Embodiments of the present invention relate to a winding of a rotor for use in rotating electrical machines. More particularly, embodiments of the present invention relate to innovative half-coils used for the winding of the rotor. Moreover, embodiments of the invention pertain to a method for winding a rotor body of an electrical machine. According to embodiments of the invention, half-coils, instead of being manufactured as double hollow conductors, are provided in the form of two single hollow conductors, which are adjacently embedded within a respective slot of the rotor body.

The invention relates to a stator (100) which may be used within an electric rotating machine, an electric machine, an apparatus for preparing a stator and a method for preparing a stator. The stator (100) comprises a stator core (10) having a plurality of slots (11) arranged in a circumferential direction (C) of the stator core (10). At least a first conductor (12) and at least a second conductor (13) are arranged along a radial direction (R) of one slot (11). Axial end sections (22, 23) of the conductors (12, 13) are electrically connectable or connected and the axial end sections (22, 23) of radially adjacent conductors (12, 13) are distanced from each other. The distance (28) between the proximal end (29) of the axial end section (22) of a first conductor (12) and the stator core (10) is longer than the distance (26) between the distal end (27) of the axial end section (23) of a second conductor (13) and the stator core (10).

A rotor (10) for a rotating electrical machine is disclosed. The rotor comprises a plurality of salient poles (12) and rotor windings (22, 24) wound on the salient poles. A cooling vent (26) is provided through the rotor windings, the cooling vent extending through the rotor windings in an axial direction and a radial direction. The cooling vent (26) extends in an axial direction from one end of the rotor pole to the other. The cooling vent (26) may be formed by a plurality of discontinuous spacers (28), or by a spacer (78) which extends continuously around the rotor pole (12). Providing a cooling vent which extends through the rotor windings in an axial direction and a radial direction may help to improve the thermal performance of the machine in efficient and cost-effective manner.