Induction in the air gap is strictly proportional to the remaining induction and the surface of the magnet. The first defined dimension is the height of the magnet, which will then be the entire length of the rotor, with a clearance of 2.05 mm at the end. The second dimension of the magnet will be the thickness that should be determined so that the maximum current that can be presented by the converter will not demagnetize the magnets in the rotor.
Since the remaining induction is a property of the magnet, attention is focused on the size of the magnet. In the buried magnets, special care must be taken to prevent the flow from flowing and proceed from the north pole to the south pole without passing through the engine air gap. An axis in non-ferromagnetic material will be fundamental.
An alternative to be checked is the application of a ferromagnetic axis enveloped by a layer of non-ferromagnetic material, as this option reduces the cost of the shaft, however it increases the cost of manufacture, as it increases the number of assembly elements. In order to minimize the dispersed flow, the magnets lie against the non-ferromagnetic axis, so there is no path in the center of the rotor for the flow to disperse.