1. Machine types

1.1 Axial or radial field machines

High-torque magnet machines are synchronous machines with permanent magnets on the rotor. The main flux is created without losses, simplifying rotor cooling. Another advantage of this type of solution is the possibility of designing machines with small pole pitches (less than 200 mm), thereby reducing rotor and stator armature heights and stator winding coil heads.

The machines considered in this dossier have a large number of poles and therefore a low rotational speed (below 500 rpm). The shaft drive torque is therefore high, hence the name "high-torque". It rotates at speed (N _S in rpm): $N_S=\frac{60f}{p}$