A magnetic gearbox with an active region torque density of 239Nm/L

In this paper a 1:4.25 ratio ferrite magnet and NdFeB magnet flux-focusing magnetic gearbox with a high pole count is analyzed. A simple parameter sweep analysis is used to show that higher than previously published torque density values are achievable. Experimental results are then presented for the NdFeB design that confirm the calculations and also demonstrate that the proposed magnetic gearbox can operate with a low torque ripple.