Patents by Inventor Takanori Kurokawa

Takanori Kurokawa 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: 10228021
    Abstract: In a copper alloy machined cage for a thrust ball bearing, an inside surface of a pocket includes a cylindrical surface, a support surface which is continuous with the cylindrical surface and contacts a ball in an axial direction, and two protruding portions which are formed at an equal interval in a circumferential direction of the pocket, at a ball insertion side of the pocket which is opposite to the support surface in the axial direction and protrude from the cylindrical surface. The protruding portions prevent falling out of the ball from a ball insertion side opening of the pocket and are either elastically deformed or elastic-plastically deformed by the ball during insertion of the ball into the pocket.
    Type: Grant
    Filed: March 16, 2015
    Date of Patent: March 12, 2019
    Assignee: NSK LTD.
    Inventors: Tomoaki Sakase, Takanori Kurokawa
  • Patent number: 10190632
    Abstract: In a copper alloy machined cage for a thrust ball bearing, an inside surface of a pocket includes a cylindrical surface, a support surface which is continuous with the cylindrical surface and contacts a ball in an axial direction, and two protruding portions which are formed at an equal interval in a circumferential direction of the pocket, at a ball insertion side of the pocket which is opposite to the support surface in the axial direction and protrude from the cylindrical surface. The protruding portions prevent falling out of the ball from a ball insertion side opening of the pocket and are either elastically deformed or elastic-plastically deformed by the ball during insertion of the ball into the pocket.
    Type: Grant
    Filed: March 16, 2015
    Date of Patent: January 29, 2019
    Assignee: NSK LTD.
    Inventors: Tomoaki Sakase, Takanori Kurokawa
  • Publication number: 20170089392
    Abstract: In a copper alloy machined cage for a thrust ball bearing, an inside surface of a pocket includes a cylindrical surface, a support surface which is continuous with the cylindrical surface and contacts a ball in an axial direction, and two protruding portions which are formed at an equal interval in a circumferential direction of the pocket, at a ball insertion side of the pocket which is opposite to the support surface in the axial direction and protrude from the cylindrical surface. The protruding portions prevent falling out of the ball from a ball insertion side opening of the pocket and are either elastically deformed or elastic-plastically deformed by the ball during insertion of the ball into the pocket.
    Type: Application
    Filed: March 16, 2015
    Publication date: March 30, 2017
    Applicant: NSK LTD.
    Inventors: Tomoaki SAKASE, Takanori KUROKAWA
  • Patent number: 9121443
    Abstract: An angular ball bearing includes an outer ring having a raceway surface on the inner circumferential surface thereof, a shoulder portion on one side of the raceway surface and a counter bore on the other side thereof; an inner ring having a raceway surface on the outer circumferential surface thereof, a shoulder portion on the other side of the raceway surface and a counter bore on one side thereof; and a plurality of balls provided between the raceway surfaces of the outer ring and the inner ring so as to be rotatable at a contact angle. The outer diameter dimension of the shoulder portion of the inner ring is larger than the inner diameter dimension of the shoulder portion of the outer ring, and the shoulder portion of the outer ring and the shoulder portion of the inner ring are overlapped with each other when viewed in the axial direction.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: September 1, 2015
    Assignee: NSK LTD.
    Inventor: Takanori Kurokawa
  • Publication number: 20140219599
    Abstract: An angular ball bearing includes an outer ring having a raceway surface on the inner circumferential surface thereof, a shoulder portion on one side of the raceway surface and a counter bore on the other side thereof; an inner ring having a raceway surface on the outer circumferential surface thereof, a shoulder portion on the other side of the raceway surface and a counter bore on one side thereof; and a plurality of balls provided between the raceway surfaces of the outer ring and the inner ring so as to be rotatable at a contact angle. The outer diameter dimension of the shoulder portion of the inner ring is larger than the inner diameter dimension of the shoulder portion of the outer ring, and the shoulder portion of the outer ring and the shoulder portion of the inner ring are overlapped with each other when viewed in the axial direction.
    Type: Application
    Filed: May 29, 2012
    Publication date: August 7, 2014
    Applicant: NSK LTD.
    Inventor: Takanori Kurokawa
  • Patent number: 8042645
    Abstract: A parallel shaft gear mechanism (19a) for a steering assist of the present electric power steering apparatus (1) includes an idle gear (26) rotatably supported via a rolling bearing (39), on an outer peripheral surface (37d) of an intermediate shaft (37) supported by a rack housing (15). The idle gear (26) is arranged in an annular synthetic resin member (43) fixed on the outer peripheral surface (44a) of an outer ring (44) of the bearing (39). On the outer peripheral surface (44a) of the outer ring (44), a regulating portion (53, 53A, 53B, 53C, 53D, 53E, 53F, 53G, 54, 54A, 54B, 54C, 54D, 54E, 54F, 55, 56, 56A, 56B, 59, 59A, and 59B) for regulating relative rotation between the outer ring (44) and the synthetic resin member (43) is arranged. The synthetic resin member (43) is formed in a manner to cover the regulating portion on the outer peripheral surface (44a) of the outer ring (44), as a result of a molding process using a mold.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: October 25, 2011
    Assignee: JTEKT Corporation
    Inventor: Takanori Kurokawa
  • Patent number: 7728071
    Abstract: A gear for an electric power steering device for reducing the rotation speed of an electric motor for steering assist with a reduction gear mechanism and transmitting the rotation to a steering mechanism, the gear being incorporated and used in the reduction gear mechanism, wherein at least the teeth of the gear are formed from a resin composition of a non-reinforced type comprising (a) a polyamide resin having a carboxyl group at least at a terminal end; (b) 0.5-5 wt. % a polycarbodiimide compound, and (c) 3-15 wt. % an elastic material modified with a reactive functional group.
    Type: Grant
    Filed: May 12, 2006
    Date of Patent: June 1, 2010
    Assignees: E. I. Du Pont De Nemours and Company, JTEKT Corporation
    Inventors: Kenichi Shinohara, Takanori Kurokawa, Hirokazu Arai
  • Patent number: 7722257
    Abstract: A roller bearing cage is made of a resin and has a tapered tubular shape as a whole. In the roller bearing cage, tapered rollers are forcibly fitted to pockets while elastically deforming pillar portions at a small-diameter annular portion side. A stress alleviating portion is provided on at least an outer circumferential side of an end of the pillar portion at the small-diameter annular portion side so that a portion of the pillar portion from a crossing portion between the pillar portion and the small-diameter annular portion to a side of the large-diameter annular portion is linearly cut, thereby alleviating the stress occurring in the pillar portion when the tapered roller is forcibly fitted to the pocket.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: May 25, 2010
    Assignee: JTEKT Corporation
    Inventors: Masahiro Tabata, Takanori Kurokawa
  • Publication number: 20100051378
    Abstract: A parallel shaft gear mechanism (19a) for a steering assist of the present electric power steering apparatus (1) includes an idle gear (26) rotatably supported via a rolling bearing (39), on an outer peripheral surface (37d) of an intermediate shaft (37) supported by a rack housing (15). The idle gear (26) is arranged in an annular synthetic resin member (43) fixed on the outer peripheral surface (44a) of an outer ring (44) of the bearing (39). On the outer peripheral surface (44a) of the outer ring (44), a regulating portion (53, 53A, 53B, 53C, 53D, 53E, 53F, 53G, 54, 54A, 54B, 54C, 54D, 54E, 54F, 55, 56, 56A, 56B, 59, 59A, and 59B) for regulating relative rotation between the outer ring (44) and the synthetic resin member (43) is arranged. The synthetic resin member (43) is formed in a manner to cover the regulating portion on the outer peripheral surface (44a) of the outer ring (44), as a result of a molding process using a mold.
    Type: Application
    Filed: October 26, 2007
    Publication date: March 4, 2010
    Applicant: JTEKT Corporation
    Inventor: Takanori Kurokawa
  • Patent number: 7595095
    Abstract: A method of making a coated article is provided. The method includes electrostatically depositing powder onto a metallic article to be coated using an electrostatic spray gun while the metallic article is being rotated around its axis such that the powder is deposited around the entire circumference of the metallic article at least in a radially outward peripheral region having projections and depressions and that the powder deposited on top of the projections is larger in thickness than the powder deposited in other parts of the metallic article. Melting of the powder is performed by induction heating the metallic article to make a coating film adhere to the metallic article.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: September 29, 2009
    Assignee: Koyo Seiko Co.
    Inventors: Kouji Kitahata, Takeshi Tojo, Katsura Koyagi, Takanori Kurokawa, Atsuo Suehiro, Yoshifumi Niide, Kouichi Taniguchi, Shingo Nakamura
  • Patent number: 7562601
    Abstract: A worm wheel includes an annular metallic core portion and a resin rim portion which is fitted on an outer circumference of the core portion. The rim portion includes an annular main body portion which covers the outer circumference of the core portion and in which a toothed portion is formed on an outer circumference thereof and a pair of annular flanges which are made to extend from the main body portion in a radially inward direction X to thereby cover, respectively, outer edge portions of first and second sides of the core portion. The first annular flange 53 engages with a recess formed in the corresponding side of the core portion. A bottom portion of the recess includes an undercut portion in relation to a radially outward direction.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: July 21, 2009
    Assignee: Jtekt Corporation
    Inventors: Takanori Kurokawa, Hideo Matsubara, Akihiko Shiina
  • Patent number: 7475612
    Abstract: A resin gear for an electric power steering apparatus is provided which offers excellent mechanical strength and durability, and in which damage of teeth, does not occur even when the gear is employed in an electric power steering apparatus equipped with a high-power electric actuator. The resin gear for an electric power steering apparatus includes a worm wheel, and a gear portion thereof is formed of a resin molding material containing a thermosetting resin and polyparaphenylene-benzobisoxazole fibers (PBO fibers) as essential constituents.
    Type: Grant
    Filed: November 5, 2007
    Date of Patent: January 13, 2009
    Assignees: Asahi Organic Chemicals Industry Co., Ltd., JTEKT Corporation
    Inventors: Toshihiko Kaneiwa, Masamitsu Ohtsubo, Takanori Kurokawa, Hirokazu Arai
  • Publication number: 20080236933
    Abstract: A motor vehicle steering system includes a transmission mechanism for transmitting a power of an electric motor to a steering mechanism. The transmission mechanism includes an intermediate gear meshed with a driving gear and a driven gear. The intermediate gear includes: an annular teeth forming portion rotatably supported by an outer periphery of a support shaft via a rolling bearing, the support shaft supported by a housing; and an annular elastic member interposed between an inner periphery of the teeth forming portion and an outer ring of the rolling bearing and interconnecting the teeth forming portion and the outer ring in a manner permitting torque transmission. An axis of the support shaft and an axis of the teeth forming portion are mutually offset, whereby an inner periphery of the elastic member is located eccentrically to an outer periphery thereof.
    Type: Application
    Filed: April 1, 2008
    Publication date: October 2, 2008
    Applicant: JTEKT Corporation
    Inventor: Takanori Kurokawa
  • Patent number: 7428857
    Abstract: A gear composed of a polymer blend or a copolymer of PA66 and PA6 which contains a part having a PA66 molecular structure and a part having a PA6 molecular structure in a weight ratio of PA66/PA6=99.9/0.1 to 95.0/5.0 is excellent in durability as well as heat resistance and dimensional stability. A speed reduction gear using the gear has a reduced size, and can be used under a higher torque without a torque increase due to dimensional change of the gear. An electric power steering apparatus using the speed reduction gear has a reduced size, and can be used for a larger automobile.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: September 30, 2008
    Assignee: Jtekt Corporation
    Inventor: Takanori Kurokawa
  • Publication number: 20080066993
    Abstract: It is an object of the present invention to provide a resin gear for an electric power steering apparatus excellent in mechanical strength and durability, in which damage of teeth, for example, does not occur even when the gear is employed in an electric power steering apparatus equipped with a high-power electric actuator. In a resin gear for an electric power steering apparatus in the form of a worm wheel 10, a gear portion 16 thereof is formed of a resin molding material containing a thermosetting resin and polyparaphenylene-benzobisoxazole fibers (PBO fibers) as essential constituents.
    Type: Application
    Filed: November 5, 2007
    Publication date: March 20, 2008
    Applicants: Asahi Organic Chemicals Industry Co., Ltd., JTEKT Corporation
    Inventors: Toshihiko Kaneiwa, Masamitsu Ohtsubo, Takanori Kurokawa, Hirokazu Arai
  • Patent number: 7340934
    Abstract: A press molding die capable of preventing a workpiece from moving is provided. The press molding die includes a punch for pressing a workpiece; a molding die having a molding surface on which the workpiece is placed and a concave portion which is formed on the molding surface and which has a shape corresponding to the punch; a pad for pressing a part of the workpiece placed on the molding surface and which is on the periphery of the concave portion; and a micro-rough layer which is formed by performing a particulate coating process on at least one of a portion of the pad, for pressing the workpiece, and a portion of the molding surface, corresponding to the portion of the pad. Preferably, the height of roughness of the micro-rough layer is 0.01 to 0.06 mm, and the particulate coating process is performed using a silicofluoric chrome plating solution.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: March 11, 2008
    Assignees: Toyota Jidosha Kabushiki Kaisha, Teikoku Kuromu Co., Ltd.
    Inventors: Takanori Kurokawa, Kazuo Fukaya, Takahiro Ichikawa, Takashige Yoneda, Taketoshi Minami
  • Publication number: 20070265392
    Abstract: A gear for an electric power steering device for reducing the rotation speed of an electric motor for steering assist with a reduction gear mechanism and transmitting the rotation to a steering mechanism, the gear being incorporated and used in the reduction gear mechanism, wherein at least the teeth of the gear are formed from a resin composition of a non-reinforced type comprising (a) a polyamide resin having a carboxyl group at least at a terminal end; (b) 0.5-5 wt. % a polycarbodiimide compound, and (c) 3-15 wt. % an elastic material modified with a reactive functional group.
    Type: Application
    Filed: May 12, 2006
    Publication date: November 15, 2007
    Inventors: Kenichi Shinohara, Takanori Kurokawa, Hirokazu Arai
  • Publication number: 20070253654
    Abstract: Disclosed is a bearing retainer made of a resin composition comprising a polyamide resin which has a repeating unit represented by the formula (1) below and a repeating unit represented by the formula (2) below in which formulae R1 and R2 represent three kinds of groups, namely a p-phenylene group, a linear alkylene group having 6-10 carbon atoms, and a branched chain alkylene group having 6-10 carbon atoms. Such a bearing retainer can be used in various applications since it has sufficiently good resistance to a wider variety of lubricating oils in a wider temperature range when compared with conventional resin hearing retainers.
    Type: Application
    Filed: August 17, 2005
    Publication date: November 1, 2007
    Inventors: Setsuo Nagai, Takanori Kurokawa, Takeshi Tsuda
  • Publication number: 20070230852
    Abstract: A roller bearing cage is made of a resin and has a tapered tubular shape as a whole. In the roller bearing cage, tapered rollers are forcibly fitted to pockets while elastically deforming pillar portions at a small-diameter annular portion side. A stress alleviating portion is provided on at least an outer circumferential side of an end of the pillar portion at the small-diameter annular portion side so that a portion of the pillar portion from a crossing portion between the pillar portion and the small-diameter annular portion to a side of the large-diameter annular portion is linearly cut, thereby alleviating the stress occurring in the pillar portion when the tapered roller is forcibly fitted to the pocket.
    Type: Application
    Filed: March 29, 2007
    Publication date: October 4, 2007
    Applicant: JTEKT CORPORATION
    Inventors: Masahiro Tabata, Takanori Kurokawa
  • Publication number: 20070021558
    Abstract: A polyamide composition having good impact resistance and stiffness comprising an impact modifier, polycarbodiimide, and optionally, a phenol-formaldehyde resin. Articles formed therefrom are also disclosed.
    Type: Application
    Filed: May 12, 2006
    Publication date: January 25, 2007
    Inventors: Kenichi Shinohara, Takanori Kurokawa, Hirokazu Arai