Transmitted Torque Analysis of a Magnetic Gear Mechanism with Rectangular Magnets

Magnetic gears transmit torque by noncontact magnetic coupling rather than meshed mechanical gear teeth. In contrast to traditional mechanical gear mechanisms, non-contact magnetic gear mechanisms possess unique features of low mechanical energy loss, overload protection ability, no need for lubricants, tolerance of misalignment and vibration isolation between adjacent mechanical parts. The analysis of transmitted torque is a prerequisite task when evaluating the performance of a magnetic gear mechanism. In this study, a feasible method for predicting transmitted torque generated by external-type magnetic gear sets with rectangular magnets is demonstrated by employing the current sheet approach. Based on the current sheet mathematical model presented, the effects of geometrical and material parameters, including the number of magnet pole pairs, the width of the air gap and the remanence of permanent magnets, on transmitted torques of external-type magnetic gear sets can be analytically evaluated and discussed. The twodimensional finite-element analysis (FEA) is further employed in computing themagnetic fields and transmitted torques of external-type magnetic gear sets. The results of this paper are beneficial for further design purposes and optimization of magnetic gear mechanisms