Let's take a brief look at the common torque sensor classifications and principles.
Non-contact torque sensors are also dynamic torque sensors, also known as torque sensors, torque speed sensors, rotating torque sensors and so on. Its input and output shafts are connected by a torsion bar, with a spline on the input shaft and a keyway on the output shaft. When the torsion bar is torsioned by the rotational torque, the relative positions of the spline and keyway are changed, and their relative displacement is the torsion amount of the torsion bar. This process causes the magnetic susceptibility of the spline to change, which is converted into a voltage signal by a coil. Non-contact torque sensors are characterized by long life, high reliability, less susceptible to wear, have a smaller delay, are less affected by the shaft, and are more widely used.
Strain gauge torque sensors use strain gauge technology. Its principle is to use the elastic shaft, paste the strain gauge, composed of a measurement bridge, when the elastic shaft by the torque effect of a small deformation, the resistance of the bridge will change, and then the electrical signal changes, to achieve the measurement of torque. Strain gauge torque sensors are characterized by high resolving power, small error, large measuring range, low price, easy to choose and use in large quantities.
Phase difference torsion sensor is the torsion angle phase difference type sensor, its principle is based on the magneto-electric phase difference torque measurement technology, in the elastic shaft at both ends of the installation of two groups of teeth, shape and mounting angle of the exact same gear, the gear outside the installation of the proximity sensor. When the elastic shaft rotates, the waveforms of the two sets of sensors generate a phase difference, thus calculating the torque. It is mainly characterized by the realization of non-contact transmission of torque signals, the detected signal is a digital signal, and the speed is higher. However, this torque sensor has a large volume, and the performance at low speed is not ideal, so the application is no longer very widespread. In addition, high-performance wireless torque sensors are more commonly used, which are combined with wireless communication technology to realize the wireless transmission of data.