EP3921925A1

EP3921925A1 - Stator for an electric machine

Info

Publication number: EP3921925A1
Application number: EP20703375.4A
Authority: EP
Inventors: Andreas Bexel
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-02-08
Filing date: 2020-01-10
Publication date: 2021-12-15
Also published as: US20220052575A1; WO2020160727A1; CN113396529A; DE102019103191A1

Abstract

Stator for an electric machine, having a winding (2) comprising a plurality of interconnected conductors (3) assigned to one or more phases, wherein the ends (6) of at least some of the conductors (3) protrude axially or radially beyond the winding (2) at the inner circumference and/or at the outer circumference of the winding (2), wherein an interconnection ring (7), to which the conductors (3) are connected, is positioned axially or radially on the winding (2), and wherein the ends (6) of in each case at least two conductors (6) assigned to one phase protrude radially or axially outwards and are connected to a power connection (14) arranged radially outside the winding (2).

Description

Stator for an electrical machine

The invention relates to a stator for an electrical machine, with a winding comprising a plurality of conductors assigned to one or more phases, which are interconnected.

Electrical machines comprising a rotor and a stator are used in different areas of application. The use of electric machines for electric hybrid vehicles and electric vehicles or for hub drives is only mentioned as an example. If such an electrical machine is used as a drive machine, it is mostly designed as an internal rotor, which means that the stator surrounds the internal rotor. A wandering magnetic field is generated via the stator, which causes the rotor to rotate. For this purpose, the stator has a winding consisting of a large number of conductors, the conductors being assigned to one or usually several phases.

Not only the number of phases is included in the design of the winding geometry, but also the number of wires per phase and the number of wires per slot within the stator toothing and the number of pole pairs. This variety of conductors and winding parameters creates a complex network of conductors that is built up using different winding technologies. Examples include what is known as hairpin or rod wave winding. Here, the conductors are formed by means of rods bent in a U-shape, which are plugged together to form a winding cage. The conductors are laid on a plurality of radial levels, with the conductors moving from level to level. To form quasi-meandering, circumferential conductors, they are to be connected accordingly at their ends, which is usually done by welding the conductor ends that are adjacent to one another. The conductor ends converge at one point or on one winding side in the form of the so-called star, where they are connected to one another. In this area, the connection of the individual phases to an external power supply Supply that is used to generate the magnetic field to make, which is often very difficult to implement for reasons of space.

The invention is therefore based on the problem of specifying a stator as compact as possible.

To solve this problem, in a stator of the type mentioned inven tion provided that the ends of at least part of the conductor on the inner circumference and / or on the outer circumference of the winding protrude axially or radially over the winding, with a connection ring axially or radially on the Winding is set to which the conductors are connected, and the ends of at least two conductors associated with a phase protrude radially or axially outward and are connected to a power connection located radially outside the winding.

According to the invention, it is provided that the actual conductor interconnection, i.e. the interconnection of the individual conductors to form the corresponding phase-specific meander structures, and the interconnection for coupling to the power supply are separated via a high-voltage terminal, with the interconnection virtually radially inward and the connection to the power supply is provided radially outside. For the actual conductor connection, a connection ring is used, that is to say a conductor ring which is placed separately on the winding and which, according to the invention, is placed axially or radially on the winding. This interconnection ring engages in the area of the inner circumference and / or the outer circumference of the winding axially or radially protruding Lei terenden, when placed axially, for example, radially between in the area of the inner and outer circumference of the winding axially protruding conductor ends over the winding. The conductor ends are assigned to the individual conductor sections, unless they are connected to one another on other, for example further inward, radial planes. The conductor ends are connected to the interconnection ring, usually welded to it accordingly, so that the corresponding phase-specific conductor structures or conductor connections are generated via the interconnection ring. To connect the winding to the actual power connection, according to the invention, corresponding conductor ends that are assigned to a phase are guided protruding radially or axially outward. A power connection arranged radially next to the winding head can now be connected accordingly with these radially or axially outwardly directed conductor ends, so that the HV power connection and the individual phase-related terminals can, of course, also be welded to the corresponding phase-specific conductor ends .

Due to the quasi-nested, e.g. The axial and radial arrangement of the connection ring and the power supply terminal results in a very compact, space-saving design. In addition, the assembly is also simplified, since the conductors or wires to be connected via the interconnection ring only have to be cut to length and brought into the appropriate position when the winding cage is plugged together in order to be connected to the corresponding connection terminals of the interconnection ring, which of course are positioned accordingly . Both cutting to length and, of course, assembling can take place in an automated assembly process, as can of course also be compensated for due to the simple connection of conductor ends and interconnection ring. This is not least due to the fact that the connection ring and the power supply or the HV terminal are two separate assemblies that are connected in different process steps to the stator and then also to the finished electrical machine.

The interconnection ring expediently has several separate cable bridges to which the ends of the conductors are connected. These cable bridges, which are correspondingly stable metal sheets, which are geometrically shaped so that they reach the corresponding conductor ends to be connected, are grouped into the corresponding circuit ring and enable simple bridging of corresponding distances both in the circumferential and in the radial direction tion. These cable bridges, like the individual conductors, are of course insulated from one another. For a simple connection of the line bridges with the corresponding conductors, the line bridges expediently have radially or axially protruding connection sections on which the ends of the conductors, which protrude axially or radially from the winding, come to lie next to the connection sections in the assembly position, be welded on. The interconnection ring is consequently designed as a star distributor, comprising the corresponding line bridges and the associated, radially or axially protruding connection sections.

To enable the tightest possible packing, the bridges themselves are arranged radially and axially offset from one another and are nested as closely as possible, although the winding geometry must of course always be taken into account when designing the individual line bridges, which includes the position of the conductor ends to be connected Defined inside and outside perimeter.

For easy handling, the interconnection ring expediently has a housing in which the bridges are arranged, the preferably radially closed housing having corresponding lateral openings through which the connection sections protrude. The connection ring is therefore designed as a fully assembled unit and as such can be placed axially or radially on the winding head and in relation to the conductor ends, e.g. placed between the protruding ends of the conductor. With the insertion, the corresponding connection sections are also positioned exactly with respect to the conductor ends that are to be connected to them, so that then only the welding has to take place.

As described, the power connection or the connections of the HV terminal are arranged radially outside of the stator or the stator head. The two or more conductor ends belonging to a phase, which are to be connected to the HV terminal, are guided radially or axially outwards, that is to say bent outwards in a simple manner in the case of a radial arrangement, for example. This is easily possible with Lei terenden on the outer circumference of the winding, since they are located radially outside of the interconnection ring. In the case of conductor ends that are on the inner circumference, the ends are preferably led radially over the connection ring, i.e. the connection ring is first inserted and connected during assembly. after which only the conductor ends on the inner circumference, if any are provided there, are bent radially outward so that they overlap the interconnection ring.

The power connection itself expediently has corresponding busbars, which are preferably also accommodated in a housing which is arranged radially laterally next to the stator or the winding head and from which the corresponding connection ends of the busbars protrude. The line ends preferably overlap the busbars, so that simple welding can also take place here due to the overlap.

In addition to the stator itself, the invention also relates to an electrical machine to summarize a stator of the type described.

The invention is explained below using exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

FIG. 1 shows a basic illustration in the form of a partial view of a stator according to the invention,

Figure 2 is a partial view of the interconnection ring,

FIG. 3 shows a schematic diagram of various line bridges of the connection ring from FIG. 2, and

Figure 4 is a partial view of the power connection.

FIG. 1 shows, in the form of a partial view, a basic illustration of a stator 1 according to the invention of an electrical machine, with a winding 2 comprising a plurality of conductors 3, which are assigned to three separate phases in the example shown. Each conductor 3 is practically designed as a U-shaped bracket, with a plurality of such U-shaped conductors, often also called hairpins, to the winding 2, which is also called Winding basket can be referred to, are plugged together. The plurality of conductors 3 define different radial planes R, as shown in FIG. For this purpose, the conductors 3 stretch depending on the winding scheme from one radial plane to another radial plane, for example an adjacent radial plane, in the area in which they are connected to the conductor ends of the corresponding neighboring conductors leading to the phase.

The conductors are guided or bent and laid in such a way that corresponding recesses 4 result, which extend radially so that corresponding

Stator teeth 5 engage in these recesses 4 or the corresponding conductors are wound between the corresponding grooves of the stator teeth 5. The basic structure of such a stator or a winding 2 wound from the separate brackets described is basically known.

In the case of the stator 1 according to the invention, the ends 6 of the conductors 3, as far as the ends 6 end or are positioned at the inner circumference and the outer circumference of the annular winding 2, project axially, that is, they protrude axially from the winding 2. These ends are associated with individual conductors, which in turn are assigned under different phases, which is why the conductor ends must be connected according to the routing diagram of the conductor 3. For this purpose, a connection ring 7 is used, which is placed axially on the end face of the winding 2 and is arranged between the conductor ends 6 or engages between them. The interconnection ring 7 comprises, as will be discussed below, a plurality of corresponding power bridges and connection sections 8 which protrude to the side from the housing 9 of the interconnection ring 7 and after inserting the interconnection ring 7 between the conductor ends 6 in the exact position next to the corresponding one Conductor end 6 are positioned with which they are to be connected. The connection is made by simple welding, so that all conductors 3 are correctly and phase-specifically connected to one another when they are connected.

A power supply 14 is also provided, which is arranged radially next to the winding 2 in the area of its axial end. This power supply 14, also called HV terminal, comprises a housing 10 in which the corresponding busbar NEN 11 are arranged, which ra gene with their connection terminals 12 from the housing.

As described, a 3-phase stator is shown here, which is why three such connection terminals 12 are also provided in the example shown.

Each connection terminal 12 is to be connected to one phase of the winding 2. This is implemented in a simple manner in that two conductor ends 6a per phase are guided or bent radially outwards, as FIG. 1 clearly shows. The at the arranged on the outer circumference of the winding 2 conductor ends 6a are relatively short and can be bent directly outwards, while the two conductor ends 6a arranged on the Innenum are longer and the interconnection ring 7 overgoes. They run above the connection terminals 12, so that a simple welded connection for contacting is possible there as well. The connection to the power supply 14 takes place only when the conductors 3 are interconnected via the interconnection ring 7 with one another.

FIG. 2 shows a partial view of the interconnection ring 7 from FIG. 1. The housing 9 is shown, which is accordingly in several parts and also enables radial encapsulation. It can be seen that the corresponding connection sections 8, which are assigned to different phases, protrude from the housing 9 through corresponding openings. As already described, the individual connection sections are assigned to different phases, that is to say connect different conductor ends 6.

To implement the connection section 8, see FIG. 3, a corresponding plurality of separate line bridges 13 are arranged in the interior of the housing 9, seven in the example shown, which are arranged axially and radially offset from one another. On the respective inner or outer circumference of the line bridges 13, the corresponding terminal sections 8 are formed, which in their entirety form a corresponding star distributor. Corresponding conductor ends arranged offset in the circumferential direction can accordingly be connected accordingly on the inner and outer circumference via the line bridges 13 extending in the circumferential direction. den, so that the corresponding meander structure of the individual phase conductors is formed over it.

Like the conductors 3, of course, the line bridges 13 are also appropriately insulated or provided with an insulating coating or the like.

Finally, FIG. 4 shows, in an enlarged partial view, the power supply 14, al so the HV terminal, with its housing 10, which is also multi-part here and which completely encapsulates the power rails 11. It is designed to be slightly arched so that it can be placed on the side of the stator to suit its shape. Each busbar 11 respekti ve each connection terminal 12 is assigned to a corresponding phase, these phases are usually referred to as U, V and W. Like the housing 9 of the connection ring 7, the housing 10 of the power connection 14 also has corresponding openings through which the individual connections protrude.

While in the embodiment shown, the conductor ends protrude axially on the inner and outer circumference, it is conceivable to provide head ends axially protruding only on the inner or only on the Außenum catch. Furthermore, the conductor ends can also protrude radially and be connected to the axially arranged connection ring. The connection ring can also be attached radially and contact can be made with the axially or radially protruding conductor ends. So there are different types of configurations both with regard to the conductor routing and the positioning of the interconnection ring possible.

The connection section 8 of the line bridges can finally also protrude axially from the housing 9; an axial and radial arrangement is also conceivable, depending on the configuration of the guidance and positioning of the conductor ends. Reference list

stator

Winding

ladder

Recess

Stator tooth

End of ladder

a end of the ladder

Interconnection ring

Connection section

casing

0 housing

1 power rail

2 connection terminal

3 wire bridge

4 power connector

Claims

1. Stator for an electrical machine, with a winding (2) comprising a plurality of conductors (3) assigned to one or more phases, which are interconnected with one another, characterized in that the ends (6) at least some of the conductors ( 3) on the inner circumference and / or on the outer circumference of the winding (2) protrude axially or radially beyond the winding (2), with a connection ring (7) being placed axially or radially on the winding (2) on which the conductors (3) are connected, and wherein the ends (6) each of at least two conductors (6) assigned to a phase protrude radially or axially outwards and are connected to a power connection (14) arranged radially outside the winding (2).

2. Stator according to claim 1, characterized in that the interconnection ring (7) has several separate line bridges (13) to which the ends (6) are connected.

3. Stator according to claim 2, characterized in that the line bridges (13) have radially or axially projecting connection sections (8), to which the ends (6) are connected.

4. Stator according to claim 2 or 3, characterized in that the line bridges (13) are arranged radially and axially offset from one another.

5. Stator according to one of claims 2 to 4, characterized in that the interconnection ring (7) has a housing (9) in which the line bridges (13) are arranged.

6. Stator according to claim 5 and 3, characterized in that the radially closed GE housing (9) has openings through which the connection sections (8) protrude.

7. Stator according to one of the preceding claims, characterized in that the radially or axially outwardly guided ends (6a) of a conductor (3) arranged on the inner circumference overlap the interconnection ring (7).

8. Stator according to one of the preceding claims, characterized in that the power connection (14) comprises a number of busbars (11) corresponding to the number of phases.

9. Stator according to claim 8, characterized in that the busbars (11) are received in a housing (10).

10. An electrical machine comprising a stator (1) according to one of the preceding claims.