a machine which is unstressed in regard to suspension nearly the entire winding cross section is used for the production of a torque in a winding arrangement in accordance with fig9 such a free association is not possible since for example during the idling of the machine only the winding cross section of the suspension force winding is available the rotor type of the machine can in principle be chosen freely in particular when the machine operation takes place via a rotary field instead of an alternating field usable are for example permanent magnet rotors short circuit cage rotors rotors with an electrically highly conducting metal jacketing instead of the short circuit cage or reluctance rotors with angle dependent air gap variations in the event of insufficient fractionally pitching or distribution respectively of the windings and in the event of non sinusoidal excitation field distributions angle dependent radial force fluctuations 42 such as are illustrated for example in fig1 arise through the harmonic content of the air gap fields in the current excitation of the winding in accordance with fig5 or fig6 or respectively of the loops ii u2032 or iii u2032 in accordance with fig9 with a constant current amplitude when the rotor is rotated this effect should be taken into account in the current excitation of the windings in order to achieve a good operating behaviour an approximately sinusoidal excitation field distribution can be achieved in the use of permanent magnet rotors 85 for.