Patents Assigned to JTEKT
  • Publication number: 20140096634
    Abstract: A ball screw nut of a ball screw device is fastened to a motor shaft by engaging a male thread portion thereof with a female thread portion of the motor shaft. In a case where, in a movement pathway for balls, an area where the balls roll under load from a rack shaft and the ball screw nut is set as a load area, an area that does not receive the load is set as a no-load area, and areas for transition from the load area to the no-load area are set as transition areas, the male thread portion is formed such that the transition area on the nut-side joint portion-side closest to a seating surface does not overlap phase ranges of cut portions in a state where the ball screw nut is fastened to the motor shaft.
    Type: Application
    Filed: October 1, 2013
    Publication date: April 10, 2014
    Applicant: JTEKT CORPORATION
    Inventors: Satoshi MOTOYAMA, Masashi YAMAGUCHI
  • Publication number: 20140099051
    Abstract: A steel material which contains 0.16 to 0.19% of carbon by mass, 0.15 to 0.35% of silicon by mass, 0.20 to 1.55% of manganese by mass, and 2.5 to 3.2% of chromium by mass, of which remaining part is formed of iron and incidental impurities, and which contains 0.01 to 0.2% of nickel by mass as an incidental impurity and higher than or equal to 0.001% and lower than 0.15% of molybdenum by mass as an incidental impurity, and which has a hardenability index of higher than or equal to 5.4 is subjected to a carbonitriding step, a process annealing step, a quenching step, a tempering step and a finishing step. Thus, there is obtained a rolling sliding member made of the steel material, and having satisfactory corrosion resistance and crack resistance and having a sufficiently long useful life even under an environment where rust is easily formed.
    Type: Application
    Filed: September 30, 2013
    Publication date: April 10, 2014
    Applicant: JTEKT CORPORATION
    Inventors: Wataru YOSHIDA, Katsuhiko KIZAWA
  • Patent number: 8689927
    Abstract: An electric power steering device includes a metallic housing, a steered shaft, an electric motor, a ball screw device, a rolling bearing, elastic members, and a plain bearing. The plain bearing is provided between the housing and an outer ring of the rolling bearing, and formed from a resin material.
    Type: Grant
    Filed: January 23, 2012
    Date of Patent: April 8, 2014
    Assignee: JTEKT Corporation
    Inventors: Yasuharu Yamamoto, Yuki Bando
  • Patent number: 8689926
    Abstract: An electric power steering apparatus (1) comprises a control device (12), which controls driving of an electric motor (18) based on the detection signals from a rotational position-detecting sensor (72; 72A), which detects the rotational position of the rotor (64) of the electric motor (18), and a steering status detecting sensor (11; 11A). The control device (12) is housed in a housing (100) that is partitioned by a first housing (23), which is at least a portion of the motor housing (25) for the electric motor (18), and a second housing (24; 24A; 24B) that touches the first housing (23). At least one of the rotational position-detecting sensor (72; 72A) and steering state detecting sensor (11; 11A) is connected to the control device (12) by means of only a signal wire (81; 134) inside the first housing (23) or the second housing (24; 24A; 24B).
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: April 8, 2014
    Assignee: JTEKT Corporation
    Inventors: Shigeki Nagase, Shiro Nakano, Ken Matsubara, Motoo Nakai, Kunihiro Oka, Naotake Kanda, Nobuhiro Uchida, Kouya Yoshida, Minoru Sentoku
  • Patent number: 8690448
    Abstract: There is provided a rolling bearing apparatus which can more disperse stress which concentrates on a root portion of a flange portion formed on an outer circumferential surface of an outer ring as compared with a related art. In a rolling bearing apparatus 1, a surface which continues from a vehicle outer side end face 220 of an outer ring flange portion 22 to an outer circumferential surface 210 of an outer ring main body portion 21 is formed to have a smoothly continuing curved surface 200, and a protruding curved surface 203 which protrudes radially outwards is formed on a part of the curved surface 200.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: April 8, 2014
    Assignee: JTEKT Corporation
    Inventor: Kenji Shitsukawa
  • Patent number: 8689960
    Abstract: A torque limiter in which an area of a region where an area of a region where an inner face of a circumferentially extending chamber intersects an oil pressure expanding chamber in an extended plane extended toward the oil pressure expanding chamber is larger than a sectional area of an opening of the oil removing hole which is opened to the circumferentially extending chamber.
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: April 8, 2014
    Assignee: JTEKT Corporation
    Inventors: Akihide Nagayama, Takeshi Miyachi
  • Publication number: 20140090945
    Abstract: A one-way clutch used in a wind turbine generator connects an input rotor with an output rotor so that the input rotor and the output rotor are rotatable together with each other when a main shaft rotates in a forward direction and rotation speed of the input rotor is higher than rotation speed of the output rotor, and disconnects the input rotor and the output rotor from each other when the rotation speed of the input rotor is lower than the rotation speed of the output rotor. Further, the wind turbine generator includes a second one-way clutch that permits transmission of force caused by the rotation of the main shaft, to the input rotor when the main shaft rotates in the forward direction, and restricts the rotation of the main shaft when the main shaft tries to rotate in a reverse direction.
    Type: Application
    Filed: September 30, 2013
    Publication date: April 3, 2014
    Applicant: JTEKT CORPORATION
    Inventors: Hideki FUJIWARA, Kazushige OOTSUKA, Takafumi UEMOTO, Nobuyuki RITO
  • Publication number: 20140093199
    Abstract: A bearing unit for a railway vehicle, which is disposed in an axle box disposed at each of opposite ends of an axle of a railway vehicle, includes an inner ring secured to the axle; an outer ring disposed outside the inner ring, and secured to the axle box; and rolling elements rollably disposed between the inner ring and the outer ring. A displacement-load sensor is disposed at an inner peripheral surface of the outer ring.
    Type: Application
    Filed: September 20, 2013
    Publication date: April 3, 2014
    Applicant: JTEKT CORPORATION
    Inventor: Hideki FUJIWARA
  • Patent number: 8686672
    Abstract: A current command value computation section 22 is provided with a q-axis current command value correction section 31 and an expected voltage utilization factor computation section 32. The expected voltage utilization factor computation section 32 estimates an expected voltage utilization factor f based on a rotational angular velocity ? of a motor 12, a q-axis current command value Iq*, and a power voltage Vb (the maximum voltage Vmax). The expected voltage utilization factor f is the ratio of required output voltage to the maximum voltage Vmax applicable to a drive circuit 18. Based on the expected voltage utilization factor f, the q-axis current command value correction section 31 corrects the q-axis current command value Iq* such that the corrected expected voltage utilization factor f does not exceed a predetermined value that corresponds to the voltage saturation limit.
    Type: Grant
    Filed: August 20, 2009
    Date of Patent: April 1, 2014
    Assignee: Jtekt Corporation
    Inventor: Hiroshi Suzuki
  • Patent number: 8683887
    Abstract: A rack-and-pinion steering apparatus comprises pinion teeth formed according to proper tooth specifications in other aspects under a larger pressure angle, thereby stably offering smooth and comfortable steering feeling over a long time. The module (m), number of teeth (z), tooth depth (h) and helix angle (?) of the pinion teeth (4) are set within the following ranges, under a pressure angle (?) set within a range of 24° to 30° and a given stroke ratio. module (m): 1.8 to 2.0 number of teeth (z): 7 to 13 tooth depth (h): 2 m to 2.
    Type: Grant
    Filed: January 12, 2005
    Date of Patent: April 1, 2014
    Assignee: JTEKT Corporation
    Inventors: Takayasu Yamazaki, Shirou Nakano
  • Patent number: 8684127
    Abstract: An electric power steering system includes a shaft coupling that drivably couples a worm gear to an output shaft such that the worm gear is tiltable with respect to the output shaft. The shaft coupling includes a fixing part coupled to the output shaft and a cylindrical part having an inner periphery in rectangular cross section and fixed to the fixing part. A coupling part that is inserted in the cylindrical part and that has an outer periphery in non-circular cross section, engageable with the inner periphery, is formed at a proximal end part of the worm gear, and the outer periphery is ridged such that gaps that allow the coupling part to tilt are provided inside the cylindrical part. Then, the cylindrical part presses an inner ring of the first rolling bearing toward an axially distal end side of the worm gear.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: April 1, 2014
    Assignee: JTEKT Corporation
    Inventors: Takeshi Hama, Yutaka Nagahashi
  • Patent number: 8684129
    Abstract: A controller applies slight rotational torque to a drive gear of a reduction mechanism also in a predetermined range in which a motor does not produce any steering operation assist force. That is, the motor is caused to produce slight rotational torque not enough to drive a driven gear, and the rotational torque direction is reversed under a given condition. Accordingly, a backlash between the drive gear and the driven gear is eliminated.
    Type: Grant
    Filed: June 21, 2010
    Date of Patent: April 1, 2014
    Assignee: JTEKT Corporation
    Inventors: Shinsuke Terada, Hideki Higashira, Yasuyuki Yoshii, Naoki Maeda, Shirou Nakano
  • Publication number: 20140086521
    Abstract: A pin-type cage includes a plurality of pins passed through respective through-holes formed along the central axes of a plurality of rolling elements that are arranged in the circumferential direction of a rolling bearing, and annular retaining members that connect the pins to each other at axially opposite ends of the pins. Each of the pins has a reservoir space that is formed in the pin and that is filled with lubricant, and supply holes used to supply the lubricant from the reservoir space to an outer periphery of the pin.
    Type: Application
    Filed: September 17, 2013
    Publication date: March 27, 2014
    Applicant: JTEKT CORPORATION
    Inventors: Takeshi TERAMOTO, Hideki FUJIWARA
  • Publication number: 20140086744
    Abstract: In a torque limiter, wedge-shaped spaces are formed between inner and outer rings so as to be arranged in the circumferential direction. In each wedge-shaped space, there are arranged a first roller and a second roller that transmit torque between the inner and outer rings by being brought into wedge-engagement when the inner and outer rings rotate relative to each other in one direction and in the other direction, respectively. Between the first and second rollers, there is arranged an urging device that urges the first and second rollers in such directions that the first and second rollers are brought into wedge-engagement. Each wedge-shaped space is formed such that when the torque becomes equal to or higher than a predetermined value, a first wedge angle of the first roller or a second wedge angle of the second roller becomes such an angle that wedge-engagement of the roller is cancelled.
    Type: Application
    Filed: September 17, 2013
    Publication date: March 27, 2014
    Applicant: JTEKT CORPORATION
    Inventor: Hideki FUJIWARA
  • Patent number: 8678405
    Abstract: When a motor vehicle is steered, as turning reaction forces from the road surface, for example, rearward radial loads are applied from rear wheels to corresponding end portions of a steered shaft via corresponding knuckles and corresponding tie rods. A motor vehicle steering system includes first and second counter load application mechanisms that apply counter loads against the radial loads to the corresponding end portions of the steered shaft. Each of the counter load application mechanisms includes a motion conversion mechanism that converts torsional motion of the corresponding end portion of an axle beam caused by a ground contact reaction force of the corresponding rear wheel via the corresponding knuckle and a corresponding king pin into, for example, forward motion of the corresponding end portion of the steered shaft.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: March 25, 2014
    Assignee: Jtekt Corporation
    Inventor: Takashi Tashiro
  • Patent number: 8678719
    Abstract: A cutting tip including a cutting edge portion made of a high-hardness material to take a thin-plate shape; and a support portion made of a material which is more worn in contact with a workpiece than the cutting edge portion not to exert a machining action on the workpiece even in contact with the workpiece, and securing and supporting the cutting edge portion on a reverse side of a rake face of the cutting edge portion. Thus, the width of flank wear is prevented from increasing and chipping of the cutting edge is prevented, so that the life of the cutting tip can be extended.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: March 25, 2014
    Assignee: JTEKT Corporation
    Inventors: Naoto Ono, Shinji Soma, Yasuo Niino, Tomokazu Yamashita
  • Patent number: 8680798
    Abstract: A motor control device for driving a brushless motor includes a current detecting unit which detects respective phase currents which flow into the brushless motor; a control calculation unit which calculates instruction values showing respective phase voltages to be applied to the brushless motor, and outputs the instruction values as phase voltage instruction values; a phase resistance calculation unit which calculates respective phase resistance values based on detection values of the respective phase currents detected by the current detecting unit, and the instruction values of the respective phase voltages applied to the brushless motor at the time of the detection of the detection values; a correction unit which corrects the phase voltage instruction values according to the respective phase resistance values calculated by the phase resistance calculation unit; and a driving unit which drives the brushless motor based on the phase voltage instruction values after correction by the correction unit.
    Type: Grant
    Filed: December 26, 2012
    Date of Patent: March 25, 2014
    Assignee: JTEKT Corporation
    Inventors: Takeshi Ueda, Nobuhiro Uchida, Kouya Yoshida
  • Patent number: 8678660
    Abstract: A sealing device includes a bottom of an axial concave portion in a surface of an elastic member forming a radial lip, facing away from a flange portion in an axial direction overlaps an end face of a radially-extending portion of a core metal member, facing a tubular portion, in a radial direction. A bottom of a radial concave portion of the elastic member forming the radial lip, facing the tubular portion of a slinger is spaced from the end face of the core metal member toward a flange portion in the axial direction.
    Type: Grant
    Filed: November 19, 2008
    Date of Patent: March 25, 2014
    Assignees: JTEKT Corporation, Koyo Sealing Techno Co., Ltd.
    Inventors: Masahiro Tabata, Syuji Fujita, Shunichi Fujiwara, Kasumi Yamamoto
  • Patent number: 8681506
    Abstract: A motor control device comprising a control board for controlling driving of an electric motor, the control board including a multilayer circuit board having inner layers and outer layers, a ground pattern disposed around an output shaft of the electric motor formed on one of the inner layers, and a severed portion formed on a part of the ground pattern, so as to sever through the ground pattern in a radial direction of the output shaft. The construction reduces noise from the motor control device.
    Type: Grant
    Filed: February 2, 2009
    Date of Patent: March 25, 2014
    Assignees: JTEKT Corporation, Koyo Electronics Industries Co., Ltd.
    Inventors: Motoo Nakai, Shigeki Nagase, Akira Sugimoto
  • Patent number: 8682538
    Abstract: A vehicle steering device performs a tilt operation of a steering shaft to a predetermined position by using a driving force of a motor, a steering wheel being mounted to an upper end of the steering shaft. The vehicle steering device includes: a tilt drive motor allows the steering shaft to move during the tilt operation; and a control unit which controls driving of the tilt drive motor. The control unit drives the tilt drive motor so as to determine a tilt displacement amount from an open loop transfer function of a mechanical system which takes inertia and viscosity of a steering column into consideration, based on a resultant force of torque of the tilt drive motor and steering torque, which is generated in the steering column in which the steering shaft is rotatably supported.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: March 25, 2014
    Assignee: JTEKT Corporation
    Inventor: Tatsuma Kouchi