diameter of the hub 34 and the shaft 30 thus an annular space is formed between the inner circumference of the godet casing 32 and the outer circumference of the hub 34 and shaft 30 this annular space is filled by a package of individual primary windings which are arranged stationarily and unmovingly to this end a cooling tube 39 concentric with shaft 30 is attached to a stationary holder 38 the cooling tube projects into the aforesaid annular space and extends up to the front cover 33 it should be emphasized that the cooling tube 39 is stationary and surrounds the shaft 30 concentrically and without contacting it arranged on the cooling tube 39 are four zones with individual primary windings 40 each package of an individual primary winding comprises a flux tube 41 flux poles 42 as well as the individual primary winding 40 the flux tubes 41 and flux poles 42 consist of a magnetically highly conductive material each flux tube extends into the range of a respective individual primary winding fixedly attached to the ends of the tubes 41 are two annular flux poles 42 one individual primary winding 40 each is arranged between two flux poles 42 the thus formed packages are threaded with the flux tubes 41 on the cooling tube 39 with a narrow clearance and are held in position with the holder by longitudinal screws there being further provided flux disks 43 at the end of the entire.