Patent ID: 6880254

Claim:
A torque detector comprising: a case; bearings provided in the case; a first rotor provided with a gear on outer periphery thereof, and retained in a rotatable manner by one of the bearings; a second rotor provided with a gear on outer periphery thereof, and retained in a rotatable manner by another of the bearings; a first magnet having a pair of magnetic poles, and disposed to an end of the first rotor; a second magnet having a pair of magnetic poles, and disposed to an end of the second rotor; a first magneto-sensitive element for detecting a magnetic field produced by the first magnet, the first magneto-sensitive element placed along an axial direction of the first rotor in a manner to face the first magnet with a predetermined space; a second magneto-sensitive element for detecting magnetic field produced by the second magnet, the second magneto-sensitive element placed along an axial direction of the second rotor in a manner to face the second magnet with a predetermined space; an input shaft provided with a gear in engagement with the gear on the first rotor; and an output shaft provided with a gear in engagement with the gear on the second rotor, the output shaft connected to one end of the input shaft, wherein the torque detector obtains an amount of relative rotational displacement, if the relative rotational displacement occurs between the input shaft and the output shaft, based on a first detection signal output by the first magneto-sensitive element responsive to the magnetic field of the first magnet and a second detection signal output by the second magneto-sensitive element responsive to the magnetic field of the second magnet.