Abstract: The present invention is directed towards a hydraulic power unit including a housing, an internal hydraulic power means, an external hydraulic power means, and a mechanical power shaft associated with the hydraulic power means. In addition, the hydraulic power unit comprises a transducer adapted for measuring torque mounted in the housing in a non-contact relation to the mechanical power shaft adjacent a portion of the shaft imposed with a magnetic field. The hydraulic power unit further comprises a controller associated with the transducer to monitor the measured torque and adjust the operation of the hydraulic power unit accordingly.

Abstract: A rotation sensor includes a first rotor constituted by a magnetic material and having an outer face that has first conductive layers disposed in two levels as viewed in the direction of a rotation axis and second conductive layers disposed outwardly of and between the first conductive layers, a second rotor having metal members corresponding to the first conductive layers of the first rotor, and a stationary core having a stationary core body that accommodates therein two exciting coils that are spaced from each other in the direction of the rotation axis. The second rotor is disposed between the first rotor mounted to a first shaft and the stationary core fixed to a stationary member, and is mounted to a second shaft which is rotatable relative to the first shaft.

Abstract: The torque detecting apparatus comprises: an input shaft to which a torque is inputted; an output shaft for outputting the inputted torque; a connecting shaft for connecting the input shaft and the output shaft to transmit the torque; a coil for detecting a torque applied from the input shaft to the connecting shaft based on a torsional angle which arises at the connecting shaft; and a holding cylinder for holding the coil coaxially, wherein the holding cylinder has inside thereof a recess extending in the circumferential direction, and the coil is fitted in the recess. Projections for supporting the holding cylinder at a predetermined position are provided on the outer surface of an axial portion which does not have the recess. Accurate torque detection can be effected even when pressure applied to the projections provided at the holding cylinder constituting the torque detecting apparatus is changed.

Abstract: 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.

Abstract: Device for determining a torque exercised on a shaft, wherein the shaft comprises a first shaft section and a second shaft section, wherein the two shaft sections can be rotated relative to another, with a multi-pole magnetic ring which surrounds the first shaft section and is connected thereto, and a stator holder which is mounted to the second shaft section, wherein two stator elements are mounted to a stator holder and each stator element comprises fingers projecting in an axial or radial direction which are distributed uniformly at least over part of the periphery with gaps between them, wherein the fingers of each stator element are interconnected via a magnetic flux ring, wherein the magnetic flux rings have a mutual separation and a magnetic field sensor is disposed between the magnetic flux rings, wherein at least one magnetic flux concentrator is associated with the magnetic field sensor, wherein the magnetic flux concentrator surrounds the magnetic flux rings.

Abstract: The present invention is directed towards a hydraulic power unit including a housing, an internal hydraulic power means, an external hydraulic power means, and a mechanical power shaft associated with the hydraulic power means. In addition, the hydraulic power unit comprises a transducer adapted for measuring torque mounted in the housing in a non-contact relation to the mechanical power shaft adjacent a portion of the shaft imposed with a magnetic field. The hydraulic power unit further comprises a controller associated with the transducer to monitor the measured torque and adjust the operation of the hydraulic power unit accordingly.

Abstract: 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.

Abstract: A neutral point voltage regulator of a torque sensor which has a pair of coils having inductances changing in opposite directions based on torques, and torque detecting means for outputting a torque detecting voltage Vt based on a voltage difference between a first voltage and a second voltage based on respective inductance changes of the pair of coils.

Abstract: A magnetic first detecting cylinder covers a magnetism leakage preventing member covering a first shaft. A second detecting cylinder is rotated along with a second shaft connected to the first shaft and one end thereof is opposed to one end of the first detecting cylinder with a clearance. A reluctance with respect to a passing magnetic flux in a first magnetic circuit constituted by generating the magnetic flux passing the first detecting cylinder and the second detecting cylinder by a first coil, is changed in accordance with an elastic relative rotational amount by a change in a transmitting torque of the two shafts. The magnetism leakage preventing member is molded from a synthetic resin material injected into a molding die. The first shaft and the first detecting cylinder are integrated to the magnetism leakage preventing member molded by being inserted into the molding die before injecting the synthetic resin material.

Abstract: A torque sensing apparatus for picking up a magnetic field of a magnetostrictive material disposed on a shaft, comprising: a first integrating ring; a second integrating ring; a first fluxgate return strip and a second fluxgate return strip each being connected to the first integrating ring at one end and the second integrating ring at the other end; an excitation coil; and a feedback coil; wherein the first integrating ring and the second integrating ring are configured to be positioned to pick up flux signals along the entire periphery of the ends of the magnetostrictive material.

Abstract: A torque sensor has a torsion bar coaxially in alignment with input and output shafts, a ring shaped magnet fixed to an axial end of the input shaft, a pair of magnetic yokes fixed to an axial end of the output shaft, and a magnetic sensor for detecting magnetic flux density generated between the pair of magnetic yokes. Each of the magnetic yokes is provided with claws, which are circumferentially spaced at constant intervals, and whose number is equal to that of each of N and S poles alternately arranged circumferentially in the magnet. Each center of the claws coincides with a boundary between immediately adjacent N and S poles of the magnet, when the torsion bar is not twisted. The magnetic sensor is inserted into an axial gap between the pair of magnetic yokes without contacting the magnetic yokes.

Abstract: A torque sensing apparatus for picking up a magnetic field of a magnetostrictive material disposed on a shaft, the torque sensing apparatus having: a first integrating ring; a second integrating ring; a first fluxgate return strip and a second fluxgate return strip each being connected to the first integrating ring at one end and the second integrating ring at the other end; an excitation coil; and a feedback coil; wherein the first integrating ring and the second integrating ring are configured to be positioned to pick up flux signals along the entire periphery of the ends of the magnetostrictive material.

Abstract: Torque in a shaft is detected by means of non-contacting sensors sensing a torque-dependent magnetic field emanated by an integral transducer region of the shaft that is circumferentially or longitudinally magnetized. The shaft is driven by a motor and subject to a longitudinal magnetic field which acts on interference field. In one implementation of the invention coils are energized to provide a counteracting magnetic field to compensate the interference field.

Abstract: 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.

Abstract: 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.

Abstract: The rotation sensor (10) has a cylindrical first rotor (11) made of an insulating magnetic material, having conductor layers (11a) arranged circumferentially, the first rotor being attached to a rotating first shaft (5a) at a predetermined axial position; a fixed core (12) having an exciting coil (12b), the core being fixed to a fixing member with a space secured in the axial direction with respect to the first shaft; a second rotor (13) having nonmagnetic metal bodies (13b) arranged circumferentially to oppose the conductor layers respectively, the second rotor being attached to a second shaft located adjacent to and rotating relative to the first shaft (5a) and being located between the first rotor (11) and the fixed core (12); and oscillating device connected to the exciting coil (12b), the oscillating device transmitting an oscillation signal of a specific frequency.

Abstract: A method of assembling a torque sensor includes the steps of fixing a first inner coil portion at one end side of a torsion bar, fixing a second inner coil portion at an other end side of the torsion bar, measuring an angle difference between an angle of the first inner coil portion and an angle of the second inner coil portion, fixing a first outer coil portion and a second outer coil portion, of which angle difference is substantially equivalent to the measured angle difference between the first inner coil portion and the second inner coil portion, at a housing, and rotatably disposing the torsion bar fixed with the first inner coil portion and the second inner coil portion in the housing.

Abstract: A method of detecting a sensed parameter for a motor control system comprising: receiving a sensor signal, the sensor signal exhibiting a frequency responsive to an inductance of a non-contacting variable reluctance rotational displacement sensor, wherein the inductance is indicative of a displacement of the sensor and responsive to the sensed parameter; capturing a first transition of the sensor signal and a time associated therewith; capturing a second transition of the sensor signal and a time associated therewith; calculating a period for the sensor signal; and computing a value for the sensed parameter, the value responsive to the period.

Abstract: In an automatic transmission having a torque converter with a pump impeller, a turbine runner, and a stator, a stator shaft is provided to support the stator on its outer periphery and to rotatably support a transmission input shaft on its inner periphery. A magnetostrictive torque sensor is provided to detect the magnitude of input torque transmitted to the transmission input shaft. The magnetostrictive torque sensor includes a magnetic material having a magnetostrictive property and attached onto the outer periphery of the transmission input shaft, and a cylindrical magnetic-property detector mounted on the inner periphery of the stator shaft and arranged to be opposite to the magnetic material to detect a change in a magnetic property of the magnetic material, occurring owing to the input torque applied to the transmission input shaft.

Abstract: 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.

Abstract: An apparatus for measuring relative displacement between a first shaft and a second shaft includes first and second rotor assemblies. The first rotor assembly is coupled to the first shaft and is centered on an axis. The second rotor assembly is coupled to the second shaft. The second rotor assembly has first and second stator plates. Each of the first and second stator plates includes an upper surface and a lower surface. The upper and lower surfaces are parallel. The first and second stator plates include a plurality of teeth extending in a direction radial of the axis. The first and second stator plates form a gap between the lower surface of the first stator plate and the upper surface of the second stator plate. The apparatus further includes at least one magnet having a magnetic field and disposed on the first rotor assembly and a sensing device disposed within the gap for sensing a magnetic flux of the magnetic field.

Abstract: Torque in a shaft (61) is detected by means of non-contacting sensors (23, 24) sensing a torque-dependent magnetic field emanated by an integral transducer region (64, 32) of the shaft (61) that is circumferentially or longitudinally magnetized. The shaft (61) is driven by a motor (63) and subject to a longitudinal magnetic field (60) which acts on interference field. In one implementation of the invention coils (L1, L2: L3, L4) are energized to provide a counteracting magnetic field to compensate the interference field (60).

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: There is provided a torsion shaft for the electronic power-assisted steering (“EPAS”) system of a vehicle. The torsion shaft designed for the EPAS system is made up of a shaft, where a first portion of the shaft is magnetized, and a second portion of the shaft is non-magnetized. The torsion shaft further includes a torsion cap attached to the shaft. Also provided is a torsion shaft for an EPAS system made up of a discreet first shaft portion and a discreet second shaft portion operatively joined together, where the first shaft portion is magnetized, and a second shaft portion is non-magnetized. The torsion shaft further includes a torsion cap attached to the shaft. Further provided is a method for making a torsion shaft where at least two portions of a torsion shaft are provided. At least one portion is magnetized, and at least one portion is left free of magnetization. The portions are then joined.

Abstract: A magnetostriction-type torque sensor 20 includes a shaft 12b formed of a magnetic material and provided with at least magnetostrictive films 20b and 20c; exciting coils 20d′ and 20e′ for exciting the magnetostrictive films 20b and 20c provided on the shaft 12b; detection coils 20d and 20e for detecting a change in a magnetic field; and yoke portions 20f respectively provided around outer peripheries of the exciting coils 20d′ and 20e′ and the detection coils 20d and 20e, wherein a magnetic shield section 20a formed of a magnetic material is provided around the outer peripheries of the yoke portions 20f.

Abstract: A torque sensing apparatus for picking up a magnetic field of a magnetostrictive material disposed on a shaft, comprising: a first integrating ring; a second integrating ring; a first fluxgate return strip and a second fluxgate return strip each being connected to the first integrating ring at one end and the second integrating ring at the other end; an excitation coil; and a feedback coil; wherein the first integrating ring and the second integrating ring are configured to be positioned to pick up flux signals along the entire periphery of the ends of the magnetostrictive material.

Abstract: A calculation processing circuit 10 executes a predetermined operation on the detection signals of a plurality of magnetic sensors A and B, disposed to face a target 3a made of a magnetic material and provided on a rotating member 6, for outputting detection signals with mutually different phases according to a rotation of the rotating member 6, calculates the electrical angle of the detection signals based on a table 2arepresenting the correlation of the result of the operation executed in advance with a corresponding electrical angle of detection signals, and detects the rotational angle of the rotating member 6 based on the calculated electrical angle. The calculation processing circuit 10 stores a plurality of tables 2a through 2c for different gaps between the target 3a and the magnetic sensors A and B, determines the gap based on the detection signals of the magnetic sensors A and B, and calculates the electrical angle of the detection signals based on the table corresponding to the determined gap.

Abstract: A sensor for measuring divergent magnetic fields emanating from a rotatable magnetoelastic shaft without directly contacting the shaft comprises diametrically opposed sensing elements held in spaced relation to the shaft. Each sensing element is adjacent a corresponding one of the magnetic zones and on opposite sides of the shaft so as to create a cross-axial sensor arrangement.

Abstract: A magnetic first detecting cylinder covers a magnetism leakage preventing member covering a first shaft. A second detecting cylinder is rotated along with a second shaft connected to the first shaft and one end thereof is opposed to one end of the first detecting cylinder with a clearance. A reluctance with respect to a passing magnetic flux in a first magnetic circuit constituted by generating the magnetic flux passing the first detecting cylinder and the second detecting cylinder by a first coil, is changed in accordance with an elastic relative rotational amount by a change in a transmitting torque of the two shafts. The magnetism leakage preventing member is molded from a synthetic resin material injected into a molding die. The first shaft and the first detecting cylinder are integrated to the magnetism leakage preventing member molded by being inserted into the molding die before injecting the synthetic resin material.

Abstract: The present invention provides a temperature compensator for a torque sensor, including a pair of coils, which are connected to an AC power supply circuit via transistors and in which inductances change in opposite directions depending on torque, and a torque detecting means which obtains a voltage difference between a first voltage and a second voltage output via smoothing circuits based on changes in inductance of each pair of coils, and outputs as a torque detection voltage, the temperature compensator having a correcting voltage extracting means for extracting a voltage between terminals of a transistor in the AC power supply circuit as a temperature correcting voltage, and a correcting means for correcting the torque detection voltage based on a temperature correcting voltage Vs extracted by the correcting voltage extracting means.

Abstract: A magnetoelastic torque sensor assembly is provided for sensing torsion load of a shaft, such as an automotive steering column. The assembly includes a molded plastic body that defines an axial channel and includes an axial opening. The assembly also includes a U-shaped lead frame that is embedded within the molded plastic body and includes side portions that extend within side sections of the molded plastic body about the channel. Magnetic flux sensors are embedded in the side sections of the molded plastic body and connected to the lead frame. For use, the shaft is radially received through the axial opening in the molded plastic body and coaxially positioned within the channel. The magnetic flux sensors are positioned about the shaft in a predetermined and fixed arrangement. The sensor array preferably includes sensors that are disposed in a plane through the axis, either diametrically opposed or axially spaced.

Abstract: A method of detecting a sensed parameter for a motor control system comprising: receiving a sensor signal, the sensor signal exhibiting a frequency responsive to an inductance of a non-contacting variable reluctance rotational displacement sensor, wherein the inductance is indicative of a displacement of the sensor and responsive to the sensed parameter; capturing a first transition of the sensor signal and a time associated therewith; capturing a second transition of the sensor signal and a time associated therewith; calculating a period for the sensor signal; and computing a value for the sensed parameter, the value responsive to the period.

Abstract: A magnetic transducer element (22) is formed by rotating an integral region of a shaft (20) about an axis (A-A) in the presence of a magnetic source (30). An annulus (42) of magnetisation results in having its magnetisation in the axial direction. The exterior magnetic field (40) emanated by the annulus (42) exhibits respective axial magnetic profiles of its axially and radially directed components (FIGS. 7 and 8) which have an axial shift under torque. The direction of profile shift depends on the rotational direction of the shaft (20) while magnetisation proceeds. A pair of regions (122a, 122b: 242, 244) exhibiting opposite shift directions provide signals in which torque-dependent shift is separated from axial displacements of the shaft (FIG. 22, FIG. 24). An annulus (42) of magnetisation may be non-uniform with angle about the shaft axis.

Abstract: An angle detection device that accurately detects a rotational angle even if the ratio of an detection voltage relative to an excitation voltage of a resolver fluctuates. The angle detection device includes an angle detector and a controller connected to the angle detector. The angle detector includes an excitation coil, which is arranged on a predetermined rotary shaft and supplied with excitation voltage, and a pair of detection coils. Each detection coil is arranged near the excitation coil to induce detection voltage when excitation voltage excites the excitation coil. The detection voltages of the detection coils have different phases. A controller calculates the rotational angle of the excitation coil with the detection voltages induced to the detection coils. Further, the controller includes a correction unit for correcting the amplitude of the excitation voltage to maintain each of the induced detection voltages at a predetermined value.

Abstract: Disclosed herein is a variable reluctance rotational displacement sensor comprising: an annular sleeve; a coil coaxially aligned within the sleeve; a first ring in magnetic communication with the sleeve, coaxially aligned and configured to rotate relative to the sleeve. The first ring including a first plurality of axially directed teeth arranged substantially equidistant about a circumference of the ring on a front portion thereof. The sensor also includes a second ring in magnetic communication with the first ring and the sleeve, the second ring coaxially aligned and configured to rotate relative to the first ring and the sleeve and including a second plurality of axially directed teeth configured substantially the same as the first plurality of axially directed teeth and oriented adjacent to the first plurality of axially directed teeth on a rear portion of the second ring. The coil generates a signal responsive to a differential rotational displacement between the first ring and the second ring.

Abstract: 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.

Abstract: The present invention relates to a proximity sensor system comprising a sensor generating two types of pulse signals having opposite polarities in order to detect two different, small, metallic objects and to distinguish the objects. The proximity sensor system can involve at least two metallic objects to be detected having different magnetic properties; a sensor comprising a magnetic core having a plurality of legs and a toroidal coil winding fitted and supported onto at least one of the legs of the magnetic core; and an electronic circuit processing output signals from the sensor. The sensor generates predetermined signals having opposite polarities when metallic objects pass in proximity to the sensor. Suitable metallic objects include those made of ferromagnetic metal and diamagnetic or paramagnetic metal.

Abstract: 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.

Abstract: A sensing system for monitoring a property of an electrically conductive moving element of turbomachinery. The sensing system includes a sensing system housing. A magnetic core is contained within the sensing system housing. A coil is positioned about at least a portion of the core. The coil is electrically connectable to a property data analysis device. A first magnet and a second magnet are positioned about the coil and positionable proximate a moving element of turbomachinery to be monitored. A primary magnetic field is generated by the first and second magnets. When the moving element enters the primary magnetic field a current is induced in the moving element, thus generating a time-variable magnetic field and commensurate voltage signal generated in the coil. The voltage signal is amplified by the magnetic core and provides an indication of a property of the moving element.

Abstract: This invention is to provide an improved device for measuring torque with high accuracy and a simple structure. The device is so constructed that one end of a torsion bar (which is twisted depending on an actual steering operation) is combined with one end of an input shaft, while the other end of the torsion bar is combined with one end of an output shaft. The other end of the input shaft is combined with a steering wheel, while the other end of the output shaft is connected to vehicle wheels. A rotor of a first resolver comprising the rotor having a resolver excitation winding and a stator having a resolver output winding is fixed to the input shaft (one end of which is combined with the steering wheel). A rotor of a second resolver comprising the rotor having a resolver excitation winding and a stator having a resolver output winding is fixed to the output shaft (the other end of which is connected to the vehicle wheels).

Abstract: A torque sensor has a contoured magnetoelastic element that generates a magnetic field having a shape that exhibits gradual changes rather than sharp peaks in the axial direction, making the torque sensor less sensitive to positional changes between the magnetoelastic element and a magnetometer in the sensor. The element is contoured in any desired shape to modify the magnetic field generated by the element when it is deformed through applied torque. In one embodiment, the element is a magnetic material coating applied to a contoured shaft.

Abstract: A rotation sensor includes a first rotor constituted by a magnetic material and having an outer face that has first conductive layers disposed in two levels as viewed in the direction of a rotation axis and second conductive layers disposed outwardly of and between the first conductive layers, a second rotor having metal members corresponding to the first conductive layers of the first rotor, and a stationary core having a stationary core body that accommodates therein two exciting coils that are spaced from each other in the direction of the rotation axis. The second rotor is disposed between the first rotor mounted to a first shaft and the stationary core fixed to a stationary member, and is mounted to a second shaft which is rotatable relative to the first shaft.

Abstract: In a torque sensor having a magnetic metal film with magnetic anisotropy attached to a torque transmission shaft, and an exciting coil and a pair of detector coils each installed near the magnetic metal film, outputs of the detector coils and a reference signal are respectively added in waveform adders when the exciting coil is energized by an exciting power source. Then, the outputs of the adders and the reference signal are respectively compared in phase in phase comparators, and the outputs of the comparators are respectively converted in voltage values. A differential amplifier amplifies a difference between the voltage values, and a torque detector detects direction and magnitude of the torque applied to the torque transmission shaft from polarity and magnitude of the difference voltage value, thereby enabling to accurately detect applied torque even when installed near noise-producing electrical equipment such as an electric power steering system.

Abstract: 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.

Abstract: In an abnormality detecting device of a torque sensor including a pair of coils in which inductance is changed in opposite directions corresponding to torque and a torque detecting means for outputting a torque detection voltage from both voltages based on a change in inductance of each of the pair of the coils, the abnormality detecting having: a pair of filter circuits for extracting the DC component of each voltage based on the pair of the coils and change in each inductance, a differential means for outputting a difference in voltage of the DC voltage outputted from each of the filter circuits as the abnormality detection voltage a memory means for memorizing a normal tolerance range preliminarily set up about the abnormality detection voltage of the differential means and a determining means for determining whether or not the abnormality detecting voltage outputted by the differential means is in the normal tolerance range memorized by the memory means.

Abstract: A method of measuring torque in a part, for example a shaft, in which at least one coil, wound about an axis of the part about which axis torque is applied, is A.C. energised to create an alternating polarity magnetic field in the part, which field emanates a component dependent on torque. A magnetic field sensor arrangement is responsive to the emanated component to produce a torque-indicating signal. The at least one coil is energised by a series of energising pulses of current of alternating polarity which pulses have a relatively small duty cycle. The sensor arrangement produces sensor pulses of alternating polarity corresponding to said energising pulses, and the sensor pulses are measured in a peak-to-peak fashion to produce an output signal representing torque.

Abstract: A device for measuring the angle of rotation of a rotating member of a machine, comprising a signal transmitting rotor which includes a magnet rim consisting of magnets having alternatingly arranged south poles and north poles and being moved with respect to a stationary measuring sensor is characterized in that each magnet or each magnet zone has a thickness which varies substantially sinusoidally in circumferential direction, having its maximum in the pole center of each magnet and/or forms an air gap with the measuring sensor varying sinusoidally in circumferential direction.

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 transducer for measuring displacement comprises a transducer assembly in which there is a coil wound about an axis and energisable to generate a magnetic field, and first and second magnetic field sensor devices, that are axially spaced with the coil therebetween, each device being in proximity to the coil to respond to a magnetic field component generated by energisation of the coil. A ferromagnetic member is disposed to interact with the field generated by the coil, the ferromagnetic member and the transducer assembly being mounted for relative displacement in the direction of said axis, such that the balance of the respective field components sensed by the first and second sensor devices is a function of the axial position of the ferromagnetic member relative to the transducer assembly.

Abstract: A non-contact rotation speed and torque sensing device which detects the inhomogeneities in the magnetic properties of a rotating element (4). An alternating magnetic field is applied in the region of a rotating element (4) and a signal representing the change in magnetic flux caused by the inhomogeneities of the magnetic structure of the object is received at a sensor (1). Using mathematical methods, in particular, auto-correlation, based on the signal received at a sensor (1), the speed of rotation of the element (4) may be determined through inspection of the periodicity of the signal Two sensors (1, 8) may be placed a pre-determined distance apart along the length of the element (4) and using mathematical methods, in particular, cross-correlation, based on the signal received from each sensor (1, 8), the torque applied to the element (4) may be determined.