CN115136462A

CN115136462A - Insulation arrangement, stator arrangement, electric machine and method for producing a stator arrangement

Info

Publication number: CN115136462A
Application number: CN202080087617.5A
Authority: CN
Inventors: N.克雷斯; S.丹辛格
Original assignee: Valeo Siemens eAutomotive Germany GmbH
Current assignee: Valeo eAutomotive Germany GmbH
Priority date: 2019-12-17
Filing date: 2020-12-10
Publication date: 2022-09-30
Also published as: WO2021122255A1; EP4078777A1; DE102019134792A1

Abstract

The invention relates to an insulation device (9) for a stator (5) having a hairpin winding (6), comprising a first wall which extends axially and circumferentially relative to a central axis of the insulation device (9), and a plurality of second walls which extend axially and radially relative to the central axis and project from the first wall, wherein the wall pairs of adjacent second walls each form a boundary in the circumferential direction of a receiving space for a winding overhang (8) of the hairpin winding (6), and the first walls form a boundary in the radial direction of the respective receiving space, and one or more latching elements (17) for positively securing the insulation device (9).

Description

Insulation arrangement, stator arrangement, electric machine and method for producing a stator arrangement

The invention relates to an insulation device for a stator having a hair pin or a hairpin winding. The invention further relates to a stator arrangement, to an electric machine and to a method for producing a stator arrangement.

Stators with hairpin windings have become the focus of industrial development efforts, particularly in the field of electric drive of vehicles. In particular, it allows a largely automated production compared to distribution windings, since no complex pulling-in of windings made of thin wires is required.

DE 102012219668 a1 discloses an electric motor with a stator having a plurality of slots. The hairpin coil is inserted into the slot. An electrically conductive connector is also provided that surrounds the end regions of the two hairpin coils to electrically connect the two hairpin coils to one another. An insulating cap is placed over the connector.

It is very expensive to arrange a separate insulation cap on the winding head of the hairpin winding. As an alternative, it has already been proposed to powder coat the winding heads projecting from the stator after the hairpin winding has been connected, for which purpose they are dipped in a powder lacquer. However, this is also expensive, sometimes resulting in contamination with powder paint and the risk of the paint being trapped in undesired locations where it may reach the stator. Furthermore, cracks may occur in the powder lacquer layer thus obtained after a long period of operation of the stator.

The object of the invention is therefore to provide an improved insulation solution for the winding overhang of a stator with a hairpin winding, which insulation is particularly less costly, more durable and less polluting.

In order to solve this problem, according to the invention, an insulation arrangement for a stator having a hairpin winding is proposed, which comprises a first wall which extends axially and circumferentially with respect to a central axis of the insulation arrangement, and a plurality of second walls which extend axially and radially with respect to the central axis and project from the first wall, wherein the wall pairs of adjacent second walls each form a boundary in the circumferential direction of an accommodation space for the winding heads of the hairpin winding, and the first walls form a boundary in the radial direction of the respective accommodation space.

The invention is based on the consideration that the insulation of the winding overhang is achieved by an insulation device which can be mounted on the stator end side and which provides an accommodation space for the respective winding overhangs which need to be insulated relative to one another. The receiving space is formed by the first and second walls with a boundary in the radial and circumferential direction and thus defines the air gap and the creepage distance required between radially adjacent winding overhangs.

In this way, the insulation of the winding overhang can be advantageously carried out in a single step by installing the insulation device, so that the expenditure of time and production costs for the insulation is greatly reduced. In particular, no extensive insulating caps need to be mounted in a complex manner on the respective winding heads. In particular, expensive and contamination-laden powder coatings can be dispensed with. At the same time, a more durable insulation in view of the risk of cracks forming in the powder coating can be achieved by means of the insulation device.

The insulating means is preferably composed of an electrically insulating plastic. In general, the insulation device according to the invention is designed as an injection-molded part. Advantageously, the insulation arrangement according to the invention can have at least twelve, preferably at least twenty-four, particularly preferably at least thirty-six, very particularly preferably at least forty-eight second walls.

A hairpin winding in the sense of the present invention is a winding consisting of essentially rigid, optionally curved, needles. Hairpin windings are also referred to as "hair-pin windings" and the term "hair-pin" may therefore also be replaced by "hair-pin" in the phrase. The "clips" may also be replaced by "metal strips".

Preferably, the insulating device according to the invention further comprises a third wall which extends axially and circumferentially at a radial spacing from the first wall and which forms a further boundary of the respective receiving space in the radial direction. Radial insulation of both sides of the winding overhang is thus achieved.

Advantageously, in the insulating device according to the invention, it can also be provided that the second wall intersects the first wall in such a way that the wall pairs each form a boundary in the circumferential direction of a second receiving space for the winding overhang of the hairpin winding, the second receiving space being radially spaced apart from the first receiving space, and the first wall forming a boundary in the radial direction of the respective second receiving space. In this way, a very effective insulation of the hairpin winding with two winding heads at corresponding positions in the circumferential direction can be achieved.

It is furthermore preferred that the insulating device further comprises a fourth wall which extends axially and circumferentially at a radial distance from the first wall, so that the fourth wall forms a further boundary of the respective second receiving space in the radial direction. Radial insulation of both sides of the second accommodation space can thus be achieved.

In a preferred embodiment of the insulating device according to the invention, the insulating device further comprises a rear wall from which the first wall and the second wall project and which delimits the receiving space in the axial direction. In particular, the boundary is designed such that the winding overhang can project into the first receiving space on the side of the first receiving space opposite the rear wall. The air gap and the creepage distance required in the axial direction, for example, relative to the stator housing can thus be advantageously defined.

In this case, it can be provided that the rear wall forms a boundary of the respective second receiving space in the axial direction. In particular, the boundary is designed such that the winding overhang can project into the second receiving space on the side of the second receiving space opposite the rear wall. Typically, the third wall protrudes from the rear wall. Alternatively or additionally, the fourth wall protrudes from the rear wall.

It is also preferred that the rear wall is inclined relative to the axial direction relative to the first wall. The insulating device can thus advantageously be adapted to the shape of the stator housing.

The insulating device according to the invention particularly advantageously also comprises one or more latching elements for positively securing the insulating device. The insulating device can therefore be fixed securely with little effort by means of a snap-in connection, but at the same time.

The invention also relates to an insulation arrangement for a stator with a hairpin winding, comprising a first wall which extends in an axial direction and in a circumferential direction with respect to a central axis of the insulation arrangement, and a plurality of second walls which extend in an axial direction and in a radial direction with respect to the central axis and which project from the first wall, wherein the wall pairs of adjacent second walls form a boundary in the circumferential direction of a receiving space for the winding heads of the hairpin winding, respectively, and the first walls form a boundary in the radial direction of the respective receiving space. The insulating device comprises one or more latching elements for positively securing the insulating device.

The object of the invention is also achieved by a stator arrangement for an electrical machine, comprising an insulation arrangement according to the invention and a stator, wherein the winding overhang is inserted into the receiving space.

Advantageously, in the stator arrangement according to the invention, each winding overhang can be formed from at least two hairpin elements of the hairpin winding which are joined to one another in a bonded manner. Typically, the hairpin elements are welded or brazed to each other.

The hairpin winding of the stator arrangement according to the invention can generally be constituted by hairpin elements. The hairpin elements or parts of the hairpin elements can be, for example, U-shaped clips which are passed through the stator slots, bent over on the end side of the stator opposite the winding ends and led back through the other stator slots. The hairpin element or a part of the hairpin element can also be an I-clip which is materially connected to the other hairpin element on both end sides of the stator.

Typically, the hairpin winding has an electrically insulating surface layer outside the insulation means.

In the stator arrangement according to the invention, it is particularly preferred that the stator arrangement comprises a stator housing, wherein the insulation means can be fastened to the stator housing, preferably to a bearing end cap of the stator housing. Advantageously, the stator housing comprises latching elements for establishing a latching connection with said latching elements or corresponding latching elements of the insulation device.

Alternatively or additionally, it can be provided that the insulating device is fixed to the stator by means of a potting compound and/or an adhesive, which potting compound is arranged in at least a part of the receiving space and surrounds the winding overhang accommodated in the receiving space.

The object of the invention is also achieved by an electric machine comprising a stator arrangement according to the invention. The electric machine is usually designed for driving an electric vehicle, for example a pure electric vehicle (BEV) or a hybrid vehicle. Typically, the central axis of the insulation means coincides with the rotational axis of the electrical machine.

The object of the invention is also achieved by a method for producing a stator arrangement, comprising the following steps: providing an insulation arrangement according to the invention; providing a stator having a hairpin winding; arranging insulating means on the winding overhang of the hairpin winding such that the winding overhang is inserted into the accommodation space; and the insulating means is fixed.

It can advantageously be provided here that the production method according to the invention further comprises the following steps: providing a stator housing; the insulating device is fixed to the stator housing, preferably to a bearing end cap of the stator housing. Alternatively or additionally, the following steps can be specified: the potting compound and/or the adhesive is arranged in at least one part of the receiving space, so that after the potting compound and/or the adhesive has cured, the insulation arrangement is fixed to the stator.

All the descriptions concerning the insulating device according to the invention and the stator device according to the invention can be transferred analogously to the manufacturing method according to the invention, so that the advantages mentioned above can also be achieved by means of the manufacturing method.

Further advantages and details of the invention emerge from the exemplary embodiments described below and from the figures. These figures are schematic and wherein:

fig. 1 shows a cross-sectional view of an embodiment of an electrical machine with an embodiment of a stator arrangement according to the invention and an embodiment of an insulation arrangement according to the invention;

fig. 2 shows a detailed view of fig. 1 in the region of the first and second receiving spaces of the insulating device.

FIG. 3 shows a top view of the insulation unit;

figure 4 shows a perspective view of the insulation arrangement and the stator of the stator arrangement; and

fig. 5 shows a detailed view of the latching element of the insulating device.

Fig. 1 is a cross-sectional view of an embodiment of an electrical machine 1.

The electric machine 1 comprises a stator arrangement 2 in which a rotor 4 is rotatably mounted, which rotor is connected to the shaft 3 in a rotationally fixed manner.

The stator arrangement 2 comprises a stator 5 which is formed from a plurality of laminar individual plates and has stator slots which are configured axially with respect to the axis of rotation of the rotor 4. The hairpin winding 6 is accommodated in a stator slot of the stator 5 and forms a winding overhang 8 on a first end side 7. The stator arrangement 2 further comprises an embodiment of the insulation arrangement 9.

Fig. 2 is a detailed view of fig. 1 in the region of the first accommodation space 10 and the second accommodation space 11 of the insulation arrangement 9.

The insulation means 9 comprises a first wall 12, which extends in the axial and circumferential direction with respect to a central axis, which here is identical to the axis of rotation of the rotor 4 (see fig. 1). The insulating device 9 further comprises a plurality of

second walls

13a, 13b (see fig. 3), of which only the second wall 13a is visible in fig. 2. The

second walls

13a, 13b extend axially and radially with respect to the central axis, respectively, and project radially from the first wall 12. The wall pairs of the adjacent

second walls

13a, 13b in each case form a boundary in the circumferential direction of the first receiving space 10 for receiving the winding overhang 8. The first wall 12 constitutes a radially inner boundary of the respective first accommodation space 10.

Furthermore, the insulating device 9 comprises a third wall 14, which extends axially and circumferentially radially outwardly at a distance from the first wall 12. The third wall 14 constitutes the outer boundary of the respective first accommodation space 10 in the radial direction.

The

second walls

13a, 13b and the first wall 12 intersect such that the wall pairs of adjacent

second walls

13a, 13b respectively form a boundary of the second receiving space 11 in the circumferential direction. The first wall 12 here forms the outer boundary of the respective second accommodation space 11 in the radial direction. In this case, one of the winding overhang 8 is accommodated in each case in the second accommodation space 11.

The fourth wall 15 of the insulating device 9 extends axially and circumferentially radially inwardly at a distance from the first wall 12, so that the fourth wall 15 forms the radially inner boundary of the respective second receiving space 11.

Furthermore, the insulating device 9 comprises a rear wall 16, from which rear wall 16 the first wall 12, the

second walls

13a, 13b, the third wall 14 and the fourth wall 15 project in the axial direction. The rear wall 16 delimits the first and

second accommodation spaces

10, 11 in the axial direction. The rear wall 16 is inclined in relation to the axial direction in relation to the first wall 12.

Fig. 3 is a top view of the insulation means 9. It can be seen that the insulating device 9 has forty-eight

second walls

13a, 13b in the present example, which are arranged circumferentially equidistant. Here, the number of the first and second

accommodating spaces

10, 11 is equal to the number of the

second walls

13a, 13b, respectively.

Fig. 4 is a perspective view of the insulation means 9 and the stator 5 of the stator arrangement 2. The insulating device 9 further comprises three latching elements 17, which latching elements 17 are arranged circumferentially at equal distances from one another on the rear wall 16.

Fig. 5 is a detailed view of the catch element 17. It can be seen that the latching element projects axially from the rear wall 16 and has a latching lug 18 extending radially inward.

Referring again to fig. 1, the stator arrangement 2 has a stator housing 19 comprising a bearing cap 20 arranged on the end side 7. The insulating device 9 is supported on a bearing cap 20, wherein the inclination of the rear wall 16 follows the inclination of the bearing cap 20. The bearing cap 20 further comprises latching elements 21, which are designed to mate with the latching elements 17 of the insulating device 9 and form a form-fitting latching connection with the latching elements of the insulating device in order to fasten the insulating device 9 to the stator housing 19 or to the bearing cap 20.

The stator housing 19 also comprises a second bearing end cap, which is not shown in fig. 1 for the sake of clarity and is arranged on a second end side 22 opposite the first end side 7.

It can also be seen in fig. 1 that the winding overhang 8 is formed by the free ends of the

hairpin elements

23, 24, respectively, which are connected to one another in a bonded manner. The

hairpin elements

23, 24 forming the winding overhang 8 are in this case each a U-shaped clip which extends from the free end shown in fig. 2 through the stator slot, is bent through 180 ° at the second end face 22 and extends axially from there through the further stator slot. There, the

hairpin elements

23, 24 are connected in a materially bonded manner to further hairpin elements according to a predetermined winding pattern.

An embodiment of a method of manufacturing the stator arrangement 2 is described below.

In a first step the insulation means 9 are provided. In a second step the stator 5 is provided. In a further step, the insulation means 9 is arranged on the winding heads 8 of the hairpin winding 6 such that the winding heads 8 are inserted into the receiving

spaces

10, 11. The insulating means 9 is then fixed. This is achieved in that the insulating device 9 is connected to the bearing cap 20 by a snap-in connection.

Alternatively or additionally, a potting compound or adhesive can be filled into all or part of the receiving

spaces

10, 11, the winding overhang 8 being inserted into the receiving

spaces

10, 11 in such a way that the potting compound or adhesive at least partially surrounds the winding overhang. After the casting compound has solidified, the insulation means 9 is fixed to the stator 5.

Claims

1. An insulating arrangement (9) for a stator (5) with a hairpin winding (6), comprising:

-a first wall (12) extending axially and circumferentially with respect to a central axis of the insulation means (9); and

-a plurality of second walls (13a, 13b) which extend in the axial and radial direction, respectively, with respect to the central axis and project from the first wall (12), wherein the wall pairs of adjacent second walls (13a, 13b) form a boundary in the circumferential direction of a receiving space (10) for the winding heads (8) of the hairpin winding (6), respectively, and the first walls (12) form a boundary in the radial direction of the respective receiving space (10),

the insulating device further comprises one or more latching elements (17) for positively securing the insulating device (9).

2. The insulation arrangement according to claim 1, further comprising a third wall (14) which extends axially and circumferentially at a radial spacing from the first wall (12) and which forms a further boundary of the respective receiving space (10) in the radial direction.

3. The insulation arrangement according to claim 1 or 2, wherein the second wall (13a, 13b) intersects the first wall (12) such that the pair of walls respectively forms a boundary in the circumferential direction of a second accommodation space (11) for the winding heads (8) of the hairpin winding (6), which is radially spaced from the first accommodation space (10), and the first wall (12) forms a boundary in the radial direction of the respective second accommodation space (11).

4. An insulating device according to claim 3, further comprising a fourth wall (15) extending axially and circumferentially at a radial spacing from the first wall (12), such that the fourth wall (15) constitutes a further boundary of the respective second receiving space (11) in the radial direction.

5. Insulation arrangement according to any one of the preceding claims, further comprising a rear wall (16), from which rear wall (16) the first wall (12) and the second wall (13a, 13b) protrude and which constitutes a boundary of the receiving space (10) in the axial direction.

6. The insulating device according to claim 5, when depending on claim 3, the rear wall (16) constituting a boundary of the respective second housing space (11) in the axial direction.

7. An insulating device according to claim 5, or when dependent on claim 2 and/or 4, wherein the third wall (14) protrudes from the rear wall (16) and/or the fourth wall (15) protrudes from the rear wall (16).

8. The insulation arrangement according to any one of claims 5 to 7, wherein the rear wall (16) is inclined with respect to the axial direction with respect to the first wall (12).

9. Stator arrangement (2) for an electrical machine (1), comprising an insulation arrangement (9) according to one of the preceding claims and the stator (5), wherein the winding heads (8) are inserted into the receiving spaces (10, 11).

10. Stator arrangement according to claim 9, wherein each winding head (8) is composed of at least two hairpin elements (23, 24) of the hairpin winding (6) which are material-jointly connected to one another.

11. A stator arrangement according to any one of claims 9 or 10, wherein

-the stator arrangement (2) comprises a stator housing (19), wherein the insulation arrangement (9) is fixed on the stator housing (19), preferably on a bearing end cap (20) of the stator housing (19), and/or

The insulation device (9) is fixed to the stator (5) by means of a potting compound and/or an adhesive, wherein the potting compound is arranged in at least a part of the receiving space (10, 11) and surrounds the winding overhang (8) received in the receiving space (10, 11).

12. An electrical machine (1) comprising a stator arrangement (2) according to any of claims 9 to 11.

13. A method for manufacturing a stator arrangement, comprising the steps of:

-providing an insulation arrangement (9) according to any one of claims 1 to 8;

-providing a stator (5) having a hairpin winding (6);

-arranging insulating means (9) on the winding heads (8) of the hairpin winding (6) such that the winding heads (8) are inserted into said accommodation spaces (10, 11); and is

-a stationary insulating means (9).

14. The manufacturing method according to claim 13, further comprising the steps of:

-providing a stator housing (19); wherein the insulation device (9) is fixed to the stator housing (19), preferably to a bearing cap (20) of the stator housing (19); and/or

-arranging a potting compound in at least a part of the receiving space (10, 11) such that the insulating device (9) is fixed to the stator (5) by the potting compound after the potting compound has solidified.