Patent ID: 7584672

Claim:
A magnetostrictive torque sensor, comprising: a rotating shaft to rotate around a center axis, the rotating shaft comprising magnetostrictive characteristics; a cylindrical magnetic core formed around said center axis at a predetermined distance from an outer periphery of the rotating shaft; a flexible substrate coil disposed on an entire inner periphery of the cylindrical magnetic core such that said flexible substrate coil has a width in an axial direction that is equal to a width in the axial direction of said cylindrical magnetic core, the flexible substrate coil comprising: a first cylindrical detection coil layer formed on and occupying the entire inner periphery of the cylindrical magnetic core; and a second cylindrical detection coil layer formed on and occupying an entire inner periphery of said first cylindrical detection coil layer such that said outer periphery of said rotating shaft is nearer to said second cylindrical detection coil layer than said first cylindrical detection coil layer; and a bridged circuit comprising said first and second cylindrical detection coil layers, wherein a circumference of an outer surface of the flexible substrate coil and a circumference of an outer surface of the first cylindrical detection coil layer is equal to a circumference of the entire inner periphery of the cylindrical magnetic core.