total amount of the base oil and a thickener.

Rolling bearing

The present invention provides a grease composition capable of effectively preventing a rolling surface from having hydrogen brittleness-caused peeling, a grease-enclosed bearing in which the grease composition is enclosed, and a one-way clutch in which the grease composition is enclosed at a sliding portion. The grease composition contains a base grease consisting of a base oil and a thickener and an additive added to the base grease. The grease composition is capable of preventing hydrogen brittleness-caused peeling from occurring on a frictionally worn surface of a bearing portion containing an iron-based metal material or a newly generated surface consisting of the iron-based metal material exposed owing to wear. The additive contains at least one aluminum-based additive selected from among an aluminum powder and inorganic aluminum compounds. The mixing ratio of the aluminum-based additive to 100 parts by weight of the base grease is set to 0.05 to 10 parts by weight.

Grease composition, grease-enclosed bearing, and one-way clutch

A lubricant composition capable of effectively preventing a rolling surface of a bearing from flaking owing to hydrogen embrittlement. The bearing is lubricated with the lubricant composition. The lubricant composition is lubricating oil or grease. The lubricant composition contains a molybdate. The lubricant composition also contains an organic acid salt. At least one molybdate is selected from sodium molybdate, potassium molybdate, and lithium molybdate. The organic acid salt is a sodium salt of an organic acid having one to 20 carbon atoms. 0.01 to 5 wt % of the molybdate is added to the entirety of the lubricant composition. 5 wt % to 70 wt % of the organic acid salt is added to the addition amount of the molybdate. The lubricant composition forms a film containing a molybdenum compound in addition to an iron oxide film on a worn surface of the bearing.

Lubricant composition and bearing using same

The present invention provides a thickener which allows grease having an excellent durability in a high-temperature and high-speed condition to be produced, the grease containing the thickener, a method of producing the thickener and the grease, and a grease-packed bearing. A grease () to be packed in a bearing () is obtained by adding a thickener for a grease comprising a compound shown by a chemical formula (1) shown below or a compound shown by a chemical formula (2) shown below;  In the chemical formula (1) or the chemical formula (2), Rshows a diamine residue or a diisocyanate residue; Rshows a residue of a dicarboxylic acid in which two adjacent carbon atoms form an imide ring or residues of derivative of the dicarboxylic acid; Rshows a tetracarboxylic acid residue or residues of derivatives of the tetracarboxylic acid; Rshows a hydrogen atom residue, a monoamine residue or a monoisocyanate residue; and n indicates integers of 0 through 5.

Thickener, grease, method for producing the same, and grease-packed bearing

The present invention provides a grease composition which contains a small amount (not more than 0.06 wt %) of molybdenum and yet is capable of achieving an excellent low friction property when mechanical parts in which the grease composition has been packed are operated under a severe sliding condition in which they are subjected to a high speed and a high contact pressure. The present invention also provides a bearing, a universal joint, and a linear motion device in which the grease composition of the present invention is packed. A grease composition () is packed inside a grease-packed bearing () in such a way that the grease composition () is applied to at least the circumference of each rolling element (). The grease composition () contains base oil, a thickener, and an additive. The additive includes molybdenum dithiocarbamate and sodium dithiocarbamate.

Grease composition, grease-packed bearing, universal joint and linear motion device

It is an object of the present invention to provide a grease composition () which can be used for a long term in a wide temperature range from low to high temperatures by using comparatively inexpensive base oil. It is another object of the present invention to provide a rolling bearing and a universal joint in which the grease composition () is enclosed. The grease composition () is composed of base grease, consisting of base oil and a thickener, to which an additive is added. The base oil contains not less than 50 wt % of highly refined oil having a viscosity index of 120 to 180. The additive contains at least ZnDTP and 0.2 to 6 parts by weight of poly (metha) acrylate having a kinematic viscosity of not less than 100 mm/s and less than 850 mm/s at 100&#xb0; C. for 100 parts by weight of the base grease. The grease composition () is enclosed in the circumferences of rolling elements () of a rolling bearing ().

Grease composition and grease composition-enclosed rolling bearing and universal joint

The present invention provides a rust resisting grease composition showing an excellent rust resisting performance without using nitrites and the grease composition-enclosed bearing. The rust resisting grease composition contains a base oil, a thickener, and a rust resisting component. The rust resisting component contains a metallic salt of a polybasic acid, a polyvalent alcohol in which a part of a hydroxyl group is blocked, and at least one compound selected from an organic sulfonate and a fatty ester. The content of the component is 0.1 to 10 parts by weight based on the total amount of the base oil and the thickener. The base oil contains at least one oil selected from synthetic hydrocarbon oil and ether oil. The thickener is a urea thickener. The content of the thickener is 5 to 30 parts by weight based on the total amount of the base oil and the thickener.

Rust resisting grease composition, grease-enclosed bearing, and rust resisting agent for use in grease composition

The present invention relates to a nitrite free grease composition having an oil base, a thickener, and several additives, including a metal salt of dibasic acid. The metal salt having sub-groups that can either be aliphatic or aromatic hydrocarbons. Additionally, the present invention relates to a grease-sealed bearing with a longer lifetime and excellent rust preventative properties.

Grease composition having a base oil, a thickener and an additive including a metal salt of dibasic acid

The present invention provides a grease composition () which has a low friction and a low viscosity and is durable at a high temperature and a grease-sealed bearing () in which the grease composition is enclosed. The grease composition contains base oil, a thickener, and an additive. The base oil contains an ionic liquid consisting of a cation component and an anion component. The additive contains a corrosion inhibitor such as nitrites, molybdates or dibasic acid salts. The thickener is fluorine resin such as polytetrafluoroethylene. The grease composition () is applied to a periphery of each rolling element () of the grease-sealed bearing ().

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Mie, Japan

Takayuki Kawamura