DE102021133409A1 - Stator for an electric machine - Google Patents

Abstract

The invention relates to a stator (1) for an electrical machine, having an annular stator core (2), a plurality of stator coils (3) arranged on the stator core (2) and having coil connections (4a-4l), an annular interconnection element (10) for electrical interconnection of the stator coils (3), the interconnection element (10) having an annular base body (21) which consists of an electrically insulating material and has a plurality of concentrically arranged grooves (11) running in the circumferential direction of the base body (21) on the end face, and electrical Connecting elements (16a-c, 17, 18a-c), which are at least partially accommodated in the grooves (11) of the base body (21) and at least partially run along the grooves (11).The electrical connecting elements (16a-c, 17, 18a-c) consist of three-dimensionally bent sheet metal parts, with at least three electrical connecting elements (16a-c) of the same shape being provided, which are each accommodated in at least two grooves (11) of different diameters and bridge at least one groove (11) in the radial direction.

Description

The invention relates to a stator for an electrical machine according to the preamble of patent claim 1.

The EP 1 526 628 B1 discloses a stator for an electric motor with an annular stator core, a plurality of stator coils arranged on the stator core with coil terminals, and an annular interconnection element for electrically interconnecting the stator coils, the interconnection element having an annular base body made of an electrically insulating material and one in the circumferential direction of the base body having running cavity. Switching rings in the form of ring segments are arranged in the hollow space and have contacting elements that are guided to the outside through slots.

The construction of this interconnection element for the stator and the interconnection of the stator coils is relatively complex.

The switching rings, as electrical conducting elements, are accommodated in the groove-shaped cavity of the base body and run, at least partially, along the cavity, the electrical conducting elements being designed to electrically connect the coil terminals of the stator coils to one another and to electrically connect the coil terminals to power terminals of the electrical machine .

The DE 10 2014 201 637 A1 relates to a stator with an interconnection element for interconnecting the stator windings, which has an accommodating space running in the circumferential direction for a plurality of busbars.

The busbars are designed as flat sheet metal parts in the shape of an arc of a circle and are inserted into the receiving space in a radially offset manner and isolated from one another. The busbars have corresponding terminals for connection to the coil terminals.

The object of the present invention is to specify a stator for an electrical machine with an interconnection element for electrically interconnecting the stator coils, the interconnection element being simple and inexpensive to produce and suitable for high currents. The assembly and connection of the connection element should also be possible in a simple and cost-effective manner.

According to the invention, this object is achieved by a stator having the features of patent claim 1 .

Advantageous refinements of the invention and further features are specified in the dependent claims.

According to the invention, the electrical connection elements consist of three-dimensionally bent sheet metal parts.

At least three electrical connecting elements of the same shape are provided, which are each accommodated in at least two grooves of different diameters of the base body and bridge at least one groove in the radial direction.

An advantage of the invention lies in the use of a plurality of identically shaped connecting elements, the production of which is very cost-effective in this way.

Due to the shape of the connecting elements, the electrical connection between the stator coils and the motor current connections can be made in a very easy and space-saving manner, and only a few connecting elements are required overall.

The connecting elements preferably consist of stamped and bent parts with which a large line cross section can be implemented, so that high currents can be transmitted.

The stator is designed as part of a multi-phase electrical machine, with preferably several stator coils directly next to one another being connected in series and each forming a coil group and the coil group being assigned to a motor phase, with at least two coil groups of the same phase being connected in series. Adjacent stator coils belonging to the same motor phase are preferably wound in opposite directions.

The stator is preferably designed for an electronically commutated three-phase motor, with the stator coils of the three phases being star-connected to one another.

The interconnection element of the stator is preferably arranged as an extension of an end face of the stator.

The electrical connection elements are essentially designed as sheet metal parts in the form of ring segments.

A number of electrical connection elements are preferably used to produce an electrical connection between the individual coil groups of a phase.

Furthermore, the electrical connection elements are used to establish an electrical connection between the coils of one phase and a star point.

At the same time, the electrical connection elements serve to establish an electrical connection between the coils of one phase and a power connection.

For connection to the coil connections or the power connections, the electrical connection elements have one or more connection lugs or connection lugs.

The coil ends or coil connections are threaded into the connection lugs and preferably soldered or welded to them.

The electrical connection element has a curved section and at each end of the curved section a connecting section with connecting lugs or connecting lugs, the curved section and the connecting sections being arranged axially offset on different levels.

In this case, the arcuate section is arranged in one or more grooves of the base body and is angled multiple times in the radial direction, so that the arcuate section is divided into a plurality of radially offset sections.

Some of the connecting elements are arranged in grooves with different radial diameters and overlap in the circumferential direction of the body, i. H. several electrical connection elements can be provided radially offset in a peripheral section of the base body. At least one connection section of the electrical connection element is preferably designed in such a way that it bridges at least one other electrical connection element in the radial direction.

The stator, the base body of the interconnection element and the electrical connection elements are preferably cast or overmoulded with a casting compound after interconnection, with the terminal lugs being kept free.

The invention relates to an electrical machine with a stator having the features mentioned above.

A preferred exemplary embodiment of the invention is described in more detail below with reference to the drawings.

• 1 zeigt eine perspektivische Darstellung des erfindungsgemäßen Stators in noch nicht vergossenem Zustand.
• 2a zeigt eine Aufsicht auf den Stator von 1.
• 2b zeigt eine Aufsicht auf die elektrischen Verbindungselemente.
• 3 zeigt eine perspektivische Ansicht der verwendeten elektrischen Verbindungselemente und des Grundkörpers.
• 4 zeigt ein bevorzugtes Wickelschema für den erfindungsgemäßen Stator.

This results in further features and advantages of the invention.

• 1 shows a perspective representation of the stator according to the invention in the not yet encapsulated state.
• 2a shows a plan view of the stator 1 .
• 2 B shows a top view of the electrical connection elements.
• 3 shows a perspective view of the electrical connection elements used and of the base body.
• 4 shows a preferred winding scheme for the stator according to the invention.

In 1 , 2a and 2 B the stator 1 according to the invention is shown for an electrical machine.

The stator 1 comprises an annular stator core 2 made of a ferromagnetic material, with a row of stator coils 3 being arranged in a known manner over the circumference of the annular stator core 2 .

In the present example, the stator comprises a number of 18 stator coils 3 and is designed for use in an electronically commutated three-phase motor, with six stator coils 3 being assigned to each motor phase.

Corresponding coil connections 4a - 4l are led out upwards from the end face of the stator coils 3, preferably on the outer diameter of the stator coils 3.

The outer circumference of the stator coils 3 is surrounded by a magnetic yoke ring 5 .

On the end face of the stator coils 3, on which the coil connections 4a-4l are led out, a connection element 10 is arranged according to the invention, which is approximately ring-shaped and whose base body 21 consists of an electrically insulating material, for example plastic.

The coil terminals 4a-4l are passed through axially continuous openings 15 in the base body 21 of the interconnection element 10 in the axial direction.

The base body 21 of the interconnection element 10 has, on the end face facing away from the stator coils 3 , upwardly open grooves 11 which run in the shape of a circular arc in the circumferential direction of the base body 21 on different diameters.

The grooves form a plurality of groove circles 12, 13, 14 which are located on different radial diameters of the base body 21, each groove circle 12, 13, 14 comprising a plurality of arc-shaped grooves 11 distributed over the circumference.

The grooves 11 of the different circles of grooves 12, 13, 14 are separated from one another by webs 22 in the form of arcs of a circle. Openings 23 are provided in the webs 22 separating the groove circles 12, 13, 14 between the individual circles of grooves 12, 13, 14.

The openings 23 in the webs allow a transition from one groove circle 12, 13, 14 to another groove circle 13, 14, 12.

Correspondingly shaped and electrically conductive connecting elements 16a-16c, 17, 18a-18c are provided for the electrical interconnection of the coil terminals 4a-4l protruding through the openings 23 of the interconnection element 10.

These connecting elements 16a-16c, 17, 18a-18c are preferably formed from electrically conductive sheet metal as stamped and bent parts and are correspondingly three-dimensionally bent.

The connecting elements 16a-16c, 17, 18a-18c are designed in such a way that they can be placed upright in a curved shape in grooves 11 of the base body 21 provided for this purpose.

3 shows an example of a connecting element 30, which, for example, in 1 and 2 illustrated connecting elements 16a - 16c corresponds. The connecting elements 16a - 16c are shaped and constructed in the same way.

The connecting element 30 comprises an arcuate section 31 which, in the example shown, has two bends 32, so that the arcuate section 31 is divided into three shorter arcuate sections with different diameters.

A connecting section 33 is provided at one end of the arcuate section 31, which stands out from the arcuate section 31 in the axial direction and comprises a terminal lug 34, which is used to fasten a coil terminal 4a-4l.

At the other end of the arcuate section 31 there is another connecting section 35 which initially protrudes axially from the plane of the arcuate section 31 and then extends radially towards the outside of the arcuate section 31 and likewise ends in a connecting lug 36 . This connection lug 36 is also used to attach a coil connection 4a - 41.

For a better understanding of the interconnection of the individual stator coils 3, reference is made to in 4 shown winding scheme referenced.

In 4 you can see the stator coils, which are each numbered 1 to 18. Numbers 1 to 18 in 4 differ from the reference numerals 1 to 18 of 1 until 3 .

In each case three directly adjacent stator coils 3, for example coils no. 1, 2, 3, are connected together to form a coil group 7a.

Here, for example, coil no. 1 is wound clockwise and the winding wire is then fed to coil no. 2, which is wound counterclockwise and then the winding wire is fed to coil no. 3, which in turn is wound clockwise.

Similarly, coils Nos. 10-12 become coil group 7b, coils Nos. 4-6 become coil group 8a, coils Nos. 13-15 become coil group 8b, and coils Nos. 7-9 become coil group 9a and the coil group 9b is formed from the coils Nos. 16-18.

Each coil group 7a, 7b, 8a, 8b and 9a, 9b has two coil connections 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j and 4k, 4l, which are led out of the winding package and by means of the Interconnection element 10 are interconnected.

For example, the coil group 7a includes the coil terminals 4a and 4b, the coil group 8a, the coil terminals 4c, 4d, and so on.

In the 1 and 2 these coil terminals 4a - 4l, which are passed through the opening 15 of the base body 21, are shown.

These coil connections 4a-4l are now electrically connected to one another by means of the connecting elements 16a-16c, 17 and 18a-18c and also connected to the power connections for the electrical supply of the stator.

Two coil groups each, i. H. 7a and 7b, 8a and 8b and 9a and 9b are connected in series by the connecting elements 16a, 16b, 16c and are assigned to a motor phase U, V, W, the associated coil groups 7a and 7b, 8a and 8b, 9a and 9b respectively offset by 60 degrees from one another on the circumference of the stator.

The connecting elements 16a - 16c are used to connect the individual coil groups 7a, 7b, 8a, 8b and 9a and 9b to one another.

Here, the z. B. Coil connection 4b of the coil group 7a is connected to the coil connection 4g of the coil group 7b by means of the connecting element 16a.

The connecting element 16a is inserted into the grooves 11 of the base body in such a way that the connection lugs 34, 36 ( 3 ) seen in the circumferential direction come to rest on the associated coil terminals 4b and 4g and can be connected in these terminal lugs 34, 36 by soldering or welding.

Starting, for example, from the terminal lug 34 of the connecting element 16a, which protrudes beyond the base body 21 and is connected to the terminal 4b of the coil group 7a, the curved section of the connecting element 16a initially runs in the radially outer circle of grooves 14 - towards the first bend 32 of the curved section, which passes through an opening 15 from the circle of grooves 14 into the circle of grooves 13, with the arcuate section then continuing radially further inwards in the circle of grooves 13.

At a further bend 32 of the curved section 31, the curved circle of the connecting element 16a changes into the circle of grooves 12 and extends along the circle of grooves 12 to the connecting section 35, which is now led out axially out of the circle of grooves 12 and is led radially over the circles of grooves 13 and 14. ie this bridges up to the coil connection 4g, where the connection lug 36 of the connecting element 16a is electrically connected to the coil connection 4g.

Similarly, the coil terminal 4d is connected to the coil terminal 4i by the connecting member 16b, and the coil terminal 4f is connected to the coil terminal 4k by the connecting member 16c.

All connecting elements 16a - 16c are constructed in the same way and run with their curved section in sections in the groove circles 12, 13 and 14, as described above.

How out 4 As can be seen, the coil groups 7a, 7b, 8a, 8b and 9a and 9b are star-connected to one another and connected to one another at a star point CT.

The coil groups are connected to the star point CT by the connecting element 17, one coil connection 4h, 4j and 4l of the respective coil group 7b, 8b and 9b being electrically connected via the connecting element 17 to the star point CT.

The connecting element 17 runs, for example, on the radially outer groove circle 14 and connects the connections 4h, 4j and 4l to one another and forms the star point CT.

The coil terminals 4h, 4j and 4l are fed into corresponding terminal lugs of the connecting element 17, similar to the terminal lugs 34, 36 in 3 , and soldered or welded to the terminal lugs to establish an electrical connection to the star point CT.

The stator 1 is supplied with power via further connecting elements 18a-18c, which are connected to corresponding connections 4a, 4c and 4e of the coil groups 7a, 8a and 9a.

Referring to 4 For example, the coil groups 7a, 7b are assigned to the motor phase U and are connected to the connecting element 18a at the coil connection 4a.

This connecting element 18a has a short curved section, which is arranged, for example, in the inner groove circle 12 and is used to fix the connecting element in the groove.

how to get in 1 As can be seen clearly, the connection element 18a is guided with a radial section over the groove circles 13 and 14 lying radially further outside and has a connection lug at the radially outer end, which is electrically connected to the coil connection 4a.

The radially running section of the connection element 18a has a connection lug 37 which forms the current connection for the coils of the motor phase U of the stator 1 .

A plug connector, for example, can be connected or a current-carrying line can be soldered to the corresponding terminal lug 37 of the connecting element 18a.

The corresponding connections 4c for the motor phase W and 4e for the motor phase V are also electrically connected to the connecting elements 18b and 18c, respectively, by means of connecting lugs. The connecting elements 18b and 18c also have connection lugs 37 which are used for the power supply of the corresponding phase connections V and W.

The connecting elements 18a - 18c are shaped in the same way.

According to the invention, it is also possible to form the curved sections of the connecting elements 18a - 18c in one piece and to insert them into a continuous groove of the inner circle of grooves 12 and only after the assembly of this one-piece component to cut the continuous curved section, for example by separating, punching or drilling, as indicated by the bores 24 , to be divided into three shorter, electrically separate arc sections.

The entire stator 1 with the interconnection element 10 built on it can be encapsulated or encapsulated by means of an encapsulation compound after assembly and interconnection have been completed, with only the connecting lugs 37 of the connecting elements 18a, 18b and 18c for the motor phases U, V, W being radially or axially upwards protrude from the casting compound and serve to feed in the supply current.

A reliable connection for high currents in a stator 1 can be achieved with a few connecting elements 16a-16c, 17, 18a-18c. The connecting elements 16a-16c and 18a-18c are shaped in the same way and are therefore simple and inexpensive to manufacture.

The connecting elements can be designed for the corresponding motor current by selecting the sheet thickness and the axial height.

Reference List

1

stator

2

stator core

3

stator coils

4a-4l

coil terminals

5

magnetic inference

7a, b

coil group

8a, b

coil group

9a, b

coil group

10

interconnection element

11

grooves

12

groove circle

13

groove circle

14

groove circle

15

openings

16a-c

fastener

17

fastener

18a-c

fastener

19

terminal lug

20

connection tab

21

body

22

web

23

opening

24

drilling

30

fastener

31

arc section

32

Bend (Radial Offset)

33

connection section

34

connection tab

35

connection section

36

connection tab

37

terminal lug

CT

star point

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• EP 1526628 B1 [0002]
• DE 102014201637 A1 [0005]

Claims (16)

Stator (1) for an electrical machine, with an annular stator core (2), a plurality of stator coils (3) arranged on the stator core (2) and having coil terminals (4a-4l), an annular interconnection element (10) for electrically interconnecting the stator coils (3 ), wherein the interconnection element (10) has an annular base body (21), which consists of an electrically insulating material and has a plurality of concentrically arranged grooves (11) running in the circumferential direction of the base body (21) on the end face, and electrical connecting elements (16a- c, 17, 18a-c), which are at least partially accommodated in the grooves (11) of the base body (21) and at least partially run along the grooves (11), the connecting elements (16a-c, 17, 19a-c) are designed to electrically connect the coil terminals (4a-4l) of the stator coils (3) to one another and to electrically connect the coil terminals (4a-4l) to power terminals of the electrical machine, characterized in that the electrical connecting elements (16a-c, 17, 18a -c) consist of three-dimensionally bent sheet metal parts, and at least three electrical connecting elements (16a-c) of the same shape are provided, which are each accommodated in at least two grooves (11) of different diameters and bridge at least one groove (11) in the radial direction. stator after claim 1 , characterized in that it has a multi-phase design, with several stator coils directly next to one another being connected in series and each forming a coil group (7a, 7b, 8a, 8b, 9a, 9b), and the coil group (7a, 7b, 8a, 8b , 9a, 9b) is assigned to a phase (U, V, W), with at least two coil groups (7a, 7b, 8a, 8b, 9a, 9b) of the same phase being connected in series. Stator after one of Claims 1 or 2 , characterized in that it is designed for an electronically commutated three-phase motor and the stator coils (3) of the three phases (U, V, W) are star-connected to one another. Stator after one of Claims 1 until 3 , characterized in that the interconnection element (10) is arranged in an extension of an end face of the stator core (2). Stator after one of Claims 1 until 4 , characterized in that the electrical connection elements (16a-c, 17, 18a-c) are at least partially designed as metal parts in the form of ring segments. Stator after one of Claims 1 until 5 , characterized in that the electrical connecting elements (16a-c) are designed to produce an electrical connection between the individual coil groups (7a, 7b, 8a, 8b, 9a, 9b) of a phase (U, V, W). Stator after one of Claims 1 until 6 , characterized in that the electrical connecting elements (17) are designed to establish an electrical connection between the coil groups (7a, 7b, 8a, 8b, 9a, 9b) of one phase (U, V, W) with a neutral point (CT). Stator after one of Claims 1 until 7 , characterized in that the electrical connecting elements (18a-c) for producing an electrical connection of the coil groups (7a, 7b, 8a, 8b, 9a, 9b) of a phase (U, V, W) are designed with a power connection. Stator after one of Claims 1 until 8th , characterized in that the electrical connecting elements (16a-c, 17, 18a-c) have one or more connection lugs (24, 26) or connection lugs (37) for connection to the coil connections (4a-l) or the power connections. Stator after one of Claims 1 until 9 , characterized in that the electrical connecting elements (30, 16a-c, 17, 18a-c) have a curved section and at the ends of the curved section each have a connecting section (33, 35) with connecting lugs (24, 26) or connecting lugs (37). , wherein the curved section (31) and the connecting sections (33, 35) with the connecting lugs (37) and connecting lugs (34, 36) are arranged on different axial planes. Stator after one of Claims 1 until 10 , characterized in that the curved section (31) of the electrical connecting element (30, 16a-c, 17, 18a-c) is arranged in the grooves (11) of the base body (21). Stator after one of Claims 1 until 11 , characterized in that the arcuate section (31) of the electrical connecting element (30, 16a-c, 17, 18a-c) is angled multiple times in the radial direction. Stator after one of Claims 1 until 12 , characterized in that at least one connecting section (33, 35) of the connecting element (30, 16a-c, 17, 18a-c) is designed in such a way that it bridges at least one other electrical connecting element in the radial direction. Stator after one of Claims 1 until 13 , characterized in that the connecting elements (30, 16a-c, 17, 18a-c) overlap in the circumferential direction on different radial diameters. Stator after one of Claims 1 until 14 , characterized in that the stator (1), the interconnection element (10) and the electrical connecting elements (30, 16a-c, 17, 18a-c) are cast or encapsulated with a casting compound, the terminal lugs (37) being kept free . Electrical machine with a stator according to one of Claims 1 until 15 .

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