Patents by Inventor Takayuki Kawamura
Takayuki Kawamura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240102687Abstract: An aspect of this electrical device includes: a body controller which controls the electrical device; a voltage generator which generates a voltage supplied to the electrical device; a wiring which connects the body controller to the voltage generator; and an electrical device casing which accommodates the body controller and the voltage generator, wherein the electrical device casing includes: a wiring chamber in which the wiring is arranged; a first chamber in which the body controller is accommodated; and a second chamber in which the voltage generator is accommodated, wherein an inside of the first chamber and an inside of the second chamber are connected to each other through the inside of the wiring chamber.Type: ApplicationFiled: March 29, 2021Publication date: March 28, 2024Inventors: Takayuki SETO, Shuhei TOMITA, Takeshi KAWAMURA
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Publication number: 20240084853Abstract: To provide an axle bearing having a low torque property and superior bearing lifetime. A hub bearing 6 is configured to rotatably support a wheel of a vehicle, and has a grease composition 10 sealed in an inner space thereof. The grease composition 10 contains a base oil and a thickener. The shear stress of the grease composition at the shear rate of 1,000-10,000 s?1 at 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.Type: ApplicationFiled: October 8, 2020Publication date: March 14, 2024Inventors: Takayuki KAWAMURA, Ryouta KONDOU, Makoto SEKI, Susumu YAMAJI
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Patent number: 11851627Abstract: 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 bearing 11 includes an inner ring 12 having a raceway surface 12a, an outer ring 13 having a raceway surface 13a and a plurality of tapered rollers 14, and a flange part of the inner ring 12 gets into sliding contact with the tapered rollers 14. Grease 16 is filled around the tapered rollers 14. The grease 16 includes a base oil, a thickener and an additive. A frequency in which a storage modulus, which varies depending on frequency, of the grease 16 becomes minimum is equal to 7 Hz or more.Type: GrantFiled: April 20, 2020Date of Patent: December 26, 2023Assignee: NTN CORPORATIONInventors: Ryouta Kondou, Takayuki Kawamura
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Publication number: 20230090287Abstract: To provide a grease composition that is capable of effectively preventing an early-flaking caused by hydrogen embrittlement, and a grease-sealed bearing in which the grease composition is sealed. A grease composition 7 contains a base oil, a thickener, and an additive. The additive contains sodium molybdate, and zinc alkyldithiophosphate having a 1-30 C primary alkyl group. The grease composition contains 0.1-5 mass % of the sodium molybdate relative to the whole of the grease composition. The grease composition contains 0.1-5 mass % of the zinc alkyldithiophosphate relative to the whole of the grease composition.Type: ApplicationFiled: January 15, 2021Publication date: March 23, 2023Inventor: Takayuki KAWAMURA
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Publication number: 20220204881Abstract: 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 bearing 11 includes an inner ring 12 having a raceway surface 12a, an outer ring 13 having a raceway surface 13a and a plurality of tapered rollers 14, and a flange part of the inner ring 12 gets into sliding contact with the tapered rollers 14. Grease 16 is filled around the tapered rollers 14. The grease 16 includes a base oil, a thickener and an additive. A frequency in which a storage modulus, which varies depending on frequency, of the grease 16 becomes minimum is equal to 7 Hz or more.Type: ApplicationFiled: April 20, 2020Publication date: June 30, 2022Inventors: Ryouta KONDOU, Takayuki KAWAMURA
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Publication number: 20200340530Abstract: A method for selecting a steel material for a rolling component to be used in an environment in which hydrogen enters steel. The method includes determining a maximum contact surface pressure Pmax acting on a rolling surface of the rolling component, and using, as a material for the rolling component, a material whose inclusion has a radius not greater than a radius d determined by the following formula (1) and not less than 1.0 ?m, d=64729(Pmax/4)?1.441 ??(1).Type: ApplicationFiled: July 8, 2020Publication date: October 29, 2020Applicant: NTN CORPORATIONInventors: Noriaki MIWA, Takayuki KAWAMURA, Yoshinori SUGISAKI, Motohiro ITOU
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Patent number: 10597598Abstract: 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 bearing 1 is obtained by sealing a grease composition 7 in the periphery of a rolling element 4, this grease composition 7 is 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.Type: GrantFiled: July 29, 2016Date of Patent: March 24, 2020Assignee: NTN CORPORATIONInventors: Motohiro Ito, Ryouta Kondou, Takayuki Kawamura
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Patent number: 10465140Abstract: 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 (7) 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). R1—NHCONH—R2—NHCONH—R1??(1) wherein a reference symbol R2 denotes a divalent aromatic hydrocarbon group having a carbon number of 6 to 15, and a reference symbol R1 denotes a cyclohexyl group.Type: GrantFiled: March 9, 2016Date of Patent: November 5, 2019Assignee: NTN CORPORATIONInventors: Masaharu Inoue, Kazuhiro Watanabe, Tomoyoshi Izutsu, Takayuki Kawamura, Hiroyuki Amari, Minoru Hasegawa, Kouhei Nakano
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Publication number: 20180230396Abstract: 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 bearing 1 is obtained by sealing a grease composition 7 in the periphery of a rolling element 4, this grease composition 7 is 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.Type: ApplicationFiled: July 29, 2016Publication date: August 16, 2018Inventors: Motohiro ITO, Ryouta KONDOU, Takayuki KAWAMURA
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Publication number: 20180079988Abstract: 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 (7) 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). R1—NHCONH—R2—NHCONH—R1??(1) wherein a reference symbol R2 denotes a divalent aromatic hydrocarbon group having a carbon number of 6 to 15, and a reference symbol R1 denotes a cyclohexyl group.Type: ApplicationFiled: March 9, 2016Publication date: March 22, 2018Inventors: Masaharu INOUE, Kazuhiro WATANABE, Tomoyoshi IZUTSU, Takayuki KAWAMURA, Hiroyuki AMARI, Minoru HASEGAWA, Kouhei NAKANO
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Patent number: 9796944Abstract: 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 (1) has an inner ring (2), an outer ring (3), and a plurality of rolling elements (4). A sealing member (6) for sealing a grease composition (7) is provided at openings (8a) and (8b) disposed at both axial ends of the inner ring (2) and the outer ring (3). The grease composition (7) 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.Type: GrantFiled: December 18, 2014Date of Patent: October 24, 2017Assignee: NTN CORPORATIONInventors: Hidenobu Mikami, Yosuke Taguchi, Takayuki Kawamura
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Patent number: 9765821Abstract: 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 bearing 1 has plural bearing elements formed of an iron-based metal, and a lubricant composition 7 that lubricates metal contact surfaces of the respective bearing elements, the lubricant composition 7 is 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-?-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.Type: GrantFiled: July 18, 2014Date of Patent: September 19, 2017Assignee: NTN CORPORATIONInventors: Takayuki Kawamura, Motohiro Ito
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Publication number: 20170152457Abstract: The present invention provides a lubricant composition which can be used as a lubricant for a rolling component, the composition capable of maintaining enhanced lubrication performance over a long period of time even under high temperature conditions such as temperatures of 180° C. or higher, and a rolling bearing including the lubricant composition sealed therein. A lubricant composition-sealed bearing 1 includes a lubricant composition 7 that is sealed in the peripheries of the rolling bodies 4. The lubricant composition 7 contains a base oil and an antioxidant. The base oil is an oil mixture of an alkyl diphenyl ether oil and at least one oil selected from a poly-?-olefin oil and an ester oil, and contains the alkyl diphenyl ether oil in an amount of 50% or more by weight of the total base oil. The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline or a polymer thereof, and is contained in an amount of 0.1% to 10% by weight of the total lubricant composition.Type: ApplicationFiled: June 30, 2015Publication date: June 1, 2017Inventors: Ryouta KONDOU, Takayuki KAWAMURA, Hidenobu MIKAMI
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Publication number: 20170146061Abstract: A rolling component material of the present invention is a steel material for a rolling component to be used in an environment in which hydrogen enters steel, and is a material used for a rolling component of a rolling bearing, for example, a bearing ring. In the rolling component material, a non-metallic inclusion of the steel material has a radius not greater than a radius d determined by the following formula (1) and not less than 1.0 ?m, where Pmax is defined as a maximum contact surface pressure acting on a rolling surface of the rolling component, d=64729(Pmax/4)?1.441??(1).Type: ApplicationFiled: February 7, 2017Publication date: May 25, 2017Applicant: NTN CORPORATIONInventors: Noriaki MIWA, Takayuki KAWAMURA, Yoshinori SUGISAKI, Motohiro ITOU
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Patent number: 9394500Abstract: 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.Type: GrantFiled: February 15, 2007Date of Patent: July 19, 2016Assignee: NTN CORPORATIONInventors: Hidenobu Mikami, Takayuki Kawamura
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Publication number: 20160160923Abstract: 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 bearing 1 has plural bearing elements formed of an iron-based metal, and a lubricant composition 7 that lubricates metal contact surfaces of the respective bearing elements, the lubricant composition 7 is 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-?-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.Type: ApplicationFiled: July 18, 2014Publication date: June 9, 2016Inventors: Takayuki KAWAMURA, Motohiro ITO
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Patent number: 9217471Abstract: 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.Type: GrantFiled: April 30, 2012Date of Patent: December 22, 2015Assignee: NTN CORPORATIONInventors: Mika Kohara, Takayuki Kawamura, Kenji Tamada
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Patent number: 9150809Abstract: 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 (7) to be packed in a bearing (1) 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), R1 shows a diamine residue or a diisocyanate residue; R2 shows a residue of a dicarboxylic acid in which two adjacent carbon atoms form an imide ring or residues of derivative of the dicarboxylic acid; R3 shows a tetracarboxylic acid residue or residues of derivatives of the tetracarboxylic acid; R4 shows a hydrogen atom residue, a monoamine residue or a monoisocyanate residue; and n indicates integers of 0 through 5.Type: GrantFiled: February 18, 2011Date of Patent: October 6, 2015Assignee: NTN CORPORATIONInventor: Takayuki Kawamura
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Patent number: 9139793Abstract: 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 (7) is packed inside a grease-packed bearing (1) in such a way that the grease composition (7) is applied to at least the circumference of each rolling element (4). The grease composition (7) contains base oil, a thickener, and an additive. The additive includes molybdenum dithiocarbamate and sodium dithiocarbamate.Type: GrantFiled: December 16, 2011Date of Patent: September 22, 2015Assignee: NTN CORPORATIONInventors: Takayuki Kawamura, Mitsunari Asao
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Publication number: 20150105304Abstract: 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 (1) has an inner ring (2), an outer ring (3), and a plurality of rolling elements (4). A sealing member (6) for sealing a grease composition (7) is provided at openings (8a) and (8b) disposed at both axial ends of the inner ring (2) and the outer ring (3). The grease composition (7) 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.Type: ApplicationFiled: December 18, 2014Publication date: April 16, 2015Inventors: Hidenobu MIKAMI, Yosuke TAGUCHI, Takayuki KAWAMURA