EP4078777A1

EP4078777A1 - Insulating device, stator device, electrical machine and method for producing a stator device

Info

Publication number: EP4078777A1
Application number: EP20824510.0A
Authority: EP
Inventors: Nils Krais; Stefan Denzinger
Original assignee: Valeo eAutomotive Germany GmbH
Current assignee: Valeo eAutomotive Germany GmbH
Priority date: 2019-12-17
Filing date: 2020-12-10
Publication date: 2022-10-26
Also published as: DE102019134792A1; WO2021122255A1; CN115136462A

Abstract

The invention relates to an insulating device (9) for a stator (5) having hairpin windings (6), the insulating device comprising: a first wall, which extends along an axial direction and a peripheral direction with respect to a central axis of the insulating device (9); a plurality of second walls, which each extend along the axial direction and a radial direction with respect to the central axis and protrude from the first wall, pairs of adjacent second walls forming boundaries of respective receiving spaces for a winding overhang (8) of the hairpin windings (6) in the peripheral direction, and the first wall forming a boundary of each receiving space in the radial direction; and one or more detent elements (17) for interlockingly fastening the insulating device (9).

Description

Isolation device, stator device, electrical machine and method for manufacturing a stator device

The present invention relates to an insulation device for a stator having hairpin windings. In addition, the invention relates to a stator device, an electrical machine and a method for producing a stator device.

Stators with hairpin windings are the focus of industrial development efforts, especially in the field of electric drives for vehicles. Compared to distributed windings, they allow in particular a largely automated production, because there is no need for laborious pulling in of windings formed from thin wires.

The document DE 102012219668 A1 discloses an electric motor with a stator having a plurality of slots. Hairpin bobbins are set in the slots. Furthermore, an electrically conductive connector is provided which surrounds the end regions of two hairpin coils in order to electrically connect the two hairpin coils to one another. An insulating cap is placed on the connector.

The arrangement of individual insulation caps on the end windings of the hairpin windings is very complex. Alternatively, it has already been proposed, after connecting the hairpin windings, to coat winding heads protruding from the stator by powder coating, for which purpose these are dipped in a powder coating. However, this is also time-consuming, sometimes results in soiling from the powder coating, and there is a risk that the coating can reach undesired locations on the stator. In addition, after a long period of operation of the stator, cracks can arise in a powder coating obtained in this way. The invention is therefore based on the object of providing a possibility for the improved, in particular less expensive, more durable and less dirt-free insulation of end windings of a stator having hairpin windings.

To solve this problem, an insulation device for a stator having hairpin windings is proposed according to the invention, comprising a first wall which extends along an axial direction and a circumferential direction with respect to a central axis of the insulation device and a plurality of second walls which each extend along the axial direction and a Radialrich device extend with respect to the central axis and protrude from the first wall, where in pairs of adjacent second walls there are boundaries of a receiving space for a winding head of the hairpin windings in the circumferential direction and the first wall forms a delimitation of a respective receiving space in the radial direction.

The invention is based on the idea of realizing the insulation of the winding heads by an insulation device which can be attached to the end of the stator and which provides a receiving space for winding heads that are to be insulated from each other. The receiving space forms boundaries in the radial direction and in the circumferential direction through the first wall and the second walls and thus defines required air and creepage distances between adjacent winding heads in the radial direction.

The isolation of the winding heads can thus advantageously be carried out in a single operation by attaching the Isolationsvorrich device, whereby the isolation becomes considerably less complex in terms of both time and manufacturing costs. In particular, there is no need for the complex attachment of a large number of insulation caps to a respective winding head. In particular, an expensive and polluting powder coating can be dispensed with. At the same time, the insulation device enables a more durable insulation with regard to the risk of crack formation in the case of a powder coating. The insulation device is preferably formed from an electrically insulating plastic. The insulation device according to the invention is typically designed as an injection-molded part. The insulation device according to the invention can expediently have at least twelve, preferably at least twenty-four, particularly preferably at least thirty-six, very particularly preferably at least forty-eight second walls.

Hairpin windings in the context of the present invention are windings that are formed from essentially rigid, possibly curved, pins. The term “hairpin winding” is also known for hairpin winding, so that the term “hairpin” - also in word combinations - can be replaced by “hairpin”. The term “pin” can also be replaced by “metal rod”.

The insulation device according to the invention preferably further comprises a third wall which extends radially spaced from the first wall along the axial direction and the circumferential direction and forms a further delimitation of the respective receiving space in the radial direction. In this way, radial insulation of the winding heads on both sides is achieved.

Advantageously, in the insulation device according to the invention it can also be provided that the second walls cross the first wall, so that the pairs each form boundaries of a second receiving space, which is radially spaced from the first receiving space, for a winding head of the hairpin windings in the circumferential direction and the first wall forms a boundary of a respective second receiving space in the radial direction. In this way, an effective insulation of hairpin windings, which have two winding heads at respective positions in the circumferential direction, can be realized.

It is also preferred if the insulation device further comprises a fourth wall, which extends along the axial direction and the circumferential direction at a radial distance from the first wall, so that the fourth wall has a further one Delimitation of the respective second receiving space in the radial direction ausbil det. In this way, radial isolation of the second receiving spaces on both sides can be realized.

In a preferred development of the insulation device according to the invention, it also includes a rear wall from which the first wall and the second walls protrude and which forms a delimitation of the receiving space in the axial direction. In particular, the delimitation is designed in such a way that the winding heads can protrude into the receiving space on a side of the first receiving space opposite the rear wall. As a result, the necessary air and creepage distances can advantageously be defined in the axial direction, for example with respect to a stator housing.

It can be provided that the rear wall forms a delimitation of the respective second receiving space in the axial direction. In particular, the delimitation is designed such that the end winding can protrude into the second receiving space on a side 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 if the rear wall is inclined with respect to the first wall with respect to the axial direction. As a result, the insulation device can advantageously be adapted to the shape of a stator housing.

The isolation device according to the invention particularly advantageously comprises one or more latching elements for positively locking the isolation device. As a result, the isolation device can be attached with little effort, but at the same time robustly, by means of a latching connection.

The invention also relates to an insulation device for a stator having hairpin windings, comprising a first wall which extends along an axial direction device and a circumferential direction with respect to a central axis of the Isolationsvorrich device and a plurality of second walls, which each extend along the axial direction and a radial direction with respect to the central axis and protrude from the first wall, pairs of adjacent second walls each delimiting a receiving space for a winding head form the hairpin windings in the circumferential direction and the first wall forms a delimitation of a respective receiving space in the radial direction. The isolation device comprises one or more latching elements for positively locking the isolation device.

The object on which the invention is based is also achieved by a stator device for an electrical machine, comprising an insulation device according to the invention and the stator, the end windings being introduced into the receiving spaces.

In the stator device according to the invention, each winding head can expediently be formed from at least two cohesively connected hairpin elements of the hairpin windings. The hairpin elements are typically welded or soldered.

In general, the hairpin windings of the stator device according to the invention can be formed from hairpin elements. The hairpin elements or some of the hairpin elements can be U-pins, for example, which penetrate stator slots, are bent over on an end face of the stator opposite the winding heads and are guided back through another stator slot. The hairpin elements or some of the hairpin elements can also be I-pins, which are materially connected to other hairpin elements on both end faces of the stator.

The hairpin windings typically have an electrically insulating surface layer outside the insulation device. In the case of the stator device according to the invention, it is particularly preferred if it comprises a stator housing, it being possible for the insulation device to be attached to the stator housing, preferably to a bearing plate of the stator housing. The stator housing expediently comprises locking elements for producing a locking connection with the or a respective locking element of the isolation device.

Alternatively or additionally, it can be provided that the insulation device is attached to the stator by means of a potting compound arranged in at least some of the receiving spaces, enclosing the winding heads received in the receiving spaces and / or by means of an adhesive.

The object on which the invention is based is also achieved by an electrical machine, comprising a stator device according to the invention. The electrical cal machine is typically designed to drive an electrically drivable vehicle, for example an electric vehicle (BEV) or a hybrid vehicle. Typically, the central axis of the Isolationsvor direction corresponds to an axis of rotation of the electrical machine.

The object on which the invention is based is also achieved by a method for producing a stator device, comprising the following steps: providing an insulation device according to the invention; Providing the stator with the hairpin windings; Arranging the isolation device on the Wickelköp fen the hairpin windings, so that the winding heads are introduced into the receiving spaces; and attaching the isolation device.

It can advantageously be provided that the manufacturing method according to the invention further comprises the following steps: providing a Statorge housing; wherein the isolation device is attached to the stator housing, preferably to egg nem end shield of the stator housing. Alternatively or additionally, the following steps can be provided: arranging a potting compound and / or that of an adhesive in at least some of the receiving spaces so that the Isolation device is attached to the stator after curing of the potting compound and / or the adhesive.

All statements relating to the insulation device according to the invention and to the stator device according to the invention can be applied analogously to the production method according to the invention, so that the aforementioned advantages can also be achieved with this.

Further advantages and details of the present invention emerge from the exemplary embodiments described below and with reference to the drawings. These are schematic representations and show:

Fig. 1 is a sectional view of an embodiment of an electrical machine's rule with an embodiment of the stator device according to the invention and an embodiment of the insulation device according to the invention;

FIG. 2 shows a detailed view of FIG. 1 in the area of a first and second exception room of the isolation device.

3 shows a plan view of the isolation device;

4 shows a perspective view of the insulation device and the stator of the stator device; and

5 shows a detailed view of a latching element of the insulation device.

1 is a sectional illustration of an exemplary embodiment of an electrical machine 1.

The electrical machine 1 comprises a stator device 2, within which a rotor 4 connected non-rotatably to a shaft 3 is rotatably mounted. The stator device 2 comprises a stator 5, which is formed from a multiplicity of historical individual laminations and has stator slots formed axially with respect to an axis of rotation of the rotor 4. Hairpin windings 6 are received in the stator slots of the stator 5 and form winding heads 8 on a first end face. The stator device 2 furthermore comprises an exemplary embodiment of an isolation device 9.

FIG. 2 is a detailed view of FIG. 1 in the area of a first receiving space 10 and a second receiving space 11 of the insulation device 9.

The insulation device 9 comprises a first wall 12, which extends along an axial direction and a 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 Isolationsvor 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 each extend along the axial direction and a radial direction with respect to the central axis and protrude from the first wall 12 in the Ra dial direction. Adjacent pairs of the second walls 13a, 13b each form a delimitation of the first receiving space 10 for receiving a winding head 8 in the circumferential direction. The first wall 12 forms an inner boundary Be a respective first receiving space 10 in the radial direction.

In addition, the insulation device 9 comprises a third wall 14, which extends along the axial direction and the circumferential direction at a radially outward distance from the first wall 12. The third wall 14 forms an outer boundary of the respective first receiving space 10 in the radial direction.

The second walls 13a, 13b and the first wall 12 intersect so that the pairs of the adjacent second walls 13a, 13b each form boundaries of the second receiving spaces 11 in the circumferential direction. The first Wall 12 forms an outer boundary of the respective second receiving space 11 in the radial direction. One of the winding heads 8 is received in each of the second receiving spaces 11.

A fourth wall 15 of the insulation device 9 extends along the axial direction and the circumferential direction radially inwardly spaced from the first wall 12, so that the fourth wall 15 forms an inner boundary of the respective second receiving space 11 in the radial direction.

In addition, the insulation device 9 includes a rear wall 16 from which the first wall 12, the second walls 13a, 13b, the third wall 14 and the fourth wall 15 protrude in the axial direction. The rear wall 16 forms a delimitation of the first and second receiving spaces 10, 11 in the axial direction. The rear wall 16 is inclined relative to the first wall 12 with respect to the axial direction.

3 is a plan view of the insulation device 9. It can be seen that the insulation device 9 in the present example has forty-eight second walls 13a, 13b which are arranged equidistantly in the circumferential direction. The number of first receiving spaces 10 and the number of second receiving spaces 11 correspond to the number of second walls 13a, 13b.

4 is a perspective view of the insulation device 9 and the stator 5 of the stator device 2. The insulation device 9 further comprises three locking elements 17, which are arranged equidistantly from one another in the circumferential direction on the rear wall 16.

5 is a detailed view of a latching element 17. It can be seen that it protrudes axially from the rear wall 16 and has a latching lug 18 extending radially inward. Again with reference to FIG. 1, the stator device 2 has a stator housing 19 which comprises a bearing plate 20 arranged on the end face 7. The Isola tion device 9 rests on the bearing plate 20, the inclination of the rear wall 16 tracks an inclination of the bearing plate 20. The end shield 20 also includes locking elements 21, which are designed opposite the locking elements 17 of the Isola tion device 9 and with these form a positive locking connection for fastening the isolation device 9 on the stator housing 19 or on the end shield 20.

The stator housing 19 also includes a second end shield, which is not shown in FIG. 1 for reasons of clarity and is arranged on a second end face 22 opposite the first end face 7.

In FIG. 1 it can also be seen that the winding heads 8 are each formed from free ends of hairpin elements 23, 24 that are connected to one another in a materially bonded manner. Here, the hairpin elements 23, 24 forming the winding heads 8 are each U-pins, which extend from the free end shown in FIG. 2 through the stator slots, are bent at the second end face 22 by 180 ° and from there pass through another stator slot extend axially. There they are cohesively connected to other hairpin elements according to a predetermined winding scheme.

An exemplary embodiment of a production method for the stator device 2 is described below.

In a first step, the insulation device 9 is provided. In a second step, the stator 5 is provided. In a further step, the insulation device 9 is arranged on the winding heads 8 of the hairpin windings 6, so that the winding heads 8 are inserted into the receiving spaces 10, 11. The insulation device 9 is then attached. This takes place in that the insulation device 9 is connected to the end shield 20 by means of the latching connection. Alternatively or in addition, all or part of the receiving rooms 10,

11, a potting compound or an adhesive can be filled in, the winding heads 8 being inserted into the receiving spaces 10, 11 in such a way that the potting compound or the adhesive at least partially encloses them. After the potting compound has hardened, the insulation device 9 is attached to the stator 5.

Claims

1 . Insulation device (9) for a hairpin windings (6) having Sta tor (5), comprising a first wall (12) which extends along an axial direction and a circumferential direction with respect to a central axis of the insulation device (9) and a plurality of second walls ( 13a, 13b), which each extend along the axial direction and a radial direction with respect to the central axis and protrude from the first wall (12), pairs of adjacent second walls (13a, 13b) each delimiting a receiving space (10) for a winding head (8 ) Form the hairpin windings (6) in the circumferential direction and the first wall (12) forms a delimitation of a respective receiving space (10) in the radial direction, further comprising one or more latching elements (17) for positively locking the isolation device (9).

2. Isolation device according to claim 1, further comprising a third wall (14) which extends radially spaced apart from the first wall (12) along the axial direction and the circumferential direction, and forms a further limitation of the respective receiving space (10) in the radial direction .

3. Isolation device according to claim 1 or 2, wherein the second walls (13a, 13b) cross the first wall (12) so that the pairs each Weil boundaries of a second receiving space (11) which is radially spaced from the first receiving space (10) , form a winding head (8) of the hairpin windings (6) in the circumferential direction and the first wall (12) forms a delimitation of a respective second receiving space (11) in the radial direction.

4. Isolation device according to claims 3, further comprising a fourth wall (15) which extends along the axial direction and the circumferential direction radially spaced from the first wall (12), so that the fourth wall (15) forms a further delimitation of the respective second receiving space (11) in the radial direction.

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

6. Isolation device according to claim 5, when, depending on claim 3, the rear wall (16) forms a delimitation of the respective second receiving space (11) in the axial direction.

7. Isolation device according to claim 5 or, if 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. Isolation device according to one of claims 5 to 7, wherein the rear wall (16) is inclined relative to the first wall (12) with respect to the axial direction.

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

10. Stator device according to claim 9, wherein each winding head (8) is formed from at least two cohesively connected hairpin elements (23, 24) of the hairpin windings (6).

11. stator device according to one of claims 9 or 10, wherein - The stator device (2) comprises a stator housing (19), the insulation device (9) being attached to the stator housing (19), preferably to a bearing plate (20) of the stator housing (19), and / or

- The insulation device (9) by means of a potting compound and / or an adhesive on the stator (5), which is arranged in at least part of the receiving spaces (10, 11) and enclosing the winding heads (8) in the receiving spaces (10, 11) is attached.

12. Electrical machine (1), comprising a stator device (2) according to one of claims 9 to 11.

13. A method for manufacturing a stator device, comprising the following steps:

- Provision of an insulation device (9) according to one of claims 1 to 8;

- Provision of the stator (5) with the hairpin windings (6);

- Arranging the insulation device (9) on the winding heads (8) of the hairpin windings (6), so that the winding heads (8) are introduced into the receiving spaces (10, 11); and

- Fasten the isolation device (9).

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

- Providing a stator housing (19); wherein the insulation device (9) is attached to the stator housing (19), preferably to a bearing plate (20) of the stator housing (19); and or

Arranging a potting compound in at least some of the receiving spaces (10, 11), so that the insulation device (9) is fastened to the stator (5) after the potting compound has hardened.