A Torque Sensor Utilizing Magnetostrictive Effect

摘要

A new type of magnetostrictive torque sensor has been developed. The sensor can directly measure shaft stress without the magnetostrictive layer on the torsional bar. Opposite torques applied axially to a polycrystalline ferromagnetic rod result in tensile and compressive stresses acting perpendicularly by the rod surface at 45° to the rod axis. When a magnetic filed is applied parallel to the rod axis, these stresses affect the magnetization of the rod. The sensor structure is designed with relatively small size and easy installation. The result of tests shows that it is a direct and effective method.