Ntn Corporation

Nippon Steel Chemical Co., Ltd.

Kyodo Yushi Co., Ltd.

Hidenobu Mikami

Takayuki Kawamura

Mitsunari Asao

Yosuke Taguchi

Katsumi Nagano

Yoji Sato

Yoshihiko Oeda

Masaki Egami

Tetsuya Kurimura

Toshiaki Endo

Seiichi Takada

Yoshinobu Akamatsu

Eiichirou Shimazu

Toshiyuki Mizutani

Masakazu Hirata

Hiroki Iwamatsu

Seiji Okamura

Takahiro Koremoto

Masaaki Honda

Masaki Nakanishi

Koya Ohira

Masashi Mitsuoka

Motohiro Ito

Atsushi Morooka

Masami Tada

Yuji Oonuki

Kunio Takemura

Takashi Yasunishi

Osamu Hirano

To provide a rolling bearing having a hard film on an inner ring raceway surface and an outer ring raceway surface of the rolling bearing that improves peeling resistance of the hard film, shows the original property of the hard film, and suppresses the attackability to a mating material. A rolling bearinghas an inner ringhaving an inner ring raceway surfaceon an outer circumference, an outer ringhaving an outer ring raceway surfaceon an inner circumference, and rolling elementsthat roll between the inner ring raceway surfaceand the outer ring raceway surface. A hard filmincludes a foundation layer formed directly on the inner ring raceway surface 2or the outer ring raceway surfaceand mainly formed of Cr and WC, a mixed layer having a gradient composition formed on the foundation layer and mainly formed of WC and DLC, and a surface layer formed on the mixed layer and mainly formed of DLC. In a roughness curve of a surface on which the foundation layer is formed, the arithmetical mean roughness Ra is 0.3 &#x3bc;m or less and the root mean square gradient R&#x394;q is 0.05 or less.

Rolling bearing and wind power generation rotor shaft support device

The present invention provides a rotation-transmitting apparatus with a built-in one-way clutch which is capable of preventing rolling contact surfaces and rolling surfaces of inner and outer rings of a rolling bearing from peeling and fretting wearing and is excellent in its resistance to heat and wear. The rotation-transmitting apparatus with a built-in one-way clutch has an inside rotational member; a cylindrical outside rotational member disposed concentrically with the inside rotational member; a one-way clutch connecting the outside surface of the inside rotational member and the inside surface of the outside rotational member to each other only when the outside rotational member rotates at a higher speed than the inside rotational member; and a pair of rolling bearings allowing the inside rotational member and the outside rotational member to rotate relative to each other. Grease is enclosed inside an internal space of a clutch where a plurality of rollers is mounted and inside a space of the bearing where a plurality of rolling elements is mounted. The grease contains a base oil, a thickener, and an additive. The base oil is PAO oil. As the additive, 0.01 to 15 wt % of at leas one compound selected from among ZnDTC and ZnDTP is contained for the entire amount of the grease.

Rotation transmitting apparatus with built-in one-way clutch

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 cage for a rolling bearing having a film, formed on a surface thereof, which wears little over a long period of time from an initial stage of sliding contact between the film and rolling elements as well as other members and does not peel off the surface of a base material of the cage or dissolve in lubricating oil containing a sulfur-based additive and a rolling bearing having the cage. A cage () retains needle rollers () which are rolling elements of a needle rolling bearing (). Of an entire outer surface of the cage (), a tin alloy film consisting of tin and a metal other than the tin is formed on at least a sliding-contact surface of the cage () to be subjected to sliding contact with the needle rollers () and a sliding-contact surface thereof to be subjected to sliding contact with other members.

Cage for rolling bearing and 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

The present invention provides a grease composition having an excellent fretting wear resistance in a wide temperature region from low to high temperatures and particularly even at low temperatures and a rolling bearing in which the grease composition is packed. A grease composition () is packed inside a grease-packed bearing (). The grease composition () contains base oil, a thickener, and an additive. The additive contains at least, one kind selected from among a phosphite ester of formula (1) or a phosphite ester of formula (2): 

Grease composition and rolling bearing

A rolling bearing which has excellent performance at high-temperatures and has high-speed durability and quietness, is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface thereof, and has a low environmental load. The rolling bearing () is constructed of an inner ring () having a rolling surface on its peripheral surface, an outer ring () having a rolling surface on its inner peripheral surface, a plurality of rolling elements () disposed between both rolling surfaces, and a cage () retaining the rolling elements (). The inner ring (), the outer ring (), the rolling elements () or the cage () are metal-made bearing members. Film-coating treatment is conducted on a sliding surface or a rolling surface of at least one of these metallic bearing members with plant-derived polyvalent alcohol compounds such as curcumin, quercetin, chlorogenic acid or the like.

Rolling bearing

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

A rolling bearing () having an inner ring (); an outer ring (); a plurality of rolling elements () interposed between the inner ring () and the outer ring (); a retainer () retaining the rolling elements (); and a seal () provided at an open portion, of the inner ring () and the outer ring (), which is disposed at both axial ends thereof. The rolling bearing () is lubricated with a grease () enclosed in a space, inside the bearing, which is constructed of the inner ring (), the outer ring (), the retainer (), and the seal ().

Rolling bearing and seal for rolling bearing

The present invention provides a grease composition capable of effectively preventing a rolling surface of a grease-enclosed bearing from having hydrogen brittleness-caused peeling and the grease-enclosed bearing. The grease composition includes a base grease consisting of a base oil and a thickener and an additive added to the base grease. The additive contains at least an epoxy compound. A mixing ratio of the epoxy compound to 100 parts by weight of the base grease is set to 0.05 to 10 parts by weight. The grease-enclosed bearing using the grease composition includes an inner ring () and an outer ring (); a plurality of rolling elements () disposed between the inner ring () and the outer ring (); and a sealing member () for covering openings () disposed at both axial ends of the inner ring () and the outer ring (). The grease composition () is enclosed on peripheries of the rolling elements ().

Grease composition and grease-enclosed bearing

A rolling bearing, for use in household appliances, having a high degree of quietness, an excellent durability at high temperatures and rotational speeds, a low torque, and excellent fretting property; and a lubricant composition which can be sealed into the rolling bearing. The lubricant composition includes a base oil and a thickening agent. The base oil is a mixed oil having the following characteristics of (a) to (c): (a) The base oil consists essentially of a synthetic hydrocarbon oil and an ester oil; (b) A kinematic viscosity of the mixed oil at 40&#xb0; C. is 40 to 70 mm/second; (c) A mixing weight ratio between the ester oil of the mixed oil and the synthetic hydrocarbon oil thereof is 30:70 to 70:30. The thickening agent comprises a diurea compound shown by a formula (1): where Rand Rare a straight-chain alkyl groups having 9 to 22 carbon atoms respectively, and Ris an aromatic hydrocarbon group having 6 to 15 carbon atoms. The lubricant composition is sealed into the rolling bearing.

Lubricant composition and sealed bearing thereof

The present invention provides grease which prevents frictional wear on a lubricating surface and excellent in performance of preventing occurrence of flaking, heat-resistant performance, and long-term durability, a grease-enclosed rolling bearing, a constant velocity joint, and rolling parts. Grease is composed of base grease, essentially containing a thickener, to which at least 0.01 to 15 wt % of one substance selected from among bismuth and inorganic bismuth compounds is added. The inorganic bismuth compounds are at least one inorganic bismuth selected from among bismuth sulfate, bismuth trioxide, bismuth carbonate, and sodium bismuthate. The above-described grease is used for the rolling bearing and the constant velocity joint. A coating film of at least one substance selected from among the bismuth and the inorganic bismuth is formed on surfaces of the rolling parts.

Grease, rolling bearing, constant velocity joint, and rolling parts

The present invention provides a grease composition which prevents frictional wear of a lubricating surface in a high load-applied state or in a state in which sliding motion is generated and is durable for a long time, a method of manufacturing capable of easily determining an addition ratio of an extreme-pressure agent of the grease composition, and a rolling bearing in which the grease composition is enclosed. A grease composition is composed by adding a thickener and an extreme-pressure agent containing sulfur in a molecular structure thereof to base oil. The extreme-pressure agent is added to the base oil so that a product of an amount (mgS/g) of active sulfur contained in the extreme-pressure agent and an addition amount (wt %) of the extreme-pressure agent with respect to an entire amount of the grease composition is in a range of 3 to 13.

Grease composition and method for production thereof, and rolling bearing having the grease composition sealed therein

The present invention provides a grease composition capable of effectively preventing a rolling surface of a bearing from having hydrogen brittleness-caused peeling, a grease-enclosed bearing in which the grease composition is enclosed, and a rotation-transmitting apparatus with a built-in 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 prevents a frictional wear surface of the sliding portion or a newly generated surface consisting of iron or the like exposed owing to wear from being peeled owing to hydrogen brittleness. The additive contains a bismuth-based additive or a magnesium-based additive. The bismuth-based additive consists of at least one of inorganic bismuth and organic bismuth not containing a sulfur component. The magnesium-based additive consists of at least one of inorganic magnesium and organic magnesium. The grease-enclosed bearing encloses the above-described grease composition.

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Mie, Japan

Hidenobu Mikami