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).
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Patent number: 7284634Abstract: 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: GrantFiled: April 11, 2002Date of Patent: October 23, 2007Assignee: NSK, Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
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Publication number: 20070227804Abstract: 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: ApplicationFiled: May 24, 2007Publication date: October 4, 2007Applicant: NSK Ltd.Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano
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Patent number: 7240763Abstract: 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: GrantFiled: January 30, 2004Date of Patent: July 10, 2007Assignee: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
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Publication number: 20070151794Abstract: 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: ApplicationFiled: December 28, 2005Publication date: July 5, 2007Applicant: NSK LTD.Inventors: Hiroto Mizutani, Osamu Tatewaki
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Patent number: 7219761Abstract: 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: GrantFiled: March 19, 2004Date of Patent: May 22, 2007Assignee: NSK Ltd.Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano, Mineki Okamoto
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Patent number: 7025169Abstract: 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: GrantFiled: May 10, 2005Date of Patent: April 11, 2006Assignee: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
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Publication number: 20050205342Abstract: 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: ApplicationFiled: May 10, 2005Publication date: September 22, 2005Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
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Patent number: 6938723Abstract: 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: GrantFiled: January 30, 2004Date of Patent: September 6, 2005Assignee: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
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Patent number: 6915874Abstract: 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: GrantFiled: August 15, 2003Date of Patent: July 12, 2005Assignee: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
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Patent number: 6860360Abstract: 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: GrantFiled: August 15, 2003Date of Patent: March 1, 2005Assignee: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
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Patent number: 6851508Abstract: 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: GrantFiled: July 23, 2001Date of Patent: February 8, 2005Assignee: NSK Ltd.Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano
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Publication number: 20040245041Abstract: 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: ApplicationFiled: March 19, 2004Publication date: December 9, 2004Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano, Mineki Okamoto
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Publication number: 20040182638Abstract: 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: ApplicationFiled: January 30, 2004Publication date: September 23, 2004Applicant: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
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Publication number: 20040182639Abstract: 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: ApplicationFiled: January 30, 2004Publication date: September 23, 2004Applicant: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
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Publication number: 20040154857Abstract: 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: ApplicationFiled: December 31, 2003Publication date: August 12, 2004Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano
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Publication number: 20040050615Abstract: 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: ApplicationFiled: August 15, 2003Publication date: March 18, 2004Applicant: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
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Publication number: 20040050613Abstract: 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: ApplicationFiled: August 15, 2003Publication date: March 18, 2004Applicant: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
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Patent number: 6702060Abstract: 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: GrantFiled: June 25, 2002Date of Patent: March 9, 2004Assignee: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Osamu Saito, Jun Okada
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Patent number: 6662897Abstract: 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: GrantFiled: June 11, 2002Date of Patent: December 16, 2003Assignee: NSK Ltd.Inventors: Osamu Tatewaki, Hiroshi Eda, Toshihiro Fukuda, Jun Okada
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Publication number: 20030019686Abstract: 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: ApplicationFiled: August 12, 2002Publication date: January 30, 2003Inventors: Toshihiro Fukuda, Shuji Endo, Hiroshi Eda, Osamu Tatewaki, Kenichi Hayakawa, Hirotaka Hatano