DE102023200701A1 - Distributed winding for an electrical machine - Google Patents

Abstract

A distributed winding (10) for an electrical machine, comprising a coil body (11) with a plurality of slots (12) distributed over a circumference of the coil body, at least one winding strand (14) formed from a plurality of hair pins (13), wherein the hair pins (13) each have axially extending slot regions (13-N) which are arranged in the radial direction in different winding layers in the slots (12) of the coil body (11), and wherein the winding strand (14) has a connection region at each of its two ends, which is formed by one end of a respective connection hair pin (15) and protrudes axially beyond the coil body (11), wherein the connection hair pin (15) has a radial region (15-R) which runs in the radial direction and extends radially over one or more winding layers.

Description

The present invention relates to a distributed winding for an electrical machine, in particular for use in a motor vehicle with a hybrid drive consisting of an internal combustion engine and an electrical machine.

In addition to concentrated windings, electrical machines with distributed windings are also known in the state of the art. Distributed windings are usually manufactured using the so-called hairpin technology, in which several conductor elements (hairpins) are inserted into the grooves of a coil body and connected to form corresponding winding strands.

A distributed winding therefore comprises at least one winding strand formed from a plurality of hairpins, but usually several winding strands. The hairpins each have axially extending legs or groove areas that are arranged in the radial direction in different winding layers in grooves of the coil body. A winding strand has a connection area at each of its two ends, which is formed by one end of a respective connection hairpin and protrudes axially beyond the coil body.

Traditionally, the ends of the connection hairpins are all located either on the inner or outer diameter of a winding head, which limits the flexibility of a distribution of phase or star point connections.

An object of the present invention is to provide a distributed winding which can provide an improved flexibility of the distribution of phase or star point connections.

This object is achieved by devices and methods according to the independent patent claims. Advantageous further developments emerge from the dependent claims.

According to a first aspect, the present invention provides a distributed winding for an electrical machine. The distributed winding comprises a coil body with a plurality of slots distributed over a circumference of the coil body. The distributed winding further comprises at least one winding strand formed from a plurality of hairpins. The hairpins each have axially extending slot regions which are arranged in the radial direction in different winding layers in the slots of the coil body. The winding strand has a connection region at each of its two ends which is formed by one end of a respective connection hairpin and protrudes axially beyond the coil body. At least one connection hairpin of the winding strand has a radial region which runs in the radial direction and extends radially over one or more winding layers. The radial region of the connection hairpin(s) enables the desired flexibility in the distribution of phase or star point connections.

In a distributed winding, the winding strands overlap at the axially upper and lower ends of the coil body. This overlap area is also called the winding head. The radial area of the connection hairpin allows the proposed connection hairpin to be used to change from the inner to the outer diameter or from the outer to the inner diameter of a winding head across all winding layers, for example. A change from the inner diameter to an area between the inner and outer diameter or a change from the outer diameter to an area between the inner and outer diameter is also possible. This can provide increased flexibility in the distribution of phase or star point connections.

According to some embodiments, the radial region of the connection hairpin extends between a radially inner winding layer and a winding layer located radially further outward. For example, the radial region of the connection hairpin can extend between a radially innermost winding layer and a radially outermost winding layer.

According to some embodiments, the radial region of the connection hairpin extends from a radially inner (for example innermost) winding layer in the direction of a radially further outward winding layer, i.e. from the inside to the outside. As a result, the proposed connection hairpin can be used to change from a radially inner (for example innermost) region to a radially further outward region of the winding head.

According to some embodiments, the radial area of the connection hairpin extends from a radially innermost winding layer to a radially outermost winding layer. This means that the connection hairpin can be used to change from the inner to the outer diameter of the winding head across all winding layers.

According to some embodiments, the radial region of the connection hairpin extends from a radially outer (for example outermost) winding layer in the direction of a radially further inner winding layer, i.e. from the outside inwards. This means that the connection hairpin can be used to change from a radially outer area to a radially further inner area of the winding head.

According to some embodiments, the radial area of the connection hairpin extends from a radially outermost winding layer to a radially innermost winding layer. This means that the connection hairpin can be used to change from the outer to the inner diameter of the winding head across all winding layers.

According to some embodiments, the connection hairpin has a bending region that protrudes from a groove of the coil body and extends between an axial groove region and the radial region of the connection hairpin. The bending region bends at a first angle in the circumferential direction relative to the axial groove region of the connection hairpin. This means that the connection hairpin can have a bend in the circumferential direction at a groove exit point.

According to some embodiments, the radial region of the connection hairpin bends at a second angle in the radial direction relative to the bending region of the connection hairpin. This means that the connection hairpin can have a bend in the radial direction between the bending region and the radial region.

According to some embodiments, the connection hairpin has an axial end region that adjoins the radial region of the connection hairpin. This means that after the radial region, the connection hairpin can have a kink in the axial direction.

According to some embodiments, a line cross-section of the axial end region can be rotated relative to a line cross-section of the groove region of the connection hairpin.

According to some embodiments, the axial end region and the axial groove region of the connection hairpin extend radially offset by one or more winding layers and parallel (axially).

According to a further aspect, the present invention provides an electrical machine with a distributed winding according to one of the preceding embodiments, wherein the distributed winding is designed as a stator or rotor winding of the electrical machine. The electrical machine can be an electric motor or a generator.

According to yet another aspect, the present invention provides a drive train for a vehicle with an electric machine according to an embodiment.

Furthermore, the present invention provides a method for producing a distributed winding for an electrical machine. The method comprises providing a coil body with a plurality of slots distributed over a circumference of the coil body, introducing at least one winding strand formed from a plurality of hairpins into the slots, so that the hairpins each have axially extending slot regions which are arranged in the radial direction in different winding layers in the slots of the coil body, and so that the winding strand has a connection region at each of its two ends which is formed by one end of a respective connection hairpin. The method is characterized in that a radial region which runs in the radial direction and extends radially over one or more winding layers is formed in the connection hairpin.

The proposed distribution of connection pins on the inner and outer diameters allows axial space to be saved through the expanded distribution option of interconnection/star points. This can be made possible, for example, by a slight modification of a standard cover hairpin. Using this pin does not result in any additional increase in the winding head.

In the following, individual embodiments of the present invention are described by way of example with reference to the figures.

• 1 eine verteilte Wicklung für eine elektrische Maschine mit Anschluss-Hairpins mit jeweiligem Radialbereich gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;
• 2 eine Umwandlung eines herkömmlichen Cover-Hairpins zu einem Anschluss-Hairpin mit Radialbereich gemäß der vorliegenden Erfindung;
• 3 eine verteilte Wicklung für eine elektrische Maschine mit Anschluss-Hairpins mit jeweiligem Radialbereich gemäß einem weiteren Ausführungsbeispiel der vorliegenden Erfindung;
• 4 eine verteilte Wicklung für eine elektrische Maschine mit Anschluss-Hairpins mit jeweiligem Radialbereich von radial außen nach innen gemäß einem weiteren Ausführungsbeispiel der vorliegenden Erfindung; und
• 5 eine verteilte Wicklung für eine elektrische Maschine mit Anschluss-Hairpins mit jeweiligen Radialbereich von radial innen nach außen gemäß einem weiteren Ausführungsbeispiel der vorliegenden Erfindung.

Show it:

• 1 a distributed winding for an electrical machine with connection hairpins with respective radial areas according to an embodiment of the present invention;
• 2 a conversion of a conventional cover hairpin to a connection hairpin with radial area according to the present invention;
• 3 a distributed winding for an electrical machine with connection hairpins with respective radial areas according to a further embodiment of the present invention;
• 4 a distributed winding for an electrical machine with connection hairpins with respective radial areas from radially outside to inside according to a further embodiment of the present invention; and
• 5 a distributed winding for an electrical machine with connection hairpins with respective radial areas from radially inside to outside according to a further embodiment of the present invention.

The 1 shows a distributed winding 10 for an electrical machine according to a first embodiment.

The distributed winding 10 comprises a coil body 11, which can be formed, for example, from layered metal sheets. The coil body 11 has a plurality of grooves 12 distributed over a circumference of the coil body 11. The grooves 12 are located here on an inner circumference of the coil body 11 and run in the axial direction.

The distributed winding 10 further comprises a plurality of winding strands. In the present case, three winding strands for three different phases (current-carrying lines) are shown as an example. A winding strand 14 is formed from a plurality of interconnected hairpins 13. Individual hairpins 13 are generally bent in a U-shape and can have a rectangular conductor cross-section. Due to their U-shape, individual hairpins 13 have two essentially parallel legs, which are also referred to below as groove regions or sections. The hairpins 13 arranged in the coil body 11 each have axially extending groove regions 13-N, which are arranged in the radial direction in different winding layers in the grooves 12 of the coil body 11. In other words, a plurality of axially extending grooves 12 are provided on the inner circumference of the coil body 11, in which groove sections 13-N of the hairpins 13 are arranged in several radially layered winding layers. In the example shown, six layers of hairpins 13 are provided, although another even number of layers is also possible.

After all hairpins 13 have been installed, conductor ends protruding from the lower end of the coil body 11 in the circumferential direction of the coil body 11 are bent in different directions and angles, cut to length and welded together. The winding strands or hairpins 13 overlap at the axially upper and lower ends of the coil body 11. This overlapping area is also called the winding head. Each of the winding strands has a connection area 15 at both ends, which is formed by one end of a respective connection hairpin and protrudes axially over the coil body 11 or the winding head.

According to embodiments, the connection area or connection hairpin 15 of at least one winding strand has a radial area 15-R of the connection hairpin that runs in the radial direction. According to the invention, the radial area 15-R of the connection hairpin extends radially over one or more winding layers. This means that the radial area 15-R of the proposed connection hairpin 15 radially covers at least one further winding layer than that of a groove area 15-N of the connection hairpin. According to some embodiments, the groove area 15-N of the connection hairpin runs either in the radially innermost or in the radially outermost winding layer. A connection hairpin 15 proposed here differs from a so-called cover hairpin in that one leg or limb of the connection hairpin 15 is bent and shortened by approximately 180° (i.e. in the opposite direction) compared to that of a cover hairpin. This is shown schematically in 2 shown.

Cover hairpins are hairpins that jump from the radially outermost to the radially innermost layer or from the radially innermost to the radially outermost winding layer on the winding head and cover the other hairpins. As can be seen from 2 As can be seen, a (cover) hairpin 13 has a bending region or section 13-T protruding from a groove 12 of the coil body 11, which extends between an axial groove region or section 13-N and a radial region or section 13-R of the (cover) hairpin 13. The bending region 13-T bends relative to the axial groove region 13-N of the (cover) hairpin 13 by an angle ϕ ₁ in the circumferential direction. A (cover) hairpin 13 has two opposing axial groove regions (legs) 13-N and accordingly also two opposing bending regions 13-T.

A connection hairpin 15 according to the present invention can be obtained from a (cover) hairpin 13 by, for example, shortening an axial groove region (leg) 13-N and bending the corresponding bending region 13-T in such a way that it becomes an axial end region 15-E of the connection hairpin 15, which adjoins the radial region 15-R of the connection hairpin. The radial region 15-R of the connection hairpin can emerge from the radial region 13-R of the (cover) hairpin 13.

The bending area 15-T of a connecting hairpin bends in the circumferential direction relative to the axial groove area 15-N of the connecting hairpin by an angle ϕ _1. The radial area 15-R of a connecting hairpin bends in the radial direction relative to the bending area 15-T of the connecting hairpin by an angle ϕ ₂ (see Fig. 1). A connecting hairpin 15 has an axial end area 15-E which adjoins the radial area 15-R of the connecting hairpin. The end area 15-E can, for example, result from a shortened and bent axial groove area (leg) 13-N of a (cover) hairpin 13. The axial end area 15-E and the axial groove area 15-N of the connection hairpin can therefore be radially offset and run parallel in the axial direction. Other directions of the end area 15-E are also conceivable.

In the enlarged view of the 1 three connection hairpins 15 according to the present invention can be seen, the respective radial areas 15-R of which extend from a radially innermost winding layer to a radially outermost winding layer. Thus, by means of the connection hairpins 15 according to the present invention, connections can be distributed from the inner to the outer diameter of the winding layers. In the enlarged view of the 1 Three conventional connection hairpins 16 without radial area can also be seen, which provide connections on the inner diameter of the winding layers.

In the 3 an embodiment is shown with three connection hairpins 15 according to the present invention, the respective radial areas 15-R of which extend from a radially innermost winding layer to the radially penultimate outer winding layer. Thus, by means of the connection hairpins 15 according to the present invention, connections can be distributed from the inner diameter in the direction of the outer diameter of the winding layers. The radial areas 15-R of the connection hairpins 15 do not have to extend over all winding layers. In the representation of the 3 Three conventional connection hairpins 16 without radial area can also be seen, which provide connections on the inner diameter of the winding layers. Compared to the embodiment of the 1 It can also be seen that the cross-sectional areas of the end regions 15-E of the connection hairpins 15 are rotated clockwise compared to the cross-sectional areas of the end regions of the conventional connection hairpins 16.

This means that it is possible to rotate the end sections 15-E around their axial axis as desired in order to advantageously enable/implement further possibilities for connection to the circuitry.

The 4 shows a further embodiment of a distributed winding 10, in which radial regions 15-R of some connection hairpins 15, which are configured in pairs here, extend from a radially innermost winding layer in the direction of a radially further outer winding layer.

In contrast, 5 an embodiment of a distributed winding 10 in which radial regions 15-R of the connection hairpins 15 extend from a radially outermost winding layer in the direction of a radially further inner winding layer. The radially further inner winding layer can correspond to the innermost winding layer.

In summary, the present invention proposes converting at least one cover hairpin in such a way that a leg/leg of the cover hairpin is bent upwards, allowing connection pins to change from the inner to the outer diameter or from the outer to the inner diameter. By using the geometry of the cover hairpins, this change can be made without additional axial installation space, since this additional bend of the new connection hairpins 15 is located between the existing cover hairpins. By distributing connection pins across the inner and outer diameters, axial space can be saved due to the expanded distribution option for interconnection/star points.

Furthermore, the following claims are hereby incorporated into the Detailed Description, each claim may stand on its own as a separate example. While each claim may stand on its own as a separate example, it should be noted that although a dependent claim may refer to a particular combination with one or more other claims in the claims, other examples may also include a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are explicitly suggested herein unless it is stated that a particular combination is not intended. Furthermore, features of a claim for any other independent claim are also intended to be included, even if that claim is not made directly dependent on the independent claim.

Reference symbols

10

Distributed winding

11

Coil body

12

Grooves

13

Hairpin

15

inventive connection hairpin

15-R

Radial area

15-T

Bending area

15-E

axial end area

16

conventional connection hairpin

Claims (10)

Distributed winding (10) for an electrical machine, comprising a coil body (11) with a plurality of slots (12) distributed over a circumference of the coil body; at least one winding strand (14) formed from a plurality of hair pins (13), wherein the hair pins (13) each have axially extending groove regions (13-N) which are arranged in the radial direction in different winding layers in the grooves (12) of the coil body (11), and wherein the winding strand (14) has at each of its two ends a connection region which is formed by one end of a respective connection hair pin (15) and projects axially beyond the coil body (11), characterized in that at least one connection region of the winding strand has a radial region (15-R) of the connection hair pin (15) which runs in the radial direction, wherein the radial region (15-R) extends radially over one or more winding layers. Distributed winding (10) according to Claim 1 , wherein the radial region (15-R) of the connection hairpin (15) extends between a radially inner winding layer and a winding layer located radially further outward. Distributed winding (10) according to Claim 1 or 2 , wherein the radial region (15-R) of the connection hairpin (15) extends from a radially inner winding layer in the direction of a radially outer winding layer. Distributed winding (10) according to Claim 3 , wherein the radial region (15-R) of the connection hairpin (15) extends from a radially innermost winding layer to a radially outermost winding layer. Distributed winding (10) according to Claim 1 or 2 , wherein the radial region (15-R) of the connection hairpin (15) extends from a radially outer winding layer in the direction of a radially further inner winding layer. Distributed winding (10) according to Claim 5 , wherein the radial region (15-R) of the connection hairpin (15) extends from a radially outermost winding layer to a radially innermost winding layer. Distributed winding (10) according to one of the preceding claims, wherein the connection hairpin (15) has a bending region (15-T) protruding from a groove (12) of the coil body (11) and extending between an axial groove region (15-N) and the radial region (15-R) of the connection hairpin (15). Distributed winding (10) according to Claim 7 , wherein the bending region (15-T) bends relative to the axial groove region (15-N) of the connecting hairpin (15) by a first angle in the circumferential direction. Distributed winding (10) according to Claim 7 or 8th , wherein the radial region (15-R) bends by a second angle in the radial direction relative to the bending region (15-T) of the connecting hairpin. Distributed winding (10) according to one of the preceding claims, wherein the connection hairpin (15) has an axial end region (15-E) which adjoins the radial region (15-R) of the connection hairpin, wherein the axial end region (15-E) and the axial groove region (15-N) of the connection hairpin are radially offset and extend parallel in the axial direction.

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