Inductance Or Reluctance Sensor Patents (Class 73/862.331)
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Patent number: 7389702Abstract: A magnetostrictive torque sensor comprises a rotary shaft rotating around its center axis and having a magnetostrictive characteristic and a cylindrical ferrite magnetic core disposed at a predetermined distance from the outer periphery of the rotary shaft and coaxially with the rotary shaft and having on its inner peripheral surface a coil serving to detect the strain of the rotary shaft and having an insulating cover. The cylindrical ferrite magnetic core has a pair of opposed coil-forming inner peripheral surfaces defined by dividing the inner peripheral surface into two parts along a plane including the center axis.Type: GrantFiled: December 1, 2004Date of Patent: June 24, 2008Assignee: Hitachi Cable, Ltd.Inventors: Song Ouyang, Ryoichi Menju
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Patent number: 7386930Abstract: For forming an annular magnetostrictive coat on an outer peripheral surface of a rotational shaft associated with a magnetostrictive torque sensor, a magnetostrictive coat forming method comprises a step of fitting a cylindrical masking jig over the outer peripheral surface of the rotational shaft and securing the masking jig to the outer peripheral surface, a step of placing the rotational shaft in a plating tank to thereby form the magnetostrictive coat by plating on the outer peripheral surface, and a step of detaching the masking jig from the rotational shaft.Type: GrantFiled: November 7, 2007Date of Patent: June 17, 2008Assignee: Honda Motor Co., Ltd.Inventors: Yasuo Shimizu, Yoshito Nakamura, Shunichiro Sueyoshi, Nobuhiko Yoshimoto, Koji Kobayashi, Yuichi Fukuda, Mizuho Doi, Hitoshi Harada, Tomohiro Hoshi
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Patent number: 7387034Abstract: A torque detecting apparatus having a permanent magnet fixed to an input shaft, magnetic yokes fixed to an output shaft coaxially connected to the input shaft via a torsion bar and disposed within a magnetic field of the permanent magnet to form a magnetic circuit, and a Hall IC for detecting a magnetic flux induced by the magnetic yokes. The permanent magnet is of a truncated conical shape, and the bevel circumference surface thereof is magnetized by magnetic poles alternately in a reverse polarities along circumference direction, so as to oppose the magnetic yokes. A torque applied to the input shaft or the output shaft can be detected through detection by the Hall IC of the magnetic flux generated between the magnetic yokes. The configuration allows reducing the length in an axial direction of the input shaft.Type: GrantFiled: August 25, 2005Date of Patent: June 17, 2008Assignees: Koyo Seiko Co., Ltd., Favess Co., Ltd., Denso CorporationInventors: Toshiharu Ishihara, Taisuke Tsujimoto, Naoki Nakane
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Patent number: 7370541Abstract: A torque detecting apparatus detects torque applied upon a torsion bar of an electric power steering apparatus, as two sensors, which have ratiometric characteristics and have the same characteristics, simultaneously detect the amount of torsion of the torsion bar. With a gain of one of the two sensors set to the positive polarity and a gain of the other sensor set to the negative polarity, a control circuit calculates the torque applied upon the torsion bar by multiplying a difference between detection outputs from the two sensors by a predetermined coefficient. A torque detecting apparatus which is capable of detecting the torsional angle of a rotation shaft, namely, torque applied upon the rotation shaft easily and accurately using two sensors is thus realized.Type: GrantFiled: December 1, 2005Date of Patent: May 13, 2008Assignee: JTEKT CorporationInventors: Yoshitomo Tokumoto, Shunsuke Nakaura, Ken Fukuda
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Publication number: 20080099272Abstract: Even in the even that, when a steering torque is applied to a steering wheel 11 of an electric power steering system, a pinion shaft 21 of a rack-and-pinion steering gear box 16 is curved by a bending moment generated by a reaction force which a pinion 20 receives from a rack 18, since a steering shaft 14 on which a magnetostriction torque sensor 34 is provided is connected to the pinion shaft 21 via a universal joint 15, the transmission of the bending moment to the steering shaft 14 is made difficult to occur. As a result, the effect imposed by the bending moment on the detection accuracy of the magnetostriction torque sensor 34 provided on the steering shaft 14 can be suppressed to a minimum level.Type: ApplicationFiled: October 24, 2007Publication date: May 1, 2008Applicant: Honda Motor Co., Ltd.Inventors: Yasuo SHIMIZU, Katsuji WATANABE, Atsuhiko YONEDA
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Patent number: 7363827Abstract: A torque sensor includes a shaft and a magnetic sensor. The shaft may have at least one active region having an elliptical magnetization. The magnetic sensor may be configured to sense a magnetic field about the shaft, where the magnetic field is representative of a torque applied to the shaft. The elliptical magnetization may have a nonzero axial component directed along a center line axis of said shaft at zero torque.Type: GrantFiled: November 9, 2005Date of Patent: April 29, 2008Assignee: Stoneridge Control Devices, Inc.Inventors: Kayvan Hedayat, Norman Poirier
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Publication number: 20080092671Abstract: A torque sensor is provided in which a magnetic body can be easily positioned and fixed, and in which an excessive force is prevented from being exerted on a resin or the magnetic body when the magnetic body is press-fitted to a shaft, whereby no resin is damaged, and further stress is not left at the magnetic body. The torque sensor is characterized in that a press-fit member to be press-fitted to a shaft is molded with a resin in a state in which a part thereof is exposed to the outside of the resin, whereby the part thereof becomes a pressure receiving portion, and the pressure receiving portion is pressed with an assembly jig when a magnetic yoke assembly is incorporated to a shaft.Type: ApplicationFiled: April 19, 2007Publication date: April 24, 2008Inventor: Hideo Maehara
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Patent number: 7347107Abstract: Device for a torque or shear transmitter for determining fibre concentration or viscosity in pulp suspensions and which is adapted to measure an angle deviation between two concentric shafts whereby the angle deviation forms a function of the torque applied on the measuring body. The device includes a feedback system for bringing the inner or measuring shaft to a zero position independent of the magnitude of the torque. The system includes an electromagnetic feedback coil, which encircles two pole shoes journalled in bearing points at the end of the outer shaft, at the same time as each pole shoe is connected to the measuring shaft, whereby a current, generated by a transducer and dependent on the angle deviation, is sent to the winding of the coil, where a magnetic field of force is generated.Type: GrantFiled: December 6, 2004Date of Patent: March 25, 2008Assignee: BTG Pulp and Paper Sensors ABInventors: Peter Lundberg, Joakim Kullander
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Patent number: 7343825Abstract: A magnetostriction-type torque sensor has a rotating shaft having magnetostrictive properties and first and second coils which each constitute three or more closed loops. For each coil, the closed loop is disposed in a concentric relationship (a concentric circle located on a plane perpendicular to the rotating shaft) with the rotating shaft. Further, the direction of magnetostrictive properties of the rotating shaft detected by the first coil is made different from the direction of magnetostrictive properties of the rotating shaft detected by the second coil.Type: GrantFiled: January 25, 2005Date of Patent: March 18, 2008Assignee: Hitachi Cable, Ltd.Inventors: Ryoso Masaki, Ryoichi Menju
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Patent number: 7331247Abstract: First and second shafts (1, 2) are interconnected via a torsion bar (3) for torsional (or rotational) movement relative to each other, and first and second magnetic body sections (10, 20) are provided to rotate in interlocked relation to the rotation of the first and second shafts, respectively. The first and second magnetic body sections form at least two ring-shaped variable magnetic coupling sections opposed to each other via a gap, magnetic coupling in each of the boundary sections varies in response to variation of a relative rotational position between the first and second shafts, and variation of the magnetic coupling differs in phase between the boundary sections. Coil section (30) includes magnetic-coupling detecting coils (L1-L4) provided in corresponding relation to the boundary sections.Type: GrantFiled: August 27, 2004Date of Patent: February 19, 2008Assignee: Amiteq Co., Ltd.Inventors: Atsutoshi Goto, Kazuya Sakamoto, Hiroshi Sakamoto
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Patent number: 7320255Abstract: The magnetometer assembly according to this invention includes a first coil assembly and a second coil assembly for detecting separate magnetic fields along an axial portion of a torque transducer. The first and second coil assemblies are driven by independently adjustable circuits. Each of the circuits are independently adjustable to adjust the gain that is distributed to each of the first and second coils. This provides for an adjustment and precise alignment of a magnetic field generated by the first coil and the second coil assembly such that external magnetic fields can be cancelled providing increased accuracy and reduced hysteresis effects.Type: GrantFiled: February 13, 2006Date of Patent: January 22, 2008Assignee: Siemens VDO Automotive CorporationInventor: David W. Cripe
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Publication number: 20070295109Abstract: A yoke assembly is constructed by retaining integrally a yoke ring having positioning holes aligned with pole claws arranged equally on the inner circumference and a yoke ring having positioning holes aligned with the space between pole claws arranged equally on the inner circumference by a retaining cylinder made of a resin. The retaining cylinder has a pin hole remaining after pulling out a common positioning pin inserted into the positioning holes during molding.Type: ApplicationFiled: June 20, 2007Publication date: December 27, 2007Applicants: JTEKT CORPORATION, NAKANISHI METAL WORKS, CO., LTD.Inventors: Yoshitomo Tokumoto, Masashi Hashiya, Tadashi Kitahata
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Patent number: 7310870Abstract: For forming an annular magnetostrictive coat on an outer peripheral surface of a rotational shaft associated with a magnetostrictive torque sensor, a magnetostrictive-coat forming method comprises a step of fitting a cylindrical masking jig over the outer peripheral surface of the rotational shaft and securing the masking jig to the outer peripheral surface, a step of placing the rotational shaft in a plating tank to thereby form the magnetostrictive coat by plating on the outer peripheral surface, and a step of detaching the masking jig from the rotational shaft.Type: GrantFiled: May 12, 2004Date of Patent: December 25, 2007Assignee: Honda Motor Co., Ltd.Inventors: Yasuo Shimizu, Yoshito Nakamura, Shunichiro Sueyoshi, Nobuhiko Yoshimoto, Koji Kobayashi, Yuichi Fukuda, Mizuho Doi, Hitoshi Harada, Tomohiro Hoshi
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Patent number: 7308834Abstract: A torque sensor is provided with a torsion bar, first and second elongate sleeves respectively secured to one and the other ends of the torsion bar, and a pair of resolvers respectively mounted on the first and second elongate sleeves. First and second stop portions are provided respectively at overlapping portions of the first and second elongate sleeves where the second elongate sleeve is fit partly on the external surface of the first elongate sleeve with a play. A rotary sleeve given to one of the resolvers is press-fit on the external surface of the stop portion provided on the second elongate sleeve for mounting one of the resolvers thereon as well as for reinforcing the mechanical strength of the stop portion provided on the second elongate sleeve. Further, the resolvers used therein are chosen as those respectively having n-poles and m-poles.Type: GrantFiled: March 24, 2006Date of Patent: December 18, 2007Assignee: JTEKT CorporationInventors: Mitsunori Naruse, Yuji Yoshizawa, Yusuke Mochizuki
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Publication number: 20070283767Abstract: The torque sensor includes a plurality of coil units having a substantially cylindrical shape, the coil units including a plurality of detection coils arranged to face a magnetic characteristic change portion formed on a rotary shaft. The coil units include a first coil unit and a second coil unit, and the first coil unit and the second coil unit are disposed in the axial direction of the shaft. The first coil unit and the second coil unit are fixed in an integrally molded resin. Thereby, there is provided a torque sensor having a high productivity and an easy configuration and a method of manufacturing the torque sensor.Type: ApplicationFiled: March 21, 2007Publication date: December 13, 2007Inventors: Katsuji Watanabe, Yasuo Shimizu, Atsuhiko Yoneda, Tsunehiko Fukatsu
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Patent number: 7302867Abstract: A magnetic transducer element is formed by rotating an integral region of a shaft about an axis in the presence of a magnetic source. An annulus of magnetization results in having its magnetization in the axial direction. The exterior magnetic field emanated by the annulus exhibits respective axial magnetic profiles of its axially and radially directed components which have an axial shift under torque. The direction of profile shift depends on the rotational direction of the shaft while magnetization proceeds. A pair of regions exhibiting opposite shift directions provide signals in which torque-dependent shift is separated from axial displacements of the shaft. An annulus of magnetization may be non-uniform with angle about the shaft axis. Measures to prevent eddy currents generated in the rotting region of the shaft under magnetization are disclosed as we “sweet spots” for sensor placement to mitigate non-uniformity effects.Type: GrantFiled: September 24, 2004Date of Patent: December 4, 2007Assignee: Abas, Inc.Inventor: Lutz Axel May
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Publication number: 20070272036Abstract: A magnetic memory cell that includes at least two magnetoresistive memory bits is presented. The memory cell is capable of storing at least two logical states. The first logical state occurs when the bits share the same orientation, such as a parallel orientation or an antiparallel orientation. The second logical state occurs when the bits have opposite orientations. In the second logical state one of the bits has a parallel orientation and the other bit has an antiparallel orientation.Type: ApplicationFiled: May 25, 2006Publication date: November 29, 2007Applicant: Honeywell International Inc.Inventor: Daniel S. Reed
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Patent number: 7293472Abstract: In a torque detecting apparatus, in each of two flux concentrating rings, a portion along a circumferential direction is raised outward in a radial direction so that a flux concentrating section is provided that has a plate shape extending on one side in an axial direction. These flux concentrating rings are fixedly arranged such that the flux concentrating sections should oppose to each other in the circumferential direction with a predetermined gap in between. Leakage flux between opposing surfaces of the flux concentrating sections is detected by magnetic sensors aligned in an axial direction between these opposing surfaces. This improves the utilization of materials for the flux concentrating rings including the flux concentrating sections, and hence reduces the product cost.Type: GrantFiled: January 13, 2006Date of Patent: November 13, 2007Assignee: JTEKT CorporationInventors: Yoshitomo Tokumoto, Toshiharu Ishihara, Naoki Nakane
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Publication number: 20070245833Abstract: A magnetostrictive torque sensor includes a shaft having a magnetostrictive film; a detection coil for detecting a change in a magnetic property of the magnetostrictive film; and a cutoff circuit for supplying an excitation signal for detecting the change in the magnetic property and inhibiting the excitation signal from being supplied to the detection coil for a predetermined interval from power on. The cutoff circuit cuts off the excitation signal I and its inverted signal to the bridge circuit.Type: ApplicationFiled: April 12, 2007Publication date: October 25, 2007Inventors: Atsuhiko Yoneda, Yasuo Shimizu, Yoshihiro Oniwa
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Publication number: 20070240522Abstract: A magnetostrictive torque sensor includes first and second magnetostrictive films which are provided at a shaft and have different magnetic anisotropies; a first measurement coil and a second measurement coil which face the first magnetostrictive film; and a third measurement coil and a fourth measurement coil which face the second magnetostrictive film. A torque applied to the shaft is measured based on a variation in magnetic characteristics of the first and the second magnetostrictive films; and a failure of the magnetostrictive torque sensor is detected based on a first difference between output values from the first and the second measurement coils and a second difference between output values from the third and the fourth measurement coils. An electric steering system includes the magnetostrictive torque sensor for measuring a steering torque of the system; and an electric motor driven based on the measured magnetostrictive torque for steering the vehicle.Type: ApplicationFiled: June 13, 2007Publication date: October 18, 2007Applicant: HONDA MOTOR CO., LTD.Inventors: Yasuo Shimizu, Yoshito Nakamura, Shunichiro Sueyoshi, Atsuhiko Yoneda
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Patent number: 7279890Abstract: A tandem rotation detector is provided for effectively preventing the occurrence of leakage flux between rotation angle detection mechanisms so that high-precision detection can be always realized. The tandem rotation detector of the present invention includes a first rotation angle detection mechanism 2A configured to generate a magnetic flux through a coil 11A of a first outer core 10A provided inside a cylindrical housing 1 for detecting the rotation angle of a rotary shaft 4A arranged in the central portion of the housing 1, and a second rotation angle detection mechanism 2B, placed side by side with the first rotation angle detection mechanism 2A, and configured to generate a magnetic flux through a coil 11B of a second outer core 10B provided inside the housing 1 to detect the rotation angle of a rotary shaft 4B, in which current flows through the coil 11A of the first outer core 10A and the coil 11B of the second outer core 10B in different directions from each other.Type: GrantFiled: September 27, 2004Date of Patent: October 9, 2007Assignee: Minebea Co., Ltd.Inventor: Mutsumi Matsuura
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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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Patent number: 7270017Abstract: A torque measuring device for a rotating body is provided, which includes: a stationary section; a rotary section; a rotary transformer composed of a primary coil disposed at the stationary section, and a secondary coil disposed at the rotary section, wherein an electric power is transmitted from the stationary section to the rotary section by electromagnetic induction, a torque generated at a rotating body is detected at the rotary section by means of the electric power transmitted, and wherein a detection result is transmitted from the rotary section to the stationary section. In the torque measuring device, a capacitor is connected at the side of the secondary coil of the rotary transformer, and a series resonant circuit is formed by the capacitor in combination with a leakage inductance of the rotary transformer.Type: GrantFiled: May 13, 2005Date of Patent: September 18, 2007Assignee: Minebea Co., Ltd.Inventors: Shinya Suzuki, Shigeyuki Adachi
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Patent number: 7263904Abstract: To provide a torque detecting device having a sufficient mechanical strength, capable of accomplishing an accurate torque measurement, having a processability excellent for mass-production, and effective to eliminate problems associated with damages which would be brought about during a heat treatment. This torque detecting device includes a target area subject to torque detection (3) provided in a surface region of a torque transmitting shaft (2) made of a steel material; a detecting coil (4) provided in a non-contact fashion in face-to-face relation to an outer periphery of the target area subject to torque detection (3); and a detection signal processing circuit (5). The target area subject to torque detection (3) is a layer of magnetostrictive material comprised of an Al diffusion layer. This diffusion layer contains Al diffused in a steel material in a concentration which gradually decreases from the surface in a direction radially inwardly of the torque transmitting shaft (2).Type: GrantFiled: May 10, 2004Date of Patent: September 4, 2007Assignee: NTN CorporationInventors: Kazuhiko Yoshida, Takashi Koike, Kenichi Iwamoto
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Patent number: 7263905Abstract: A Hall-Effect sensor assembly for a rotating electric machine comprises a thin, removable tubular substrate with Hall-Effect sensors and associated connection wiring mounted on it that slips underneath the wound stator end turns of the stator for the rotating electric machine to make the assembly easily removable for installation and repair.Type: GrantFiled: January 28, 2005Date of Patent: September 4, 2007Assignee: Hamilton Sundstrand CorporationInventors: George H. Seffernick, Mahesh J. Shah, James K. Kersting
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Patent number: 7258027Abstract: A detector of an absolute rotation angle and torque includes a first gear coupled to an input shaft of a torsion-bar unit, a gear A engaging with the first gear, and a first detecting section of an absolute rotation angle placed at the center of the gear A. The detector also includes a second gear coupled to an output shaft of the torsion-bar unit, a gear B engaging with the second gear, and a second detecting section of an absolute angle placed at the center of gear B.Type: GrantFiled: August 31, 2004Date of Patent: August 21, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Koji Oike, Kiyotaka Uehira, Masaharu Ushihara
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Publication number: 20070186693Abstract: The number n of N-poles and S-poles circumferentially aligned on the cylindrical magnet that integrally rotates with the first shaft is determined so as to be a greatest integer that satisfies the following formula that includes a maximum value Tmax (Nm) of the torque to be detected and a torsion spring constant k (Nm/deg) of the torsion bar connecting the first shaft and the second shaft: 2·n·Tmax /k<360. The cylindrical magnet includes teeth-shaped portions in which portions corresponding to the N-poles and the S-poles are of a protruding shape, so that adhesion of magnetic dust concentrates at the protruding portions. Thus, a torque detecting apparatus is provided that reduces the effect of the adhesion of the magnetic dust, so as to attain higher detection sensitivity and thereby improve the detection accuracy, without incurring an increase in cost.Type: ApplicationFiled: May 13, 2005Publication date: August 16, 2007Applicants: JTEKT CORPORATION, DENSO CorporationInventors: Yoshitomo Tokumoto, Toshiharu Ishihara, Naoki Nakane
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Publication number: 20070186694Abstract: An inventive torque detection device includes: a magnetic circuit forming member having a tubular magnet provided at an outer circumferential portion of a first rotating body, and a magnetic ring that is located circumferentially of the tubular magnet and rotated together with a second rotating body connected to the first rotating body; a magnetic flux collecting ring part for collecting a magnetic flux generated by the magnetic circuit forming member; and a detection part for detecting, based on a density of the magnetic flux collected by the magnetic flux collecting ring part, a torque applied to the first or second rotating body, wherein the tubular magnet is formed by curing and magnetizing a synthetic resin, into which a magnetic powder is mixed, around the outer circumferential portion of the first rotating body.Type: ApplicationFiled: January 8, 2007Publication date: August 16, 2007Applicants: JTEKT Corporation, DENSO CORPORATIONInventors: Yoshitomo Tokumoto, Toshiharu Ishihara, Naoki Nakane
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Publication number: 20070186692Abstract: An electrical machine apparatus having magnetic gearing embedded therein includes a moveable rotor having a first magnetic field associated therewith, a stator configured with a plurality of stationary stator windings therein, and a magnetic flux modulator interposed between the moveable rotor and the stator windings. The magnetic flux modulator is configured to transmit torque between the first magnetic field associated with said moveable rotor and a second magnetic field excited by the plurality of stationary stator windings.Type: ApplicationFiled: February 14, 2006Publication date: August 16, 2007Inventors: Michal-Wolfgang Waszak, Jan Hemmelmann, Ronghai Qu, Patrick Jansen
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Publication number: 20070169569Abstract: An inventive torque detection device includes: a magnetic circuit forming member provided at a rotating body to which a torque is applied; a magnetic flux collecting ring for collecting a generated magnetic flux; a detection part for detecting, based on the density of the collected magnetic flux, the torque applied to the rotating body; a holding ring, having a flange, for holding the magnetic flux collecting ring and the detection part; and a sealing ring for sealing between the flange and a housing.Type: ApplicationFiled: January 11, 2007Publication date: July 26, 2007Applicants: JTEKT Corporation, DENSO CORPORATIONInventors: Akio Osuka, Toshiharu Ishihara, Naoki Nakane
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Patent number: 7246531Abstract: A first shaft and a second shaft are connected coaxially. A torsion bar converts a torque applied between two shafts into a torsion displacement. A multipolar magnet is fixed to the first shaft. One set of magnetic yokes is fixed to the second shaft and disposed in a magnetic field generated by the multipolar magnet. The magnetic yokes are opposed to each other via an air gap in an axial direction. A magnetic sensor is provided for detecting the density of magnetic flux generated in the air gap. A non-magnetic spacer is disposed between the magnetic yokes as a means for positioning the magnetic yokes. The spacer and the magnetic yokes are integrated by resin molding.Type: GrantFiled: July 7, 2005Date of Patent: July 24, 2007Assignees: DENSO CORPORATION, NIPPON SOKEN, INC.Inventors: Naoki Nakane, Shigetoshi Fukaya
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Patent number: 7243557Abstract: A torque sensor having a sensor element, wherein the sensor element is manufactured in accordance with the manufacturing steps of applying a first current pulse to the sensor element, wherein the first current pulse is applied such that there is a first current flow in a first direction along a longitudinal axis of the sensor element, wherein the first current pulse is such that the application of the current pulse generates a magnetically encoded region in the sensor element.Type: GrantFiled: December 29, 2004Date of Patent: July 17, 2007Assignee: NCTEngineering GmbHInventor: Lutz May
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Publication number: 20070157741Abstract: To provide a torque sensor with which a bipolar output signal can be obtained and which can reduce affects on the output signal resulting from axial eccentricity.Type: ApplicationFiled: February 17, 2005Publication date: July 12, 2007Applicant: Mitsubishi Denki KabushikiInventors: Yoshio Yoshikuwa, Akihiko Imagi
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Patent number: 7237444Abstract: A torque detection system is provided for detecting torque applied to a rotary shaft. A spring element is connected to an input and output shaft. As torque is applied to the shaft system, the input shaft is rotationally offset from the output shaft and a sensing system is provided for sensing the amount of rotational offset which is then correlated to a rotational torque level.Type: GrantFiled: June 29, 2005Date of Patent: July 3, 2007Assignee: Freudenberg-Nok General PartnershipInventors: Alexander Berdichevsky, Vahidin Alajbegovic
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Patent number: 7225687Abstract: Power steering apparatus includes input and output shafts connected by a torsion bar; and a coil unit disposed around one of the shafts and arranged to sense torque between the input and output shafts. A housing includes an axial bore in which the shafts and coil unit are installed. The housing is further formed with an insertion opening which extends radially into the axial bore and which is sized to allow insertion of the coil unit radially into the axial bore.Type: GrantFiled: March 7, 2005Date of Patent: June 5, 2007Assignee: Hitachi, Ltd.Inventor: Yoshimori Kondo
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Patent number: 7225686Abstract: A torque sensor includes a substantially tubular giant magnetostrictive member, a shaft passing through the inner bore of the giant magnetostrictive member and capable of transmitting torque to the giant magnetostrictive member, and a detection coil for detecting changes in the magnetic permeability or remnant magnetization of the giant magnetostrictive member. Torque changes of the shaft are detected as changes in the magnetic permeability or remnant magnetization of the giant magnetostrictive member, based on the deformation of the giant magnetostrictive member. The torque sensor enables a reduction in the number of components and costs, as well as detection of torque changes with high sensitivity.Type: GrantFiled: March 3, 2005Date of Patent: June 5, 2007Assignee: TDK CorporationInventors: Teruo Mori, Toshihiro Suzuki, Shiro Tomizawa, Kesaharu Takatoh
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Publication number: 20070113683Abstract: A torque sensor includes a shaft and a magnetic sensor. The shaft may have at least one active region having an elliptical magnetization. The magnetic sensor may be configured to sense a magnetic field about the shaft, where the magnetic field is representative of a torque applied to the shaft. The elliptical magnetization may have a nonzero axial component directed along a center line axis of said shaft at zero torque.Type: ApplicationFiled: November 9, 2005Publication date: May 24, 2007Inventors: Kayvan Hedayat, Norman Poirier
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Patent number: 7219563Abstract: A non-contact position sensor having improved rotational angle measuring accuracy is provided. A magnet is attached To a rotating shaft. An angle sensor element detects magnetic field changes generated from the magnet due to rotation of the rotating shaft. A signal processor, on the basis of a temperature detected by a temperature sensor, corrects variance between the sensors including the sensor element, the signal processor, and the magnet by correcting an amplitude value and/or an offset value of a signal or variance due to time of the amplitude value. The sensor element 1 outputs the first and second outputs v1 and v2 and the signal processor obtains the temperature coefficients of the amplitude values of the output v1 and output v2, or the temperature coefficients of the offset values, or the coefficients of variance due to time of the amplitude values, obtains the ratio of the first and second outputs corrected by these coefficients, and calculates the angle using the corrected ratio.Type: GrantFiled: August 4, 2004Date of Patent: May 22, 2007Assignee: Hitachi, Ltd.Inventor: Masashi Saito
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Patent number: 7219562Abstract: The invention provides an angular position sensor (1) comprising two magnets (32, 33) attached to the inside face of a rotor (31) for generating a magnetic field (50) and a magnetism detection device (43) disposed in the magnetic field (50). The magnets (32, 33) are arranged substantially opposite each other with a pole of opposite polarity of each magnet (32, 33) directed towards the center of the rotor (31). A uniform magnetic field (50) is generated around the magnetism detection device (43) which provides more accurate sensor measurements over both small and large angles of rotation of the rotor (31). Furthermore, the magnets (32, 33) need only be axially magnetised which simplifies construction of the sensor.Type: GrantFiled: May 12, 2003Date of Patent: May 22, 2007Inventor: Padraig Joseph Keane
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Publication number: 20070089539Abstract: A sensor includes a shaft and a magnetic sensor. The shaft may have at least one magnetized active region. The magnetic sensor may be configured to sense a magnetic field about the shaft, and may provide an output representative of torque applied to the shaft, shaft rotational speed and shaft rotational position.Type: ApplicationFiled: October 23, 2006Publication date: April 26, 2007Applicant: Stoneridge Control Devices, Inc.Inventors: Kayvan Hedayat, Norman Poirier
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Publication number: 20070089538Abstract: A method for manufacturing a magnetostrictive torque sensor compriseis the steps of forming magnetostrictive films on a rotating shaft of a magneto-strictive torque sensor, creating magnetic anisotropy in the magnetostrictive films formed in the magnetostrictive film formation step, and demagnetizing the rotating shaft. The demagnetization step is provided in any of the stages after the magnetostrictive film formation step, and comprises initializing the remanent magnetism created in the rotating shaft.Type: ApplicationFiled: October 2, 2006Publication date: April 26, 2007Inventors: Yukiya Kashimura, Mizuho Doi, Hitoshi Harata, Yuichi Fukuda, Nobuhiko Yoshimoto
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Publication number: 20070074588Abstract: A magnetostrictive torque sensor includes a rotating shaft that is rotated by an applied torque, magnetostrictive films formed around the entire circumferential periphery of a surface of the rotating shaft in at least one location, sensor coils for sensing a change in impedance of the magnetostrictive films, and a torque calculation unit for calculating the torque applied to the rotating shaft on the basis of a signal relating to the change in impedance outputted from the sensor coils. In this magnetostrictive torque sensor, a width of the magnetostrictive films in the axial direction of the rotating shaft and a width of the sensor coils in the axial direction of the rotating shaft are set so as to fulfill the relationship 1<(W1/W2)<1.35.Type: ApplicationFiled: October 4, 2006Publication date: April 5, 2007Inventors: Hitoshi Harata, Tomohiro Hoshi, Yuichi Fukuda, Yukiya Kashimura
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Patent number: 7197946Abstract: A torque measuring device for electric motors having a rotor and a stator is proposed, said apparatus comprising a holding apparatus to hold the stator non-rotatably, an eddy current brake device which can be used to brake the rotor and a torque sensor connected to the eddy current brake device.Type: GrantFiled: July 14, 2004Date of Patent: April 3, 2007Assignee: Minebea Co., Ltd.Inventors: Hermann Flammer, Hubert Hauser, Norbert Irmer, Guido Schmid
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Publication number: 20070068280Abstract: A method of fabricating a magnetoelastic torque sensor includes plating a magnetoelastic material to a magnetically inert substrate, and its endowment with uniaxial magnetic anisotropy through the creation within the transducer element of stress anisotropy. The plating of magnetostrictive material to the magnetically inert substrate provides a less expensive torque element that exhibits desired levels of accuracy and reliability.Type: ApplicationFiled: September 23, 2005Publication date: March 29, 2007Applicant: Siemens VDO Automotive CorporationInventor: David Cripe
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Patent number: 7191668Abstract: A torque measuring device for a rotating body comprises: a rotary section including first and second flanges provided respectively at driving and driven sides, and a hollow cylinder provided between the first and second flanges; light emitting elements provided at an outer circumference of the rotary section, and adapted to emit light based on output from each of torque detectors provided at an inner surface of the hollow cylinder thereby sending an optical signal; a light conductive member to receive the optical signal at a light receiving surface thereof, and to guide the optical signal along its longitudinal directions; and a torque calculator to calculate torque of the rotary section based on the optical signal guided by the light conductive member, wherein the light conductive member has an optical path converting means formed at either the light receiving surface or a surface thereof opposite to the light receiving surface.Type: GrantFiled: April 22, 2005Date of Patent: March 20, 2007Assignee: Minebea Co.,, Ltd.Inventors: Atsushi Kitamura, Shigeyuki Adachi, Sawa Tanabe
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Patent number: 7191669Abstract: A torque sensor is provided which consists of a magnet, an assembly of magnetic rings, and a magnetic sensor. The magnetic rings have claws arrayed thereround at regular intervals. Each of the claws of one of the rings is interposed between adjacent two of the claws of the other ring. Upon input of torque, the magnet is rotated relative to the ring assembly, thereby causing the density of magnetic flux to change as a function of the torque which is sensed by the magnetic sensor. Each of the claws is geometrically shaped so as to increase the density of magnetic flux flowing through the ring assembly, thereby improving the sensitivity of the sensor.Type: GrantFiled: February 8, 2005Date of Patent: March 20, 2007Assignees: Denso Corporation, Nippon Soken, Inc.Inventors: Naoki Nakane, Shigetoshi Fukaya
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Publication number: 20070051188Abstract: A device and method for the non-contact measurement of dynamic torsion in a rotating shaft using magnetostrictive sensors (MsS). The monitoring and detection system have specially configured magnetostrictive signal detectors that include inductive pickup coils, in which signals corresponding to localized shaft torques are induced. The non-contact method for measuring dynamic torques includes fixing a ferromagnetic strip to a ferromagnetic or non-ferromagnetic shaft and inducing a circumferential residual magnetization therein. An MsS in the form of either an encircling coil positioned around the shaft on a cylindrical substrate, or a partially encircling coil positioned on a flexible substrate and wrapped partially about the shaft.Type: ApplicationFiled: November 6, 2006Publication date: March 8, 2007Inventors: Hegeon Kwun, Sang-Young Kim
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Patent number: 7181983Abstract: A system to diagnose a malfunction of a torque sensor in a vehicle steering system includes a voltage difference generator that outputs a voltage difference by comparing a voltage of a contact part between a temperature correcting coil and a torque detecting coil in a torque sensor for a steering system and an offset voltage generated from an offset voltage generator, a malfunction determining part that determines a malfunction by comparing a reference voltage and an output voltage of said voltage difference generator, and a controller that executes a neutral steering when a malfunction is determined in said malfunction determining part.Type: GrantFiled: January 11, 2005Date of Patent: February 27, 2007Assignee: Hyundai Mobis Co., Ltd.Inventor: Seung-Ho Paek
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Patent number: 7181984Abstract: The present invention discloses a magnetic sensor, comprising a circular base, the center of said base having a circular hole, the lower surface of said circular base being provided with a flange; and a plurality of ring-shaped permanent magnets of varying sizes, said ring-shaped permanent magnets having a plurality of magnetic poles, and said plurality of ring-shaped permanent magnets adhering individually to said circular base and having the center of said circular base as their center, with sensing action being achieved through use of the plurality of magnetic poles of said plurality of ring-shaped permanent magnets.Type: GrantFiled: December 17, 2004Date of Patent: February 27, 2007Assignee: Taigene Metal Industry Co., Ltd.Inventors: Ko Ching-shun, Yang Yao-song
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Publication number: 20070034021Abstract: A magnetometer for a force sensor assembly includes first inner and outer coils that are spaced axially apart from second inner and outer coils. Between the inner and outer coils is a plurality of magnetic strips. These magnetic strips are disposed at axially distinct portions within the inner and outer coils to detect magnetic field asymmetry. A drive circuit is connected to the inner coils and the outer coils generate an alternating magnetic field. The magnetometer of this invention creates an artificially enhanced demagnetization field reducing hysteresis within the sensor assembly.Type: ApplicationFiled: February 13, 2006Publication date: February 15, 2007Applicant: Siemens VDO Automotive CorporationInventor: David Cripe