STATOR FOR AN ELECTRIC MACHINE
A stator for an electric machine includes a stator core and a stator winding which has N strands. Each strand is formed by shaped conductors which have leg portions and form connecting portions, which connect in each case two of the leg portions, at the end sides. The stator winding has, for each strand, at least one current path formed from series connection of a plurality of leg portions and in which a last leg portion of a first current path portion and a first leg portion of a second current path portion are arranged in a reference layer which is a first layer or an L-th layer of an associated slot, a last leg portion of the second current path portion and a first leg portion of a third current path portion are arranged in the other layer, and outer leg portions of the current path are arranged in a double layer having the reference layer.
1 . A stator for an electric machine, the stator comprising a stator core which has a longitudinal axis, a first end side, a second end side situated opposite the first end side, and a plurality of slots extending from the first end side to the second end side, and the stator comprising a stator winding which has a number N of strands, wherein N≥2, wherein
a first circumferential direction and a second circumferential direction that is opposite to the first circumferential direction are defined in relation to the longitudinal axis, wherein
each strand is formed by shaped conductors which have leg portions arranged within the slots and form connecting portions which electrically conductively connect in each case two of the leg portions to one another at the end sides, wherein
the slots form, for each strand, a plurality of winding zones, and each slot is subdivided radially into first to L-th layers, which are named according to their order in the radial direction, and L/2 double layers of radially immediately adjacent layers, wherein L≥2 and is an even number, wherein
the stator winding has, for each strand at least one current path, which is formed from a plurality of the leg portions and a plurality of connecting portions which interconnect the leg portions form a series connection, wherein
the at least one current path has a first outer leg portion in relation to the series connection and has a second outer leg portion that is situated opposite the first outer leg portion in relation to the series connection, wherein
the at least one current path has a first current path portion, which comprises the first outer leg portion and one leg portion or a plurality of leg portions which are successive in terms of the series connection, and has a second current path portion and a third current path portion which each comprise a plurality of leg portions which are successive in terms of the series connection, wherein
a last of the leg portions of the first current path portion is connected by means of one of the connecting portions directly to a first of the leg portions of the second current path portion, and a last of the leg portions of the second current path portion is connected by means of one of the connecting portions directly to a first of the leg portions of the third current path portion, wherein
the last leg portion of the first current path portion and the first current path portion of the second current path portion of the at least one current path are arranged in a reference layer which is one out of the first layer and the L-th layer, and the last leg portion of the second current path portion and the first leg portion of the third current path portion of the at least one current path are arranged in the other out of the first layer and the L-th layer, wherein
the outer leg portions of the at least one current path are arranged in that double layer which comprises the reference layer, wherein
the leg portions of the second current path portion occupy immediately adjacent winding zones of the same strand from the first to the last leg portion of the second current path portion along one of the circumferential directions as reference direction, and the leg portions of the third current path portion occupy immediately adjacent winding zones of the same strand proceeding from the first leg portion of the third current path portion along that circumferential direction which is opposite to the reference direction, wherein
one current path is formed as a current path of a first type in which the reference layer is the first layer and the reference direction is the first circumferential direction.
2 . The stator as claimed in claim 1 , wherein
the last leg portion of the first current path portion and the first leg portion of the second current path portion of the at least one current path are formed by the same shaped conductor, and/or the last leg portion of the second current path portion and the first leg portion of the at least one current path of the third current path portion are formed by the same shaped conductor.
3 . The stator as claimed in claim 1 , wherein
the leg portion or the leg portions of the first current path portion of the at least one current path occupies or occupy only that double layer which comprises the reference layer, and/or
the leg portions of the second current path portion of the at least one current path occupy each double layer, and/or
the leg portions of the third current path portion of the at least one current path occupy each double layer, and/or
the plurality of leg portions, which are successive in terms of the series connection, of the first current path portion of the at least one current path occupy immediately adjacent winding zones of the same strand along that circumferential direction which is opposite to the reference direction.
4 . The stator as claimed in claim 1 , wherein
the outer leg portions of the at least one current path are arranged in immediately adjacent winding zones of the same strand and/or in different layers of the same double layer.
5 . The stator as claimed in claim 1 , wherein
in the current path of the first type,
the first leg portion of the second current path portion follows the last leg portion of the first current path portion along the second circumferential direction, and/or the first leg portion of the third current path portion follows the last leg portion of the second current path portion along the first circumferential direction, or
the first leg portion of the second current path portion follows the last leg portion of the first current path portion along the first circumferential direction, and/or the first leg portion of the third current path portion follows the last leg portion of the second current path portion along the second circumferential direction.
6 . The stator as claimed in claim 1 , wherein
one current path is formed as a second current path of the first type, wherein the outer leg portions of the current paths of the first type are arranged in the same winding zones.
7 . The stator as claimed in claim 6 , wherein
one of the outer leg portions of the first current path of the first type connected in series with one of the outer leg portions of the second current path of the first type, or the first current path of the first type and the second current path of the first type are connected in parallel.
8 . The stator as claimed in claim 6 , wherein
the leg portions of the first current path of the first type and of the second current path of the first type occupy each layer in all winding zones of the same strand, and/or
the leg portions of the second current path portion of each one of the current paths of the first type occupy all winding zones of the same strand in each double layer, and/or
the number of leg portions arranged in that double layer which comprises the reference layer, of the first and third current path portions each one of the current paths of the first type corresponds to the number of winding zones of one of the strands.
9 . The stator as claimed in claim 1 , wherein
one current path is formed as a current path of a second type, in which the reference layer is the first layer and the reference direction is the first circumferential direction, and
the first leg portion of the second current path portion follows the last leg portion of the first current path portion in the opposite circumferential direction in relation to the current path of the first type, and/or
the first leg portion of the third current path portion follows the first leg portion of the second current path portion in the opposite circumferential direction in relation to the current path of the first type.
10 . The stator as claimed in claim 9 , wherein
one current path is formed as a second current path of the second type, and
each strand has first and second current paths of the first type and first and second current paths of the second type, or
one subset of the strands has first and second current paths of the first type and one subset of the strands has first and second current paths of the second type.
11 . The stator as claimed in claim 1 , wherein
one current path is formed as a current path of a third type, in which the reference layer is the L-th layer and the reference direction is the second circumferential direction.
12 . The stator as claimed in claim 11 , wherein,
in the current path of the third type,
the first leg portion of the second current path portion follows the last leg portion of the first current path portion along the same circumferential direction as in the current path of the first type, and/or the first leg portion of the third current path portion follows the last leg portion of the second current path portion in the same circumferential direction as in the current path of the first type, and/or
the outer leg portions are arranged in the same winding zones as in the current path of the first type.
13 . The stator as claimed in claim 11 , wherein
one current path is formed as a second current path of the third type, wherein the outer leg portions of the current paths of the third type are arranged in the same winding zones, and/or the number of leg portions of the first current path portion of the current paths of the first type and of the current path of the third type in one subset of the strands differs from that number in another subset of the strands.
14 . The stator as claimed in claim 10 , wherein
the current paths of the first type and the current paths of the second or third type occupy all winding zones of the same strand, and/or
the leg portions of the second current path portion of each one of the current paths of the first type and of each one of the current paths of the second or third type occupy half of the winding zones in each double layer, and/or
the number of leg portions, arranged in that double layer which comprises the reference layer, of the first and third current path portions of each one of the current paths of the first type and of the current paths of the second or third type corresponds to half of the number of winding zones of one of the strands.
15 . The stator as claimed in claim 1 , wherein
each shaped conductor integrally forms two of the leg portions and one of the connecting portions provided on the first end side and the connecting portions provided on the second end side are formed by electrically conductive and mechanical, in particular cohesive, connection of two of the shaped conductors, wherein
each one of the outer leg portions of the at least one current path is connected, by one of the connecting portions provided on the first end side, to that leg portion which is directly connected to said outer leg portion by the series connection, and/or
the last leg portion of the first current path portion and the first leg portion of the second current path portion of the at least one current path are connected by one of the connecting portions provided on the first end side, and/or
the last leg portion of the second current path portion and the first leg portion of the third current path portion of the at least one current path are connected by one of the connecting portions provided on the first end side, and/or
the stator furthermore comprises a connection device which contacts at least a subset of the outer shaped conductors of the at least one current path of each one of the strands in order to feed in a multi-phase AC voltage at the second end side, and/or
a pair of first and last leg portions, arranged in the same winding zones and in the same layer, of different current paths are formed a shaped conductor arrangement composed of a first of the shaped conductors, the leg portions of which are spaced apart by a specified number of slots), and a second of the shaped conductors, the leg portions of which are spaced apart by a number of slots that is lower than the specified number, wherein the connecting portion, provided on the first end side, of the second shaped conductor is arranged axially between the stator core and the connecting portion, provided on the first end side of the first shaped conductor, and/or
a pair of first and last leg portions, arranged in the same winding zones and in the same layer, of different current paths are formed a shaped conductor arrangement composed of a first of the shaped conductors, the leg portions of which are spaced apart by a specified number of slots and a second of the shaped conductors, the leg portions of which are spaced apart by a number of slots that is lower than the specified number, wherein the shaped conductors of the shaped conductor arrangement each have two oblique portions which each adjoin one of the leg portions and extend in the axial direction pointing away from the stator core and in the circumferential direction wherein each one of the oblique portions is adjoined by an axial portion which extends further axially away from the stator core than the connecting portions formed by the other shaped conductors, wherein each one of the axial portions is adjoined by a radial portion which covers the other shaped conductors, and the radial portions are connected by a bridge portion which extends along the other shaped conductors in the circumferential direction, wherein the connecting portion of the first shaped conductor borders the connecting portion of the second shaped conductor.
16 . The stator as claimed in claim 2 , wherein
the leg portion or the leg portions of the first current path portion of the at least one current path occupies or occupy only that double layer which comprises the reference layer, and/or
the leg portions of the second current path portion of the at least one current path occupy each double layer, and/or
the leg portions of the third current path portion of the at least one current path occupy each double layer, and/or
the plurality of leg portions, which are successive in terms of the series connection, of the first current path portion of the at least one current path occupy immediately adjacent winding zones of the same strand along that circumferential direction which is opposite to the reference direction.
17 . The stator as claimed in claim 2 , wherein
the outer leg portions of the at least one current path are arranged in immediately adjacent winding zones of the same strand and/or in different layers of the same double layer.
18 . The stator as claimed in claim 2 , wherein
in the current path of the first type,
the first leg portion of the second current path portion follows the last leg portion of the first current path portion along the second circumferential direction, and/or the first leg portion of the third current path portion follows the last leg portion of the second current path portion along the first circumferential direction, or
the first leg portion of the second current path portion follows the last leg portion of the first current path portion along the first circumferential direction, and/or the first leg portion of the third current path portion follows the last leg portion of the second current path portion along the second circumferential direction.
19 . The stator as claimed in claim 2 , wherein
one current path is formed as a second current path of the first type, wherein the outer leg portions of the current paths of the first type are arranged in the same winding zones.
20 . The stator as claimed in claim 7 , wherein
the leg portions of the first current path of the first type and of the second current path of the first type occupy each layer in all winding zones of the same strand, and/or
the leg portions of the second current path portion of each one of the current paths of the first type occupy all winding zones of the same strand in each double layer, and/or
the number of leg portions, arranged in that double layer which comprises the reference layer, of the first and third current path portions of each one of the current paths of the first type corresponds to the number of winding zones of one of the strands.