Design and optimization of a novel 2-DOF synchronous linear rotary drive

Design and optimization of a novel 2-DOF synchronous linear rotary drive

Kategorien Konferenz (reviewed)
Jahr 2021
Autoren Denkena, B., Bergmann, B., Ahlborn, P., Fuchs, J.:
Veröffentlicht in Proceedings of the 21st international conference of the european society for precision engineering and nanotechnology (euspen's), June 7th - 10th June 2021, Virtual Conference, Copenhagen, DK, 4 Seiten.

Achieving movements of machine tool components in 2 degrees of freedom (DOF) usually requires a serial arrangement of at least two drives. The serial kinematic reduces the stiffness at the tool center point (TCP) and leads to an accumulation of the positioning and measuring errors of each drive. To achieve a high level of precision, a novel 2-DOF drive without serial kinematics is being developed. The drive consists of a static primary part and a secondary part with a linear and a rotary DOF. The secondary part is able to move in both DOFs independently. For this purpose, two separate windings which generate rotation and translation forces are stacked in the primary part. To generate magnetic forces in both DOFs, the secondary part is equipped with a checkerboard-like array of permanent magnets. The coupling between both windings and thus the induction of forces can be bypassed. This means that the windings can be controlled independently. The combination of the primary and secondary parts reduces the drive length. In comparison to current linear rotary drives, the novel drive is more compact and has a higher performance. In this paper, the motor geometry is optimized by parametric FEM-simulations. The goal of said optimization is to improve the torque and feed force as well as to reduce power losses and disturbing forces. For this purpose, a parametric model of the drive is developed. The simulations are carried out in ANSYS Maxwell and are run in 2D to save computing time. A genetic algorithm and sequential nonlinear programming are used to optimize the magnet height, pole-to-pole coverage, tooth angle and slot height. The simplifying assumptions of the 2Dsimulation are compared to an additionally performed 3D-simulation. The result is an optimized drive with 8% higher performance and 65% less power loss compared to the non-optimized initial geometry.