Distributed Double Litz Wire Winding in Open Slots

An electric machine, comprising:

• a stator formed by a stator armature (100) provided with a plurality of slots (110), each slot having a height and an open end and extending in transversal direction of the stator armature (100),
• coils (10, 10a-10n) positioned in said slots (110), each of the coils comprising a first coil side (11) and a second coil side (12),
• several conductors (20A-20D, 20E-20H) positioned in-line one after another along the height of the slot (110), each conductor defining an axis,
• end-winding areas (30) connecting the first coil side (11) and second coil side (12) outside each slots (110), wherein
• the first coil side (11) and second coil side (12) of respective coils (10, 10a-10n) are arranged in separate non-adjacent slots (110),
• the first coil side (11) of the respective coil (10, 10a-10n) is positioned in one of the slots (110) closer to a bottom (111) of the slot (110) and the second coil side (12) of the respective coil (10, 10a-10n) is positioned in the non-adjacent slot (110) closer to an opening (112) of the slot (110),
• the conductors (20A-D, 20A-H) of respective coils (10, 10a-n) are litz wire conductors,
• some or all of the conductors (20A-20D, 20E-20H) are transposed at an end-winding area (30) of the respective coil (10, 10a-10n) changing their vertical positions in the coil sides (11, 12),
• the end-winding portions of the conductors (20A-20D, 20E-20H) are not twisted or turned around the axis of the respective conductor (20A-20D, 20E-20H), and the end-winding portions of a conductor (20D, 20H) in the end-winding area (30) is positioned axially closest to an active length section of the coils (10, 10a-10n), and
• the end-winding portions of subsequent conductors (20C-20A, 20G-20E) of the respective coils (10, 10a-10n) are positioned next to the end-winding portions of a preceding conductor (20D-20A, 20H-20E), while axially outside and further from the active length section of the coils (10, 10a-10n) than the preceding conductor (20D-20A, 20H-20E).