Patents by Inventor Masako Tsutsumi

Masako Tsutsumi 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).

  • Publication number: 20140363115
    Abstract: On the contact surface of the rolling bearing part made of alloy steel containing appropriate amounts of Cr and Mo, the C+N content is 0.9 to 1.4 mass % and the area ratio of carbide is 10% or less. At the depth of 1% of the diameter of the rolling element from the contact surface, the hardness is 720 to 832 in Hv, the amount of retained austenite is 20 to 45 volume %, and the compressive residual stress is 50 to 300 Mpa. At the depth of 1 to 3% of the diameter of the rolling element from the contact surface, the average value of the prior austenite grain size is 20 ?m or less and the maximum value of the prior austenite grain size is 3 times or less the average value, and the hardness of the core portion is 400 to 550 in Hv.
    Type: Application
    Filed: November 29, 2012
    Publication date: December 11, 2014
    Applicant: NSK LTD.
    Inventors: Hiroki Yamada, Hideyuki Uyama, Masako Tsutsumi, Yusuke Morito