High speed surface permanent magnet synchronous machines for a screwdriver application

In this article, a novel methodology is presented in order to design a permanent magnet synchronous machine associated to a gearbox for a screwdriver application. The study shows how, from a specified maximum volume, a maximum heating, torque and speed profiles, it is possible to formulate the sizing problem. The modeling is based on a purely analytical formulation. We show that it is possible to establish rules in order to make optimal choices of materials (magnets and stator core). The optimization of the pole paire number and the choice of gear ratio is also discussed.