Patents Assigned to JTEKT
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Patent number: 7889978Abstract: An angle computing section determines an angle of a rotor, and an angular velocity computing section determines angular velocity of the rotor. A command current computing section determines, from a steering torque and vehicle velocity, command currents and taken along d-q axes. An open loop control section determines, from command currents and angular velocity, command voltages taken along the d-q axes in accordance with motor circuit equations. A d-q axis/three-phase conversion section converts the command voltages into command voltages of three phases. A ? computing section determines the number of armature winding flux linkages included in a motor circuit equation from a q-axis command voltage, the current value detected by a current sensor, and the angular velocity. Circuit resistance including armature winding resistance R included in the motor circuit equation may also be determined by means of the same configuration.Type: GrantFiled: January 31, 2008Date of Patent: February 15, 2011Assignee: JTEKT CorporationInventors: Takeshi Ueda, Shigeki Nagase, Hiroshi Sumasu
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Publication number: 20110030219Abstract: A method of producing a rolling sliding member, wherein, after a work for a rolling sliding member, which is made of a bearing steel and formed in a predetermined shape, is quenched, a heating start temperature is set to be 10 to 100° C., a heating finish temperature is set to be 220 to 350° C., a time between the heating finish time and the heating start time is set to be a heating time, the quenched work for the rolling sliding member is heated so that a rate of temperature increase indicated by the following formula becomes 7 to 35° C./s rate of temperature increase=(heating finish temperature?heating start temperature)/heating time, the work is tempered by being cooled without being maintained at a heating finish temperature from the heating finish time.Type: ApplicationFiled: August 10, 2010Publication date: February 10, 2011Applicant: JTEKT CorporationInventors: Towako MATSUI, Katsuhiko KIZAWA
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Publication number: 20110035110Abstract: The steering system of the invention includes a processing means (26) comprising a means for determining (30) a driving signal (S3) of the power means (25) on the basis of: a first control signal (S1) determined from the measure of a torque applied by the driver on the steering wheel by applying a gain that depends on the longitudinal speed of the vehicle; a second correction signal (S2) determined from the measure of the torque applied by the driver on the steering wheel, and a setpoint determined on the basis of at least one characteristic parameter of the lateral dynamics of the vehicle.Type: ApplicationFiled: July 10, 2008Publication date: February 10, 2011Applicant: JTEKT EUROPEInventors: Stephane Cassar, Jean-Marc Kasbarian
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Publication number: 20110035107Abstract: An electric power steering apparatus comprises a charge-discharge circuit capable of configuring a circuit for charging an auxiliary power supply and a circuit for discharging a battery and the auxiliary power supply as well as configuring a discharge-preference circuit which enables only the discharge of the auxiliary power supply while avoiding the charge thereof. In the apparatus, a control circuit performs a power latch operation of carrying on control till the end of a predetermined period of time following an operation of turning off an ignition key, and also causes the charge-discharge circuit to configure the discharge-preference circuit thereby enabling steering assist accompanied by the discharge of the auxiliary power supply.Type: ApplicationFiled: April 2, 2009Publication date: February 10, 2011Applicant: JTEKT CORPORATIONInventors: Keisuke Izutani, Kazuyuki Yoshida
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Publication number: 20110033146Abstract: A first fit portion and a second fit portion of an inner ring according to the invention have a spring property. Therefore, the first and second fit portions may be flexed radially outward by elasticity thereof and then fitted to a shaft. Thus, the inner ring is tightly fitted to the shaft with a set interference with respect to the shaft. Accordingly, it is easy to fit/remove the inner ring to/from the shaft. Therefore, an outer peripheral face of the shaft is pushed radially inward by elasticity of the first and second fit portions, that is, the inner ring is tightly fitted to the shaft, without reducing the ease of fitting/removing the inner ring to/from the shaft. As a result, it is possible to minimize generation of creep.Type: ApplicationFiled: July 27, 2010Publication date: February 10, 2011Applicant: JTEKT CORPORATIONInventor: Toshihiko SHIRAKI
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Publication number: 20110034256Abstract: A spline telescopic shaft includes an inner shaft having an outer tooth surface, and a cylindrical outer shaft having an inner tooth surface and arranged to fit to the inner shaft slidably in an axial direction of the inner shaft. Either one of the outer tooth surface and the inner tooth surface includes a first resin coating. The other of the outer tooth surface and the inner tooth surface includes a second resin coating. The second resin coating is formed by processing for sliding an intermediate member for manufacturing the inner shaft and an intermediate member for manufacturing the outer shaft in the axial direction, to transfer a part of a resin material provided in the intermediate member for manufacturing the shaft including the one tooth surface for forming the first resin coating to the intermediate member for manufacturing the shaft including the other tooth surface.Type: ApplicationFiled: July 30, 2010Publication date: February 10, 2011Applicants: JTEKT Corporation, KOYO MACHINE INDUSTRIES CO., LTD.Inventor: Ryoichi Tokioka
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Publication number: 20110034278Abstract: A power transmission device includes a tubular stabilizer which is arranged between a primary pulley and a secondary pulley, and through which a string portion of a power transmitting chain is passed so as to be movable relative to the stabilizer whereby movement of the power transmitting chain is restricted. The stabilizer is supported by the power transmitting chain and is moved in the traveling direction of the power transmitting chain as the power transmitting chain moves in the traveling direction, and a movement of the stabilizer of which the amount is larger than or equal to a predetermined amount is restricted by a restricting device.Type: ApplicationFiled: July 27, 2010Publication date: February 10, 2011Applicant: JTEKT CORPORATIONInventors: Yuya INOUE, Shinji Yamane, Yoshihisa Miura, Teruko Nagaoka
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Publication number: 20110030496Abstract: There is provided a spline telescopic shaft having first and second shafts that are fitted to each other slidably in an axial direction. First and second splines that engage with each other are respectively provided in the first and second shafts. A resin coating that is provided on at least a tooth surface of the first spline is fitted to a tooth surface of the second spline. The resin coating is subjected to heat fitting processing for sliding the first and second shafts in the axial direction under predetermined conditions, to fit a surface of the resin coating to the tooth surface of the second spline.Type: ApplicationFiled: August 3, 2010Publication date: February 10, 2011Applicants: JTEKT Corporation, KOYO MACHINE INDUSTRIES CO., LTD.Inventor: Ryoichi Tokioka
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Patent number: 7883271Abstract: In a rolling bearing including an oil supply unit for supplying lubricating oil stored in a tank by a pump via a nozzle which is made to open in an annular space defined between an inner ring and an outer ring, the nozzle is made to open in a space between an inner circumferential surface of a case and the inner ring, and the inner circumferential surface of the cage is formed into a surface in which an inside diameter of the cage is reduced gradually in a continuous or intermittent fashion from an axial center portion towards at least an end portion lying on a side where the nozzle is inserted, whereby a lubricating oil dropped on to the inner circumferential surface of the cage is caused to flow towards the axial center portion by virtue of centrifugal force generated by the rotation of the cage, so as to prevent the lubricating oil from flowing out to the outside of the bearing unit.Type: GrantFiled: January 16, 2006Date of Patent: February 8, 2011Assignee: JTEKT CorporationInventors: Kazuya Suzuki, Kiyoshi Tanimoto, Hiroshi Ueno, Shinji Fukuda
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Patent number: 7882689Abstract: In the state where plural sheets of link plates which are single parts are laminated, tension for widening a distance between through-holes is loaded by a pair of pins which are inserted through the through-holes of the link plates so as to load pretension serving as a predetermined compressive residual stress on the link plates. Subsequently, the pair of pins are extracted from the link plates. Consequently, connection members are inserted through the corresponding through-holes of the plurality of link plates so as to assemble a chain with an endless shape.Type: GrantFiled: January 25, 2008Date of Patent: February 8, 2011Assignee: JTEKT CorporationInventors: Seiji Tada, Kozue Matsumoto, Kazuo Rokkaku
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Patent number: 7884509Abstract: A tool moving device with a linear motor is provided with a movable body which is movable bodily with a tool on a support frame through a pair of fluid bearings. A plurality of magnet constructs are circumferentially arranged on the movable body to respectively face stationary coils secured to the support frame. Each of the magnet constructs comprises at least one pair of magnet members juxtaposed in the moving direction of the magnet yoke and arranged with their polarities of magnet pole being opposite to each other, wherein respective pairs of the magnet members attached to the circumferential surface form first and second rows spaced from each other in the moving direction of the magnet yoke. Each magnet member in each of the first and second rows is arranged to be opposite in polarity of magnet pole to each of the magnet members next thereto in the circumferential direction.Type: GrantFiled: January 14, 2008Date of Patent: February 8, 2011Assignee: JTEKT CorporationInventor: Naomasa Mukaide
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Publication number: 20110025238Abstract: A command current setting portion has a target value corrector that calculates d-axis and q-axis current command values idc, iqc that are to be supplied to an open-loop controller, based on d-axis and q-axis current target values id*, iq*. When d-axis and q-axis voltage target value vd*, vq* calculated from the d-axis and q-axis current target values id*, iq* by the motor circuit equations exceed a voltage limit, this target value corrector 26 corrects the d-axis and q-axis current target values id*, iq* by the field weakening control such that d-axis and q-axis voltages vd, vq and d-axis and q-axis currents id, iq satisfy ?(vd2+vq2)?Vlim and ?(id2+iq2)?Ilim respectively. The d-axis and q-axis current command values idc, iqc are obtained by this correction.Type: ApplicationFiled: March 30, 2009Publication date: February 3, 2011Applicant: JTEKT CORPORATIONInventors: Takeshi Ueda, Yuji Kariatsumari, Shigeki Nagase, Noboru Niguchi, Hiroshi Sumasu
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Publication number: 20110026867Abstract: A tapered cylinder portion, a radially extending portion, a cylindrical portion, a center backup portion, and a large diameter side curved portion are formed from an integral metallic plate.Type: ApplicationFiled: July 26, 2010Publication date: February 3, 2011Applicant: JTEKT CORPORATIONInventors: Kazuki HAMADA, Hiroshi UENO, Hitoshi YANO, Kanichi KODA, Masashi SAKAGUCHI, Toshihiko SHIRAKI, Ryo OONISHI
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Publication number: 20110024224Abstract: In an electric power steering system, when a motor rotation angular speed ? and a motor rotation angular acceleration ? of a steering assisting motor both exceed corresponding predetermined values ?s and ?s, respectively, an abnormal external force application-determining section determines that an external force equal to or greater than a predetermined value is applied to a steering mechanism, and sets an abnormal external force application determination flag (FLG) to 1. When the abnormal external force application determination flag (FLG) is 1, a d-axis electric current command value-calculating section activates a motor rotation angular speed-reducing section and performs field-strengthening control based on a motor rotation speed/d-axis electric current command value map.Type: ApplicationFiled: July 9, 2010Publication date: February 3, 2011Applicant: JTEKT CORPORATIONInventors: Yutaka MORI, Yoshiyuki Shibata
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Publication number: 20110025244Abstract: In an electric power steering system, an ECU 11 that controls the operation of the system includes three independent microcomputers 18u, 18v, 18w that perform phase current feedback control with respect to the corresponding phases, so that sinusoidal current is applied to each phase of the motor 12 as a non-connected motor. Also, each of the microcomputers 18u, 18v, 18w monitors a deviation of an actual current value from a phase current command value, with respect to each of two phases other than the corresponding phase, and determines that an abnormality occurs in the phase in question when the deviation exceeds a predetermined threshold value. When two of the microcomputers 18u, 18v, 18w determine that the abnormality occurs in the remaining one phase, the ECU 11 confirms the determination that the phase in question is in an abnormal condition.Type: ApplicationFiled: July 9, 2010Publication date: February 3, 2011Applicant: JTEKT CORPORATIONInventor: Noritake URA
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Patent number: 7878295Abstract: A vehicle steering apparatus 1 includes an EPS actuator 17 and an EPS ECU 18 that controls the EPS actuator 17. The EPS actuator 17 applies an assist force that assists a steering operation. A microcomputer 43 of the EPS ECU 18 determines whether the currently executed oversteer control (OS control) is being intensified or converged. In the OS control intensification state, in which the vehicle stability is low, the microcomputer 43 reduces a damper compensation current command Idp* (Idp**), which is a damper compensation component for attenuating a steering wheel turning speed ?s.Type: GrantFiled: July 22, 2008Date of Patent: February 1, 2011Assignee: JTEKT CorporationInventors: Hiroaki Kato, Satoru Mikamo
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Patent number: 7880411Abstract: In a motor controller which supplies electric power to a motor of an electric power steering device from a main power supply and an auxiliary power supply, an N-channel MOS-FET is connected in parallel with a diode which is provided to prevent a sneak current from the auxiliary power supply to the main power supply. When electric power is supplied to the motor from the main power supply, the MOS-FET is turned on. Then, most of currents flow into the MOS-FET such that a power loss is reduced and a reduction in efficiency is prevented. The MOS-FET has high speed responsibility and excellent durability.Type: GrantFiled: February 26, 2008Date of Patent: February 1, 2011Assignee: JTEKT CorporationInventor: Shigeki Nagase
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Patent number: 7878715Abstract: A cage of a thrust roller bearing includes: a pair of crank-shaped bent portions arranged in a circumferential direction of the cage; a pair of inner wall surfaces arranged in a radial direction of the cage; and a pocket for housing a roller defined by the pair of bent portions and the pair of inner wall surfaces and formed by punching the cage. Radially inner one of the inner wall surfaces is formed as a guiding surface for guiding a substantial roller PCD position of an end surface of the roller. Each of the pair of bent portions includes a first extended portion extending in one of cage thickness directions and a second extended portion extending in the other cage thickness direction. A roller retaining pawl for retaining the roller is provided at each of the first and second extended portions so as to protrude into the pockets.Type: GrantFiled: February 23, 2007Date of Patent: February 1, 2011Assignee: Jtekt CorporationInventors: Kazuyuki Kotani, Yoshihito Nakashima
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Patent number: 7880417Abstract: In a motor controller, in the case that occurrence of a failure of electric current flow is detected in any phase of a motor, a phase electric current command value changing in accordance with a secant curve or a cosecant curve with an asymptotic line at a predetermined rotation angle corresponding to the phase in which the failure of electric current flow has occurred is calculated. The calculated phase electric current command value is limited in such a manner as to become within a predetermined range. In the case that a rotation angle of the motor exists in a range in which the phase electric current command value is limited, the execution of an anomaly detection of a control system utilizing an electric current deviation of a d/q coordinate system is inhibited.Type: GrantFiled: June 13, 2008Date of Patent: February 1, 2011Assignee: JTEKT CorporationInventor: Hiroshi Suzuki
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Publication number: 20110022271Abstract: An angle calculator detects a rotation angle ?a of a rotor. A three-phase/d-q axis converter outputs detected current id, iq on d-q coordinate axes by making a conversion, based on a corrected detection angle ?c obtained by adding or subtracting an amount of detection deviation from a time point of current detection to or from the detection angle ?a. A command current calculator calculates command current id*, iq* on the d-q coordinate axes based on a steering torque T and a speed S. A feedback controller calculates command voltages vd, vq on the d-q coordinate axes based on the command current id*, iq* and the detected current id, iq. A d-q axis/three-phase converter converts the command voltages vd, vq into three-phase command voltages, based on a corrected detection angle ?b obtained by adding an amount of detection deviation from a time point when a motor is driven to the detection angle ?a. The deviation can be eliminated by the command voltages, and the motor can be driven with high precision.Type: ApplicationFiled: March 30, 2009Publication date: January 27, 2011Applicant: JTEKT CORPORATIONInventors: Takeshi Ueda, Shigeki Nagase, Kouya Yoshida