Stator for an electric machine, electric machine and vehicle

Abstract

A stator (1) for an electric machine (20) comprising: - a stator core (2) having stator slots (3) formed in an axial direction relative to a central axis (4) of the stator (1) and arranged in a circumferential direction distributed manner relative to the central axis (4); - a hairpin winding (5) having a multiplicity of hairpin element arrangements (6) arranged in the stator slots (3) and each hairpin element arrangement emerging from an end side of the stator core (2); and at least one insulation arrangement (8) having a main body (9) in which a multiplicity of passage openings (10) arranged in a circumferential direction distributed manner are formed, wherein a respective hairpin element arrangement (6) passes through one of the passage openings (10) and the insulation arrangement (8) specifies a distance of the hairpin element arrangement (6) from an edge (11) of the stator slot (3) receiving the hairpin element arrangement (6).

Description

Technical Field

[0001] The present invention relates to a stator for an electric motor, comprising: a stator core having stator slots formed axially relative to the central axis of the stator and arranged in a circumferentially distributed manner relative to the central axis; and a hairpin winding having a plurality of hairpin element devices arranged in the stator slots, each hairpin element device protruding from an end face of the stator core.

[0002] Furthermore, the present invention relates to an electric motor and a vehicle. Background Technology

[0003] Stator windings with hairpin windings have become a focus of industrial development efforts, particularly in the field of electric vehicle drives. Compared to distributed windings, they especially allow for largely automated manufacturing processes because they eliminate the need for the complex introduction of windings made of fine wires.

[0004] Document DE102017201533A1 discloses a stator for an electric motor, comprising an annular laminated core having a longitudinal axis and a plurality of slots extending along the longitudinal axis, a plurality of connecting wires designed in a hairpin shape and respectively arranged in the slots forming an annulus, and an insulating layer of the slots, the insulating layer being disposed on its inner side and implemented as insulating paper.

[0005] In this type of stator, the insulating paper serves not only as an electrical insulator but also as a means of positioning the hairpin element assembly within the stator slots. For this purpose, the insulating paper is introduced into the stator slots and completely covers them. The hairpin element assembly is then pushed into the stator slots, thus separating the hairpin element assembly from the stator core. Typically, the assembly formed in this way is fixed by an impregnation process.

[0006] The disadvantages of this type of stator include that the insulating paper only allows for low positioning accuracy, and that a thermal insulator is formed between the hairpin element assembly and the stator core. Summary of the Invention

[0007] The present invention is based on the purpose of specifying the improved possibility of arranging hairpin windings in the stator core.

[0008] According to the invention, in order to achieve this objective, a stator of the type described at the beginning is proposed, the stator further comprising at least one insulating device having a body in which a plurality of channel openings are formed in a manner distributed in a circumferential direction, wherein a corresponding hairpin element device passes through one of the channel openings, and the insulating device predefines the distance between the hairpin element device and the edge of the stator slot receiving the hairpin element device.

[0009] This invention is based on the consideration of defining the position of the hairpin element device within the corresponding stator slot through an insulating device, the channel opening of which predefines the position of the hairpin element device relative to the stator slot. This eliminates the need for conventionally used insulating paper, which must be introduced into the stator slot in a complex manner during a separate working step. In the case of the stator according to the invention, electrical insulation between the hairpin winding and the stator core is ensured by a distance predetermined by the insulating device.

[0010] The hairpin winding in the sense of this invention is a winding formed from a substantially rigid, optionally flexible molded conductor. In German, the term "Haarnadelwicklung" is called "Hairpinwicklung" [hairpin winding], and therefore the German term "Hairpin" can be replaced by the German term "Haarnadel" [hairpin], even in word combinations.

[0011] The main body of the insulation device is typically ring-shaped. The central axis of the insulation device preferably corresponds to the central axis of the stator.

[0012] Advantageously, in the case of the stator according to the invention, the edge of the corresponding channel opening can be specified to have a protrusion pointing into the channel opening and at a predetermined distance. Here, the protrusion provides a suitable support point or support surface for the hairpin element device so as to reliably predefine its distance from the stator groove.

[0013] In the case of the stator according to the invention, it is further preferred that each hairpin element device has a plurality of hairpin elements arranged in a stacked manner in the stator slot relative to the central axis in the stacking direction.

[0014] In a favorable development, it can be specified that, for a given hairpin element in the hairpin element device, one of the protrusions is formed on one or a corresponding edge portion of the channel opening, which extends along or parallel to the stacking direction. As a result, each hairpin element can be individually supported, particularly on both sides, for pre-defined distances.

[0015] Alternatively or additionally, it may be specified that, for one or a corresponding hairpin element of a hairpin element device that is an external hairpin element relative to the stacking direction, one of the protrusions is formed on an edge portion of the channel opening that extends laterally relative to the stacking direction. The hairpin element device can thus be reliably supported along the stacking direction to allow for a predetermined distance.

[0016] The stacking direction typically extends radially relative to the central axis of the stator.

[0017] In the case of the stator according to the invention, it is particularly advantageous that the casting compound surrounding the hairpin element assembly is arranged in the stator slots. As a result, heat generated during motor operation can be transferred to the stator core via the casting compound. Compared to conventional stators with insulating paper forming a thermal barrier between the hairpin winding and the stator core, this significantly improves heat dissipation of the hairpin winding. That is, heat can be transferred directly from the casting compound to the stator core. Improved heat dissipation increases the efficiency of the motor, particularly improving the continuous output of the motor. The casting compound is preferably a cured resin.

[0018] Furthermore, preferably, the casting compound can substantially completely fill and seal the space between the stator slot and the hairpin element assembly, with virtually no air. Therefore, heat dissipation can be further increased. Thus, "substantially" means only unintentional manufacturing tolerances are considered.

[0019] Preferably, in the case of the stator according to the invention, the insulating device is arranged on the end face of the stator core. Therefore, this insulating device can also be regarded as a stator end plate.

[0020] Furthermore, the insulation device can be arranged on the opposite end face of the stator core, opposite the first end face. The hairpin winding is thus supported on both sides to predefine the distance. This insulation device can also be considered as a stator end plate.

[0021] Furthermore, in the case of the stator according to the invention, the stator core can be subdivided into at least two stator core portions along the axial direction, with insulating devices arranged between corresponding pairs of adjacent stator core portions. Therefore, additional tangential or radial support for the hairpin winding can be achieved. Combined tangential and radial support is also possible.

[0022] The objective of this invention is also achieved by an electric motor comprising a stator according to the invention and a rotor rotatably arranged within the stator.

[0023] Furthermore, the objective of this invention is achieved by a vehicle comprising a motor according to the invention, the motor being configured to drive the vehicle. Attached Figure Description

[0024] Further advantages and details of the present invention will become apparent from the exemplary embodiments described below with reference to the accompanying drawings. The drawings are schematic diagrams, in which...

[0025] Figure 1 A perspective view of an end face of a stator according to a first exemplary embodiment of the present invention is shown;

[0026] Figure 2 A detailed cross-sectional view of the stator according to a first exemplary embodiment is shown;

[0027] Figure 3 A detailed perspective view of the stator according to a first exemplary embodiment is shown;

[0028] Figure 4 A schematic diagram of a second exemplary embodiment of the stator according to the present invention is shown;

[0029] Figure 5 A schematic diagram of a third exemplary embodiment of the stator according to the present invention is shown; and

[0030] Figure 6 A schematic diagram of an exemplary embodiment of a vehicle according to the present invention, having an exemplary embodiment of an electric motor according to the present invention, is shown. Detailed Implementation

[0031] Figure 1 This is a perspective view of the end face of the first embodiment of stator 1.

[0032] The stator 1 includes a stator core 2 with stator slots 3, the stator slots 3 being concealed within... Figure 1 (See also) Figure 2 and Figure 3 The stator slots 3 are formed in the stator core 2 in an axial direction relative to the central axis 4 of the stator. The stator slots 3 are arranged in the stator core 2 in a circumferential direction relative to the central axis 4.

[0033] Furthermore, the stator 1 includes a hairpin winding 5 having a plurality of hairpin element devices 6 arranged in a circumferentially distributed manner in the stator slots 3, and each hairpin element device 6 protruding from an end face of the stator core 2. The hairpin winding 5 thus forms a winding head 7 on both end faces of the stator core 2.

[0034] According to a first exemplary embodiment, an insulating device 8 is disposed in the stator 1. The insulating device has an annular body 9 in which a plurality of channel openings 10 are formed in a circumferentially distributed manner. A corresponding hairpin element device 6 passes through one of the channel openings 10.

[0035] Figure 2 A detailed cross-sectional view of the stator 1 according to a first exemplary embodiment is shown.

[0036] Insulation device 8 (see) Figure 1 The distance between the hairpin element device 6 and the edge 11 of the stator slot 3 that receives it is predetermined.

[0037] Figure 3 This is a detailed perspective view of the stator 1 according to a first exemplary embodiment. Only one hairpin element device 6 (in...) Figure 3 The centrally located section 3 is shown in full, while the other stator slots 3 are shown as unoccupied or only partially occupied, so that the insulation device 8 can be described more accurately.

[0038] Each hairpin element device 6 includes multiple hairpin elements 12a, 12b, four of which are exemplified here. These hairpin elements are positioned relative to the central axis 4 (see...). Figure 1 The components are arranged in the stator slot 3 in a stacked manner in the stacking direction indicated by arrow 13. Each channel opening 10 of the insulating device 8 includes two edge portions 14a, 14b extending along the stacking direction, and two edge portions 15a, 15b extending laterally relative to the stacking direction. For the corresponding hairpin elements 12a, 12b of the hairpin element device 6, a protrusion 16 is formed on each opposite edge portion 14a, 14b. Furthermore, for each outer hairpin element 12a relative to the stacking direction, a protrusion 17 is provided on each edge portion 15a, 15b extending laterally relative to the stacking direction.

[0039] Although for clear reasons not in Figure 2 and Figure 3 As shown, the stator slot 3 is filled with a casting compound surrounding the hairpin element assembly 6. The casting compound is a cured resin.

[0040] Other exemplary embodiments of the stator 1 are described below, and all statements relating to the first exemplary embodiment apply accordingly to these embodiments, except for the differences described below. Identical components or components that function in the same manner have the same reference numerals.

[0041] Figure 4 This is a schematic diagram of a second embodiment of the stator 1. In this exemplary embodiment, two identical insulating devices 8 are arranged on two opposite end faces of the stator core 2.

[0042] Figure 5 This is a schematic diagram of a third exemplary embodiment of the stator 1. In this exemplary embodiment, the stator core 2 is subdivided into two partial stator cores 18. In addition to the two insulating devices 8 arranged on the end faces, according to the second exemplary embodiment, another insulating device 8 is arranged between adjacent partial stator cores 18, the insulating device being formed in a manner substantially corresponding to the other two insulating devices 8. Of course, the stator core 2 may also be subdivided into more than two partial stator cores 18, with the insulating devices 8 disposed between corresponding adjacent pairs of partial stator cores 18.

[0043] Figure 6 This is a schematic diagram of an exemplary embodiment of a vehicle 19 having an exemplary embodiment of the motor 20. The motor 20 is configured to drive the vehicle 19 and includes a stator 1 according to one of the foregoing exemplary embodiments, in which a rotor 21 is rotatably arranged. The vehicle is a battery electric vehicle (BEV) or a hybrid electric vehicle. It can be seen that the central axis 4 corresponds to the axis of rotation of the rotor 21.

Claims

1. A stator (1) for an electric motor (20), comprising: - A stator core (2) having stator slots (3), the stator slots (3) being formed axially relative to the central axis (4) of the stator (1) and arranged in a circumferential direction relative to the central axis (4); and - A hairpin winding (5) having multiple hairpin element devices (6) arranged in stator slots (3), with each hairpin element device protruding from the end face of the stator core (2). Its features are, At least one insulating device (8) having a body (9) in which a plurality of channel openings (10) are formed in a manner distributed in a circumferential direction, wherein a corresponding hairpin element device (6) passes through one of the channel openings (10), and the insulating device (8) predefines the distance between the hairpin element device (6) and the edge (11) of the stator slot (3) receiving the hairpin element device (6).

2. The stator as claimed in claim 1, wherein, The edge of the corresponding channel opening (10) has protrusions (16, 17) that point into the channel opening and are predetermined at the distance.

3. The stator as described in claim 2, wherein, Each hairpin element device (6) has multiple hairpin elements (12a, 12b) arranged in stator slots (3) in a stacked manner relative to the central axis (4) in the stacking direction.

4. The stator as described in claim 3, wherein, For the corresponding hairpin element (12a, 12b) of the hairpin element device (6), one of the protrusions (16) is formed on one or a corresponding edge portion (14a, 14b) of the channel opening (10), which extends along or parallel to the stacking direction.

5. The stator as described in claim 3 or 4, wherein, For one or a corresponding hairpin element (12a) of a hairpin element device (6) with the hairpin element being an external hairpin element relative to the stacking direction, one of the protrusions (17) is formed on the edge portion (15a, 15b) of the channel opening (10), which extends laterally relative to the stacking direction.

6. The stator as claimed in any one of claims 1 to 4, wherein, The casting compound surrounding the hairpin element device (6) is arranged in the stator slot (3).

7. The stator as claimed in any one of claims 1 to 4, wherein, An insulating device (8) is arranged on the end face of the stator core (2).

8. The stator as claimed in claim 7, wherein, An insulating device (8) is arranged on the other end face of the stator core (2) opposite to the first end face.

9. The stator as claimed in any one of claims 1 to 4, wherein, The stator core (2) is subdivided into at least two part stator cores (18) along the axial direction, and the insulating device (8) is arranged between the corresponding pair of adjacent part stator cores (18).

10. An electric motor (20) comprising a stator (1) as claimed in any one of claims 1 to 9 and a rotor (21) rotatably arranged within the stator (1).

11. A vehicle (19) including an electric motor (20) as claimed in claim 10, configured to drive the vehicle (19).

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