Patents by Inventor Mitsunari Asao
Mitsunari Asao 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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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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Patent number: 8609598Abstract: 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.Type: GrantFiled: July 21, 2003Date of Patent: December 17, 2013Assignee: NTN CorporationInventors: Hidenobu Mikami, Takayuki Kawamura, Mitsunari Asao, Eiichirou Shimazu
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Publication number: 20130276563Abstract: 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. The content of the molybdenum for the whole weight of the grease composition (7) is set to not more than 0.06 wt %.Type: ApplicationFiled: December 16, 2011Publication date: October 24, 2013Applicant: NTN CORPORATIONInventors: Takayuki Kawamura, Mitsunari Asao
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Patent number: 8182155Abstract: A lubricating grease is provided which is excellent in durability at high temperatures, inhibits the reaction between fluorine and steel and has a long life and a rolling bearing in which the lubricating grease is enclosed. The lubricating grease contains perfluoropolyether oil as a base oil thereof and fluorocarbon resin powder as a thickener thereof, a diurea compound having an —NH— bond in the molecular structure thereof, an organic-acid metal salt or a bismuth-containing compound such as bismuth sulfate. The rolling bearing has an inner ring and an outer ring disposed concentrically with each other, a plurality of rolling elements interposed between the inner ring and the outer ring, and a retainer dividedly holding the rolling elements.Type: GrantFiled: September 1, 2006Date of Patent: May 22, 2012Assignee: NTN CorporationInventors: Masaki Egami, Mitsunari Asao
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Patent number: 8048835Abstract: The present invention provides a grease composition capable of securely preventing generation of a low-temperature abnormal noise when it is cold and a grease-enclosed bearing. A grease composition comprises a base oil and a thickener, wherein the base oil has a pour point not more than ?50° C. and a kinematic viscosity not less than 15 mm2/s at 40° C. The base oil is at least one oil selected from a PAO oil and a perfluoro ether oil. The thickener is at least one substance selected from a urea compound and a fluororesin. A mixing consistency of the grease composition is in the range of 250 to 350. A grease-enclosed bearing has an inner ring, an outer ring, rolling elements interposed between the inner ring and the outer ring, and a grease composition enclosed on a periphery of the rolling elements. The grease-enclosed bearing is used for an automotive electric auxiliary machine.Type: GrantFiled: March 25, 2005Date of Patent: November 1, 2011Assignee: NTN CorporationInventors: Takayuki Kawamura, Mitsunari Asao, Masaki Egami
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Publication number: 20090232432Abstract: The present invention provides lubricating grease which is excellent in durability at a high temperature, restrains a reaction from occurring between fluorine and steel, and has a long life; and a rolling bearing in which the lubricating grease is enclosed. The lubricating grease contains perfluoropolyether oil as a base oil thereof and fluorocarbon resin powder as a thickener thereof. The lubricating grease further contains an additive containing a substance capable of forming a film on a metal surface. The substance is a diurea compound having an —NH— bond in a molecular structure thereof, an organic-acid metal salt such as sodium sebacate, molybdate such as potassium molybdate or sodium molybdate, or a bismuth-containing compound such as bismuth sulfate. The rolling bearing has an inner ring and an outer ring disposed concentrically with each other, a plurality of rolling elements interposed between the inner ring and the outer ring, and a retainer dividedly holding the rolling elements.Type: ApplicationFiled: September 1, 2006Publication date: September 17, 2009Applicant: NTN CORPORATIONInventors: Masaki Egami, Mitsunari Asao
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Publication number: 20090190873Abstract: A sealing member, for sealing urea compound-containing grease enclosed in a rolling bearing, in which an elastic body deteriorates to a low extent when the rolling bearing is subjected to a high temperature and which is capable of maintaining a preferable sealing performance for a long time and excellent in reliability and durability. The sealing member used for the rolling bearing to seal grease to be enclosed in the rolling bearing includes a rubber molding which contacts the grease. The rubber molding is formed by molding a curable fluororubber composition consisting of a copolymer containing tetrafluoroethylene, propylene, and a crosslinkable monomer consisting of unsaturated fluoro-hydrocarbon, having two to four carbon atoms, in which a part of hydrogen atoms is substituted with fluorine atoms.Type: ApplicationFiled: March 26, 2009Publication date: July 30, 2009Inventors: Masaki Egami, Mitsunari Asao, Eiichi Urakami
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Publication number: 20070287646Abstract: The present invention provides a grease composition capable of securely preventing generation of a low-temperature abnormal noise when it is cold and a grease-enclosed bearing. A grease composition comprises a base oil and a thickener, wherein the base oil has a pour point not more than ?50° C. and a kinematic viscosity not less than 15 mm2/s at 40° C. The base oil is at least one oil selected from a PAO oil and a perfluoro ether oil. The thickener is at least one substance selected from a urea compound and a fluororesin. A mixing consistency of the grease composition is in the range of 250 to 350. A grease-enclosed bearing has an inner ring, an outer ring, rolling elements interposed between the inner ring and the outer ring, and a grease composition enclosed on a periphery of the rolling elements. The grease-enclosed bearing is used for an automotive electric auxiliary machine.Type: ApplicationFiled: March 25, 2005Publication date: December 13, 2007Applicant: NTN CORPORATIONInventors: Takayuki Kawamura, Mitsunari Asao, Masaki Egami
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Publication number: 20070253655Abstract: The present invention provides a reliable and durable rolling bearing incorporated in various industrial machines, vehicles, and the like, having a sealing member which deteriorates to a low extent and maintains preferable sealing performance for a long time. The rolling bearing includes an inner ring; an outer ring; a plurality of rolling elements interposed between the inner ring and the outer ring; and the sealing member provided at an open portion which is disposed at both axial ends of the inner ring and the outer ring. The sealing member comprises a rubber molding that contacts at least water, an alkali solution, grease, or the like. The rubber molding is made of a vulcanizable fluororubber composition which comprises a copolymer containing tetrafluoroethylene; propylene; and a crosslinkable monomer which is an unsaturated hydrocarbon having two to four carbon atoms, in which a part of hydrogen atoms is substituted with fluorine atoms.Type: ApplicationFiled: June 22, 2007Publication date: November 1, 2007Applicant: NTN CORPORATIONInventors: Masaki Egami, Mitsunari Asao, Tomoaki Goto
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Patent number: 7271135Abstract: A rolling bearing, for application in electric auxiliaries for a car, durable owing to high resistance to high temperatures and capable of restraining noises from being generated at low temperatures; and lubricant grease, for low and high temperature application, which can be sealed in the rolling bearing. The lubricant grease includes 100 parts by weight of a mixture of fluorine-containing lubricant grease containing perfluoropolyether oil as a base oil thereof and fluorocarbon resin powder as a thickening agent thereof and urea-containing lubricant grease containing polyester oil as a base oil thereof and a urea compound as a thickening agent thereof; and 3 to 30 parts by weight of polyolefin oil added to the mixed grease. The polyolefin oil has a pour point of not more than ?50° C. and a kinematic viscosity of 10 to 70 mm2/s at 40° C.Type: GrantFiled: April 8, 2004Date of Patent: September 18, 2007Assignee: NTN CorporationInventors: Mitsunari Asao, Masaki Egami
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Patent number: 7053028Abstract: Disclosed is a grease that provides a prolonged lubricating lifetime to applied portions for use at high temperature, and a grease sealed bearing in which the bearing is sealed with this grease. This grease comprises a base oil, a thickener, and an amide-based wax. The amide-based wax is contained in an amount of 0.5 to 10% by weight based on the total amount of the grease, has a melting point of 80° C. or more, and an antioxidative ability to the base oil. The base oil is at least one base oil selected from the group consisting of an ether-based oil, an ester-based oil and a synthetic hydrocarbon oil, and has kinematic viscosity of 20 to 150 mm2/s at 40° C. The thickener is an urea-based thickener, and is contained in an amount of 5 to 30% by weight based on the total amount of the grease.Type: GrantFiled: September 23, 2002Date of Patent: May 30, 2006Assignees: NTN Corporation, Kyodo Yushi Co. Ltd.Inventors: Takayuki Kawamura, Hidenobu Mikami, Mitsunari Asao, Yuji Oonuki, Toshiaki Endo
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Publication number: 20050152628Abstract: A rolling bearing for use in a vehicle, particularly in an electric device on said vehicle, said bearing having a sealing member for sealing urea compound-containing grease, in which an elastic body deteriorates to a low extent when the rolling bearing is subjected to a high temperature and which is capable of maintaining a preferable sealing performance. The grease-sealing member has a rubber molding which contacts the grease. The rubber molding is formed by molding a curable fluororubber composition consisting of a copolymer containing tetrafluoroethylene, propylene, and a crosslinkable monomer consisting of unsaturated hydrocarbon, having two to four carbon atoms, in which a part of hydrogen atoms is substituted with fluorine atoms.Type: ApplicationFiled: January 10, 2005Publication date: July 14, 2005Inventors: Masaki Egami, Mitsunari Asao, Tomoaki Goto
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Publication number: 20050100259Abstract: A sealing member, for sealing urea compound-containing grease enclosed in a rolling bearing, in which an elastic body deteriorates to a low extent when the rolling bearing is subjected to a high temperature and which is capable of maintaining a preferable sealing performance for a long time and excellent in reliability and durability. The sealing member used for the rolling bearing to seal grease to be enclosed in the rolling bearing includes a rubber molding which contacts the grease. The rubber molding is formed by molding a curable fluororubber composition consisting of a copolymer containing tetrafluoroethylene, propylene, and a crosslinkable monomer consisting of unsaturated fluoro-hydrocarbon, having two to four carbon atoms, in which a part of hydrogen atoms is substituted with fluorine atoms.Type: ApplicationFiled: November 4, 2004Publication date: May 12, 2005Inventors: Masaki Egami, Mitsunari Asao, Eiichi Urakami
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Publication number: 20040198612Abstract: A rolling bearing, for application in electric auxiliaries for a car, durable owing to high resistance to high temperatures and capable of restraining noises from being generated at low temperatures; and lubricant grease, for low and high temperature application, which can be sealed in the rolling bearing. The lubricant grease includes 100 parts by weight of a mixture of fluorine-containing lubricant grease containing perfluoropolyether oil as a base oil thereof and fluorocarbon resin powder as a thickening agent thereof and urea-containing lubricant grease containing polyester oil as a base oil thereof and a urea compound as a thickening agent thereof; and 3 to 30 parts by weight of polyolefin oil added to the mixed grease. The polyolefin oil has a pour point of not more than −50° C. and a kinematic viscosity of 10 to 70 mm2/s at 40° C.Type: ApplicationFiled: April 8, 2004Publication date: October 7, 2004Inventors: Mitsunari Asao, Masaki Egami
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Publication number: 20040033911Abstract: Disclosed is a grease composition comprising a base oil, a thickener, and an additive; the base oil having a kinetic viscosity of 20 to 150 mm2/s at 40° C., and the additive containing as an essential component 0.Type: ApplicationFiled: July 21, 2003Publication date: February 19, 2004Inventors: Hidenobu Mikami, Takayuki Kawamura, Mitsunari Asao, Eiichirou Shimazu
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Patent number: 6605574Abstract: Disclosed is a grease sealed bearing for automobile that has the high temperature resistance as well as shear stability, and prevents the noise at low temperature as well as the brittle flaking under high speed rotation and high load. The grease comprises a base oil containing a synthesized hydrocarbon oil and one or more ester oils at a weight ratio of 0.1 to 0.49:0.9 to 0.51; 5 to 30% by weight of a urea based thickener, and 0.1 to 10% by weight of dithiozinc phosphate based on the whole grease. The grease sealed bearing for automobile is obtained by sealing a bearing used in a device driven by an automobile engine with the grease.Type: GrantFiled: January 16, 2002Date of Patent: August 12, 2003Assignee: NTN CorporationInventors: Mitsunari Asao, Hidenobu Mikami, Takayuki Kawamura, Takahiro Koremoto, Kunio Takemura
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Publication number: 20030069147Abstract: Disclosed is a grease that provides a prolonged lubricating lifetime to applied portions for use at high temperature, and a grease sealed bearing in which the bearing is sealed with this grease. This grease comprises a base oil, a thickener, and an amide-based wax. The amide-based wax is contained in an amount of 0.5 to 10% by weight based on the total amount of the grease, has a melting point of 80° C. or more, and an antioxidative ability to the base oil. The base oil is at least one base oil selected from the group consisting of an ether-based oil, an ester-based oil and a synthetic hydrocarbon oil, and has kinematic viscosity of 20 to 150 mm2/s at 40° C. The thickener is an urea-based thickener, and is contained in an amount of 5 to 30% by weight based on the total amount of the grease.Type: ApplicationFiled: September 23, 2002Publication date: April 10, 2003Inventors: Takayuki Kawamura, Hidenobu Mikami, Mitsunari Asao, Yuji Oonuki, Toshiaki Endo
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Publication number: 20030027731Abstract: A heat-resistant, high-speed, high-load rolling bearing for automotive accessories and electric part is provided which develops no abnormal flaking and is sufficiently long in life and superior in durability. It is a heat-resistant, high-speed, high-load rolling bearing in which is sealed a grease composition which comprises a base oil which is a mixture alkyldiphenyl ether oil and aromatic ester oil at the ratio (in weight) of 50:50 to 80:20, a diurea compound expressed by the following formula as a thickening agent, and 0.1 to 5 wt % of a passivating agent.Type: ApplicationFiled: June 28, 2002Publication date: February 6, 2003Inventors: Takayuki Kawamura, Hidenobu Mikami, Mitsunari Asao
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Publication number: 20020137639Abstract: Disclosed is a grease sealed bearing for automobile that has the high temperature resistance as well as shear stability, and prevents the noise at low temperature as well as the brittle flaking under high speed rotation and high load. The grease comprises a base oil containing a synthesized hydrocarbon oil and one or more ester oils at a weight ratio of 0.1 to 0.49:0.9 to 0.51; 5 to 30% by weight of a urea based thickener, and 0.1 to 10% by weight of dithiozinc phosphate based on the whole grease. The grease sealed bearing for automobile is obtained by sealing a bearing used in a device driven by an automobile engine with the grease.Type: ApplicationFiled: January 16, 2002Publication date: September 26, 2002Inventors: Mitsunari Asao, Hidenobu Mikami, Takayuki Kawamura, Takahiro Koremoto, Kunio Takemura
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Patent number: 5804536Abstract: A solid lubricant for bearings which is less likely to be washed away by water or liquid mud coming into bearings, and which can restrain the development of rust even in a harsh environment where high-concentration salt water comes into the bearings. A rust preventive in the form of a sulfonate or a fatty polyhydric alcohol partial ester is added to a composition made up of 5-97% by weight of a lubricating grease, 93-1% by weight of an ultra-high-molecular-weight polyolefin powder, and 1-50% by weight of oil exudation inhibitor, and mixed together. The mixture is then heated to a temperature higher than the gel point of the ultra-high-molecular-weight polyolefin and preferably lower than the dropping point of the lubricating grease and molded into the solid lubricant for bearings.Type: GrantFiled: March 27, 1997Date of Patent: September 8, 1998Assignee: NTN CorporationInventors: Mitsunari Asao, Hidenobu Mikami