Design and Deformation Analysis of Disk-type Torque Sensor

In torque sensors used for high-speed power machines and robot joints, the usage of disk-type torque sensors in place of flange-type torque sensors with cylindrical sensing parts can solve the issue of space limitation and improve the rotational characteristics such as vibration. In this study, a disk-type torque sensor that detects the shear deformation was designed, and a deformation analysis was performed to predict the output of the Wheatstone bridge circuit of the sensing part. The rated output obtained by testing the manufactured torque sensor was measured to be 33.7% smaller than the rated output predicted by the Euler beam theory. To investigate the cause, a three-dimensional deformation analysis using an approximate solution and a finite element analysis were performed. The distribution of the shear strain according to the shape of the sensing beam was analyzed in detail. The magnitude and distribution of the shear strain calculated using the three-dimensional beam approximation solution was significantly different from those calculated using the two-dimensional beam theory.