Patent ID: 7389702

Claim:
A magnetostrictive torque sensor, comprising: a rotating shaft rotating around a center axis and having magnetostrictive characteristics; and a cylindrical ferrite magnetic core disposed at a predetermined distance from an outer periphery of the rotating shaft and coaxially with the rotating shaft, and provided with a coil having an insulation coating to detect a strain of the rotating shaft, wherein the coil is provided on an inner peripheral surface of the core; wherein: the cylindrical ferrite magnetic core comprises a pair of opposed coil-forming inner peripheral surfaces formed by dividing the inner peripheral surface of the core into two parts along a plane that includes the center axis; and the coil has, on each of the pair of the opposed coil-forming inner peripheral surfaces, a first coil including a forward current coil and a feedback current coil connected in series and disposed at a same position inclined with an angle of +45° to the center axis, adapted to flow a forward current and a feedback current in a same direction, and a second coil including a forward current coil and a feedback current coil connected in series adapted to flow a forward current and a feedback current in a same direction, and disposed at a same position inclined with an angle of −45° to the center axis and crossing with the first coil.