A torque sensor for sensing the torque applied to a first shaft has a multipolar magnet rotated therewith and is connected to a second shaft via a torsion bar. The torque sensor includes a pair of magnetic yokes adapted to be disposed in a magnetic field of the multipolar magnet and adapted to be rotated together with the second shaft. A magnetic detection element has a detection surface and is capable of detecting a magnetic flux in a direction parallel to the detection surface.

A low-cost magnetostrictive torque sensor having a high sensitivity is obtained. A torque sensor 10 includes a substrate 12, a magnetostrictive portion 26, a magnetostrictive portion 28, a detection coil 18a, a detection coil 18b, a detection circuit 48, and a detection circuit 50. The substrate 12 has a tubular shape. Each of the magnetostrictive portions 26 and 28 is constituted by a plating film and disposed on the outer peripheral surface of the substrate 12. The detection coil 18a generates a magnetic flux passing through the magnetostrictive portion 26. The detection coil 18b generates a magnetic flux passing through the magnetostrictive portion 28. Each of the detection circuits 48 and 50 detects a potential between the detection coil 18a and the detection coil 18b.

Provided is a method for manufacturing a magnetostrictive torque sensor shaft mounting a sensor portion of a magnetostrictive torque sensor. The method includes conducting heat treatment on a shaft material including chrome steel or chrome-molybdenum steel by carburizing, quenching and tempering, and conducting shot peening on the shaft material after the heat treatment at least on a position where the sensor portion is to be mounted. The shot peening is conducted by firing shot with a particle size of not less than 0.6 mm and a Rockwell hardness of not less than 60 at a jet pressure of not less than 0.4 MPa for a jet exposure time of not less than 2 minutes.

The present invention relates to an arrangement for measuring a force and/or a torque on a machine element extending in an axis, using the inverse magnetostrictive effect. The machine element has at least one permanent magnetization. The permanent magnetization extends along a closed magnetization path. The magnetization path runs preferably at least partially along the surface of the machine element. The arrangement further includes at least one magnetic field sensor which is arranged opposite the machine element. The magnetic field sensor serves to determine a magnetic field and is designed to measure at least one vector component of a magnetic field coming from the machine element, which field is produced on the one hand by the permanent magnetization and on the other hand by the force and/or by the torque. According to the invention, the orientation of the permanent magnetization relative to the axis changes along the magnetization path.

A magnetostrictive sensor, including a tubular or columnar substrate extending along an axis, and a magnetostrictive portion disposed on an outer peripheral surface of the substrate and including a plurality of magnetostrictive lines. The plurality of magnetostrictive lines include adjacent first and second magnetostrictive lines that extend along an extension direction, and that are disposed on the outer peripheral surface of the substrate via respectively first and second contact areas. In a cross sectional view of the magnetostrictive portion taken orthogonally to the extension direction, a first length, which is a width of a widest portion of the first magnetostrictive line in a width direction parallel to the outer peripheral surface of the substrate, is larger than a width of the first contact area in the width direction, and than a shortest distance between the first and second contact areas in the width direction.

A magnetostrictive sensor including a magnetic structure. The magnetic structure has a columnar substrate extending along an axis, and a magnetostrictive portion disposed on an outer peripheral surface of the substrate. The magnetostrictive portion includes a plurality of portions that have different concentrations of at least one of a plurality of elements, the portions being so arranged as to satisfy at least one of a first requirement that in a first cross sectional view of the magnetostrictive portion orthogonal to the axis, the portions are arranged clockwise about the axis, a second requirement that in the first cross sectional view, the portions are arranged in a thickness direction of the magnetostrictive portion, and a third requirement that, in a second cross sectional view of the magnetostrictive portion that is orthogonal to the first cross sectional view and passes through the axis, the portions are arranged along the axis.

A torque sensor for being attached around a magnetostrictive rotating shaft includes a bobbin that is provided coaxially with the rotating shaft, wherein the bobbin includes a resin, a hollow cylindrical shape, and first inclined grooves and second inclined grooves formed on an outer peripheral surface thereof, wherein the first inclined grooves are inclined at a predetermined angle relative to an axial direction, and wherein the second inclined grooves are inclined at a predetermined angle relative to the axial direction in an opposite direction of the first inclined grooves, a first detection coil including an insulated wire wound around the bobbin along the first inclined grooves, a second detection coil including the insulated wire wound around the bobbin along the second inclined grooves, and a measurement portion that detects a inductance variation of the first and second detection coils so as to measure a torque applied to the rotating shaft.

A soft magnetic component for a torque sensor, formed by resin-molding a soft magnetic material that contains Ni, Fe in such an amount that Fe/(Fe+Ni) is within a range from 10.0% to 16.0% in terms of mass ratio, and 3.5% by mass to 7.5% by mass of M (the M represents one or more elements selected from among Mo, Nb, Cr, Cu, Ti, and W) and has a saturation magnetostriction of at least 4.0 ppm and less than 0 ppm, is provided.

A torque sensor for measuring a torque on a shaft using the measuring principle of inverse magnetostriction, on which a magnetised sleeve is fastened as the primary sensor. The sleeve is provided with at least two circumferential portions which are arranged at an axial distance from one another and magnetised in opposing directions and interact in a contactless manner with respective measuring coils arranged fixedly opposite hereto for acquiring measured values. The magnetised sleeve consists of a non-magnetic carrier sleeve part, on the outer lateral surface of which the magnetized circumferential portions are attached by deposition welding of a ferromagnetic material.

A torque sensor comprises: a shaft having a first magnetized region which generates a first magnetic field in response to a torque applied to the shaft; a first magnetic field sensor for detecting the first magnetic field, the magnetic field sensor being adapted to output a signal in response to a strength of the first magnetic field at the location of the first magnetic field sensor; and a first magnetic field guiding arrangement for guiding the first magnetic field to the location of the first magnetic field sensor.