Abstract: An air-gap winding within an electrical machine is arranged with the conductors thereof extending in the axial direction of the machine and are embedded in an electrically insulating cylinder which serves as the winding support. The conductors, or at least some of them, are concentrated into conductor bundles which lie approximately upon a cylindrical surface extending between the inner and outer surfaces of the winding support and coaxially with the latter. The conductors of the bundles are electrically associated with the one or more phases of the machine winding and the number of conductors of each bundle associated with a particular phase satisfies the equation N.sub.LP =C, where C is any whole number constant, the value of which lies between zero and number N.sub.L of the conductors of that bundle.