Patents by Inventor Hiroki Iwamatsu

Hiroki Iwamatsu 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).

  • Patent number: 10041540
    Abstract: A grease composition which is excellent in seizure resistance can be provided without deteriorating resistance to stirring in the rolling device, and a rolling device in which the grease composition intervenes to a predetermined portion can be also provided by use of a grease composition comprising a base oil and a thickener, the thickener being a diurea compound obtained by allowing an amine mixture comprising alkylphenylamine, an alkyl group of which has 8 to 16 carbon atoms, and cyclohexylamine, to react with a diisocyanate compound, the amount of cyclohexylamine in the amine mixture being 80% by mole or more and less than 91% by mole, and a worked penetration being 300 to 330.
    Type: Grant
    Filed: March 22, 2013
    Date of Patent: August 7, 2018
    Assignees: JTEKT CORPORATION, NIPPON GREASE CO., LTD.
    Inventors: Koji Yoshizaki, Kensuke Suzuki, Hiroki Iwamatsu, Masashi Mitsuoka
  • Patent number: 8993497
    Abstract: The present invention provides a grease composition which has excellent conductivity and can rapidly remove static electricity generated by using a bearing. The grease composition comprises a base oil, a thickener and a tungsten disulfide powder, wherein the average particle diameter of the tungsten disulfide powder is 0.5 to 5.0 ?m and the amount of tungsten disulfide powder based on 100 parts by mass of the total amount of base oil and thickener is 2.0 to 4.0 parts by mass.
    Type: Grant
    Filed: November 23, 2012
    Date of Patent: March 31, 2015
    Assignee: Nippon Grease Co., Ltd.
    Inventors: Hiroki Iwamatsu, Kenji Yuki, Masahiro Okumiya
  • Publication number: 20150078687
    Abstract: A grease composition which is excellent in seizure resistance can be provided without deteriorating resistance to stirring in the rolling device, and a rolling device in which the grease composition intervenes to a predetermined portion can be also provided by use of a grease composition comprising a base oil and a thickener, the thickener being a diurea compound obtained by allowing an amine mixture comprising alkylphenylamine, an alkyl group of which has 8 to 16 carbon atoms, and cyclohexylamine, to react with a diisocyanate compound, the amount of cyclohexylamine in the amine mixture being 80% by mole or more and less than 91% by mole, and a worked penetration being 300 to 330.
    Type: Application
    Filed: March 22, 2013
    Publication date: March 19, 2015
    Inventors: Koji Yoshizaki, Kensuke Suzuki, Hiroki Iwamatsu, Masashi Mitsuoka
  • Patent number: 8951945
    Abstract: There is provided a rolling bearing which inhibits spalling of a rolling element and has a long service life even under rigorous environments. The rolling bearing comprises grease for lubricating rolling contact parts and/or sliding contact parts between a first raceway surface and a rolling elements and/or between a second raceway surface and a rolling elements, wherein the grease comprises a base oil, a thickener and an extreme pressure additive, the thickener is a diurea compound obtained by allowing an amine mixture comprising alkylphenylamine, alkyl group of which has 8 to 16 carbon atoms, and cyclohexylamine, to react with a diisocyanate compound, an amount of cyclohexylamine in the total amount of the alkylphenylamine and cyclohexylamine is from 91 to 99% by mole, and a reaction temperature of the extreme pressure additive with iron is 260° C. or lower.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: February 10, 2015
    Assignees: JTEKT Corporation, Nippon Grease Co., Ltd.
    Inventors: Koji Yoshizaki, Kunihiro Yamaguchi, Komatsugu Nishimura, Michiru Ueda, Hiroki Iwamatsu, Masashi Mitsuoka
  • Publication number: 20150023622
    Abstract: A grease composition which is excellent in seizure resistance can be provided without deteriorating resistance to stirring, in the rolling device, and a rolling device in which the grease composition intervenes to a predetermined portion can be also provided by use of a grease composition comprising a base oil, a thickener and an amine antioxidant, the thickener being a diurea compound obtained by allowing an amine mixture comprising alkylphenylamine, an alkyl group of which has 8 to 16 carbon atoms, and cyclohexylamine, to react with a diisocyanate compound, the amount of cyclohexylamine in the amine mixture being 91 to 99% by mole, and the amount of the amine antioxidant in the grease composition being 21% by mass or more.
    Type: Application
    Filed: March 22, 2013
    Publication date: January 22, 2015
    Inventors: Koji Yoshizaki, Kensuke Suzuki, Hiroki Iwamatsu, Masashi Mitsuoka
  • Patent number: 8741823
    Abstract: There is provided a grease composition, in which a grease film on the surface of the applied part is made thicker compared with conventional grease compositions, this thickness is maintained for a long period of time, and as a result, a longer service life against seizure compared with conventional grease compositions is assured. The grease composition comprises a base oil and a thickener, wherein the thickener is a diurea compound obtained by allowing an amine mixture comprising alkylphenylamine, an alkyl group of which has 8 to 16 carbon atoms, and cyclohexylamine, to react with a diisocyanate compound, and an amount of cyclohexylamine in the total amount of the alkylphenylamine and cyclohexylamine is from 91 to 99% by mole.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: June 3, 2014
    Assignee: Nippon Grease Co., Ltd.
    Inventors: Hiroki Iwamatsu, Masashi Mitsuoka
  • Publication number: 20120269472
    Abstract: There is provided a rolling bearing which inhibits spalling of a rolling element and has a long service life even under rigorous environments. The rolling bearing comprises grease for lubricating rolling contact parts and/or sliding contact parts between a first raceway surface and a rolling elements and/or between a second raceway surface and a rolling elements, wherein the grease comprises a base oil, a thickener and an extreme pressure additive, the thickener is a diurea compound obtained by allowing an amine mixture comprising alkylphenylamine, alkyl group of which has 8 to 16 carbon atoms, and cyclohexylamine, to react with a diisocyanate compound, an amount of cyclohexylamine in the total amount of the alkylphenylamine and cyclohexylamine is from 91 to 99% by mole, and a reaction temperature of the extreme pressure additive with iron is 260° C. or lower.
    Type: Application
    Filed: April 12, 2012
    Publication date: October 25, 2012
    Applicants: NIPPON GREASE CO., LTD., JTEKT CORPORATION
    Inventors: Koji YOSHIZAKI, Kunihiro Yamaguchi, Komatsugu Nishimura, Michiru Ueda, Hiroki Iwamatsu, Masashi Mitsuoka
  • Publication number: 20120270762
    Abstract: There is provided a grease composition, in which a grease film on the surface of the applied part is made thicker compared with conventional grease compositions, this thickness is maintained for a long period of time, and as a result, a longer service life against seizure compared with conventional grease compositions is assured. The grease composition comprises a base oil and a thickener, wherein the thickener is a diurea compound obtained by allowing an amine mixture comprising alkylphenylamine, an alkyl group of which has 8 to 16 carbon atoms, and cyclohexylamine, to react with a diisocyanate compound, and an amount of cyclohexylamine in the total amount of the alkylphenylamine and cyclohexylamine is from 91 to 99% by mole.
    Type: Application
    Filed: April 12, 2012
    Publication date: October 25, 2012
    Applicant: NIPPON GREASE CO., LTD.
    Inventors: Hiroki IWAMATSU, Masashi Mitsuoka
  • Patent number: 8044005
    Abstract: 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° C. is 40 to 70 mm2/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 R1 and R3 are a straight-chain alkyl groups having 9 to 22 carbon atoms respectively, and R2 is an aromatic hydrocarbon group having 6 to 15 carbon atoms. The lubricant composition is sealed into the rolling bearing.
    Type: Grant
    Filed: May 24, 2004
    Date of Patent: October 25, 2011
    Assignee: NTN Corporation
    Inventors: Hidenobu Mikami, Seiji Okamura, Hiroki Iwamatsu, Masashi Mitsuoka
  • Patent number: 7696139
    Abstract: A grease composition for a pivot assembly bearing is provided and includes a thickener of 5 to 25% by mass and a base oil of 95 to 75% by mass with respect to the total mass of the thickener and the base oil. Two or more ureas selected from: urea A: a urea comprising diurea compounds having an aliphatic (ALA)/alicyclic (ACA) substituent; urea B: a urea comprising diurea compounds having an alicyclic (ACA)/aromatic (ARA) substituent; and urea C: a urea comprising diurea compounds having an aromatic (ARA)/aliphatic (ALA) substituent are used as the thickener. A poly ?-olefin mixture having a kinematic viscosity at 40° C. of 40 to 70 mm2/s prepared by mixing poly ?-olefin (PAO HV) having a kinematic viscosity at 40° C. of 350 to 450 mm2/s with poly ?-olefin (PAO LV) having a kinematic viscosity at 40° C. of 25 to 40 mm2/s in a mass ratio of 15:85 to 30:70 is used as a base oil. A lead free additive may be used as an additive.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: April 13, 2010
    Assignees: Minebea Co., Ltd., Nippon Grease Co., Ltd.
    Inventors: Seiji Okamura, Motoharu Akiyama, Hiroki Iwamatsu, Yasuhiro Miyamoto
  • Patent number: 7491683
    Abstract: Bismuth dithiocarbamate (BiDTC) is added to a urea grease containing a lubricating base oil having a poly-?-olefin synthetic oil or a diphenyl ether synthetic oil and a diurea thickening agent, or a fluorine grease containing a lubricating base oil having fluorinated synthetic oil and a polytetrafluoroethylene thickening agent. By taking such constitution as described above, a surface film is formed on a surface of a raceway of any one of inner and outer rings or a surface of a rolling element of a bearing. Therefore, the rolling bearing in which a grease composition having the constitution is packed can maintain an excellent lubricity for a long period of time even under severe conditions such as a high rotation, a high temperature and a heavy load. Further, the grease composition for the rolling bearing is low in harmfulness to a human body and gives little load to the environment.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: February 17, 2009
    Assignees: JTEKT Corporation, Nippon Grease Co., Ltd.
    Inventors: Hiroshi Komiya, Seiji Okamura, Hiroki Iwamatsu
  • Publication number: 20090029881
    Abstract: A heat-resistant noise-reduction grease and a bearing containing the grease for a small motor such as a motor for imaging equipment such as a blower fan and motor bearing for a household electrical appliance such as an air conditioner, which is eco-friendly and excellent in noise-reduction properties is provided.
    Type: Application
    Filed: August 1, 2005
    Publication date: January 29, 2009
    Inventors: Seiji Okamura, Motoharu Akiyama, Seiji Hashimoto, Hiroki Iwamatsu
  • Publication number: 20080305973
    Abstract: A lithium grease composition which can be sealed in a small motor bearing to reduce noise, composed of 5-20% by weight of a thickener and 95-80% by weight of a base oil, wherein said grease composition adopts lithium soap as the thickener, which is synthesized from lithium hydroxide and a higher fatty acid with 10 to 20 carbon atoms and/or a higher hydroxyfatty acid with one or more hydroxyl groups and 10 or more carbon atoms, and the base oil includes, as a main component, a polymer ester oil (A) in which 8 or more ester groups are arranged in a comb tooth form on one side of chain molecules constituted by eight or more carbon atoms which is expressed by general formula 1: (In the formula, each of R1, R2, R3 and R4 is an alkyl group, where x is an integer and x?2, and y is an integer and y?2.) and the base oil (40 C) has a viscosity of 25 to 80 mm2/s.
    Type: Application
    Filed: July 29, 2005
    Publication date: December 11, 2008
    Inventors: Hiroki Iwamatsu, Motoharu Akiyama, Yasuhiro Miyamoto, Seiji Okamura
  • Publication number: 20070072777
    Abstract: A grease composition for a pivot assembly bearing is provided and includes a thickener of 5 to 25% by mass and a base oil of 95 to 75% by mass with respect to the total mass of the thickener and the base oil. Two or more ureas selected from: urea A: a urea comprising diurea compounds having an aliphatic (ALA)/alicyclic (ACA) substituent; urea B: a urea comprising diurea compounds having an alicyclic (ACA)/aromatic (ARA) substituent; and urea C: a urea comprising diurea compounds having an aromatic (ARA)/aliphatic (ALA) substituent are used as the thickener. A poly ?-olefin mixture having a kinematic viscosity at 40° C. of 40 to 70 mm 2/s prepared by mixing poly ?-olefin (PAO HV) having a kinematic viscosity at 40° C. of 350 to 450 mm2/s with poly ?-olefin (PAO LV) having a kinematic viscosity at 40° C. of 25 to 40 mm2/s in a mass ratio of 15:85 to 30:70 is used as a base oil. A lead free additive may be used as an additive.
    Type: Application
    Filed: September 25, 2006
    Publication date: March 29, 2007
    Inventors: Seiji Okamura, Motoharu Akiyama, Hiroki Iwamatsu, Yasuhiro Miyamoto
  • Publication number: 20050043190
    Abstract: Bismuth dithiocarbamate (BiDTC) is added to a urea grease containing a lubricating base oil having a poly-?-olefin synthetic oil or a diphenyl ether synthetic oil and a diurea thickening agent, or a fluorine grease containing a lubricating base oil having fluorinated synthetic oil and a polytetrafluoroethylene thickening agent. By taking such constitution as described above, a surface film is formed on a surface of a raceway of any one of inner and outer rings or a surface of a rolling element of a bearing. Therefore, the rolling bearing in which a grease composition having the constitution is packed can maintain an excellent lubricity for a long period of time even under severe conditions such as a high rotation, a high temperature and a heavy load. Further, the grease composition for the rolling bearing is low in harmfulness to a human body and gives little load to the environment.
    Type: Application
    Filed: July 2, 2004
    Publication date: February 24, 2005
    Applicants: Koyo Seiko Co., Ltd., Nippon Grease Co., Ltd.
    Inventors: Hiroshi Komiya, Seiji Okamura, Hiroki Iwamatsu
  • Publication number: 20040242439
    Abstract: 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° C. is 40 to 70 mm2/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.
    Type: Application
    Filed: May 24, 2004
    Publication date: December 2, 2004
    Inventors: Hidenobu Mikami, Seiji Okamura, Hiroki Iwamatsu, Masashi Mitsuoka
  • Patent number: 6432888
    Abstract: The present invention is directed to a grease for a rolling bearing containing poly-&agr;-olefin synthetic oil or diphenyl ether synthetic oil, a diurea thickening agent, and an organic antimony compound or an organic molybdenum compound. The present invention is also directed to a rolling bearing in which the grease for a rolling bearing is sealed. The organic antimony compound or the organic molybdenum compound reacts with a metal composing inner and outer bearing rings and a rolling element to form a compound film contributing to the reduction of the force in the tangential direction on a raceway surface of the bearing rings and a surface of the rolling element, thereby preventing an excessively large force in the tangential direction under high-speed rotation. This enables to lengthen the life of the rolling bearing used under particularly severe conditions such as high temperature, high-speed rotation and high road.
    Type: Grant
    Filed: June 19, 1997
    Date of Patent: August 13, 2002
    Assignees: Koyo Seiko Co., Ltd., Nippon Grease Co., Ltd.
    Inventors: Hiroshi Komiya, Toshikazu Kouno, Masayuki Kitamura, Toshihiro Kawaguchi, Seiji Okamura, Hiroki Iwamatsu
  • Patent number: 5910470
    Abstract: A grease to be sealed in bearings which shows good lubricating properties within a wide temperature range from low to high temperatures, whereby it can prevent bearing noise while it is cold, and maintain its good properties including excellent high-temperature durability for a long period of time. The grease contains a base oil made up of a synthetic hydrocarbon oil and an ester synthetic oil having eight or more ester groups arranged in a comb-like fashion on one side of an oil chain molecule made up of eight of more carbon atoms, as expressed by Formula below, the ratio of contents in weight of the synthetic hydrocarbon oil and the ester synthetic oil being 0.65-0.75:0.35-0.25, and 5-20 wt % of a urea thickening agent. The grease may further contain 0.1-10 wt % dithiophosphate as an extreme pressure agent. The grease may be used as grease to be sealed in a ball bearing for supporting a pulley engaging belts for transmitting automotive engine torque to prevent noise immediately after the engine is started.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: June 8, 1999
    Assignee: NTN Corporation
    Inventors: Masami Minami, Takao Yoshimatsu, Hiroki Iwamatsu, Takahiro Koremoto