Optimization design of radial meshing nutation magnetic gear system based on D-APSO algorithm

To combine the high transmission ratio of nutation drives with the non-contact power transfer of permanent-magnet gears, this paper proposes a novel radial meshing nutation magnetic drive system (RMNMD) and investigates its magnetic coupling mechanism and kinematic principle. First, an analytical model for the RMNMD output torque is established based on an equivalent-current magnetic-field model, incorporating coordinate transformations and Lorentz torque integration, and is numerically evaluated using the double Simpson’s 1/3 rule. Comparison with three-dimensional finite-element simulations in ANSYS Maxwell verifies that the model is suitable for torque prediction. Then, under engineering constraints such as a constant total amount of permanent-magnet material, a fitness-feedback-based dynamic inertia-weight particle swarm optimization algorithm (D-APSO) is developed to jointly optimize key magnet geometric parameters, including the central angle, length, thickness, and inner radius, with dual objectives of maximizing torque and minimizing overall volume. The results show a 4.82% increase in output torque, a 1.58% reduction in volume, and a 6.51% improvement in torque density. Moreover, compared with PSO and APSO, the proposed method achieves better overall performance and faster convergence. This integrated “analytical modeling–D-APSO optimization–simulation validation” framework enhances RMNMD torque density without increasing magnet usage, providing a reference for compact, high-torque-density nutation-based PM transmissions.