A3.4 - A Novel Torsion Sensor

SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg
Proceedings SENSOR 2009, Volume I
A3 - Mechanical Sensors I
E. Kisker - Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
89 - 93


Torque and twisting angle sensors are broadly used in industry, The mostly used technique is based or strain gauges that measure the elastic deformation of a shaft to which they are attached at the outside. Due to the elastic limits of the strain gauge element the torsion angle is restricted to very small values. A different type of torque sensors is based on bye stress-induced anisotropy of a magnetic shaft or a magnetic layer plated on a nonmagnetic shaft, referred to as magnetoelastic torque sensors. There the stress-dependent permeability or a magnetic flux emanating upon deformation is detected by means o adjacent coils or other types of magnetic held sensors. Due to this principle the torque on spinning shaft can be measured conveniently whereas the strain gauge based sensors additionally require power transmission to the spinning sensor to operate the sensor electronics. The magnetoelastic sensors an sensitive to external magnetic fields and might require magnetic shielding. For a recent review on the sensor principles see P. Ripka. Here we present a novel and principally rather simple type of torque sensor that is based on the combination of magneto elastic effects with spin electronic effects in a single piece. Accordingly, it does not require external coils or magnetic field detectors. Due to its low powe consumption and high output signal the sensor arrangement can easily be incorporated into a spinning shaft.