An Optimized Magnet Circuit Design to Reduce Power Consumption for Torsional Electromagnetic Actuators

A torsional electromagnetic actuator that is actuated by the torque applied to a planar coil in an external magnetic field is designed, modeled, and analyzed in this letter. The analytical model of the magnetic torque is established. A magnet combination consisting of a rectangular magnet and a square-ring magnet magnetized in opposite directions is developed. A novel magnetic circuit is designed and analyzed to increase the driving torque. The electromagnetic and mechanical responses of the device are characterized by finite element simulation. In the case study, the power consumption of the actuator is significantly reduced by 54.3%, and down to 3.05 mW at the mechanical torsion angle of 11°. The effect of air gap on power consumption is also studied quantitatively.