Design Analysis of a Magnetic Gear Box with Continuous Ratio Shifting

Magnetic gears offer important potential benefits compared with mechanical gears such as reduced maintenance, improved reliability, inherent overload protection, and physical isolation between the input and output shafts. This paper presents the theory and simulation results for a continuous magnetic gear box employed in wind generators, electric vehicles and other related applications in which continuous ratio of gear box is essential. The analysis is performed by Finite Element Method (FEM) to predict output torque, speed and magnetic field distribution inside the gear box. The gear box made up of an inner rotating part which is similar to the rotor of a 3 phase wound rotor induction motor and an outer rotating part which consists of 6 PM poles. Both the inner rotor and outer rotor can be exploited as a low/high speed rotating part. The output torque and other parameters are evaluated in steady state condition using vector analysis. Simulation results are in good agreement with theoretical analysis as well.