Patent ID: 7987734

Claim:
A torque sensor comprising: a housing; a torsion bar inserted into the housing, the torsion bar having a rotation axis, the torsion bar having opposite first and second ends; a magnetic force generating part which rotates together with the first end of the torsion bar while generating a magnetic flux in a direction of the rotation axis; a rotating magnetic circuit which rotates together with the second end of the torsion bar, the rotating magnetic circuit comprising a first soft magnetic member and a second soft magnetic member, the first soft magnetic member comprising a first magnetic ring disposed around the torsion bar, a first magnetic tip disposed to face the magnetic force generating part in the direction of the rotation axis, and a first magnetic column connecting the first magnetic tip magnetically to the first magnetic ring, and the second soft magnetic member comprising a second magnetic ring disposed around the torsion bar in a position offset from a position of the first magnetic ring in the direction of the rotation axis, a second magnetic tip disposed such that the second magnetic tip and the first magnetic tip are disposed on an identical plane orthogonal to the rotation axis, and a second magnetic column connecting the second magnetic tip magnetically to the second magnetic ring, the second magnetic column and the first magnetic column being oriented oppositely; a fixed magnetic circuit fixed to the housing to surround the rotating magnetic circuit so as to accept without contact a magnetic flux from the rotating magnetic circuit; and a magnetic sensor which detects a magnetic flux density in the fixed magnetic circuit.