Patents by Inventor Osamu Tatewaki

Osamu Tatewaki 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: 7284634
    Abstract: An electric power steering apparatus comprises a rotary shaft member connected to a steering wheel, an elongate member, a rack-and-pinion mechanism, a ball screw mechanism constructed of a screw member, a nut member and a multiplicity of balls interposed between the screw member and the nut member, an electric motor unit, and a meshing type rotation decelerating mechanism including a plurality of meshing components. The meshing components include an output shaft pinion gear, a deceleration gear, and an intermediate gear, interposed between the output shaft pinion gear and the deceleration gear, having a contact portion composed of a synthetic resin.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: October 23, 2007
    Assignee: NSK, Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
  • Publication number: 20070227804
    Abstract: An electrically driven power steering apparatus is structured such that a large impact on a rack shaft occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing of a presser member becomes zero, a rotation of the presser member is hindered by caulking c at a thin plate member. Therefore, the presser member does not slacken, and a predetermined axial force can be given again to the ball bearing when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.
    Type: Application
    Filed: May 24, 2007
    Publication date: October 4, 2007
    Applicant: NSK Ltd.
    Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano
  • Patent number: 7240763
    Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: July 10, 2007
    Assignee: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
  • Publication number: 20070151794
    Abstract: In an electric power steering apparatus, in which an auxiliary steering torque is generated by an electric motor according a steering torque impressed upon a steering wheel transmitted to a rack shaft of a steering mechanism via a power transmission mechanism. The power transmission mechanism has a small diameter external gear, and an outer circumferential face thereof acts as a drive side pulley, a driven side pulley driven by the internal-external gear and a ball screw mechanism driven by the driven side pulley so as to move the rack shaft. A circular support body is concentrically provided at the external gear and an annular support body, which supports the circular support body, is concentrically provided at the internal-external gear so as to be inscribed with the circular support body.
    Type: Application
    Filed: December 28, 2005
    Publication date: July 5, 2007
    Applicant: NSK LTD.
    Inventors: Hiroto Mizutani, Osamu Tatewaki
  • Patent number: 7219761
    Abstract: An electrically driven power steering apparatus is structured such that a large impact on a rack shaft occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing of a presser member becomes zero, a rotation of the presser member is hindered by caulking c at a thin plate member. Therefore, the presser member does not slacken, and a predetermined axial force can be given again to the ball bearing when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: May 22, 2007
    Assignee: NSK Ltd.
    Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano, Mineki Okamoto
  • Patent number: 7025169
    Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.
    Type: Grant
    Filed: May 10, 2005
    Date of Patent: April 11, 2006
    Assignee: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
  • Publication number: 20050205342
    Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.
    Type: Application
    Filed: May 10, 2005
    Publication date: September 22, 2005
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
  • Patent number: 6938723
    Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: September 6, 2005
    Assignee: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
  • Patent number: 6915874
    Abstract: An electric power steering apparatus comprises an electric motor having a motor housing, a ball screw mechanism connected to the electric motor through power transmission means and used for driving a rack shaft, and a steering gear case encasing the rack shaft and the ball screw mechanism. The electric motor is supported by at least two supporting portions with respect to the steering gear case, and is supported by at lest one of the two supporting portions through an elastic member.
    Type: Grant
    Filed: August 15, 2003
    Date of Patent: July 12, 2005
    Assignee: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
  • Patent number: 6860360
    Abstract: An electric power steering apparatus includes a power assist mechanism encased by a steering gear case, an electric motor coupled to the power assist mechanism, a power transmission mechanism, coupled to the electric motor and the power assist mechanism, and a protection cover, separate from the electric motor casing and attached thereto, for covering the electric motor.
    Type: Grant
    Filed: August 15, 2003
    Date of Patent: March 1, 2005
    Assignee: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
  • Patent number: 6851508
    Abstract: An electrically driven power steering apparatus is structured such that a large impact on a rack shaft (22) occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing (25) of a presser member (30) becomes zero, a rotation of the presser member (30) is hindered by caulking c at a thin plate member (30b). Therefore, the presser member (30) does not slacken, and a predetermined axial force can be given again to the ball bearing (25) when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: February 8, 2005
    Assignee: NSK Ltd.
    Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano
  • Publication number: 20040245041
    Abstract: An electrically driven power steering apparatus is structured such that a large impact on a rack shaft occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing of a presser member becomes zero, a rotation of the presser member is hindered by caulking c at a thin plate member. Therefore, the presser member does not slacken, and a predetermined axial force can be given again to the ball bearing when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.
    Type: Application
    Filed: March 19, 2004
    Publication date: December 9, 2004
    Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano, Mineki Okamoto
  • Publication number: 20040182638
    Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.
    Type: Application
    Filed: January 30, 2004
    Publication date: September 23, 2004
    Applicant: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
  • Publication number: 20040182639
    Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.
    Type: Application
    Filed: January 30, 2004
    Publication date: September 23, 2004
    Applicant: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
  • Publication number: 20040154857
    Abstract: An electrically driven power steering apparatus is structured such that a large impact on a rack shaft (22) occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing (25) of a presser member (30) becomes zero, a rotation of the presser member (30) is hindered by caulking c at a thin plate member (30b). Therefore, the presser member (30) does not slacken, and a predetermined axial force can be given again to the ball bearing (25) when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.
    Type: Application
    Filed: December 31, 2003
    Publication date: August 12, 2004
    Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano
  • Publication number: 20040050615
    Abstract: An electric power steering apparatus comprises an electric motor having a motor housing, a ball screw mechanism connected to the electric motor through power transmission means and used for driving a rack shaft, and a steering gear case encasing the rack shaft and the ball screw mechanism. The electric motor is supported by at least two supporting portions with respect to the steering gear case, and is supported by at lest one of the two supporting portions through an elastic member.
    Type: Application
    Filed: August 15, 2003
    Publication date: March 18, 2004
    Applicant: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
  • Publication number: 20040050613
    Abstract: An electric power steering apparatus comprises an electric motor having a motor housing, a ball screw mechanism connected to the electric motor through power transmission means and used for driving a rack shaft, and a steering gear case encasing the rack shaft and the ball screw mechanism. The electric motor is supported by at least two supporting portions with respect to the steering gear case, and is supported by at lest one of the two supporting portions through an elastic member.
    Type: Application
    Filed: August 15, 2003
    Publication date: March 18, 2004
    Applicant: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
  • Patent number: 6702060
    Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: March 9, 2004
    Assignee: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
  • Patent number: 6662897
    Abstract: An electric power steering apparatus comprises an electric motor having a motor housing, a ball screw mechanism connected to the electric motor through power transmission means and used for driving a rack shaft, and a steering gear case encasing the rack shaft and the ball screw mechanism. The electric motor is supported by at least two supporting portions with respect to the steering gear case, and is supported by at lest one of the two supporting portions through an elastic member.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: December 16, 2003
    Assignee: NSK Ltd.
    Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
  • Publication number: 20030019686
    Abstract: An electrically driven power steering apparatus is structured such that a large impact on a rack shaft (22) occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing (25) of a presser member (30) becomes zero, a rotation of the presser member (30) is hindered by caulking c at a thin plate member (30b). Therefore, the presser member (30) does not slacken, and a predetermined axial force can be given again to the ball bearing (25) when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.
    Type: Application
    Filed: August 12, 2002
    Publication date: January 30, 2003
    Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano