DE102017218202A1

DE102017218202A1 - Stator for an electric machine

Info

Publication number: DE102017218202A1
Application number: DE102017218202.4A
Authority: DE
Inventors: Stefan Reuter; Carsten Dotzel
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2017-10-12
Filing date: 2017-10-12
Publication date: 2019-04-18
Also published as: WO2019072471A1

Abstract

Embodiments relate to a stator for an electric machine. The stator (1) comprises at least one laminated core, which has a plurality of grooves. In the grooves of the laminated core, a winding (4) is arranged. The winding (4) comprises at least a first sub-branch (5) with a first starting point (6) and a second sub-line (7) with a second starting point (8), wherein the first starting point (6) of the first sub-branch (5) in the circumferential direction at an angle to the second starting point (8) of the second sub-string (7) is arranged.

Description

The invention relates to a stator for an electric machine.
Stators are used in a variety of electrical machines. Demands on electrical machines are usually made in terms of torque and power. The power and torque of an electric machine depend on an applied voltage and available current. However, the applied voltage is often a "fixed" parameter resulting from the available battery voltage. Nevertheless, in order to be able to realize high performances, the flowing current can be increased. This usually requires a large cable cross-section, based on an entire cable cross-section of a winding of the stator, in order to be able to "carry" the current.
There are different ways to increase the current at the same sheet metal section of the stator available. One possibility is to provide large wire cross sections. This may be detrimental in adverse circumstances to large current displacement effects and / or losses. Another possibility is to provide small conductor cross sections and to increase a number of layers of the winding of the stator. As a result, however, an effective winding length, such as a length of the winding, can also be increased. This can be undesirable.
Due to the limited number of sub-strings in conventional stators of electrical machines, which may also be referred to as E-machine, a variability in terms of a number of layers and number of turns of the winding of the stator is limited. At high speeds and / or frequencies unfavorable circumstances can lead to unfavorable effects with respect to current displacement in conventional stators.
Such a stator is for example from the US 2015/0076953 A1 known. In this stator connecting wires are designed as so-called hairpins. The connection of the connecting wires is complex. In particular, it is necessary that the connecting wires are designed on a twisting side as special pins in order to enable an orderly contacting. In order to be able to ensure sufficient contacting of the connecting wires with each other, several layers of connecting wires would have to be arranged one above the other. The space required for the stator is therefore relatively large.
Therefore, there is a need to improve the structure of a stator for an electric machine. Wear this need carries the subject matter of the independent claim bill.
The stator for an electric machine according to the invention comprises a laminated core which has a plurality of grooves. In the grooves of the laminated core, a winding is arranged. The winding comprises at least a first sub-string with a first starting point and a second sub-string with a second starting point. The first starting point of the first sub-string is offset from the second starting point of the second sub-string in the circumferential direction by an angle. In some embodiments, this can be made possible by providing an interconnection concept which makes it possible to form any number of sub-strands in a stator. As a result, under certain circumstances, a ratio between a total cross section of the winding and individual cross sections of conductor sections, which form the overall cross section of the winding, can be improved. This may be possible, for example, because a number of the parallel sub-strands and a number of layers of the winding can be increased. For example, a large overall cross section of the winding may be desired to increase power of the electric machine.
The idea of the present invention lies in a winding scheme, with which any number of partial strands can be realized. Because a plurality of starting points are provided, in some embodiments, a number of partial strands can be increased.
As a laminated core can serve, for example, each component which is designed to receive the winding. For example, the laminated core may be formed as a circular cylindrical ring. The ring may have on its radially inwardly facing side a plurality of regularly arranged grooves. The grooves or a largest extent of the grooves can be arranged parallel to a rotation axis of the laminated core. The grooves can be closed radially outward. In the circumferential direction, two directly adjacent grooves can be delimited from each other by a partition wall. The laminated core can have more than 50, for example 54 or 72 grooves. Eventually, the laminated core can be formed one or more parts.
The angle by which the first starting point is spaced from the second starting point may, in some embodiments, be greater than an angle including one, two, three, four, or five directly adjacent grooves. Two directly adjacent components, for example, two directly adjacent grooves, for example, arranged such that no further groove or another identical component is arranged in between. Two starting points, which are arranged at a distance from one another in the circumferential direction, can be arranged, for example, in the circumferential direction mechanically or geometrically spaced from each other.
For example, the winding may be understood to mean any multilayer wiring arrangement in the stator that is configured to form south and north poles alternately circumferentially adjacent to one another when subjected to current or voltage. In this case, for example, a north pole via two directly adjacent grooves and a south pole also extend over two directly adjacent grooves. In each groove, a plurality of layers of the winding may be arranged. A number of the layers may not be limited and may be evenly scalable. All grooves of the laminated core, for example, be filled with the same number of layers.
For example, a starting point can be understood to mean any part of the winding which is designed to serve as an input for a voltage source.
For example, the starting point can be directly connectable to a power connection.
In addition, the angle by which the first starting point is spaced from the second starting point may be 360 ° divided by the number of circumferentially spaced starting points. In some embodiments, this may enable the starting points to be arranged symmetrically or at least uniformly distributed relative to one another.
In some embodiments, the winding comprises two, three, four, five or more sub-strands with circumferentially offset by the angle arranged starting points. In some embodiments, this can increase the overall cross section of the winding and thus the power of the electric machine with the stator. In other words, the stator may have two, three, four, five or more starting points for sub-strands. The stator or its winding may in some embodiments include any number of sub-strands.
In some further embodiments, two partial strands are arranged at each starting point. Under certain circumstances, this can increase the number of partial strands, the overall cross section of the winding and thus the power of the electrical machine. A first sub-strand at the starting point can then be arranged, for example, from radially inward to radially outward, and a second sub-strand, which begins at the starting point, can then be arranged, for example, extending from radially outward to radially inward. Furthermore, the first sub-string can be arranged in the circumferential direction in opposite directions to the second sub-string. Each of the substrings starting at a common start point of a phase can be interconnected in parallel. An end of the first sub-string is then not contacted or electrically connected to the beginning of the second sub-string but directly to a power source. In other words, a second sub-string is then arranged separately from the first sub-string, with the beginning within the same starting point / angle range. The two sub-strings of a start point of a phase can also be connected in series. One end of the first sub-string and the beginning of the second sub-string are then contacted with each other or electrically connected. The second sub-string then represents an extension of the first sub-string. For interconnecting the sub-strings, the stator may comprise, for example, power electronics. The connections of the power electronics for all sub-connections can then, along the axis of rotation of the stator, be arranged on the same side of the stator. The power connection can be realized, for example, via a cable harness, a plug-on power board or via connecting elements (jumpers) as an attachment. The power electronics may, for example, be electrically connected to the ends of the connecting wires, for example the wire ends.
Additionally or alternatively, the winding may comprise three phases, for example U, V and W. At least one or each of the phases comprises at least two sub-strands. In some embodiments, as a result of a phase comprising at least two sub-strands, an overall line cross-section of the winding can be increased. For example, each phase may include or be formed by a plurality of sub-strands. The substrings within a phase and / or the substrings starting at a common starting point may be connected in parallel or in series with each other. An electrical property of the stator, for example star, delta connection, of the phases can be achieved in some embodiments by the power connection formed as an attachment. The starting points which are spaced apart from each other in the circumferential direction by the angle may, for example, only be starting points which belong to one phase. A sub-string can, for example, run through all the layers of the winding. A starting point of a sub-string may be, for example, at the radially outermost position, that is, for example, in the first position or in the radially innermost position, in a winding having six layers, in the sixth position.
In some embodiments, the sub-string includes a plurality of arcs. An arc includes a plurality of U-shaped connecting wires. A connecting wire may include a first leg and a second leg, wherein the first leg and the second leg are spaced apart on an open side of the connecting wire and connected together at a closed side via a connecting piece. The first leg of the connecting wire is arranged in a first position n of the winding and the second leg in a position n + 1 of the winding. In some embodiments, a relatively simple construction of the sub-string can thereby be made possible. All partial strands of a winding of the stator can have the same number of arcs. All arcs may have the same number of bond wires. Two directly adjacent connecting wires are connected in series. The connection point between two connecting wires can for example be referred to as contacting area. For this purpose, the second leg of the first connecting wire is connected to the first leg of a second connecting wire. The connection of the legs in the layers can for example be such that a partial displacement takes place in the form of a change in a twist angle of the legs in the tangential direction. In some embodiments, a shift of the Kontaktierbereiche between the individual connecting wires or arches can be made possible. This can be useful, for example, to avoid that several Kontaktierbereiche mechanically collide.
The legs of the connecting wires may have a length which is greater than a maximum extension of a groove of the laminated core. All connection wires of the winding are in some embodiments arranged such that all open sides are arranged on a first side of the stator and all connection pieces are arranged on an opposite side of the stator along the axis of rotation. In some embodiments, this can make it possible that no additional connections, for example in the form of bridges, are necessary on the stator for the basic structure of the winding. Furthermore, it may possibly also be possible for the contacting regions to lie predominantly in one plane, both radially and axially. As a result, in some embodiments, a compact construction and a concomitant small space requirement can be achieved.
A length of the arc may result in some embodiments of a ratio of a number of holes of the stator and a number of starting points of the stator. In some embodiments, this can be achieved by arranging and arranging all the arcs in an electrically symmetrical manner. The length of the arc may, for example, relate to a circumference of the stator, for example how often the arc orbits the stator or the laminated core. For example, the number of holes may indicate how many slots per pole and phase are provided in succession. The number of holes may be, for example, 1, 2, 3, 4 or 5. For example, with a hole number of 2, a left and a right groove, which are arranged directly adjacent, may be provided per pole for each phase. For example, with a hole number of 3, a left, a middle and a right-hand groove, which are arranged directly adjacent, may be provided per pole for each phase.
The arc can run X times around the stator or the laminated core. In some embodiments, the first leg of a first connection wire is spaced about x slots from the second leg of the connection wire, and the first leg of another connection wire is spaced x + 1 slots from the second leg of the further connection wire or the second leg of the first connection wire. This may be the case, in particular, at a position where the arc overlaps in the circumferential direction with a starting point. In some embodiments, by performing an extended or shortened winding step, for example, when the arc crosses a start point, an interconnection jump may be performed. Due to the interconnection jump, in some embodiments it can be achieved that all slots of a pole are filled with the winding. A Verschaltungssprung can for example be designed such that a leg of the connecting wire performs the Verschaltungssprung, instead of a right-hand groove in a left-hand groove or instead of a middle groove in a left-hand groove of a pole is arranged. Despite the mechanical jumps, the winding may be electrically symmetric in some embodiments. In some embodiments, the interconnect jump may be accomplished via a shortened or extended winding step.
Additionally or alternatively, the arc can be arranged within a double layer of the winding. In this case, a double layer comprises a first layer n of the winding and a second, directly adjacent layer n + 1 of the winding. In some embodiments, this can be achieved in that the winding is constructed electrically symmetrical. A position of the winding may, for example, describe a position of the leg of the connecting wire in the groove of the laminated core in the radial direction. The first layer (n = 1) can be arranged, for example, at one end of the groove, ie radially outermost. Radially inside can the Numbering of the layers increase. A connecting wire of a sheet is connected in series with the preceding connecting wire of the sheet and the subsequent connecting wire of the sheet. The free ends of the sheets, which are not connected to other connectors in the same double layer, constitute an end or beginning of the sheet.
In addition, the winding may comprise at least a first double layer and a second double layer directly adjacent to the first double layer, wherein the first double layer comprises two directly adjacent layers n and n + 1 and the second double layer comprises two layers n + 2 and n + 3. At a transition between two double layers, a first sheet and a second sheet may be connected in series with each other. In some embodiments, such a symmetrical winding can be constructed. A start of an arc can therefore be recognized in a completely assembled stator, for example, in that the two legs of a connecting wire are arranged in a different double layer, as the two legs of a preceding connecting wire.
Embodiments also relate to an electric machine with the stator according to one of the preceding embodiments.
The embodiments disclosed in the foregoing description, the appended claims and the appended figures, as well as their individual features, may be relevant and implemented both individually and in any combination for the realization of an embodiment in its various forms.
Thus, the figures show schematically the following views:

1a a schematic representation of a stator according to an embodiment;
1b a schematic representation of a stator according to another embodiment;
1c a schematic representation of a conventional stator;
2 to 5 different schematic representations of perspective views of a stator according to the embodiment of the 1a in the manufacture of a winding of the stator;
2a a schematic representation of a perspective view of a connecting wire, for a winding of a stator according to an embodiment;
6 a schematic representation of a perspective views of a stator according to an embodiment with a winding of the stator of a phase;
6a a schematic representation of an enlarged section of the 6 ;
7 a schematic representation of a stator according to an embodiment with a power connection;
8a a schematic representation of a circuit diagram of a first sub-string at a first starting point of the stator according to the embodiment of 6 ;
8b a schematic representation of a phase of the stator according to the embodiment of 6 ;
8c a schematic representation of a section of a sectioned view of the stator according to the embodiment of the 6 wherein only the first sub-string is displayed at the first starting point;
9a a schematic representation of a circuit diagram of a second sub-string at the first starting point of the stator according to the embodiment of the 6 ;
9b a schematic representation of a section of a sectioned view of the stator according to the embodiment of the 6 wherein only the second sub-string is displayed at the first starting point;
10a a schematic representation of a circuit diagram of a first sub-string at a second starting point in a stator according to the embodiment of 6 ;
10b a schematic representation of a section of a sectioned view of the stator according to the embodiment of the 6 wherein only the first sub-string is displayed at the second starting point;
11a a schematic representation of a circuit diagram of a second sub-string at the second starting point of the stator according to the embodiment of the 6 ; and
11b a schematic representation of a section of a sectioned view of the stator according to the embodiment of the 6 wherein only the second sub-string is superimposed at the second starting point.

In the following description of the accompanying drawings, like reference characters designate like or similar components. Further, summary reference numerals are used for components and objects that are multiple in one embodiment or in one Representation occur, however, be described together with respect to one or more features. Components or objects which are described by the same or by the same reference numerals may be the same, but possibly also different, in terms of individual, several or all features, for example their dimensions, unless otherwise explicitly or implicitly stated in the description.
The 1a shows a schematic representation of a stator 1 for an electric machine according to an embodiment. The stator 1 usually includes three phases U . V and W , In the following, only the schematic structure of a phase, for example U described. The other two phases can of course be constructed analogously.
The stator 1 includes an in 2 illustrated laminated core 2 that has a plurality of grooves 3 having. In the grooves 3 of the laminated core 2 is a winding 4 arranged. The winding 4 includes at least a first sub-string 5 with a first starting point 6 and a second sub-string 7 with a second starting point 8th , The first starting point 6 of the first sub-string 5 is in the circumferential direction U around an angle α spaced to the second starting point 8th of the second sub-string 7 arranged. The circumferential direction U is on a circumference of the stator 1 or the laminated core 2 based. In the embodiment of the 1a the angle α = 180 °.
At each of the starting points 6 and 8th is another sub strand 9 and 10 arranged. For clarity, the other sub-strands 9 and 10 radially inward of the partial strands 5 and 7 shown. When the substrings are implemented in the lamination stack, the substrings are 5 and 7 arranged so that they extend from radially outside to inside. The current flows in the substrings 5 and 7 then in a first direction. The other sub-strands 9 and 10 are arranged such that they extend from radially inward to radially outward. The current flows in the other sub-strands 9 and 10 in a second direction opposite to the first direction.
The interconnection of the partial strands 5 . 7 . 9 and 10 For example, can be made such that the sub-strands 5 and 7 at the starting points 6 and 8th via a supply line 11 be charged with voltage. The partial strands 5 and 7 are at their ends respectively with the second sub-string 9 or. 10 their starting point in series. This series connection of the partial strands 5 and 9 or. 7 and 10 is with the arrow 13 characterized. A derivative 12 takes place in each case at the ends of the second partial strands 9 and 10 , In some embodiments, the further sub-strands 9 and 10 at the starting points 6 and 8th also omitted. Depending on the embodiment, by arranging the two mutually offset starting points 6 and 8th two or even four strands per phase are provided. Alternatively, the partial strands 5 . 7 . 9 and 10 be connected in parallel, such as in the 8b shown.
The 1b shows a schematic representation of a stator 1-a for an electrical machine according to a further embodiment. The stator 1-a is substantially similar to the stator 1 built, but includes another, third starting point 14 , For the same or similar components or elements, therefore, the reference numerals as in 1 forgive. Unlike the stator 1 includes the winding 4 of the stator 1-a not just the two in the circumferential direction U spaced starting points 6 and 8th , but a third, further starting point 14 on which a third substrand 15 starts. Also at the third starting point 14 is in addition to the third sub-string 15 another sub strand 16 arranged. The interconnection of the individual partial strands is analogous to that for the stator 1 the 1a described.
The three starting points 6 . 8th and 15 are each about the angle α spaced apart. In the embodiment of the 1b the angle α = 120 °. In other embodiments, the starting points may also be spaced apart from each other by a different angle. The number of starting points per phase can specify the angular position of the starting points to each other. For example, for the angle α the angular offset between the starting points of a phase is: $α = 360 ° / Number of starting points of a phase .$
with the number of starting points meant the starting points, in the circumferential direction U offset from one another.
The other sub-strands 9 . 10 and 15 may also be omitted in some embodiments. As in the embodiment of 1b can be seen, by providing a third starting point, three or six sub-strands per phase can be arranged. In further embodiments, not shown, four or eight partial strands per phase can be provided, for example, by a fourth starting point.
The 1c shows a schematic representation of a conventional stator 17 , with a winding 18 that only have one starting point 19 having. Compared to the conventional stator 17 can be made with the winding diagram according to one of the embodiments, possibly electric machines with the same characteristic, the smaller conductor cross-section and thus a smaller Have current displacement. By doubling the layers, for example, a halved conductor cross-section can result for the same groove. As a result, however, in some embodiments, the sub-strands must be doubled, otherwise a number of turns of the winding would double and thus the length of the sub-string.
Based on 2 to 5 will be the manufacture of the winding 4 of the stator 1 of the embodiment of 1a described. The winding 4 includes the substrings 5 . 7 . 9 and 10 as already on the basis of 1 a explained. Each sub-string includes a plurality of arcs. Each arch includes a variety of connecting wires 20 , The production of a first bow 29 of the first sub-string 5 at the first starting point 6 is determined by the 2 to 4 explained.
The 2a shows a schematic representation of a perspective view of the connecting wire 20 , which can also be referred to as a hairpin, for the winding 4 of the stator 1 , The connecting wire 20 is substantially U-shaped and includes a first leg 21 and a second leg 22 , The two thighs 21 and 22 have sections 21-a and 22-a on, which are arranged parallel to each other. These sections 21-a and 22-a serve to move in the axial direction along the axis of rotation R overlapping in the grooves 3 to be included. On an open page 23 are the two thighs 21 and 22 spaced apart. Opposite to the open side 23 are the thighs 21 and 22 via a connector 24 connected with each other. At their free ends, the legs 21 and 22 one contact area each 25 and 26 on. Also the Kontaktierbereiche 25 and 26 are parallel to each other and to the parallel sections 21-a and 22-a arranged. The contact areas 25 and 26 are each about a bending section 27 and 28 with the parallel sections 21-a and 22-a connected so that the Kontaktierbereiche 25 and 26 in the axial direction higher than the parallel sections 21-a and 22-a are arranged. The contact areas 25 and 26 are from a central axis M of the connecting wire 20 From the perspective of the parallel sections 21-a and 22-a offset outwards so that the Kontaktierbereiche 25 and 26 are spaced further apart than the parallel sections 21-a and 22-a ,
In the 2 is the laminated core 2 of the stator 1 shown. The laminated core 2 points with respect to its axis of rotation R an annular cross-sectional area. At a radially inwardly facing surface of the laminated core 2 has the laminated core 2 the grooves 3 on, parallel to the axis of rotation R are arranged. At the stator 1 includes the laminated core 72 Grooves. In some other, not shown embodiments, the laminated core may also have a different number of grooves, for example more or less, for example 54 respectively.
To the bow 29 to produce a first connecting wire 20 , as in 2 shown in the laminated core 2 , which can also be referred to as a laminated stator core, joined. This will be the first leg 21 in a first groove 3-a and the second leg 22 of the connecting wire 20 in a second groove 3-b arranged. The second groove 3-b is from the first groove 3-a in the circumferential direction U spaced by nine grooves. This indicates the first connecting wire 20 or have its legs 21 and 22 a winding step of nine.
The first connecting wire 20 is so on the laminated core 2 arranged that the parallel sections 21-a and 22-a in the axial direction with the grooves 3 overlap. On one end of the stator 1 protrudes the connector 24 in the axial direction over an axial extension of the laminated core 2 out. On the opposite side in the axial direction of the stator 1 protrude the bending section 27 and 28 and the Kontaktierbereiche 25 and 26 in the axial direction over the laminated core 2 out.
The parallel section 21-a of the first thigh 21 of the first connection wire 20 is at a radially outermost position of the groove 3-a arranged, also called the first layer of the winding 4 can be designated. The parallel section 22-a of the second leg 21 of the first connection wire 20 is from a radial end 29 the groove 3-b spaced apart. Between the radial end 29 the groove 3-b and the parallel section 22-a of the second leg 21 of the first connection wire 20 is in the groove 3-b there is still room to accommodate exactly one additional leg of another connecting wire. This is the parallel section 22-a of the second leg 21 of the first connection wire 20 in a second position of the winding 4 arranged.
The two thighs 21 and 22 of the first connecting wire 20 can over the bending sections 27 and 28 to be twisted. By widening the ends, a connection with other connecting wires of the winding can be facilitated or made possible. In some embodiments, the widening of the ends may take place in front of the connecting wire is arranged on the laminated core or only when the connecting wire is already arranged on the laminated core.
As in 3 shown, becomes a second connecting wire 20-a on the laminated core 2 arranged. The connecting wire 20-a is as well as all other connecting wires, to which below Reference is made, identical to the connecting wire 20 educated.
The arrangement of the second connection wire 20-a is substantially similar to the arrangement of the first connection wire 20 , The first leg 21 of the second connection wire 20-a will be in a groove 3-c arranged in the first position. The second leg 22 of the second connection wire 20-a will be in a groove 3-d arranged in the second layer. The groove 3-b is nine grooves from the groove 3-c in the circumferential direction U spaced. The groove 3-c is nine grooves from the groove 3-d in the circumferential direction U spaced. So that's the two connecting wires 20 and 20-a each arranged in the same winding step. A first contact area 25-a of the second connection wire 20-b is in the circumferential direction U overlapping with the second contacting region 26 of the first connection wire 20 arranged. The two contact areas 25 and 26 can be electrically connected to each other to the first connecting wire 20 and the second connecting wire 20-a to be connected in series.
The 4 shows the laminated core 2 on which a complete bow 29 is arranged. The arc 29 includes exactly six connecting wires 20 . 20-a . 20-b . 20-c . 20-d . 20-e , The connecting wires 20-b . 20-c . 20-d and 20-d are essentially analogous to the bonding wires 20 and 20-a arranged. In this case, a contacting region overlaps 26-a of the second leg of the second connecting wire 20-a in the circumferential direction U with a contact area 25-b a first leg 21 a third connecting wire 20-b , The contact area 26-b of the second leg 21 of the third connecting wire 20-b overlaps in the circumferential direction with a Kontaktierbereich 25-c of the first thigh 21 a fourth connecting wire 20-c , The contact area 26-c of the second leg 22 of the fourth connecting wire 20-c overlaps in the circumferential direction with a Kontaktierbereich 25-d a first leg 21 a fifth connecting wire 20-d , The contact area 26-d of the second leg 22 of the fifth connecting wire 20-d overlaps in the circumferential direction with a Kontaktierbereich 25-e a first leg 21 a sixth connecting wire 20-e , The contact area 26-e of the second leg 22 of the sixth connecting wire 20-d puts an end to it 31 of the bow 29 dar. The contact area 25 of the first thigh 21 of the first connection wire 20 represents the beginning or starting point 6 of the bow 29 and thus also of the substring 5 represents.
To the bow 29 To form, the contacting portions of the connecting wires, which are arranged in the first layer, with the contacting portions of the adjacent connecting wires, which are arranged in the second layer, electrically connected to each other, for example, welded. In other words, all connecting wires 20 of the bow 29 connected in series. The arc 29 So runs counterclockwise on the laminated core 2 along and around this one and a half times.
In other embodiments, the arch may be with respect to the laminated core 2 have a different length. Inside the winding 4 however, all arcs may be the same length. In general, the length of the bow 29 based on the circumference of the laminated core 2 express as follows.
Basically, an arc runs X times around the laminated core. When crossing a starting point of the arc can make a Verschaltungssprung, for example in the form of a shortened or an extended winding step. The X depends on a number of holes of the stator and a number of starting points. A number of holes is understood to be the number of slots provided directly adjacent to one pole per phase.
For a stator with the number of holes 2 For example, the grooves may be provided as follows: 2 * U, 2 * V, 2 * W, 2 * U, 2 * V, 2 * W. etc. If a stator with a hole number of 2 has two starting points, then the arc rotates the laminated core once in total. First, the arc rotates one half of the laminated core, then a Verschaltungssprung, for example, from a right U-groove to a left U-groove performed (lost motion). The arc runs around the other half of the laminated core, then follows a Verschaltungssprung for example, from a left U-groove, for example in position 2 in a left U-groove, for example in position 3 , Overall, each bow can run once around the laminated core before jumping in or out.
For a stator, the number of holes 3 For example, the slots may be arranged as follows: 3 × U, 3 × V, 3 × W, 3 × U, 3 × V, 3 × W, etc. When the stator is the number of holes 3 has two starting points, then the arc rotates the laminated core a total of 1.5 times. First, the arc rotates the laminated core half a time, then a Verschaltungs jump from a right U-groove to a middle U-groove (lost motion). The arc continues to run halfway around the laminated core and again leads to an interlocking jump, for example from a central U-groove to a left U-groove (lost motion). The arc revolves the stator a further half times before a renewed Verschaltungssprung, for example, from a left U-groove in position 2 to a left U-groove in position 3 he follows. Overall, each arc passes once around the stator before jumping in or out.
For example, the following formula can be used for the calculation: $X = (Number of holes / number of starting points);$
where X is the length of the arc with respect to the circumference of the laminated core.
Furthermore, each connecting wire leads 20 to 20-e of the bow 29 a jump of location 1 on the location 2 to the formation of the bow 29 by. On the side of the laminated core 2 on the open side 23 the connecting wires 20 are arranged, a layer jump within the connection wire 20 and to the contact point 25 and 26 between the connecting wires 20 allows. By a jump of the bow 29 or the connecting wires 20 from the first layer to the second layer, the laminated core 2 of the stator 1 with the winding 4 be rounded. In most cases, the same winding step is performed. In other words, the two thighs 21 and 22 the connecting wires 20 usually around the same number of grooves 3 , For example, nine in the embodiment of the figures, spaced apart, as already for the legs in the grooves 3-a . 3-b . 3-c and 3-d described. This applies analogously to a contact side, such as the side on which the connectors 24 are arranged, and also a crown side or turning area side, as can be called the side on which the open ends 23 the connecting wires 20 protrude.
In places where the bow 29 the starting point 6 is a shortened winding step 30 executed. The second leg 22-c of the fourth connecting wire 20-c is from the first leg 21 of the fifth connecting wire 20-d only eight grooves 3 spaced apart. Analog finds a shortened winding step 30 also between the second leg 22 of the second connection wire 20-a and the first leg 21-b of the third connecting wire 20-b instead of. Although the winding steps 30 are shortened overlap the Kontaktierbereiche 25 and 26 nevertheless in the circumferential direction, so that an electrical connection is possible. To achieve this, for example, the bending sections 27 and 28 the affected connecting wires 20 be bent accordingly.
The shortened winding step 30 causes all grooves 3 the phase can be filled. Would always be carried out the same winding step, so all thighs always by the same number of grooves 3 spaced from each other, the winding would 4 again exactly to the starting point 6 come and not all grooves would 3 the phase of the laminated core 2 be filled. By shortened and / or extended jumps, the winding can after a certain number of stator passes 4 be continued, so that the grooves 3 next to the starting point 6 to be served. To the winding 4 must be able to continue, every time the starting point 6 or another starting point of the winding 4 is crossed, a shortened and / or an extended winding step are performed so as not to block other connecting wires.
The 5 shows a schematic representation of the laminated core 2 the 2 to 4 , in addition to the first sheet 29 of the first sub-string 5 a second bow 32 of the second sub-string 7 is arranged. The second bow 32 starts in the second starting point 8th , The arc 32 is essentially analogous to the bow 29 trained, rotates the laminated core 2 but opposite to a direction in which the first arch 29 the laminated core revolves.
The beginning of the bow 32 in the starting point 8th forms the contact area 25-f on a first leg of a first connecting wire 20-f , The second leg of the first connecting wire 20-f with the contact area 26 is clockwise about eight grooves spaced from the first leg of the connecting wire 20-f arranged. This is already a shortened winding step at this point 30 executed. The arc 32 rotates the laminated core 2 , analogous to the bow 29 described one and a half times and points to the end 33 the contact area 26-z of the second leg 22-z of the sixth connecting wire 20-z on.
Every bow 29 or 32 is arranged within a double layer. By this is meant that each arch has only connecting wires which are in the same two layers 1 and 2 are arranged.
Based on 6 to 11b The production and construction of the partial strands are described below. For this purpose, reference is made to a stator which has a winding 4 comprising arcs that once orbit the laminated core. Otherwise, the stator is the 6 to 11 or its winding 4 analogous to the embodiment of the 2 to 5 built up. Therefore, the same reference numerals are used.
The 6 shows a schematic representation of the stator 1 in which for one phase, for example U at the two starting points 6 and 8th two sub-strands each 5 and 9 and 7 and 10 are arranged. In the 8b are the partial strands 5 . 9 . 7 and 10 presented within the phase. The partial strands 5 . 9 . 7 and 10 are arranged in a parallel connection in this embodiment. Each substring includes three arcs. In other, not shown embodiments, a sub-string also a different number of sheets and / or the sub-strands of the phase may be connected in series.
The arrangement of the arcs in the sub-string becomes representative of the first sub-string 5 the first starting point 6 , based on 6 . 6a . 8a and 8c described. The in 6 and 6a shown Kontaktierbereich 25 of the first leg of the first arch 29 represents a beginning 34 of the first sub-string 5 in the first starting point 6 dar. The beginning 34 of the first sub-string 5 in the first starting point 6 is disposed radially outward in the first layer.
The 8a shows a schematic representation of a circuit diagram of the first sub-string 5 , In the x direction, the grooves are the stator 1 shown as settlement and in y-direction are the layers of the winding 4 shown.
To the first substring 5 the first starting point 6 Finish is the first starting point 6 radially inward of the first arc 29 a second bow 49 assigned. The first bow 29 is within the layers 1 and 2 arranged, which can also be referred to as the first double layer. The second bow 49 is analogous to the first bow 29 formed, but includes only connecting wires in a third and fourth layer of the winding 4 , which can also be referred to as a second double layer, are arranged. A beginning 44 of the second arch 49 It is arranged so that it ends with one 43 of the bow 29 can be connected in series. A first leg of the first connecting wire of the second arc 49 can from the last leg of the first bow 29 for example, a normal winding step of nine grooves 3 or a shortened winding step 30 be spaced from eight grooves. Analogous to the first sheet 29 described, the second bow ends 49 at a transition between the second double layer comprising the third and fourth layers and a third double layer covering the fifth and sixth layers of the winding 4 includes. Radial within to the second arch 49 includes the first sub-string 5 a third bow 50 which has only connecting wires in a fifth and sixth position of the winding 4 are arranged. The third arch 50 comes with the second bow 49 connected in series. The end 45 of the second arch 49 is with a beginning 46 of the third arch 50 connected. The end of the third arch 50 puts an end to it 35 of the first sub-string 5 in the first starting point 6 dar. The end 35 lies radially inward in a sixth position of the winding 4 , The first sub-string 5 includes six layers, three arcs and runs counterclockwise from radially outside to radially inside. The joining of the sheets can be effected, for example, by means of an electrical connection to the contacting regions, for example brazing or welding can be used as the joining method. In some embodiments, the winding may also have further layers or double layers, for example, a fourth double layer.
The 8c shows a schematic representation of a section of a sectioned view of the stator 1 where only the first substring 5 at the first starting point 6 is displayed. Like in the 8c recognizable, occupies the first sub-string 5 only two directly adjacent grooves of the phase and only the odd layers 1 . 3 and 5 , The remaining layers of the two grooves and the adjacent grooves are filled by further partial strands and / or phases.
The other sub-strands 7 . 9 and 10 are essentially constructed analogously and are described below with reference to 6 and 9a to 11b briefly described with their differences.
A beginning 36 of the second sub-string 9 in the first starting point 6 is arranged radially inboard in the sixth position, as in the 6 and the winding scheme of 9a recognizable. The 9a shows analogous to the 8a a schematic representation of a circuit diagram of the second sub-string 9 at the first starting point 6 in the stator 1 , Again, this is a beginning 36 of the second sub-string 9 at the starting point 6 and an end 37 of the second sub-string 9 recognizable, as well as transitions of unspecified sheets between the double layers. An end 37 of the second sub-string 9 is arranged radially outboard lying in the first position. The second sub-string 9 includes six layers, three arcs, and runs clockwise from radially inward to radially outward.
The 9b shows a schematic representation of a section of a sectioned view of the stator 1 , where only the other substring 9 at the first starting point 6 is displayed. Like in the 9b recognizable, occupies the other sub-string 9 only two directly adjacent grooves of the phase and only the even layers 2 . 4 and 6 , The remaining layers of the two grooves and the adjacent grooves are filled by further partial strands and / or phases.
The 10a shows analogous to the 8a and 9a a schematic representation of a circuit diagram of the first sub-string 7 at the second starting point 8th in the stator 1 , Also in the 6 is a beginning 38 of the second sub-string 7 in the second starting point 8th and the end 39 of the second sub-string 7 recognizable. In the first double layer is the bow 32 arranged. A beginning 38 of the first sub-string 7 in the second starting point 8th is disposed radially outward in the first layer. An end of a third bow puts an end to it 39 of the first sub-string 7 of the second starting point 8th dar. The end 39 lies radially inward in a sixth position of the winding 4 , The first sub-string 7 includes six layers, three arcs and runs counterclockwise from radially outside to radially inside.
The 10b shows a schematic representation of a section of a sectioned view of the stator 1 , where only the first substring 7 of the second starting point 8th is displayed. Like in the 10b recognizable, occupies the first sub-string 7 only two directly adjacent grooves of the phase and only the odd layers 1 . 3 and 5 , The remaining layers of the two grooves and the adjacent grooves are filled by further partial strands and / or phases.
The 11a shows analogous to the 8a . 9a and 10a a schematic representation of a circuit diagram of the second sub-string 10 at the second starting point 8th in the stator 1 , Again, this is the beginning 40 of the second sub-string 10 at the starting point 8th and the end 41 of the second sub-string 7 as well as the transition of unspecified sheets in the double layers recognizable. The beginning 40 of the second sub-string 10 in the second starting point 8th is arranged radially inboard in the sixth position. The end 41 of the second sub-string 10 is arranged radially outboard lying in the first position. The second sub-string 10 includes six layers, three arcs, and runs clockwise from radially inward to radially outward.
The 11b shows a schematic representation of a section of a sectioned view of the stator 1 , where only the second substring 10 of the second starting point 8th is displayed. Like in the 11c recognizable, occupies the second sub-string 10 only two directly adjacent grooves of the phase and only the even layers 2 . 4 and 6 , The remaining layers of the two grooves and the adjacent grooves are filled by further partial strands and / or phases.
For the interconnection of the partial strands and / or the phases, for example, a in 7 shown power connection 48 be used. The power connection 48 For example, with the beginnings and ends of the double layers so the contact areas 25 and 26 the connecting wires to be electrically connected. For example, all beginnings and ends of the double layers can be on the same side of the stator 1 be arranged. With the power connection 48 For example, the analogous to the described phase U built-up phases V and W be connected.
In other embodiments, the sub-strands may also be arranged in a different winding scheme. Each sub-string can for example be the same structure and / or go through the stator the same number of times. Each sub-string occupies the grooves and layers identical in some embodiments, so that by the same position and grooves each sub-strand has the same electrical angle. As a result, in some embodiments, a large symmetry between the sub-strands and only minor circulating current losses can be achieved. Each sub-string may for example be distributed over the entire circumference of the stator, in comparison to a loop winding, which may for example be geometrically limited to only a portion of the stator. This allows a Deachsierung be achieved, which causes the individual sub-strands are loaded evenly.
Some embodiments relate to a stator with 3 phases ( U . V . W ), each phase corresponding to one strand. Each strand consists of any number of substrings. The winding of the stator comprises at least two starting points which are spaced apart by an angular range. All starting points have the same pole. In each starting point, at least one beginning of at least one sub-string of a phase is arranged. Each substring has any number of bends. An arc is formed on two successive layers, for example 1 + 2.3 + 4.5 + 6.7 + 8, etc. Each arc comprises a plurality of connecting wires, which may also be referred to as hairpins, with two conductor legs, such as the legs of the Bonding wire can also be called, are arranged in two different position. The three strings or phases can be interconnected as a star or a delta. An interconnection of the substrings of a phase takes place in each case in a starting point. The interconnection can be parallel or in series.
In general, in the production of the second sub-string in the first starting point of a first phase, the procedure may be as follows. A partial strand that starts radially outside (position 1 ) ends radially inward (position 6 ). Due to a meandering location 1 and 2 and then back again, in the grooves, either only even or odd-numbered layers, ie either the layers 1,3,5,7 etc. or 2,4,6,8 etc. fill. In order to fill the grooves of the laminated core completely, at each starting point / angle range, a second sub-strand can begin, from the radially inward (position 6 ) to radially outward (Lage1) runs. This sub-string is constructed exactly equal to the first sub-string, except that a strand output and input are reversed and the winding is mechanically offset by an angle which corresponds exactly to a pole angle.
Under certain circumstances, almost any number of parallel phase branches can be realized with the exemplary embodiments described. For example, a strand may be at a starting point both sub-strings are connected in series. In order to realize two strands, two sub-strands may be provided at a starting point in parallel or at two starting points one sub-strand or two sub-strands connected in series. In order to realize three strands, partial strands can be connected in series at three starting points. In order to realize four strands, partial strands can be connected in parallel at two starting points, or four starting points with series strands can be provided. In order to realize five strands, partial strands can be connected in series at five starting points. In order to realize six strands, partial strands can be connected in parallel at three starting points.
The embodiments disclosed in the foregoing description, the appended claims and the appended figures, as well as their individual features, may be relevant and implemented both individually and in any combination for the realization of an embodiment in its various forms. In some other embodiments, features disclosed as a device feature in other embodiments may also be implemented as method features. Further, features that are implemented as method features in some embodiments may also be implemented as device features in other embodiments.
LIST OF REFERENCE NUMBERS

1: stator
2: laminated core
3: groove
4: winding
5: first substrand
6: first starting point
7: second substrand
8th: second starting point
9: further sub-string
10: further sub-string
11: supply
12: derivation
13: series circuit
14: third starting point
15: third substrand
16: further sub-string
17: conventional stator
18: winding
19: starting point
20: connecting wire
21: first leg
22: second leg
23: open side
24: joint
25: contactor
26: contactor
27: bending section
28: bending section
29: arc
30: shortened winding step
31: End of bow 29
32: arc
33: End bow 32
34: begin 1 , starting point 1 , partial strand
35: The End 1 , starting point 1 , partial strand
36: begin 1 , starting point 2 , partial strand
37: The End 1 , starting point 2 , partial strand
38: begin 2 , starting point 1 , partial strand
39: The End 2 , starting point 1 , partial strand
40: begin 2 , starting point 2 , partial strand
41: The End 2 , starting point 2 , partial strand
43: End double layer 1 + 2
44: Beginning double position 3 + 4
45: End double layer 3 + 4
46: Beginning double position 5 + 6
48: power connection
49: second bow
50: third arch
α: corner
U: circumferentially
R: axis of rotation
M: central axis

QUOTES INCLUDE IN THE DESCRIPTION
This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.
Cited patent literature

US 2015/0076953 A1 [0005]

Claims

Stator for an electric machine with the following features: at least one laminated core (2) having a plurality of grooves (3); a winding (4) arranged in the grooves (3) of the laminated core (2), wherein the winding (4) has at least one first sub-strand (5) with a first starting point (6) and a second sub-strand (7) with a second starting point ( 8); wherein the first starting point (6) of the first sub-string (5) is arranged in the circumferential direction at an angle to the second starting point (8) of the second sub-string (7).
Stator after Claim 1 where the angle is 360 ° divided by the number of circumferentially spaced start points (6, 8).
Stator according to one of the preceding claims, wherein the winding (4) comprises two, three or four partial strands (5, 7) with circumferentially offset by the angle to each other arranged starting points (6, 8).
Stator according to one of the preceding claims, wherein at each starting point (6, 8) two partial strands (5, 9) are arranged.
Stator according to one of the preceding claims, wherein the winding (4) comprises three phases (U, V, W) and wherein at least one phase comprises at least two partial strands (5, 7).
Stator according to one of the preceding claims, wherein the sub-strand (5) comprises a plurality of arcs (29), wherein an arc (29) comprises a plurality of U-shaped connecting wires (20), wherein a connecting wire (20) has a first leg ( 21) and a second leg (22), wherein the first leg (21) and the second leg (22) on an open side (23) of the connecting wire (20) are spaced from each other and at a closed side via a connecting piece (24 ), wherein the first leg (21) in a first position n of the winding (4) and the second leg (22) in a position n + 1 of the winding (4) is arranged.
Stator after Claim 6 wherein each arc (29) has a length relative to a circumference of the stator (1) resulting from a ratio of a number of holes of the stator (1) and a number of starting points (6, 8) of the stator (1) ,
Stator after Claim 7 wherein the first leg (21) of a first connecting wire (20) is spaced x times from the second leg (22) of the connecting wire (20) and the first leg (21) of another connecting wire (20) is x + 1 slots ( 3) is spaced from the second leg (22) of the further connecting wire (20).
Stator according to one of the preceding claims, wherein an arc (29) within a double layer of the winding (4) is arranged, wherein the double layer comprises a first layer n and a second, directly adjacent layer n + 1 of.
Stator after Claim 9 wherein the winding (4) comprises at least a first double layer and a second double layer directly adjacent to the first double layer, and wherein the first double layer comprises two directly adjacent layers n and n + 1 and the second double layer comprises two layers n + 2 and n + 3 wherein a first sheet (29) and a second sheet (49) are connected in series, the first and second sheets (29, 49) being interconnected at a transition between two double layers.