Patents by Inventor Yasuo Utsumi

Yasuo Utsumi 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: 6325867
    Abstract: A rolling bearing contains no more than 0.3 wt % of nitrogen in a grinding allowance portion after carbonitriding and hardening heat treatments, contains from 0.9 wt % (inclusive) up to 1.6 wt % (inclusive) of carbon and from 0.05 wt % (inclusive) up to 0.3 wt % (inclusive) of nitrogen in the surface layer of the finished part and has a nitrogen gradient of no more than 0.5 wt %/mm in the surface layer of the finished part. The rolling bearings are improved in grinding efficiency and which have their rolling life extended significantly.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: December 4, 2001
    Assignee: NSK Ltd.
    Inventors: Shigeru Okita, Yasuo Utsumi, Akihiro Kiuchi
  • Patent number: 5361648
    Abstract: The rolling/sliding outer ring of the cam follower apparatus withstand peeling very well, even in sever lubrication conditions, through the steps that on the outer peripheral surface of the outer ring, the depth of the surface layer is taken to be 0 to 50 .mu.m, and the maximum residual compressive stress in this surface layer is between 50 and 110 kgf/mm.sup.2, the hardness of this surface layer is between Hv830 and Hv960, and the average wavelength of the very minute protrusions on the surface is less than 25 .mu.m, and the amount of residual austenite in the surface layer exceeds 7 volume %, after processing, while the inner peripheral surface, of the outer ring is superfinished.
    Type: Grant
    Filed: April 6, 1993
    Date of Patent: November 8, 1994
    Assignee: NSK Ltd.
    Inventors: Yasuo Murakami, Yasuo Utsumi, Shoji Noguchi, Yasuyuki Shimasaki, Hiroshi Iwasa, Satoshi Kadokawa
  • Patent number: 5352303
    Abstract: An object of this invention is to provide a rolling bearing which is increased in rolling fatigue life when used with a lubricant contaminated by foreign matters, and which is improved in wear resistance and in seizure resistance. In a rolling bearing, at least one of the inner race, outer race and rolling elements thereof is made of an alloy steel which contains 0.10 to 1.0 wt of C, 0.50 to 3.0 wt % of Cr, 0.10 to 2.0 wt % of Mo, 0.15 to 1.0 wt % of Si, 0.20 to 1.5 wt % of Mn, and 0.2 to 1.0 wt % of Ni, and which is carbo-nitrided so that the sum (C+N) of the contents of carbon (C) and nitrogen (N) in the surface layer thereof is 1.0 to 2.0%, and the ratio (N/C) of the content of nitrogen (N) to the content of carbon (C) is 0.8 to 2.0.
    Type: Grant
    Filed: November 24, 1993
    Date of Patent: October 4, 1994
    Assignee: NSK Ltd.
    Inventors: Yasuo Murakami, Yasuo Utsumi, Toichi Kondou
  • Patent number: 5259886
    Abstract: A rolling member used as an outer race, inner race, a ball or roller of a bearing contains a metal flow in the structure formed by plastic working (fold forging). The angle of metal flow determined by a tangent line of the metal flow and the axis of rotation of the rolling member is 10.degree. or larger to improve the service line against rolling fatigue.
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: November 9, 1993
    Assignee: Nippon Seiko Kabushiki Kaisha
    Inventors: Yasuo Utsumi, Kousuke Nonaka
  • Patent number: 5122000
    Abstract: A rolling bearing in which a bearing ring and/or a rolling element comprises an alloy steel wherein the hardness of a surface layer over a thickness corresponding to greater than 2% of a mean diameter of a rolling element is equal to or greater than 60 HRC and the hardness at least of the raceway surface or the rolling contact surface is equal to or greater than 64 and equal to or less than 69 HRC, and carbides of equal to or greater than 6 .mu.m converted as the diameter of a circle are not contained in a range from the raceway surface of the rolling contact surface as far as the depth corresponding to 2% of the mean diameter of the rolling element.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: June 16, 1992
    Assignee: Nippon Seiko Kabushiki Kaisha
    Inventors: Yoichi Matsumoto, Yasuo Utsumi