Performance of Ideal and Practical Concentric Magnetic Gears in High Speed Applications

Ideally, magnetic gears (MGs) have numerous advantages relative to their classical mechanical counterparts. In practice, however, MGs face numerous electromagnetic and mechanical challenges that must be considered in high speed applications. This paper describes a comparative study between an ideal and a practical concentric magnetic gear of the same size in terms of torque capability, magnetic flux density in the air gaps and power loss in the iron and magnets. Both topologies were evaluated by means of 2-dimentional finite element analysis using COMSOL Multiphysics® as a simulation tool. The main findings are that practical high-speed MGs require larger air gaps, weaker magnets and mechanical reinforcements, which lead to significantly lower power transmission capability.