Looking for an optimal rotor for high speed permanent magnet synchronous machine

Using a commercially available three-phase, induction motor stator, the design of a four-pole permanent-magnet rotor is investigated for speeds up to 40000 r/min. As the machine is to be operated at high speed, considerable attention must be paid to the mechanical aspects of the rotor design and bearings. For this reason a solid steel rotor was selected instead of a laminated one. To meet design challenges encountered with the permanent-magnet machines, a finite-element technique was used for accurate computation of magnetic field within the machine.<>