Abstract: New non-contact measuring dynamic torque sensor based on magneto-elastic effect of Fe-base amorphous alloy is discussed. The principle and structure of sensor are presented, and its output characteristic equation is derived. By making an dynamic torque measuring experiment, effect of the gap between sensor probe and shaft surface, and rotational speed on measurement accuracy and sensitivity is analyzed, and U 0-δ curve which is the change of sensor output voltage with gap, the best air gap rang and dynamic output curve in three kinds of rotation speed of the shaft are got. The experimental result shows when gap is 0.5 mm, maximal repeatability error is 1.71%, maximal nonlinearity error is 2.48% and sensitiveness is 1.385 2 mV/(N•m). Sensor designed is feasible, especially for the needs of fixed non-contact monitoring of some heavy-duty low-speed shaft torque.

Key words: Amorphous alloy, Half-ring, Magneto-elastic effect, Non-contact, Torque sensor