Patents Assigned to NSK Ltd.
  • Worm reduction gear and electric power steering apparatus
    Publication number: 20070251757
    Abstract: 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: Application
    Filed: May 10, 2007
    Publication date: November 1, 2007
    Applicant: NSK LTD.
    Inventors: Toru Segawa, Kazuo Chikaraishi
  • Worm reduction gear and electric power steering apparatus
    Publication number: 20070251758
    Abstract: 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: Application
    Filed: May 10, 2007
    Publication date: November 1, 2007
    Applicants: NSK LTD., NSK Steering Systems Co., Ltd.
    Inventors: Toru Segawa, Kazuo Chikaraishi
  • Wheel supporting rolling bearing unit
    Patent number: 7287909
    Abstract: In a wheel supporting rolling bearing unit, an inner end opening out of both end openings of a space in which balls 14, 14 are provided is sealed with a cap 17a. An outer end opening is sealed with a seal ring 16c having three seal lips. A rolling resistance that changes based on a preload is regulated in a range of 0.15 to 0.45 N·m, and a running resistance of the seal ring 16c based on a friction between the seal ring and a counter surface is regulated in a range of 0.03 to 0.2 N·m.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: October 30, 2007
    Assignee: NSK Ltd.
    Inventor: Junshi Sakamoto
  • Component transport method and combination structure of component transport container and transferring jig and component transport container and supporting jig
    Publication number: 20070248447
    Abstract: Components are transported from a manufacturing factory to an assembly factory after accommodated in accommodating spaces 20 of a hollow transport container 14 made of high polymer material at the manufacturing factory. At the assembly factory, the transport container 14 is placed on a supporting jig 15. At that time, supporting walls provided on a top surface of the supporting jig 15 are inserted into hollow structure of the container 14. Then, in a state in which the transport container 14 is thus supported, the components accommodated in the accommodating spaces 20, 20 are taken out through opening in the longitudinal direction of pair of end walls 17, 17 and intermediate walls 18, 18. The above problem is solved by reducing weight of the transport container 14 and also eliminating the need of sending back the transport container 14 to the manufacturing factory.
    Type: Application
    Filed: April 19, 2007
    Publication date: October 25, 2007
    Applicant: NSK Ltd.
    Inventor: Kinji Mikami
  • Electric power steering apparatus
    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
  • Electric power steering device
    Patent number: 7284635
    Abstract: 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: Grant
    Filed: June 2, 2003
    Date of Patent: October 23, 2007
    Assignee: NSK, Ltd.
    Inventor: Kazuo Chikaraishi
  • Rolling Bearing
    Publication number: 20070243962
    Abstract: When a minimum thickness of a part where an outer ring raceway is provided on a middle portion in the axial direction of an outer ring is h, and a diameter of each rolling element is Da, the relationship 0.4Da?h 0.8Da is satisfied. As a result, even when the outer ring 4a is fixed in a transmission case of low-rigidity, elastic deformation of the outer ring can be prevented without needlessly increasing the thickness h of the outer ring. When an outer diameter of an outer ring is D, a width of this outer ring in the axial direction is W, a minimum thickness of a part where the outer ring raceway is provided on a middle portion in the axial direction of the outer ring is h, and a diameter of each ball is Da, the respective dimensions are controlled such that a value K calculated by {(h1.5·W)/(Da1.1·D0.5)} satisfies the relationship 1.20?K?2.00.
    Type: Application
    Filed: June 19, 2007
    Publication date: October 18, 2007
    Applicant: NSK LTD.
    Inventors: Hiromichi Takemura, Yoshiaki Sakajiri
  • Rotation-support apparatus with rotation sensor device for drive-wheel
    Patent number: 7281424
    Abstract: The outer race 2 is fixed to the support hole 29 in the knuckle 1, and the constant velocity joint 6 is connected to the hub 3. The first seal ring 9 is fitted into the outer race 2 to cover the opening on the end of the bearing space 26. The seal ring 28 is fitted into the support hole 29 to cover the opening on the end of the detection space 27. The encoder 7 is fitted onto the inner race 4, and the outer peripheral edge of the encoder 7 faces the inner peripheral surface on the outer race 2 in an adjacent arrangement relationship to form a labyrinth clearance 36, so that grease within the bearing space 26 is prevented from leaking toward the detection space 27, whereby the rotation resistance is small to improve parts of the automobile in acceleration and fuel consumption.
    Type: Grant
    Filed: October 11, 2002
    Date of Patent: October 16, 2007
    Assignee: NSK Ltd.
    Inventor: Junshi Sakamoto
  • Electric power steering device
    Publication number: 20070235247
    Abstract: In an electric power steering device has an electric motor for applying a steering assist force to a steering shaft connected to a steering wheel, a gear box for accommodating a speed reducing mechanism for transmitting the steering assist force of the electric motor to the steering shaft and a control unit for controlling the driving of the electric motor, the control unit is disposed in the steering wheel side from the gear box.
    Type: Application
    Filed: April 9, 2007
    Publication date: October 11, 2007
    Applicant: NSK Ltd.,
    Inventors: Tomohisa Hirakawa, Suguru Nagano
  • Ball screw device
    Patent number: 7278333
    Abstract: A ball screw device has a screw shaft which has a shaft rolling groove in a spiral shape formed on an outer surface of the screw shaft, a nut which has a nut rolling groove formed on an inner surface of the nut and opposed to the shaft rolling groove, wherein the screw shaft is to be screwed in the nut so that the shaft rolling groove and the nut rolling groove are faced through a plurality of rolling balls, and a lubrication ring which is made of a lubricant-including material, comes in slide contact with the screw shaft, and is arranged in an end portion of the nut, wherein a non-contact portion, which does not come in slide contact with the screw shaft, is formed on the slide contact surface of the lubrication ring.
    Type: Grant
    Filed: April 20, 2005
    Date of Patent: October 9, 2007
    Assignees: NSK Ltd., NSK Precision Co., Ltd.
    Inventors: Masato Kato, Takayuki Yabe, Junji Minakuchi
  • Linear motion device
    Patent number: 7278332
    Abstract: A linear motion device has: a linear motion body externally fitted onto a shaft and making a relative linear motion along the shaft; a plurality of balls retained in a rolling element groove formed in an inner surface of the linear motion body, and rolling between the rolling element groove and the shaft; separators interposed among the balls; and a circulating path formed in the linear motion body and for circulating the balls from one end side of the rolling element groove to the other end side thereof; wherein the linear motion device is charged with grease containing base oil which is 220-395 in worked penetration defined by JIS K2220 and 50-500 mm2/s in kinematic viscosity at 40° C.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: October 9, 2007
    Assignee: NSK Ltd.
    Inventors: Shinya Nakatani, Masahiko Yamazaki, Hirotoshi Miyajima, Yasuyuki Matsuda
  • Electrically driven power steering apparatus
    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
  • Control device for electric power steering apparatus
    Publication number: 20070227806
    Abstract: A control device for an electric power steering apparatus is adapted to calculate a current command value of a motor for applying a steering assist force to a steering mechanism in accordance with a steering torque and a vehicle speed so that the motor is driven and controlled under a feedback control. The control device includes an SAT estimating part for inputting an angular velocity and an angular acceleration of the motor, the steering torque and the current command value to estimate an SAT and a correcting part for determining a traveling state of a vehicle in accordance with the SAT value estimated in the SAT estimating part, the steering torque and a steering angle to correct the current command value depending on the traveling state.
    Type: Application
    Filed: April 2, 2007
    Publication date: October 4, 2007
    Applicant: NSK Ltd.
    Inventor: Yong Wei
  • Electric power steering device
    Publication number: 20070233345
    Abstract: To provide an electric power steering device that can reliably detect the abnormality of a steering angle sensor and prevent the generation of a wrong decision. When both the two differences (|?a??r |, |?a??e|) between an absolute steering angle value ?a obtained from a steering angle sensor and a relative steering angle value ?r estimated from the rotating angle sensor of a motor, and an estimated steering angle value ee estimated from the induced voltage of the motor respectively exceed predetermined values (threshold values), the steering angle sensor is determined to be failed.
    Type: Application
    Filed: March 30, 2007
    Publication date: October 4, 2007
    Applicant: NSK Ltd.
    Inventors: Shuji Endo, Takeshi Hara
  • Radial needle-like roller bearing and pinion shaft
    Patent number: 7276012
    Abstract: There is adopted a constitution of arranging a spacer 53 at a shaft center portion and arranging a retainer 52 and a roller 51 (cage & roller) at two sides thereof in order to prevent the roller (roller) from being rolled at the center portion in an axial direction of the shaft maximizing an amount of bending the shaft. At the double side rows, the bending of the shaft is not as large as that of the center portion and therefore, the roller (roller) is not hampered from being rolled smoothly.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: October 2, 2007
    Assignee: NSK Ltd.
    Inventors: Yoichi Matsumoto, Koichi Yamamoto, Seigou Urakami, Aya Kikuchi
  • Electric power steering device
    Patent number: 7275451
    Abstract: 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: Grant
    Filed: January 4, 2005
    Date of Patent: October 2, 2007
    Assignee: NSK Ltd.
    Inventor: Kazuo Chikaraishi
  • Electric power steering device
    Patent number: 7275618
    Abstract: 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: Grant
    Filed: January 28, 2003
    Date of Patent: October 2, 2007
    Assignee: NSK Ltd.
    Inventors: Manabu Abe, Kazuo Chikaraishi, Atsushi Tanaka
  • Worm reducer and electric power steering apparatus
    Publication number: 20070221004
    Abstract: In a worm reducer for reducing the rotation transmitted to a worm and transmitting the reduced rotation to a worm wheel, the worm reducer being composed of the worm with screw faces formed on its outer periphery and the worm wheel with worm wheel teeth formed on its peripheral surface, the worm wheel teeth being in mesh with the screw faces of the worm, the worm wheel teeth are formed so that the lead angle of the worm wheel is smaller than that of the worm.
    Type: Application
    Filed: March 8, 2007
    Publication date: September 27, 2007
    Applicant: NSK LTD.
    Inventor: Atsushi Maeda
  • Continuously variable transmission apparatus
    Patent number: 7273440
    Abstract: A continuously variable transmission apparatus includes a toroidal-type continuously variable transmission, a planetary gear type transmission and a clutch apparatus that connects the toroidal-type continuously variable transmission and the planetary gear type transmission. The clutch apparatus includes: a low speed clutch engaged for realizing a low speed mode and disengaged for realizing a high speed, a high speed clutch engaged for realizing the high speed mode and disengaged for realizing the low speed mode and a controller. The controller controls the transmission ratio of the toroidal-type continuously variable transmission so that rotational speeds of members connected via the clutch apparatus equals with each other, and then disengages the one of the low speed clutch and the high speed clutch after engaging the other.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: September 25, 2007
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Eiji Inoue, Takumi Sinojima, Toshiro Toyoda
  • Toroidal-type continuously variable transmission
    Patent number: 7273437
    Abstract: A toroidal-type continuously variable transmission has a casing, a rotation shaft, a pair of outer side disks having a side surface, supported on the rotation shaft, and rotating in synchronism with the rotation shaft, an inner side disk having two side surfaces, rotatably supported around a middle portion of the rotation shaft, and rotating relative to the rotation shaft, pluralities of supporting members disposed between the two side surfaces of the inner side disk and the side surfaces of the outer side disks, respectively, and swinging on a pivot shaft disposed so as to be twisted to the rotation shaft, and pluralities of power rollers rotatably supported on the respective supporting members, wherein an outer peripheral face of the inner side disk is provided with a detected portion for detecting rotation of the inner side disk.
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: September 25, 2007
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Yuji Shimomura