Patents by Inventor Jun Ujita

Jun Ujita 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: 7196028
    Abstract: The present invention provides sliding members respectively having sliding surfaces opposed to each other for creating dynamic pressure in a fluid, in which the sliding surfaces are formed of ceramics containing crystal grains of Al2O3, crystal grains of TiC contained in the crystal grains of Al2O3, and crystal grains of TiC existing independently of the crystal grains of Al2O3, and having a TiC content of 5 to 20 mass % in the total amount of Al2O3 and TiC, and the respective volume resistivity values R1 and R2 of the ceramics forming the sliding surfaces are within a range simultaneously satisfying equations (1) to (3) to prevent spark discharges from being induced between the sliding surfaces, and a fluid dynamic pressure bearing and a motor to which the configuration is applied: 106 ?·cm<R1?1012 ?·cm??(1) 106 ?·cm<R2?1012 ?·cm??(2) |R1?R2|?105 ?·cm??(3)
    Type: Grant
    Filed: May 25, 2005
    Date of Patent: March 27, 2007
    Assignee: Kyocera Corporation
    Inventors: Jun Ujita, Kazuhide Kusano, Shunji Mikaki
  • Publication number: 20050288171
    Abstract: The present invention provides sliding members respectively having sliding surfaces opposed to each other for creating dynamic pressure in a fluid, in which the sliding surfaces are formed of ceramics containing crystal grains of Al2O3, crystal grains of TiC contained in the crystal grains of Al2O3, and crystal grains of TiC existing independently of the crystal grains of Al2O3, and having a TiC content of 5 to 20 mass % in the total amount of Al2O3 and TiC, and the respective volume resistivity values R1 and R2 of the ceramics forming the sliding surfaces are within a range simultaneously satisfying equations (1) to (3) to prevent spark discharges from being induced between the sliding surfaces, and a fluid dynamic pressure bearing and a motor to which the configuration is applied: 106 ?·cm<R1?1012 ?·cm??(1) 106 ?·cm<R2?1012 ?·cm??(2) |R1?R2|?105 ?·cm??(3)
    Type: Application
    Filed: May 25, 2005
    Publication date: December 29, 2005
    Inventors: Jun Ujita, Kazuhide Kusano, Shunji Mikaki