According to the invention, the torque ripple of electrical machines is supposed to be further reduced. For this purpose, it is provided to dispose the magnetic poles, for example, on the surface of a rotor in a plurality of sections (A1, A2) at different angles. The result are helix angles (β1, β2), which have different amounts. Also more than two different helix angles, up to a continuous course of the boundary lines (G4) between the poles, can be implemented.