PURPOSE: A torque measurement is provided to measure the torque by measuring the change of the magnet force due to the twist of an input shaft and an output shaft. CONSTITUTION: A first magnet ring(140) is fixed to one side of an input shaft(110). A torsion bar(120) transfers the torque of the input shaft to the output shaft. One side of the output shaft(130) is fixed to one side of the torsion bar. The output shaft receives the torque of the torsion bar. A second magnet ring(150) is fixed in one side of the output shaft to face to the first magnet ring. A first magnetic sensor measures the magnetic line variation between the first and second magnet rings due to the twisting of the torsion bar.
