JPH0523612B

PURPOSE:To detect a torque applied to a nonmagnetic rotating shaft by providing the circumferential surface of the nonmagnetic rotating shaft with a magnetic film having a uniaxial anisotropy wherein an axis of easy magnetization is in a circumferential direction and an axis of difficult magnetization is in an axial direction and measuring the magnetic characteristics of the magnetic film by a detecting circuit having solenoid coils. CONSTITUTION:A nonmagnetic rotating shaft 20 is provided on its circumferential surface with a magnetic film 21 having a uniaxial anisotropy wherein an axis of easy magnetization is in a circumferential direction and an axis of difficult magnetization is in an axial direction. A torque applied to the rotating shaft 20 is detected by conducting the noncontact detection of the change in the magnetic characteristics of the magnetic film 21 by a detecting circuit having solenoid coils C1-C4. The solenoid coils C1 and C2 are located in a portion wherein the magnetic film 21 is present and the solenoid coils C3 and C4 are located in a portion wherein not magnetic film 21 is present. Those four solenoid coils are incorporated into a bridge circuit. The output voltage of the bridge circuit produced when a torsional stress is applied to a specimen takes the maximum value when the torque is equal to zero and is decreased inversely proportionally to the increase in the torque.