**4. Conclusions**

This chapter proposes an overview of the challenges in EV application, where the speed limits were pushed forward in the last decade. Practically, all the car manufacturers are proposing mobility solutions based on electrically propelled traction systems, which are limited because of the drawbacks of the mechanical gear, which needs to be continuously lubricated, presenting important heat and local losses; moreover, higher speeds drastically decrease the power density of motorization. To overcome these drawbacks, researchers have proposed in the last decade possible solutions based on magnetic gears (MGs). We have presented in this chapter the existent configuration of fixed transmission ratio MGs, we have also indicated some references in which the variable transmission was studied and we have presented the main analytical approaches used for the design of MGs: the harmonic, magnetic reluctance equiv‐ alent circuit, and vector potential algorithms. A quasi-complete reference list was given with respect to this topic. Next, we have investigated two variants of MG, one with integrated motor and a second one for high-speed applications and a transmission ratio of 1/16. Through numerical computation we have investigated the output mechanical performances of the studied MGs, as well as the major loss component of such devices: the iron loss within the active parts of the MG. The influence of different materials on the active parts, meaning ferromagnetic steel and permanent magnets, was evaluated and a comparison of the obtained performances was depicted.

The research on MG has gained interest in the last decade and we expect that based on advancements in materials, the performances of these devices will be even more improved and will be of real interest, especially in the field of transportation and aeronautics.
