Patents by Inventor Kazuo Chikaraishi
Kazuo Chikaraishi 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: 8087974Abstract: A manufacturing method for a worm wheel, the worm wheel meshed with an operational worm at usage, has steps of preparing a worm wheel, in which at least a surface layer of a tooth portion is made of synthetic resin, preparing a machining worm, in which pitch of teeth of the machining worm in an axial direction thereof is the same as that of an operational worm, diameters of tip and root portions of the tooth of the machining worm are equal to or more than those of the operational worm and abrasive grains are provided on a surface of the machining worm by means of electro-deposition, disposing the machining worm in a twisting position relative to the worm wheel and rotating the machining worm and the worm wheel with meshing each other so as to machining the tooth portion of the worm wheel.Type: GrantFiled: November 16, 2005Date of Patent: January 3, 2012Assignee: NSK Ltd.Inventors: Atsushi Maeda, Kazuo Chikaraishi
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Publication number: 20090266187Abstract: Under a state of a normal temperature, a pitch B2 of a feed nut 55, 65 is formed to be slightly larger than a pitch A2 of a feed shaft screw 53, 63. Accordingly, since the screw thread of the feed nut 55, 65 is pressed to the screw thread of the feed screw shaft 53, 63 with a small interference, there is no backlash between the feed screw shaft 53, 63 and the feed nut 55, 65 so that a smooth feeding operation can be carried out. Under a state of a low temperature, the feed nut 55, 65 contracts more than the feed screw shaft 53, 63. As a result, a pitch B1 of the feed nut 55, 65 has the substantially same dimension as that of a pitch A1 of the feed screw shaft 53, 63.Type: ApplicationFiled: March 7, 2007Publication date: October 29, 2009Applicant: NSK Ltd.Inventors: Jun Okada, Kazuo Chikaraishi, Masato Iwakawa, Hiroshi Kato
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Patent number: 7591204Abstract: A belt speed reducing apparatus for an electric power steering apparatus includes a drive pulley having a first helical gear, a driven pulley having a second helical gear and a drive belt having a third helical gear in which a relationship of tan ?<? is established between a twist angle ? of the respective helical gears and a friction coefficient ? between the first or the second helical gear and the third helical gear. Further, an electric power steering apparatus for adjusting a backlash between gears of a speed reducing apparatus brought in mesh with each other or adjusting a tension of a belt of a speed reducing apparatus.Type: GrantFiled: October 8, 2004Date of Patent: September 22, 2009Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventors: Seiji Ueno, Kazuo Chikaraishi
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Patent number: 7455149Abstract: A torsion coil spring 30 applies an elastic force to a worm shaft 29 in a direction towards a worm wheel, via a pre-load pad 70. The pre-load pad 70 restricts displacement in relation to the widthwise direction, by one side face portion of a holder 61 fixed to a gear housing 22. Due to the elastic deformation of the pre-load pad 70 itself based on the elastic force of the torsion coil spring 30, the side face of the pre-load pad 70 is abutted against the one side face portion of the holder 61, so that a gap between the pre-load pad 70 and the one side face portion is minimized. As a result, the occurrence of a teeth fitting noise in the worm reduction gear 16 is suppressed.Type: GrantFiled: May 10, 2007Date of Patent: November 25, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventors: Toru Segawa, Kazuo Chikaraishi
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Patent number: 7455148Abstract: A torsion coil spring 30 applies an elastic force to a worm shaft 29 in a direction towards a worm wheel, via a pre-load pad 70. The pre-load pad 70 restricts displacement in relation to the widthwise direction, by one side face portion of a holder 61 fixed to a gear housing 22. Due to the elastic deformation of the pre-load pad 70 itself based on the elastic force of the torsion coil spring 30, the side face of the pre-load pad 70 is abutted against the one side face portion of the holder 61, so that a gap between the pre-load pad 70 and the one side face portion is minimized. As a result, the occurrence of a teeth fitting noise in the worm reduction gear 16 is suppressed.Type: GrantFiled: May 10, 2007Date of Patent: November 25, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventors: Toru Segawa, Kazuo Chikaraishi
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Publication number: 20080245600Abstract: The present invention relates to an electric power steering apparatus for assisting steering of a steering shaft by the rotation power of an electric motor through a reducer based on the steering torque detected by a torque sensor. A rotary potentiometer is disposed in the reducer, and a portion of a swing arm of the potentiometer is engaged with a swirl groove formed on the side of a worm wheel in the reducer as well as the swing arm is swingingly rotated according to the rotation of the worm wheel to thereby detect the rotation angle of the steering shaft.Type: ApplicationFiled: October 7, 2004Publication date: October 9, 2008Inventor: Kazuo Chikaraishi
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Patent number: 7426978Abstract: In an electric power steering apparatus that urges a steering shaft or a rack shaft with an assist load using the drive force of a motor by a transmission mechanism via reduction gears, the reduction gears includes a rotation angle sensor assembled integrally therewith.Type: GrantFiled: November 29, 2006Date of Patent: September 23, 2008Assignee: NSK Ltd.Inventors: Toshiyuki Onizuka, Kazuo Chikaraishi, Shuji Endo
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Publication number: 20080216597Abstract: Both ends of a screw shaft 35 are supported on a vehicle body side bracket 19 so that only rotation is allowed. The screw shaft 35 is rotated by an electric motor 28. A nut member 44 is threadedly engaged with an intermediate portion of the screw shaft 35. The nut member 44 is held on inside of a nut holder 43. The nut holder 43 and nut member 44 are allowed to be shifted each other in longitudinal direction of the nut holder 43 which is perpendicular to both the shaft portion extending parallel to oscillation center axis of a steering column 4a and the axial direction of the screw shaft 35. The nut holder 43 is supported on the steering column 4a so as to be rotated about the shaft portion of the nut holder 43 relative to the steering column 4a.Type: ApplicationFiled: February 27, 2007Publication date: September 11, 2008Applicant: NSK LTD.Inventors: Masato Iwakawa, Kazuo Chikaraishi, Osamu Tatewaki
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Patent number: 7410028Abstract: A steering control apparatus in which a steering shaft coupled to a steering wheel is mechanically separated from a turning mechanism to turn a turning wheel, a steering angle of the steering wheel is detected, and the turning mechanism turns the turning wheel by a turning angle corresponding to the steering angle, includes a hypercycloidal mechanism including an external tooth gear revolving in a housing according to rotation of the steering wheel, an Oldham coupling mechanism to extract only a self-rotating movement in a rotation movement of the external tooth gear as a self-rotating movement of a rotation disk, and a rotation regulating mechanism by engagement between a groove formed in the rotation disk and a projection projecting from the housing.Type: GrantFiled: December 24, 2003Date of Patent: August 12, 2008Assignee: NSK Ltd.Inventor: Kazuo Chikaraishi
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Patent number: 7360457Abstract: The present invention relates to an electric power steering device provided with a torque sensor for detecting a torque using coil windings arranged in the inside of an electromagnetic yoke. The electric power steering device comprises coil bobbins which are housed in the inside of the electromagnetic yoke; a terminal block which projects a portion of the coil bobbins outwardly; and connection pins which are formed on the terminal block in a projecting manner. Further, the connection pins comprise connection members for connecting the connection pins to a sensor circuit substrate and the connection pins are arranged not to be covered and concealed with the sensor circuit substrate.Type: GrantFiled: May 28, 2003Date of Patent: April 22, 2008Assignee: NSK Ltd.Inventor: Kazuo Chikaraishi
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Patent number: 7360467Abstract: A torsion coil spring 30 applies an elastic force to a worm shaft 29 in a direction towards a worm wheel, via a pre-load pad 70. The pre-load pad 70 restricts displacement in relation to the widthwise direction, by one side face portion of a holder 61 fixed to a gear housing 22. Due to the elastic deformation of the pre-load pad 70 itself based on the elastic force of the torsion coil spring 30, the side face of the pre-load pad 70 is abutted against the one side face portion of the holder 61, so that a gap between the pre-load pad 70 and the one side face portion is minimized. As a result, the occurrence of a teeth fitting noise in the worm reduction gear 16 is suppressed.Type: GrantFiled: June 24, 2004Date of Patent: April 22, 2008Assignees: NSK, Ltd., NSK Steering Systems Co., Ltd.Inventors: Toru Segawa, Kazuo Chikaraishi
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Publication number: 20080079253Abstract: A telescopic adjusting electric power steering apparatus has a steering column 12 having an outer column 12a and an inner column 12b connected so as to be relatively extended and contracted, and rotatably supporting a steering shaft attaching a steering wheel 13 thereto; and an electric actuator 50 having one end portion attached to the outer column 12a and the other end portion attached to the inner column 12b, and extending and contracting the outer column 12a and the inner column 12b; wherein the electric actuator 50 has a rotation obstructing member 59 for obstructing relative rotation of the outer column 12a and the inner column 12b.Type: ApplicationFiled: July 18, 2007Publication date: April 3, 2008Applicant: NSK LTD.Inventors: Yoshiyuki SEKII, Kazuo CHIKARAISHI, Osamu TATEWAKI
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Publication number: 20070251758Abstract: A torsion coil spring 30 applies an elastic force to a worm shaft 29 in a direction towards a worm wheel, via a pre-load pad 70. The pre-load pad 70 restricts displacement in relation to the widthwise direction, by one side face portion of a holder 61 fixed to a gear housing 22. Due to the elastic deformation of the pre-load pad 70 itself based on the elastic force of the torsion coil spring 30, the side face of the pre-load pad 70 is abutted against the one side face portion of the holder 61, so that a gap between the pre-load pad 70 and the one side face portion is minimized. As a result, the occurrence of a teeth fitting noise in the worm reduction gear 16 is suppressed.Type: ApplicationFiled: May 10, 2007Publication date: November 1, 2007Applicants: NSK LTD., NSK Steering Systems Co., Ltd.Inventors: Toru Segawa, Kazuo Chikaraishi
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Publication number: 20070251757Abstract: A torsion coil spring 30 applies an elastic force to a worm shaft 29 in a direction towards a worm wheel, via a pre-load pad 70. The pre-load pad 70 restricts displacement in relation to the widthwise direction, by one side face portion of a holder 61 fixed to a gear housing 22. Due to the elastic deformation of the pre-load pad 70 itself based on the elastic force of the torsion coil spring 30, the side face of the pre-load pad 70 is abutted against the one side face portion of the holder 61, so that a gap between the pre-load pad 70 and the one side face portion is minimized. As a result, the occurrence of a teeth fitting noise in the worm reduction gear 16 is suppressed.Type: ApplicationFiled: May 10, 2007Publication date: November 1, 2007Applicant: NSK LTD.Inventors: Toru Segawa, Kazuo Chikaraishi
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Patent number: 7284635Abstract: An electric power steering apparatus comprises a steering shaft including an input shaft connected to a steering wheel, an output shaft connected to a steering gear device, a torsion bar for transferring torque to the output shaft from the input shaft, the steering shaft being rotatably supported in a steering column, torque detection coils disposed outwards along an outer periphery of the steering shaft, and a worm wheel meshing with a worm rotationally driven by a motor driven corresponding to detected torque and fixed to the output shaft in terms of its rotation, wherein the steering shaft is rotatably supported via a bearing provided between the worm wheel and a column-sided member on the front side of the vehicle.Type: GrantFiled: June 2, 2003Date of Patent: October 23, 2007Assignee: NSK, Ltd.Inventor: Kazuo Chikaraishi
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Patent number: 7275618Abstract: To provide an electrically driven power steering apparatus with a simple structure, which can prevent overloading of an electrical motor and a power transmission system, an absorbing member (121) is attached to a rack shaft (112), and is brought into contact with a rack housing face at a stroke end of the rack shaft (112). The absorbing member (121) at least partially has a material having a Young's modulus of 100 to 900 Mpa, and thus it is possible to effectively relieve an impact at the stroke end.Type: GrantFiled: January 28, 2003Date of Patent: October 2, 2007Assignee: NSK Ltd.Inventors: Manabu Abe, Kazuo Chikaraishi, Atsushi Tanaka
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Patent number: 7275451Abstract: An electric power steering device having a torque sensor for detecting torque by using a coil provided in an electromagnetic yoke. A terminal block projects to the radial outside and axial outside with respect to an axial line of a substantially cylindrical coil bobbin accommodated in the electromagnetic yoke by a predetermined offset amount and is provided in the coil bobbin. The terminal block has press-fitting holes for press-fitting and fixing connection pins for connecting the coil winding and a sensor circuit substrate, wherein the press-fitting holes have air-purging holes communicating with the outside.Type: GrantFiled: January 4, 2005Date of Patent: October 2, 2007Assignee: NSK Ltd.Inventor: Kazuo Chikaraishi
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Publication number: 20070209864Abstract: In an electric power steering apparatus in which steering torque applied on a steering wheel is detected by a torque sensor, and a steering assist torque is generated by an electric motor in accordance with the detected steering torque and transmitted to an output shaft of a steering mechanism with a speed reduced by a worm gear mechanism, the gear meshing position in the worm gear mechanism and the position of the torque sensor are arranged to be substantially coincide with each other with respect to the axial direction of the output shaft. Alternatively, a worm wheel of the worm gear mechanism is directly supported on a housing in a rotatable manner by means of a bearing. A steering shaft and an input shaft of a power assist section are fixedly connected in close contact attained by plastic deformation.Type: ApplicationFiled: April 5, 2005Publication date: September 13, 2007Inventors: Toru Segawa, Hiroshi Eda, Kazuo Chikaraishi, Kenji Someya, Toshiyuki Onizuka
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Patent number: 7204167Abstract: The present invention relates to a motor-driven power steering apparatus structured such as to apply a steering assist force generated by a motor to a steering system of a motor vehicle or a vehicle in accordance with a rotation force of an electric motor on the basis of a steering torque detected by a torque sensor. Further, the invention relates to a rotation angle sensor for detecting a rotation angle of a steering shaft, a detected portion of the rotation angle sensor is provided within the speed reduction gear, and a detecting portion of the rotation angle sensor is provided in a radial direction of the steering shaft and in an outer side of a bearing in the speed reduction gear.Type: GrantFiled: May 30, 2006Date of Patent: April 17, 2007Assignee: NSK Ltd.Inventors: Kazuo Chikaraishi, Toshiyuki Onizuka, Shuji Endo
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Publication number: 20070080016Abstract: In an electric power steering apparatus that urges a steering shaft or a rack shaft with an assist load using the drive force of a motor by a transmission mechanism via reduction gears, the reduction gears includes a rotation angle sensor assembled integrally therewith.Type: ApplicationFiled: November 29, 2006Publication date: April 12, 2007Inventors: Toshiyuki Onizuka, Kazuo Chikaraishi, Shuji Endo