Patents by Inventor Naohiro Jotaki

Naohiro Jotaki 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: 8985591
    Abstract: Provided is a sealing apparatus which can reduce the torque of a rotary portion while always exhibiting a stable and high sealing performance even when a high fluid pressure is being applied. A seal ring (4) inclines when subjected to a hydraulic pressure (P) and a pressing force by a D-ring (3), and stabilizes in a state where an entire opposite pressure-side taper surface (4c) is in contact with an opposite pressure-side side surface (5b) of an annular groove for sealing (5). With the hydraulic pressure (P) being applied to a portion (4b1) of the inner peripheral surface (4b) of the seal ring (4) where an operating oil comes into contact, a space between the portion (4b1) and a shaft (2) is enlarged, and an area of contact between the seal ring (4) and the shaft (2) is reduced. Thus, the torque can be reduced.
    Type: Grant
    Filed: January 18, 2011
    Date of Patent: March 24, 2015
    Assignee: NOK Corporation
    Inventor: Naohiro Jotaki
  • Publication number: 20120319359
    Abstract: Provided is a sealing apparatus which can reduce the torque of a rotary portion while always exhibiting a stable and high sealing performance even when a high fluid pressure is being applied. A seal ring (4) inclines when subjected to a hydraulic pressure (P) and a pressing force by a D-ring (3), and stabilizes in a state where an entire opposite pressure-side taper surface (4c) is in contact with an opposite pressure-side side surface (5b) of an annular groove for sealing (5). With the hydraulic pressure (P) being applied to a portion (4b1) of the inner peripheral surface (4b) of the seal ring (4) where an operating oil comes into contact, a space between the portion (4b1) and a shaft (2) is enlarged, and an area of contact between the seal ring (4) and the shaft (2) is reduced. Thus, the torque can be reduced.
    Type: Application
    Filed: January 18, 2011
    Publication date: December 20, 2012
    Applicant: NOK Corporation
    Inventor: Naohiro Jotaki
  • Patent number: 7341256
    Abstract: A seal ring which maintains a stable sealing performance over a long term is provided. In a first seal portion, linear contact portions which come into linear contact with the sidewall surface of an annular groove on the unsealed fluid side are continuously extended over the whole circumference of the seal ring from one side of a separation portion to the other side thereof, and the linear contact part provided at the convex part of the separation portion, and the linear contact part provided at the concave part of the separation portion are located at a distance in the radial direction of the seal ring.
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: March 11, 2008
    Assignee: NOK Corporation
    Inventors: Shinya Nakaoka, Nobuyuki Eguchi, Naohiro Jotaki, Takaaki Yasudomi
  • Publication number: 20060038355
    Abstract: A seal ring which maintains a stable sealing performance over a long term is provided. In a first seal portion 4, linear contact portions which come into linear contact with the sidewall surface of an annular groove on the unsealed fluid side are continuously extended over the whole circumference of the seal ring from one side of a separation portion 2 to the other side thereof, and the linear contact part provided at the convex part 21 of the separation portion 2, and the linear contact part provided at the concave part 24 of the separation portion 2 are located at a distance in the diametric direction of the seal ring.
    Type: Application
    Filed: July 25, 2003
    Publication date: February 23, 2006
    Inventors: Shinya Nakaoka, Nobuyuki Eguchi, Naohiro Jotaki, Takaaki Yasudomi