Design and optimization of a rotary actuator for a two degree-of-freedom zφ-module

The paper concerns the design and optimization of a rotary actuator of which the rotor is attached to a linear actuator inside a two degree-of-freedom zphi-module, which is part of a pick-and-place robot. The rotary actuator provides plusmn180deg rotation, while the linear actuator offers a z-motion of plusmn5 mm. In the paper, the optimal combinations of magnet poles and coils are determined for this slotless actuator with concentrated windings. Based on this analysis, of the rotary actuator is optimized using a multi-physical framework, which contains a coupled electromagnetic, mechanical and thermal model. Because the rotation angle is limited, both a moving-coil design with a double mechanical clearance and a moving-magnet design with a single mechanical clearance have been investigated and compared. Additionally, the influence of the edge effects of the magnets on the performance of the rotary actuator has been investigated with both 3D FEM simulations and measurements.