Moving-Magnet Actuator with Flexure Guide for Precise Positioning

Versatile high precision positioning tasks with strokes up to approx. 25 mm can advantageously be realized with simple single-phase electrodynamic linear direct drives. Especially motors with moving magnet(s) and slotted stator winding offer high force densities as well as simple and robust designs. With integration of the guide, position sensor, and embedded control very compact mechatronic actuators can be realized. In this paper, a novel cylindrical moving-magnet actuator with an integrated flexure guide is presented. After a short comparative overview of short-stroke positioning drives, the operation principle of the actuator as well as design constraints of the magnetic circuit are presented. Furthermore, the analytical and numerical design of the flexure guide is explained. Finally, preliminary technical data of the actuator and first results of its position-controlled operation obtained with a newly developed control circuit are presented.