Patents by Inventor Hirofumi ITAGAKI

Hirofumi ITAGAKI 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: 11892060
    Abstract: A frictional roller reducer having a sun roller; a ring roller; a plurality of intermediate rollers having rolling surfaces coming in rolling contact with the sun roller and the ring roller; the sun roller or the ring roller having a pair of roller elements including inclined surface portions on a circumferential surface coming in rolling with rolling surfaces, the inclined surface portions inclined in directions going toward the intermediate rollers in a radial direction as going away from each other in the axial direction; a pressing device pressing the pair of roller elements in directions going closer to each other, and an elastic member arranged between the pair of roller elements, the elastic member urging the pair of roller elements in directions going away from the rolling surface of the intermediate rollers.
    Type: Grant
    Filed: December 3, 2021
    Date of Patent: February 6, 2024
    Assignee: NSK LTD.
    Inventors: Hiroshi Kawahara, Hiroki Hashiguchi, Hirofumi Itagaki, Azusa Hidaka, Hiroki Nishida, Naofumi Fujita, Hikari Yoshimi, Naohiro Hitomi, Masahiro Kita
  • Patent number: 11867262
    Abstract: The frictional roller reducer has an input shaft, an output shaft, a pair of annular roller elements, a plurality of planetary rollers, a carrier, a pressing device, and a controller. The pressing device rotationally drives a cam disk by a pressing force adjusting motor, which causes an annular roller element of the pair of annular roller elements to displace in the axial direction. The controller, by adjusting the rotational drive of the pressing force adjusting motor, adjusts the surface pressure at the traction portions between rolling surfaces of the planetary rollers and an inner-diameter side rolling contact surface of the input shaft and outer-diameter side rolling contact surfaces of the pair of annular roller elements to a target value.
    Type: Grant
    Filed: January 10, 2020
    Date of Patent: January 9, 2024
    Assignee: NSK, LTD.
    Inventors: Hiroshi Kawahara, Hirofumi Itagaki
  • Publication number: 20230193984
    Abstract: A frictional roller reducer having a sun roller; a ring roller; a plurality of intermediate rollers having rolling surfaces coming in rolling contact with the sun roller and the ring roller; the sun roller or the ring roller having a pair of roller elements including inclined surface portions on a circumferential surface coming in rolling with rolling surfaces, the inclined surface portions inclined in directions going toward the intermediate rollers in a radial direction as going away from each other in the axial direction; a pressing device pressing the pair of roller elements in directions going closer to each other, and an elastic member arranged between the pair of roller elements, the elastic member urging the pair of roller elements in directions going away from the rolling surface of the intermediate rollers.
    Type: Application
    Filed: December 3, 2021
    Publication date: June 22, 2023
    Applicant: NSK LTD.
    Inventors: Hiroshi KAWAHARA, Hiroki HASHIGUCHI, Hirofumi ITAGAKI, Azusa HIDAKA, Hiroki NISHIDA, Naofumi FUJITA, Hikari YOSHIMI, Naohiro HITOMI, Masahiro KITA
  • Publication number: 20220221031
    Abstract: A structure is achieved capable of ensuring excellent transmission efficiency while preventing the occurrence of gross slipping at traction portions. A pressing device 9 rotationally drives a cam disk 21 by a pressing force adjusting motor 23, which causes an annular roller element 6a of a pair of annular roller elements 6a, 6b to displace in the axial direction. A controller 31, by adjusting the rotational drive of the pressing force adjusting motor 23, adjusts the surface pressure at the traction portions between rolling surfaces 16 of planetary rollers 7 and an inner-diameter side rolling contact surface 5 of an input shaft 3 and outer-diameter side rolling contact surfaces 12a, 12b of the pair of annular roller elements 6a, 6b to a target value.
    Type: Application
    Filed: January 10, 2020
    Publication date: July 14, 2022
    Inventors: Hiroshi Kawahara, Hirofumi Itagaki
  • Patent number: 11333225
    Abstract: Provided is a pressing device for a toroidal continuously variable transmission that is capable of sufficiently supplying lubrication oil to all rollers inside a pocket, and is capable of suppressing the occurrence of fretting wear on the rolling surfaces of the rollers, a first cam surface and a second cam surface. An oil passage 28 is provided for supplying lubrication oil to the inside of each pocket 25 in the inside portion in the radial direction of a retainer 14 that holds a plurality of more than one roller 13 arranged in a row in the radial direction. The center axis O29 of a discharge port 29 that is provided on an end portion on the downstream side of the oil passage 28 and that opens to the inside surface in the radial direction of the pocket 25 is inclined toward the front side in the rotational direction of the retainer 14 with respect to the center axis of the pocket 25.
    Type: Grant
    Filed: March 20, 2018
    Date of Patent: May 17, 2022
    Assignees: NSK LTD., KAWASAKI JUKOGYO KABUSHIKI KAISHA
    Inventors: Hirofumi Itagaki, Masahiro Kita, Kippei Matsuda, Kenichiro Tanaka, Hideyuki Imai, Kenji Komatsu
  • Patent number: 10948055
    Abstract: Provided is a pressing device for toroidal continuously variable transmission capable of reducing hysteresis that occurs between torque and pressing force. An intermediate sliding member 27 is provided in at least one location of a portion between an end surface on the outside in the radial direction of the retainer 13 of the roller 14 arranged on the outermost side in the radial direction and an inside surface of the pocket 25 on the outside in the radial direction, and a portion between an end surface on the outside in the radial direction of the retainer 13 of one roller 14 of adjoining rollers 14 in the radial direction and an end surface on the inside in the radial direction of the retainer 13 of another roller 14. As a result, the contact area of a sliding contact portion 32 is made smaller than in a case where an intermediate sliding member 27 is not provided.
    Type: Grant
    Filed: March 20, 2018
    Date of Patent: March 16, 2021
    Assignees: NSK LTD., KAWASAKI JUKOGYO KABUSHIKI KAISHA
    Inventors: Hirofumi Itagaki, Masahiro Kita, Kippei Matsuda, Kenichiro Tanaka, Hideyuki Imai, Kenji Komatsu
  • Publication number: 20200063837
    Abstract: Provided is a pressing device for a toroidal continuously variable transmission that is capable of sufficiently supplying lubrication oil to all rollers inside a pocket, and is capable of suppressing the occurrence of fretting wear on the rolling surfaces of the rollers, a first cam surface and a second cam surface. An oil passage 28 is provided for supplying lubrication oil to the inside of each pocket 25 in the inside portion in the radial direction of a retainer 14 that holds a plurality of more than one roller 13 arranged in a row in the radial direction. The center axis O29 of a discharge port 29 that is provided on an end portion on the downstream side of the oil passage 28 and that opens to the inside surface in the radial direction of the pocket 25 is inclined toward the front side in the rotational direction of the retainer 14 with respect to the center axis of the pocket 25.
    Type: Application
    Filed: March 20, 2018
    Publication date: February 27, 2020
    Inventors: Hirofumi ITAGAKI, Masahiro KITA, Kippei MATSUDA, Kenichiro TANAKA, Hideyuki IMAI, Kenji KOMATSU
  • Publication number: 20200011404
    Abstract: Provided is a pressing device for toroidal continuously variable transmission capable of reducing hysteresis that occurs between torque and pressing force. An intermediate sliding member 27 is provided in at least one location of a portion between an end surface on the outside in the radial direction of the retainer 13 of the roller 14 arranged on the outermost side in the radial direction and an inside surface of the pocket 25 on the outside in the radial direction, and a portion between an end surface on the outside in the radial direction of the retainer 13 of one roller 14 of adjoining rollers 14 in the radial direction and an end surface on the inside in the radial direction of the retainer 13 of another roller 14. As a result, the contact area of a sliding contact portion 32 is made smaller than in a case where an intermediate sliding member 27 is not provided.
    Type: Application
    Filed: March 20, 2018
    Publication date: January 9, 2020
    Inventors: Hirofumi ITAGAKI, Masahiro KITA, Kippei MATSUDA, Kenichiro TANAKA, Hideyuki IMAI, Kenji KOMATSU