A NEW TORQUE TRANSDUCER USING STRESS SENSITIVE AMORPHOUS RIBBONS

A new torque transducer of the noncontact type employing the magnetostrictive effect is presented. Two stress-sensitive amorphous ribbons are glued to a torsion bar which is used as a part of the shaft. Unidirectional magnetoelastic magnetic anisotropy is created in each ribbon in such a manner that one of the anisotropies lies along 45 degree to the shaft axis and another along minus 45 degree . The applied torque is detected as a difference in permeability between the amorphous ribbons by an ac bias field. The amorphous ribbon used in experiments is a Fe-Si-B system whose saturation magnetostriction lambda //s approximately equals 24 multiplied by 10** minus **6 and I//s approximately equals 1. 5T. With this transducer, instantaneous torque as well as static torque is detected with sufficient accuracy.