Abstract: An outer cylindrical section is rotatable with a first shaft. Magnetic shielding portions are formed of a magnetic shielding or antimagnetic substance and arranged on a surface of a nonmagnetic and nonconductive cylindrical base. The magnetic shielding portions are spaced apart from each other by a predetermined interval in a circumferential direction of the cylindrical base so that non-magnetically-shielding portions are formed between the magnetic shielding portions. A plurality of coils are provided on a periphery of the outer cylindrical section and excitable by a predetermined A.C. signal. An inner cylindrical section is inserted in the outer cylindrical section and rotatable with a second shaft. The inner cylindrical section includes magnetic portions each provided to present a different characteristic with respect to an arrangement of the plurality of coils.

Abstract: An apparatus and method for magnetizing a shaft in a circumferential direction is provided in which electrical current is applied to one or more electrical current conduction tubes and is directed through the tube to at least one coupler having an internal diameter sized so as to circumferentially contact the exterior diameter of a part of the shaft to be magnetized. An electric current pulse is applied to the electrical current conduction tube and radially enters the shaft from the coupler associated with the tube at a substantially 90° degree angle to the axis of the shaft. The current is forced axially along the length of the shaft in the direction of at least a second coupler to magnetize one or more bands along the shaft in a circumferential direction. The current exits the shaft by way of the second coupler and a second electrical conduction tube.

Abstract: A target plate 3 is provided onto a shaft 1 and is has targets 3a arranged on an outer circumference. Facing the outer circumference of this target plate 3 is a sensor 5 that is provided with MR elements, which are arranged in a circumferential direction in accordance with an arrangement interval of the targets 3a. A rotational angle of the target plate 3 is calculated based on an output obtained between the MR elements in accordance with the displacement in the circumferential direction of the targets 3a, 3a with the rotation of the target plate 3.

Abstract: The present invention relates to a magnetostrictive sensor for measuring a torque in a shaft. The sensor comprises at least one active magnetostrictive region on the shaft, a surface pattern in the magnetostrictive region such that it obtains anisotropic properties, a first means arranged to generate a magnetic field varying in time in the magnetostrictive region and a second means arranged to sense variation in the permeability in the magnetostrictive region. Said magnetostrictive region comprises a first layer of a magnetostrictive material which is provided on the surface of the shaft and that said surface pattern is formed by a second layer of a non-magnetostrictive material comprising a low resistivity.

Abstract: A flux-gate magnetometer torque sensor is provided having a rotatable shaft to which a torque force is to be applied, a sleeve of conductive foil affixed to the surface of the shaft over the magnetically active regions, a plurality of saturable magnetic wires or strips mounted to the rotatable shaft and parallel to an axis of rotation, sensor circuitry containing an oscillator for generating a signal, a divider coupled to the oscillator for dividing the frequency of the signal by two, a first and second coil each surrounding a different section of the rotatable shaft and having an input coupled to the divider output, a multiplier having inputs coupled to outputs of the first coil, the second coil, and the oscillator, and an integrator having an input coupled to the multiplier output and an output coupled to both outputs of the first and second coils, wherein the output voltage of the integrator corresponds to the torque being applied to the rotatable shaft.

Abstract: A shaft (40) subject to torque about its axis (A-A) has an axial bore (42). A region (44) of the shaft (40) has a stored magnetisation, the region (44) being permanently magnetised with circumferential magnetisation about the axis (A-A) or an annulus of longitudinal magnetisation which is preferred. The stored magnetisation emanates a torque-dependent field into the bore (42). A magnetic field sensor arrangement (50) is positioned in the bore to produce a torque-dependent signal. The disclosure discusses the relationship between the radial depth (tm) of the permanent magnetisation in region (44) relative to the shaft wall thickness (t). Magnetic sensor placements include axial (52, 54) or offset arrangements of pairs of sensors (52a,b, 54,b). Dependent on the nature of the field to be sensed, sensors (5) may be oriented axially, radially or tagentially with respect to the axis (A-A).

Abstract: Torque is measured in the chain wheel (50) of a pedal cycle by a non-contacting magnetic-based transducer. A magnetising source (70), a D.C. type of source such as a permanent magnet is positioned adjacent the chain wheel (50) to induce an arcuate magnetised zone (72) in the wheel (50) as it rotates. The zone emanates a torque-dependent magnetic-field component that is detectable by a sensor (74) that follows the source (70) in the direction of rotation. By having the magnetising source (70) continually in position the arcuate tranducer zone (72) is refreshed on each rotation of the chain wheel. The nature of the pulsating torque in the chain wheel due to the exertion of the rider and its relationship to the angle of the pedal cranks is discussed with a preference for positioning the source (70) and sensor (74) at positions of minimum and maximum exerted torque respectively. If the induced arcuate magnetisation is interrupted (76) pulses for measuring rotational speed are obtainable.

Abstract: An apparatus and method for magnetizing a shaft in a circumferential direction is provided in which electrical current is applied to one or more electrical current conduction tubes and is directed through the tube to at least one coupler having an internal diameter sized so as to circumferentially contact the exterior diameter of a part of the shaft to be magnetized. An electric current pulse is applied to the electrical current conduction tube and radially enters the shaft from the coupler associated with the tube at a substantially 90° degree angle to the axis of the shaft. The current is forced axially along the length of the shaft in the direction of at least a second coupler to magnetize one or more bands along the shaft in a circumferential direction. The current exits the shaft by way of the second coupler and a second electrical conduction tube.

Abstract: A torque sensor for magnetically detecting torque transmitted to a rotatable shaft without directly contacting the shaft comprises a magnetic alloy and one or more sensing elements about the magnetic alloy to measure a magnetic field emanating from the magnetic alloy without being affected by anomalies in magnetic alloy.

Abstract: A method of sensing strain in a material includes the steps of embedding in a material at least one wire formed of a conductive core and a magnetoelastic film coated around the conductive core and having a known level of saturation, interconnecting an input lead to one end portion of the wire and an output lead to another end portion of the wire, inputting an electrical current in the wire through the input lead so as to drive the magnetoelastic film of the wire to saturation such that the electrical impedance is sensitive to changes in strain in the material, and outputting an electrical signal from the output lead being proportional to a strain imposed on the material surrounding the wire.

Abstract: An outer cylinder having patterns of open windows of first to fourth channels is formed of a magnetic-shielding or antimagnetic substance. An inner cylinder is inserted in the outer cylinder, is formed of a magnetic substance and has patterns of nonmagnetic windows of the first to fourth channels. First to fourth coils excitable by A.C. are provided for the first to fourth channels. For each of the channels, the pattern of the open window in the outer cylinder and the pattern of the nonmagnetic window in the inner cylinder are arranged to overlap with each other.

Abstract: A test body deformable upon application of torque to a turning shaft. First and second bearings with the turning collar of the first bearing being connected near a first end of the test body and the turning collar of the second bearing being connected near a second end of the test body. Each bearing is equipped with a digital device for determining the angular position of the turning collar relative to the fixed collar. Each digital device includes an annular device for generating magnetic pulses, mounted for turning jointly with the turning collar, and a fixed magnetic sensor for detecting the magnetic pulses and for delivering digital signals. An electronic device processes digital signals from the magnetic sensors to determine the angular position of the annular devices, and a comparison device compares the digital signals to ascertain the torque applied to the turning shaft.

Abstract: A torque sensor is comprised of a torque detection coil for detecting a torque generated between an input shaft and an output shaft by detecting a change of a relative rotational position between a cover member fixed to the input shaft and a covered member fixed to the output shaft as a change of impedance of a torque detection coil. The cover member is located between the covered member and the torque detection coil and has an outer cylinder portion which extends from an outer periphery of the cover member along a circumferential surface of the covered member.

Abstract: To provide a rotation sensor for detecting a relative rotation angle, which shows little variation in detection accuracy even in the presence of disturbances. The rotation sensor detects a variation in impedance of each of two exciting coils (12b) which is produced depending on the strength of eddy currents induced in first and second rotors (11, 13), and determines a relative rotation angle on the basis of a difference between the amounts of both variations. A first conductive layer (11a) is provided on at least one of the opposite sides of the first rotor as viewed along a rotation axis, and consists of a plurality of portions arranged in a circumferential direction of the first rotor with predetermined spaces between. The stationary core (12) is so arranged that a core body (12a) holding the two exciting coils (12b) is symmetrical with respect to a plane normal to the rotation axis.

Abstract: A cylindrical rotating member is provided with a magnetic element, which are an object that is detected, on the outer surface thereof. The magnetic element is led around the rotating member by one turn and is at an angle relative to the rotating direction of the rotating member in an approximately linear manner. End portions of the magnetic element are disposed at approximately the same position in the radial direction of the rotating member. Magnetoresistive elements are arranged in a direction perpendicular to the rotating direction of the magnetic element (in other words, axial direction of the rotating member) with a gap therebetween and oppose the magnetic element.

Abstract: The present invention provides a steering force detecting magnetostrictive torque sensor including a magnetism detection unit 12 and a casing 15 made from a non-magnetic high conductive material. The magnetism detection unit 12 includes a coil bobbin 23 having excitation coils 22a and 22b and detection coils 20 and 21 and a yoke 24 formed into a unitary block. The magnetism detection unit 12 is attached into the casing 15. Through holes 26a and 26b are arranged in the casing 15, and a sensor shaft 8 is inserted into the through holes via bearings 27a and 27b. The casing 15 prevents magnetic leak and noise intrusion, so as to assure the torque detection accuracy by the magnetism detection unit 12 and eliminate the energy loss due to heat generation between the magnetism detection unit 12 and the casing 15.

Abstract: A device for measuring torsional couple on a mechanical element, which includes two magnetic field generators attached in a first plane of the mechanical element and two magnetic field detectors arranged in a second parallel plane offset with respect to the first plane. The magnetic field detectors are attached on a support having two housings facing the magnetic field generators and which receive sensor elements on which the magnetic field detectors are attached. The shape of the housings is suited so as to allow movement of the sensor elements in such a way as to make possible an adjustment of an initial position of a sensitive element of each magnetic field detector on the support.

Abstract: A magnetostrictive torque sensor includes a magnetostrictive film of width W provided along a circumference of a rotational shaft. The film causes magnetostriction in correspondence to a torque applied to the rotational shaft. The torque sensor also includes excitation and detection cores each having substantially U-shaped configuration. These cores are disposed in opposed relation to the film. The excitation core extends through an excitation coil while the detection core extends through a detection coil. The excitation core is disposed on the detection core at right angles. The film has a magnetic path passing therethrough. The magnetic path, the excitation coil, and the detection coil cooperate with each other to provide a magnetic circuit. The excitation coil and the detection coil provides a bridge circuit in cooperation with each other. When a torque is applied to the rotational shaft, the film causes magnetostriction in correspondence to the torque.

Abstract: A torque sensor to determine the torque exerted on an assembly comprising a component generating magnetic impulses, with this sensor comprising a number of aligned sensor components divided into two subassemblies, the signals emitted by such subassemblies being processed by an electronic circuit capable of delivering an analog signal as a function of the torque exerted. The invention also proposes a process for processing the signals emitted by such a sensor.

Abstract: A portable, pneumatic torque tool automatically controls torque applied by it to a workpiece. In a portable hand-held housing, including a trigger control, a pneumatic motor provides an output shaft output shaft to a workpiece with which is associated a torque sensor within the housing for systematically measuring the amount of torque being applied by the shaft. A control module carried by the housing includes a keypad for providing a torque control input by which the operator selects a predetermined torque value. A torque control circuit interconnected with the torque control input and torque sensors operates to compare the torque being applied by the output shaft with the predetermined torque value.

Abstract: A magnetoelastic torque sensor for providing an output signal indicative of the torque applied to a member includes a ferromagnetic, magnetostrictive, magnetoelastically active region on or in the member, the region begin proportionally subjected to the torque applied to the member. The region is endowed with an effective uniaxial magnetic anisotropy having the circumferential direction as the easy axis and is magnetically polarized in a single circumferential direction. When torque is applied to the member, the magnetoelastically active region produces a magnetic field varying with the torque, which field is sensed by magnetic field sensors arranged proximate the region.