Patents by Inventor Hiroshi Eda
Hiroshi Eda 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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Publication number: 20060191738Abstract: Provided is an electric power steering apparatus comprising a housing, a motor attached to this housing and transmitting an auxiliary steering force to a rotary shaft through a motor shaft, a worm formed on or fitted on the rotary shaft and having a gear portion formed of a metal or a resin, rolling bearings provided in the housing, disposed respectively in positions on both sides of the worm and rotatably supporting the rotary shaft, an output shaft transmitting a steering force for steering an axle and rotatably supported in a predetermined position of the housing, and a worm wheel formed on or fitted on the output shaft in a way that meshes with the worm and having a gear portion formed of the resin, wherein a pre-load mechanism for applying a pre-load acting towards the worm wheel is provided at a shaft end portion, distal from the motor, of the rotary shaft.Type: ApplicationFiled: April 12, 2006Publication date: August 31, 2006Inventors: Hiroshi Eda, Toru Segawa
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Publication number: 20060194510Abstract: A precision machining apparatus and a precision machining method capable of carrying out grinding with accuracy by performing switching control, for example, on a device for rotating a grinding wheel according to grinding stages through the amount of movement and constant pressure changed stepwise. To a second pedestal 3 supporting a rotary device 6b for rotating a grinding wheel b, an actuator 5 and a feed screw mechanism 4 constituted by at least a feed screw 41 and a nut 42 are attached. In a rough grinding stage, the movement of the rotary device 6b and the second pedestal 3 is adjusted through a predetermined amount of movement of the nut 42. In a super-precision grinding stage, the movement of the rotary device 6b and the second pedestal 3 is adjusted by pressure control using stepwise a plurality of pneumatic actuators 5a, 5b differing in pressure performance. An attitude control device 7 is interposed between a first pedestal 2 and a rotary device 6a for rotating an object a to be ground.Type: ApplicationFiled: December 27, 2005Publication date: August 31, 2006Inventors: Sumio Kamiya, Hisao Iwase, Tetsuya Nagaike, Hiroshi Eda, Libo Zhou
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Patent number: 7077235Abstract: Provided is an electric power steering apparatus comprising a housing, a motor attached to this housing and transmitting an auxiliary steering force to a rotary shaft through a motor shaft, a worm formed on or fitted on the rotary shaft and having a gear portion formed of a metal or a resin, rolling bearings provided in the housing, disposed respectively in positions on both sides of the worm and rotatably supporting the rotary shaft, an output shaft transmitting a steering force for steering an axle and rotatably supported in a predetermined position of the housing, and a worm wheel formed on or fitted on the output shaft in a way that meshes with the worm and having a gear portion formed of the resin, wherein a pre-load mechanism for applying a pre-load acting towards the worm wheel is provided at a shaft end portion, distal from the motor, of the rotary shaft.Type: GrantFiled: December 3, 2002Date of Patent: July 18, 2006Assignee: NSK Ltd.Inventors: Hiroshi Eda, Toru Segawa
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Publication number: 20060086559Abstract: A steering device comprises an upper steering shaft, a lower steering shaft for transmitting rotations of the upper steering shaft to a steering gear, an engaging projection provided on a fitted-in portion of the upper shaft, an engaging groove provided on a fitted-in portion of the lower shaft for engaging with the engaging projection with a clearance of a rotational direction and a rotational direction biasing member, provided on the fitted-in portion, for giving a biasing force of a rotational direction between the upper and lower steering shafts.Type: ApplicationFiled: October 21, 2005Publication date: April 27, 2006Inventors: Toru Segawa, Hiroshi Eda, Kazuo Chikaraishi
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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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Publication number: 20050183902Abstract: In an electric power steering apparatus that generates an auxiliary steering torque by a brushless motor in response to a steering torque applied on a steering wheel and transmits it to an output shaft of a steering mechanism while reducing it by means of a reduction gear, the apparatus comprises a rotor (10) to which a cylindrical permanent magnet for rotational driving (12) and a member to be detected (13) for detection of a rotational angle of the rotor are attached and a cylindrical stator (30) opposed to the rotor in which a laminated core (16) on which a coil is wound, detection means (17) for detecting the rotational angle of the rotor by the member to be detected and a terminal (19) for providing connection to the coil are integrally formed by resin molding. At least one bearing (8, 9) for rotatably supporting the rotor is disposed radially inside the stator and between the permanent magnet for rotational driving and the member to be detected.Type: ApplicationFiled: April 27, 2005Publication date: August 25, 2005Inventors: Toru Segawa, Yushi Momo, Hiroshi Eda, Takayoshi Kanazawa, Masaru Wada
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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: 20040245040Abstract: Provided is an electric power steering apparatus comprising a housing, a motor attached to this housing and transmitting an auxiliary steering force to a rotary shaft through a motor shaft, a worm formed on or fitted on the rotary shaft and having a gear portion formed of a metal or a resin, rolling bearings provided in the housing, disposed respectively in positions on both sides of the worm and rotatably supporting the rotary shaft, an output shaft transmitting a steering force for steering an axle and rotatably supported in a predetermined position of the housing, and a worm wheel formed on or fitted on the output shaft in a way that meshes with the worm and having a gear portion formed of the resin, wherein a pre-load mechanism for applying a pre-load acting towards the worm wheel is provided at a shaft end portion, distal from the motor, of the rotary shaft.Type: ApplicationFiled: April 5, 2004Publication date: December 9, 2004Inventors: Hiroshi Eda, Toru Segawa
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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: 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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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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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