Patents by Inventor Keisuke KOKUBUN

Keisuke KOKUBUN 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: 11401973
    Abstract: A thrust roller bearing includes a plurality of radially arranged rollers, and a pair of annular washers having raceway surfaces on which the rollers roll. The raceway surfaces are arranged to face each other. The roller is made of high-carbon chromium bearing steel and has a surface roughness of 0.01 to 0.10 in terms of Rvk and 0.01 to 0.08 in terms of Rk. At least one of the washers is made of carbon steel, surface compressive residual stress of the raceway surface is ?1400 MPa to ?1000 MPa, and Vickers hardness of surface of the raceway surface is 850 to 900.
    Type: Grant
    Filed: November 19, 2020
    Date of Patent: August 2, 2022
    Assignee: JTEKT CORPORATION
    Inventors: Keisuke Kokubun, Yoshihito Nakashima, Taizou Wakayama, Shingo Watanabe
  • Patent number: 11319994
    Abstract: A thrust roller bearing includes a plurality of radially arranged rollers, and a pair of annular washers having raceway surfaces on which the rollers roll, the raceway surfaces being arranged to face each other. The roller is made of high-carbon chromium bearing steel, and contains 1.1 mass % to 1.6 mass % of carbon and 0.1 mass % to 0.6 mass % of nitrogen in a range of 0.1 mm from a surface. A surface compressive residual stress is smaller than ?900 MPa, a surface roughness is 0.01 to 0.10 in terms of Rvk and 0.01 to 0.08 in terms of Rk, and a Vickers hardness of the surface is 860 to 980. At least one of the washers is made of carbon steel, and surface roughnesses of the raceway surfaces are 0.05 to 0.20 in terms of Rvk and 0.08 to 0.15 in terms of Rk.
    Type: Grant
    Filed: November 18, 2020
    Date of Patent: May 3, 2022
    Assignee: JTEKT CORPORATION
    Inventors: Keisuke Kokubun, Yoshihito Nakashima, Taizou Wakayama, Shingo Watanabe
  • Publication number: 20210156420
    Abstract: A thrust roller bearing includes a plurality of radially arranged rollers, and a pair of annular washers having raceway surfaces on which the rollers roll. The raceway surfaces are arranged to face each other. The roller is made of high-carbon chromium bearing steel and has a surface roughness of 0.01 to 0.10 in terms of Rvk and 0.01 to 0.08 in terms of Rk. At least one of the washers is made of carbon steel, surface compressive residual stress of the raceway surface is ?1400 MPa to ?1000 MPa, and Vickers hardness of surface of the raceway surface is 850 to 900.
    Type: Application
    Filed: November 19, 2020
    Publication date: May 27, 2021
    Applicant: JTEKT CORPORATION
    Inventors: Keisuke KOKUBUN, Yoshihito NAKASHIMA, Taizou WAKAYAMA, Shingo WATANABE
  • Publication number: 20210156428
    Abstract: A thrust roller bearing includes a plurality of radially arranged rollers, and a pair of annular washers having raceway surfaces on which the rollers roll, the raceway surfaces being arranged to face each other. The roller is made of high-carbon chromium bearing steel, and contains 1.1 mass % to 1.6 mass % of carbon and 0.1 mass % to 0.6 mass % of nitrogen in a range of 0.1 mm from a surface. A surface compressive residual stress is smaller than ?900 MPa, a surface roughness is 0.01 to 0.10 in terms of Rvk and 0.01 to 0.08 in terms of Rk, and a Vickers hardness of the surface is 860 to 980. At least one of the washers is made of carbon steel, and surface roughnesses of the raceway surfaces are 0.05 to 0.20 in terms of Rvk and 0.08 to 0.15 in terms of Rk.
    Type: Application
    Filed: November 18, 2020
    Publication date: May 27, 2021
    Applicant: JTEKT CORPORATION
    Inventors: Keisuke KOKUBUN, Yoshihito NAKASHIMA, Taizou WAKAYAMA, Shingo WATANABE