Patents by Inventor Taku Itagaki

Taku 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).

  • Publication number: 20240167518
    Abstract: In a tripod type constant velocity universal joint 1 of a double roller type, R/PCD?0.0850 and t/PCD?0.145, where PCD is a pitch circle diameter of a roller guide surface 6 of an outer joint member 2. R is a radius of curvature at an intermediate portion between a body portion 31 and a leg shaft 32 of a tripod member 3, and t is a minimum distance from a large-diameter portion 34a of a spline 34 of the tripod member 3 to an intermediate portion 33.
    Type: Application
    Filed: March 11, 2022
    Publication date: May 23, 2024
    Inventors: Taku ITAGAKI, Shota KAWATA, Tatsuro SUGIYAMA
  • Patent number: 11767876
    Abstract: A power transmission shaft includes a metal shaft member, and a resin shaft member connected to the metal shaft member in an axial direction of the power transmission shaft. The resin shaft member is made of fiber reinforced plastic. The metal shaft member and the resin shaft member are joined to each other through a close-contact fitting portion between a male spline, which is formed in an outer surface of the metal shaft member, and a female spline formed by press-fitting the male spline into the resin shaft member. An edge is formed at a radially outer edge portion of a press-fitting-start end surface of the male spline of the metal shaft member.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: September 26, 2023
    Assignee: NTN CORPORATION
    Inventors: Taku Itagaki, Minoru Ishijima
  • Publication number: 20230204078
    Abstract: A tripod type constant velocity universal joint includes an outer joint member having three track grooves each including roller guide surfaces opposing each other in a circumferential direction of each of the track grooves, a tripod member including three leg shafts, and roller units each including a roller and an inner ring to support the roller. An outer peripheral surface of the roller has a partially spherical surface having a curvature center on an axis of each of the leg shafts. The roller guide surfaces are each formed of a partially cylindrical surface having a curvature center on a horizontal line passing an intersection of a pitch circle of the track grooves and a center line of each of the track grooves, and when no torque is applied to the joint, an end portion of the outer peripheral surface of the roller abuts against the roller guide surfaces.
    Type: Application
    Filed: May 13, 2021
    Publication date: June 29, 2023
    Inventors: Taku ITAGAKI, Tatsuro SUGIYAMA, Minoru ISHIJIMA
  • Publication number: 20220090635
    Abstract: A tripod type constant velocity universal joint includes an outer joint member that includes track grooves, a tripod member that includes three leg shafts protruding in a radial direction, a roller that is inserted into the track groove, and an inner ring that is fitted onto the leg shaft, and rotatably supports the roller. A hardened layer is formed on a surface of each leg shaft by carburizing, hardening, and tempering. The tripod member is formed a steel material having a carbon content of 0.23% to 0.44%. An effective hardened layer depth of the hardened layer by using, as a Ts torque, 0.3 times a minimum static torsional torque at which a shaft coupled to the tripod member causes torsional fracture and 600HV as limit hardness is equal to or greater than a maximum shear stress depth Z when the Ts torque is applied.
    Type: Application
    Filed: December 20, 2019
    Publication date: March 24, 2022
    Inventors: Taku ITAGAKI, Tatsuro SUGIYAMA, Shouta KAWATA
  • Publication number: 20200318676
    Abstract: Provided is a power transmission shaft, including: a metal shaft member; and a resin shaft member connected to the metal shaft member in an axial direction of the power transmission shaft. The resin shaft member is made of fiber reinforced plastic. The metal shaft member and the resin shaft member are joined to each other through a close-contact fitting portion between a male spline, which is formed in an outer surface of the metal shaft member, and a female spline formed by press-fitting the male spline into the resin shaft member. An edge is formed at a radially outer edge portion of a press-fitting-start end surface of the male spline of the metal shaft member.
    Type: Application
    Filed: December 21, 2018
    Publication date: October 8, 2020
    Inventors: Taku ITAGAKI, Minoru ISHIJIMA
  • Patent number: 10443647
    Abstract: A corrugated portion is formed in one end edge portion of the metallic shaft main body (2), and a triangular corrugated portion (11) is formed in an end edge portion of the shaft auxiliary body (3) on the metallic shaft main body side. The metallic shaft main body (2) and the shaft auxiliary body (3) are integrated by being linearly arranged by way of meshing that brings a side of the triangular corrugated portion (9) on the main body side and a side of the triangular corrugated portion (11) on the auxiliary body side into contact with each other. A fiber orientation angle (?) of the fiber reinforced plastic of the shaft auxiliary body (3) is set so as to be in the same direction as a direction of stress generated in a hypotenuse of each triangular portion under a torque load state.
    Type: Grant
    Filed: November 2, 2015
    Date of Patent: October 15, 2019
    Assignee: NTN CORPORATION
    Inventors: Taku Itagaki, Yuichi Asano, Tomoshige Kobayashi, Takeyoshi Konomoto, Minoru Ishijima
  • Publication number: 20170335883
    Abstract: A corrugated portion is formed in one end edge portion of the metallic shaft main body (2), and a triangular corrugated portion (11) is formed in an end edge portion of the shaft auxiliary body (3) on the metallic shaft main body side. The metallic shaft main body (2) and the shaft auxiliary body (3) are integrated by being linearly arranged by way of meshing that brings a side of the triangular corrugated portion (9) on the main body side and a side of the triangular corrugated portion (11) on the auxiliary body side into contact with each other. A fiber orientation angle (?) of the fiber reinforced plastic of the shaft auxiliary body (3) is set so as to be in the same direction as a direction of stress generated in a hypotenuse of each triangular portion under a torque load state.
    Type: Application
    Filed: November 2, 2015
    Publication date: November 23, 2017
    Inventors: Taku ITAGAKI, Yuichi ASANO, Tomoshige KOBAYASHI, Takeyoshi KONOMOTO, Minoru ISHIJIMA
  • Publication number: 20160290450
    Abstract: A V-belt type infinitely variable transmission is provided which is made up of a smaller number of parts and which can be easily assembled and disassembled. By rotating an eccentric cam, an arm member is moved in the axial direction of a primary shaft. When the arm member is moved in this direction, a movable pulley member of a driving pulley is moved relative to a fixed pulley member of the driving pulley. Thus, it is possible to adjust the groove width of the driving pulley.
    Type: Application
    Filed: November 20, 2014
    Publication date: October 6, 2016
    Inventors: Taku ITAGAKI, Yoshiaki RYOUNO, Kazuya AKAISHI
  • Patent number: 9394949
    Abstract: A tripod type constant velocity universal joint includes an outer joint member including three track grooves having roller-guide surfaces arranged to face each other in a circumferential direction, a tripod member including three leg shafts projecting in a radial direction, and roller units each including a roller and an inner ring for supporting the roller in a freely rotatable manner. The inner ring is externally fitted to a corresponding one of the three leg shafts. The roller is movable along the roller-guide surfaces of a corresponding one of the three track grooves. Each of the three leg shafts includes a region formed into a substantially circular-arc shape in horizontal cross-section that is orthogonal to an axial line of each of the three leg shafts.
    Type: Grant
    Filed: November 5, 2012
    Date of Patent: July 19, 2016
    Assignee: NTN CORPORATION
    Inventors: Jiahua Miao, Shunsuke Makino, Hiroshi Murakami, Taku Itagaki, Hiroshi Adachi, Makoto Ikki
  • Publication number: 20140287841
    Abstract: A tripod type constant velocity universal joint includes an outer joint member including three track grooves having roller-guide surfaces arranged to face each other in a circumferential direction, a tripod member including three leg shafts projecting in a radial direction, and roller units each including a roller and an inner ring for supporting the roller in a freely rotatable manner. The inner ring is externally fitted to corresponding one of the three leg shafts. The roller is movable along the roller-guide surfaces of corresponding one of the three track grooves. Each of the three leg shafts includes a region formed into a substantially circular-arc shape in horizontal cross-section that is orthogonal to an axial line of the each of the three leg shafts.
    Type: Application
    Filed: November 5, 2012
    Publication date: September 25, 2014
    Applicant: NTN CORPORATION
    Inventors: Jiahua Miao, Shunsuke Makino, Hiroshi Murakami, Taku Itagaki, Hiroshi Adachi, Makoto Ikki
  • Patent number: 8506202
    Abstract: A constant velocity universal joint having a recess-projection engagement configuration in which backlash at a shaft connecting region does not easily occur, and an inner joint component and a shaft can he firmly connected. hi the constant velocity universal joint, the inner joint component and the shaft (5) fitted into an axis hole (22) of the inner joint component are connected by die recess-projection engagement configuration. Engagement contacting regions (38) of projections (35) and recesses (36) corresponding thereto are in close contact over the whole region.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: August 13, 2013
    Assignee: NTN Corporation
    Inventors: Tohru Nakagawa, Yuichi Asano, Hiroshi Kawamura, Kiyoshige Yamauchi, Masahiro Ozawa, Kisao Yamazaki, Taku Itagaki
  • Patent number: 8454767
    Abstract: A heat treatment method is capable of molding, by mobile quenching of induction quenching, an outer joint member of a tripod type constant velocity universal joint having excellent strength without forming hardened layers in larger radially-inner portions. Mobile quenching is performed in such a manner that a high-frequency induction heating coil is moved in an axial direction relative to an outer joint member, and thus hardened layers are formed on the roller guide surfaces. Magnetic field line cut-out bodies for cutting out generated magnetic field lines are arranged on the high-frequency induction heating coil. The larger radially-inner portions become an unquenched portion by cutting out the magnetic field lines with the magnetic field line cut-out bodies.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: June 4, 2013
    Assignees: NTN Corporation, NTN Driveshaft, Inc.
    Inventors: Taku Itagaki, Seiya Kato, Brian Drier
  • Publication number: 20120329564
    Abstract: A tripod constant velocity universal joint is configured with only three parts including an outer ring (10), a tripod (20), and spherical rollers (30). Trunnions (26) are allowed to make direct contact with the spherical rollers (30). The outer ring (10) includes three track grooves (14) parallel to its axis in the inner circumference thereof. Roller guide surfaces (16) are formed on both side walls of the respective track grooves (14). The tripod (20) is inserted inside the outer ring (10) and composed of a boss (22) and three trunnions (26) protruding radially from the boss (22). The spherical rollers (30) are rotatably supported on the trunnions (26), and can move in the axial direction of the outer ring (10) as they roll in the track grooves (14) of the outer ring (10) along the roller guide surfaces (16).
    Type: Application
    Filed: March 19, 2010
    Publication date: December 27, 2012
    Inventors: Taku Itagaki, Tatsuro Sugiyama, Masayuki Kuroda
  • Publication number: 20120222779
    Abstract: Proposed are a heat treatment method capable of molding, by mobile quenching of induction quenching, an outer joint member of a tripod type constant velocity universal joint excellent in a strength thereof without forming hardened layers in larger radially-inner portions, and the outer joint member and the tripod type constant velocity universal joint which are manufactured by the above-mentioned heat treatment method. Mobile quenching is performed in such a manner that a high-frequency induction heating coil (51) is moved in an axial direction relative to an outer joint member (21), and thus hardened layers (S) are formed on the roller guide surfaces (27) of the outer joint member (21).
    Type: Application
    Filed: March 1, 2011
    Publication date: September 6, 2012
    Inventors: Taku ITAGAKI, Seiya Kato, Brian Drier
  • Publication number: 20090317177
    Abstract: The present invention provides a constant velocity universal joint having a recess-projection engagement configuration in which backlash at a shaft connecting region does not easily occur, and an inner joint component and a shaft can be firmly connected. In the constant velocity universal joint of the present invention, the inner joint component and the shaft 5 fitted into an axis hole 22 of the inner joint component are connected by the recess-projection engagement configuration. Engagement contacting regions 38 of projections 35 and recesses 36 corresponding thereto are in close contact over the whole region.
    Type: Application
    Filed: January 17, 2008
    Publication date: December 24, 2009
    Inventors: Tohru Nakagawa, Yuichi Asano, Hiroshi Kawamura, Kiyoshige Yamauchi, Masahiro Ozawa, Kisao Yamazaki, Taku Itagaki
  • Patent number: 7160193
    Abstract: In a no-flange type outer joint member, the amount of abrasion in a large inner diameter portion formed for a track groove is intended to be restrained. In a tripod type constant velocity universal joint including: a no-flange type outer joint member; and a roller assembly including a roller, being attached to a trunnion so as to be capable of oscillating, hardened layers are formed on portions of a large inner diameter portion of the outer joint member, which are in contact with an inclined roller assembly. In this case, a value of F/D is set equal to or less than 0.45, where a distance from a center of the track groove of the outer joint member to the ends of both the hardened layers on the side of the center of the track groove is F, and a diameter of an outer circumference of the roller assembly is D.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: January 9, 2007
    Assignee: NTN Corporation
    Inventors: Taku Itagaki, Tatsuro Sugiyama, Tatsuhiro Goto, Shintaro Suzuki
  • Publication number: 20050014565
    Abstract: In a no-flange type outer joint member, the amount of abrasion in a large inner diameter portion formed for a track groove is intended to be restrained. In a tripod type constant velocity universal joint including: a no-flange type outer joint member; and a roller assembly including a roller, being attached to a trunnion so as to be capable of oscillating, hardened layers are formed on portions of a large inner diameter portion of the outer joint member, which are in contact with an inclined roller assembly. In this case, a value of F/D is set equal to or less than 0.45, where a distance from a center of the track groove of the outer joint member to the ends of both the hardened layers on the side of the center of the track groove is F, and a diameter of an outer circumference of the roller assembly is D.
    Type: Application
    Filed: June 4, 2004
    Publication date: January 20, 2005
    Inventors: Taku Itagaki, Tatsuro Sugiyama, Tatsuhiro Goto, Shintaro Suzuki
  • Patent number: 6764407
    Abstract: A constant velocity universal joint is disclosed which includes an outer joint member with three axial track grooves and a tripod member with three radially projecting trunnion journals, each of the trunnion journals carrying a roller assembly received in each of the track grooves, a projection being formed at an end of each trunnion for interference with the roller assembly.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: July 20, 2004
    Assignee: NTN Corporation
    Inventors: Tatsuhiro Goto, Taku Itagaki, Yukihiro Watanabe, Hisaaki Kura
  • Publication number: 20030073501
    Abstract: A constant velocity universal joint is disclosed which includes an outer joint member with three axial track grooves and a tripod member with three radially projecting trunnion journals, each of the trunnion journals carrying a roller assembly received in each of the track grooves, a projection being formed at an end of each trunnion for interference with the roller assembly.
    Type: Application
    Filed: September 24, 2002
    Publication date: April 17, 2003
    Inventors: Tatsuhiro Goto, Taku Itagaki, Yukihiro Watanabe, Hisaaki Kura