A Three-Position Swing Electromagnetic Actuator with an Integrated Eddy Current Brake for Suppression of the Operating Time and Improvement of the Stopping Accuracy

Abstract

A closed-loop control system is commonly used in electromagnetic actuators to ensure operating performance. However, this system frequently leads to high costs. We developed a swing electromagnetic actuator with an integrated eddy current brake to reduce the operating time and improve the stopping accuracy. The developed actuator is a three-position cylindrical actuator moving within a ±120-degree angle without closed-loop control. The rotor is composed of a bulk and thin metal laminations and the stator has three sets of pairs of coils. The rotor is stopped at an intermediate position by magnetic force generated by the coils. This paper describes the electromagnetic design and its evaluation by using an FEM simulation to predict its operating characteristics and measure its performance on a test bench. The superiority of our actuator design is verified by comparing these measurements. The operating time is reduced to one-sixth of that of a laminated rotor and the over-travel is compressed to zero. In addition, this actuator has the advantage that it is electrically robust against variations in the power supply.