Patents Assigned to JTEKT
  • Publication number: 20110118940
    Abstract: A motor is driven by the ?-axis current of a ?? coordinate system that is an imaginary rotating coordinate system. A command current value preparation unit sets the ?-axis command current value based on the command steering torque and the detected steering torque. The command current value preparation unit includes a command current increase/decrease amount calculation unit and an addition unit. The command current increase/decrease amount calculation unit calculates the current increase/decrease amount for the command current value based on the sign of the command steering torque and the deviation of the detected steering torque from the command steering torque. The current increase/decrease amount calculated by the command current increase/decrease amount calculation unit is added to the immediately preceding value of the command current value by the addition unit. Thus, the command current value in the present calculation cycle is calculated.
    Type: Application
    Filed: November 15, 2010
    Publication date: May 19, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Yuji KARIATSUMARI, Hayato KOMATSU, Terutaka TAMAIZUMI, Yoshihiro ITATSU
  • Publication number: 20110116880
    Abstract: A boring holder in a tool radius adjusting system is provided with a cutting blade and fine and coarse motion adjusting mechanisms each capable of adjusting the position of the cutting blade relative to a rotational axis of the boring holder. The tool radius adjusting system is provided with a tool radius measuring device for measuring the tool radius of the boring holder and a controller configured to calculate a compensation amount based on a tool radius measured by the tool radius measuring device and a target tool radius and to operate the fine and coarse motion adjusting mechanisms based on the compensation amount so that the tool radius is brought into agreement with the target tool radius.
    Type: Application
    Filed: November 9, 2010
    Publication date: May 19, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Eiji NAKAMURA, Norikazu Sawaki, Akihiko Kadota, Takashi Yokoyama
  • Publication number: 20110114867
    Abstract: A pressure reducing valve (10) includes: a valve unit (18) provided between a primary port (32) and a secondary port (34); a cylinder (12) provided downstream of the valve unit (18); a piston (14) that divides a space in the cylinder (12) into a pressure reducing chamber (38) and a pressure regulation chamber (96) and that opens or closes the valve unit 18 by sliding within the cylinder (12); and a seal member (24) that is disposed in an inner peripheral face of the cylinder (12) and that includes a slidably contacting piece (26a) that slidably contacts the piston (14) due to the pressing force of an elastic member (28). The cylinder (12) is formed of a body member (20) that defines the pressure reducing chamber (38) and a cover member (22) that defines the pressure regulation chamber (96). An annular groove (94) in which the first seal member (24) is disposed is formed at the boundary between the body member (20) and the cover member (22).
    Type: Application
    Filed: November 12, 2010
    Publication date: May 19, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Takuya SUZUKI, Munetoshi KUROYANAGI, Hiroaki SUZUKI, Toshikatsu KUBO
  • Publication number: 20110118937
    Abstract: When the estimated motor temperature becomes equal to or higher than the first predetermined temperature, an addition angle correction unit temporarily decreases the absolute value of the addition angle output from an addition angle limiter at time intervals. The addition angle correction unit makes the time interval shorter as the estimated motor temperature increases. When the time interval becomes equal to or shorter than the predetermined threshold, that is, when the estimated motor temperature becomes equal to or higher than the second predetermined temperature that is higher than the first predetermined temperature, the addition angle correction unit notifies a command current value changing unit of a current stop command. Thus, the ?-axis command current value is changed to 0, and therefore the steering mode is shifted to the manual steer mode.
    Type: Application
    Filed: November 10, 2010
    Publication date: May 19, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Yuji KARIATSUMARI, Yoshihiro ITATSU, Yoshinobu SHIMIZU
  • Publication number: 20110115289
    Abstract: In a motor control device that is used for, for example, an electric power steering system or another vehicle steering system equipped with a motor, a relay circuit (40) that serves as a power supply breaker is provided in a power feed line (Lp2) of a pre-driver (22) of a circuit that is a component of the motor control device. The operation of the relay circuit (40) is controlled by a relay signal (S_rly) output from a microcomputer (21).
    Type: Application
    Filed: November 9, 2010
    Publication date: May 19, 2011
    Applicant: JTEKT CORPORATION
    Inventor: Hiroshi KITAMOTO
  • Patent number: 7942583
    Abstract: A multilayer film 21 is formed by layering layers whose adjoining layers are made of mutually different metals or alloys by an electroplating process on a surface of a metallic annular main body part 20 that has a pocket to accommodate a ball by holding the ball from both sides in the axial direction.
    Type: Grant
    Filed: September 27, 2006
    Date of Patent: May 17, 2011
    Assignees: JTekt Corporation
    Inventors: Tomoya Hattori, Hiroshi Ueno, Satoshi Hashimoto, Yoshihisa Kaneko
  • Patent number: 7942649
    Abstract: An electrical driven pump unit having two hydraulic pumps and two electric motors that are fitted in such a way as to make it possible to obtain the unit's power by adding together the power of the two motors.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: May 17, 2011
    Assignee: JTEKT HPI
    Inventors: Nicaïse Lesther, Francois Fischer
  • Patent number: 7944163
    Abstract: A sensorless controlling apparatus for controlling a brushless motor includes a speed calculator for calculating speed of a rotor ?, an angle calculator for calculating rotor angle ? at a predetermined time interval, and an angle controller for calculating correction angle ?? based on the current value of a d-axis current (d-axis current value id), thereby controlling the rotor angle ?. The angle calculator uses the correction angle ?? calculated by the angle controller, the speed ? calculated by the speed calculator, a predetermined time, and the rotor angle ? calculated by the angle calculator at a predetermined time to calculate the rotor angle at the predetermined time interval. Thus, the rotor angle ? calculated by the angle calculator is converged on the true angle of the rotor.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: May 17, 2011
    Assignee: JTEKT Corporation
    Inventor: Shigekazu Okumura
  • Publication number: 20110108355
    Abstract: A transmission ratio variable mechanism includes an input member and an output member arranged to rotate around a first axis, an intermediate member arranged to connect the input member and the output member so as to be differentially rotatable, and a motor arranged to drive the intermediate member. The motor includes a cylindrical rotor arranged to rotate around the first axis. An inner periphery of the rotor is arranged to support the intermediate member and arranged to rotatably support the input member and the output member via bearings, respectively.
    Type: Application
    Filed: July 6, 2009
    Publication date: May 12, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Akihiko Shiina, Motoyasu Yamamori
  • Publication number: 20110108354
    Abstract: A transmission ratio variable mechanism includes an input member and an output member, which are rotatable around a first axis, an inner ring arranged to connect the input and output members to each other so as to be differentially rotatable, an outer ring, and a motor. A second axis serving as a center axis of the inner ring and the outer ring is inclined to the first axis. The transmission ratio variable mechanism includes uneven engagement sections including a projection provided on one of each of end surfaces of the inner ring and a power transmission surface corresponding to the end surface, and a recess. The inner ring includes a first member forming the first end surface and a second member forming the second end surface. The first and second members are formed separately from each other and coupled to each other so as to be movable together.
    Type: Application
    Filed: June 30, 2009
    Publication date: May 12, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Atsushi Yao, Satoru Murao, Yoichiro Sankai
  • Publication number: 20110108356
    Abstract: A variable transmission ratio mechanism comprises: an input member capable of rotating around a first axis; and an intermediate member that allows the differential rotation of the output member. The intermediate member is capable of rotating around a second axis that is slanted relative to the first axis. On first and second power transmission surfaces of the intermediate member, corresponding first and second engaging sections are respectively arranged according to corresponding first and second arrangement pitch circles centered on the second axis. On corresponding first and second engagement circles centered on the first axis, the first and second engaging sections are respectively engageable with corresponding first and second engageable sections. The diameter of the first arrangement pitch circle differs from the diameter of the second arrangement pitch circle.
    Type: Application
    Filed: June 26, 2009
    Publication date: May 12, 2011
    Applicant: JTEKT CORPORATION
    Inventor: Hidetaka Otsuki
  • Publication number: 20110112724
    Abstract: A motor control unit includes a detected steering torque correction unit that corrects the detected steering torque that is detected by a torque sensor and then subjected to a limitation process by a steering torque limiter. When the absolute value of the detected steering torque is equal to or smaller than a predetermined value, the detected steering torque correction unit corrects the detected steering torque to 0. When the absolute value of the detected steering torque is larger than the predetermined value, the detected steering torque correction unit outputs the detected steering torque without correction. A PI control unit calculates the addition angle based on the deviation of the control torque obtained through correction by the detected steering torque correction unit from the command steering torque.
    Type: Application
    Filed: November 12, 2010
    Publication date: May 12, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Yuji KARIATSUMARI, Terutaka TAMAIZUMI, Yoshinobu SHIMIZU
  • Patent number: 7938602
    Abstract: In a three degrees of freedom parallel mechanism, a spindle head is carried by first and second movable support members to be movable along a Z-axis and to be pivotable along each of A and B-axes. The spindle head is jointed through three rods to drive sliders which are movable along three parallel linear guides secured stationarily. For jointing, there are employed spherical joints and universal joints. Kinematic parameters used in converting each command position of the movable body to target operational positions for three actuators of the Z, A and B-axes are compensated based on inversely converted command positions and inversely converted actually measured positions which have been gathered with the spindle head being located at positions of a suitable number, so that the kinematic parameters can be updated to those newest.
    Type: Grant
    Filed: March 19, 2007
    Date of Patent: May 10, 2011
    Assignee: JTEKT Corporation
    Inventor: Hiromichi Ota
  • PLC
    Patent number: 7941239
    Abstract: The PLC according to this invention includes I/O modules, a CPU module, an input/output bus, and a PC having a display. The CPU module includes a control program storage unit which previously stores an intrinsic control program in which operation processing and an input/output information item are packaged; a library which previously stores the function block representing the operation processing; and a header file which previously stores equivalent input/output information equivalently representing the input/output information by a graphical language. Referring to the library and header file, PC causes the execution program created and stored in the main storage unit to be displayed on the display by the function block and equivalent input/output information item.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: May 10, 2011
    Assignee: JTEKT Corporation
    Inventors: Kenichi Ikegami, Tsutomu Araki
  • Patent number: 7934871
    Abstract: The large diameter cage has an asymmetric shape, a diameter (discharge diameter) of which close to an opening is larger than a diameter (inflow diameter) close to the small diameter cage, and the small diameter cage has a symmetric shape, in which a diameter (inflow diameter) of which close to an opening is equal to a diameter (discharge diameter) close to the large diameter cage.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: May 3, 2011
    Assignee: JTEKT Corporation
    Inventors: Toshihiro Kawaguchi, Toshirou Fukuda, Yuzuru Takahashi
  • Patent number: 7934872
    Abstract: A drawn cup roller bearing includes: a drawn cup outer ring that includes a cylindrical portion serving as an outer raceway surface, a first rib which is formed at one axial end portion of the cylindrical portion and is bent radially inwardly such that a step portion is formed at an intermediate portion of the first rib, and a second rib which is formed at the other axial end portion of the cylindrical portion and is radially inwardly folded back; an annular seal which is press-fitted in the step portion; and a cage which holds a plurality of rollers and is inserted into the drawn cup outer ring from the second rib to be mounted in the drawn cup outer ring in such a manner that the cage is retained against withdrawal by the step portion and the plurality of rollers is retained against withdrawal by the second rib.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: May 3, 2011
    Assignee: JTEKT Corporation
    Inventor: Kenichi Hashimoto
  • Publication number: 20110095714
    Abstract: Provided is an electric pump device that can continue to supply hydraulic pressure to hydraulically actuated equipment and that is also of reduced size. An electric pump device is provided with an oil pump that supplies oil to a stepless transmission device, a brushless motor that drives the oil pump, and a control device that controls the brushless motor. The control device is provided with a power supply part that supplies drive power to the brushless motor, and an out-of-synch determination part that determines whether or not the brushless motor is out of synch. The control device is provided with a drive control part that controls the power supply part so that supply of power to the brushless motor is stopped, and then controls the power supply part so that the brushless motor is started, when the out-of-synch determination part determines that the brushless motor is out of synch.
    Type: Application
    Filed: May 21, 2009
    Publication date: April 28, 2011
    Applicant: JTEKT CORPORATION
    Inventor: Hiroki Kagawa
  • Publication number: 20110098889
    Abstract: In an electric power steering apparatus of the invention, a control circuit determines a command value of drive voltage supplied to a motor drive circuit based on an actual current through a motor and a target current. When the command value exceeds the previous value having a lower limit equivalent to a limit value representing the limit of the power supply from a battery, the control circuit controls the amount of discharge from the auxiliary power supply according to a difference between the command value and the previous value by increasing or decreasing a duty of switching devices. Thus, the power steering apparatus can save the energy of the auxiliary power supply for efficiently using the auxiliary power supply.
    Type: Application
    Filed: June 30, 2009
    Publication date: April 28, 2011
    Applicant: JTEKT CORPORATION
    Inventor: Toshiaki Oya
  • Publication number: 20110098888
    Abstract: A motor controller controls a motor including a rotor and a stator opposed to the rotor. The motor controller includes an electric current driving unit which drives the motor with an axis electric current value defined in a rotating coordinate system defined with respect to a control angle that is a rotation angle for control, a control angle computing unit which computes a current value of the control angle by adding an addition angle to a previous value of the control angle in each predetermined computing cycle, and an addition angle computing unit which computes the addition angle according to a torque to be generated by the motor or a response of the motor to the axis electric current value.
    Type: Application
    Filed: June 29, 2009
    Publication date: April 28, 2011
    Applicant: JTEKT CORPORATION
    Inventors: Yuji Kariatsumari, Hideki Higashira, Masashi Hattori, Yoshinobu Shimizu
  • Publication number: 20110097971
    Abstract: In a grinding machine, a retraction grinding is performed after a first advance grinding. Within a rotational range for a cylindrical workpiece to rotate from a present rotational phase to a target rotational phase in the retraction grinding, target grinding resistances in respective rotational phases are generated based on residual grinding amounts in the respective rotational phases of the cylindrical workpiece. Then, the retraction grinding is performed and controlled to make a grinding resistance detected by a force sensor agree with the target grinding resistances in respective rotational phases.
    Type: Application
    Filed: October 20, 2010
    Publication date: April 28, 2011
    Applicant: JTEKT Corporation
    Inventors: Toshiki KUMENO, Masashi YORITSUNE, Takashi MATSUMOTO, Kazuyoshi OHTSUBO