Method for manufacturing stator

Abstract

The present invention relates to a method for manufacturing a stator (1) having at least two stator segments (2) adjacent to each other in the circumferential direction (3), wherein each stator segment (2) has a coil winding (4) mounted on a carrier tooth (5) of the stator segment (2). The stator (1) is simplified in manufacturing while increasing power density by mounting wall portions (10) respectively at the at least two stator segments (2) adjacent to each other in the circumferential direction (3), wherein the opposing wall portions (10) in the circumferential direction (3) form channels (12) for cooling fluid in the stator (1). The invention also relates to such a stator (1).

Description

Technical Field

[0001] This invention relates to a method for manufacturing a stator for an electric motor. The invention also relates to such a stator. Background Technology

[0002] The stator is typically a component of an electric motor and interacts with the associated rotor. To achieve electromagnetic interaction with the associated rotor, at least one coil winding is usually provided in the stator. Such a stator is typically constructed in the form of a hollow cylinder. Here, at least one coil winding is bounded by the radial inner wall and radial outer wall (also known as the yoke) of the coil. To manufacture the stator, at least one coil winding is typically mounted on a hollow cylindrical carrier.

[0003] Especially in the case of stators with larger dimensions, particularly larger diameters, segmented stator construction can be used to simplify stator manufacturing.

[0004] Here, this type of stator has multiple sections (also referred to below as stator sections) that follow each other in the circumferential direction. Each stator section typically includes carrier teeth on which the coil windings are mounted. For the manufacture of the stator, the stator sections are arranged and connected to each other in the circumferential direction.

[0005] Waste heat is generated during stator operation, necessitating stator cooling. To cool the stator, appropriate coolers can be installed. For improved cooling, it's conceivable to use a cooling fluid that absorbs heat during stator operation. However, this typically requires the installation of corresponding cooling channels, which complicate coil manufacturing and increase costs. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide an improved or at least other embodiment of a method for manufacturing a stator having at least two stator segments connected to each other, and of such a stator, characterized by simple manufacturing and increased power density.

[0007] According to the invention, this objective is achieved by the subject matter of the independent claim. Advantageous embodiments are the subject matter of the dependent claims.

[0008] This invention is based on the following general idea: In a segmented stator, before assembling the stator segments, at least two of the stator segments are provided with associated segments, which, in the assembled and connected state of the stator segments, form a channel, wherein the channel can be used to cool the stator during stator operation. As a result, the cooling system for cooling the stator is at least partially integrated into the manufacturing of the coil segments. This leads to a simplified implementation of the cooling system, particularly by eliminating or at least reducing the subsequent introduction of channels in or at the stator. Furthermore, since the cooling system is integrated into the manufacturing of the stator segments, the channels are closer to the associated coil winding arrangement and / or the channels have improved thermal transfer connections with the coil windings. This results in improved coil winding cooling, which in turn leads to an increase in stator power density.

[0009] According to the invention, the stator thus has at least two stator sections that are adjacent to and connected to each other in the circumferential direction. Preferably, the stator has three or more such stator sections. Here, each stator section includes a carrier tooth on which a coil winding is mounted. Thus, each coil winding has two outer sides that are opposite to each other in the circumferential direction. Here, for the purpose of manufacturing the coil, the coil sections are arranged adjacent to each other in the circumferential direction such that the outer sides of the adjacent coil windings are arranged opposite each other in the circumferential direction. According to the invention, before arranging the stator sections in the circumferential direction and thus before manufacturing the stator, electrically insulating walls are respectively mounted on the side of at least two coil windings that are opposite to each other in the circumferential direction, these coil windings being circumferentially opposite each other in the subsequent stator, such that in the subsequent stator, two associated walls are arranged opposite each other between the opposing outer sides. Subsequently, the stator sections are arranged adjacent to each other in the circumferential direction such that the associated walls each define a channel. For this purpose, at least one of the walls is correspondingly shaped. Then, the stator sections are connected to each other to manufacture the stator, such that the corresponding channels are fluid-sealed relative to the coil windings.

[0010] In fact, the stator has a hollow cylindrical shape. This means that by setting stator segments in the circumferential direction and connecting the stator segments, a stator that wraps around in the circumferential direction is obtained.

[0011] In principle, the stator sections can be connected in any manner. In particular, the stator sections are connected to each other by means of material fitting (e.g., by welding, especially by ultrasonic welding).

[0012] In practice, the associated (i.e., opposite in the coil) walls define cavities that form channels. These cavities, and thus channels, are permeable to cooling fluids, especially liquids, to cool the coil.

[0013] In principle, such channels and walls can only be positioned between two outer sides facing each other, and further between two stator sections that follow each other in the circumferential direction.

[0014] Preferably, such a channel is formed by installing the wall portion between at least two stator sections that are adjacent to each other in the circumferential direction, advantageously between two stator sections that are adjacent to each other in the circumferential direction respectively.

[0015] In principle, the corresponding wall section can be installed in any way to the associated stator section.

[0016] An embodiment in which at least one of the wall portions is manufactured by injection molding and then mounted at the associated stator section is considered preferred. In particular, the wall portion is sprayed at the associated stator section onto the associated outer side of the coil winding, on the side facing away from the associated carrier teeth in the circumferential direction. Thus, a simple and defined manufacturing of the wall portion is achieved, while simplifying the sealing relative to the associated coil winding.

[0017] In principle, the material used to make the corresponding wall can be any material, as long as the wall is electrically insulating.

[0018] Here, it is preferable to manufacture at least one of the corresponding wall sections using thermoplastic materials, particularly by injection molding. This enables faster installation of the wall sections, and thus greater synchronization, especially when manufacturing the associated stator sections.

[0019] In principle, at least one of the wall portions can be directly mounted on the outside of the associated coil winding.

[0020] Preferably, a protective layer is applied between the wall and the coil winding. This protective layer allows for improved insulation relative to the coil winding. This means that the protective layer is mounted on the outside of at least one of the coil windings, advantageously on the outside of the respective coil winding, and the wall is mounted on the protective layer.

[0021] In fact, the corresponding protective layer is electrically insulating.

[0022] In principle, the protective layer can only be installed on one or more outer sides of the associated coil winding.

[0023] Advantageously, the protective layer is installed over the entire coil winding. Thus, the entire coil winding is protected accordingly.

[0024] In principle, the corresponding protective layer can be installed at the associated coil winding in any manner.

[0025] Advantageously, at least one, preferably a corresponding, protective layer is installed at the coil winding by injection molding. In particular, the coil winding is overmolded with the protective layer. This achieves a simple and smooth installation of the protective layer.

[0026] In principle, the protective layer can be made of any material, as long as it is electrically insulating.

[0027] Preferably, the protective layer is a thermosetting plastic. Particularly preferably, the protective layer is also installed on the coil winding by injection molding. This means that, in order to manufacture at least one protective layer, advantageously, the corresponding protective layer is installed on the coil winding by injection molding, and in particular, the coil winding is overmolded using a thermosetting plastic. Here, due to the low viscosity and thus the smaller injection volume, installing the protective layer, and especially overmolding the coil winding with the protective layer, avoids or at least reduces cavitation in the coil winding. As a result, heat transfer from the coil winding to the cooling fluid flowing through the associated channels is improved. Furthermore, interference caused by cavitation is prevented or at least reduced during coil winding operation.

[0028] In a particularly preferred embodiment, a thermosetting plastic is first injection molded onto the coil winding to create a protective layer. Thus, the coil winding is also geometrically defined and defined, meaning that subsequent wall mounting prevents or at least reduces displacement of the coil winding.

[0029] Subsequently, thermoplastic is injection molded into the wall section. Here, the presence of the previously installed protective layer enables the injection of thermoplastic at increased pressure and / or speed, especially since the geometry of the coil winding is fixed by the protective layer and the protective layer also prevents cavitation in the coil winding. Therefore, overall, with increased synchronicity, reliable and well-defined manufacturing of the stator section and thus the stator is achieved.

[0030] In principle, the corresponding stator sections can have different shapes and / or be manufactured in different ways.

[0031] An embodiment in which at least two of the at least two stator sections, and advantageously all stator sections, are provided as identical components and thus manufactured, is preferred. This results in particularly simple and low-cost manufacturing of the stator. Simultaneously, this arrangement creates channels between the coil windings of the stator sections respectively. This leads to improved cooling and consequently, an increase in the power density of the coils.

[0032] To facilitate fluid guidance through at least one channel, it is preferable that the respective channel is manufactured to be open on at least one side in the axial direction. Thus, the respective channel advantageously has at least one opening in the axial direction for the inflow or outflow of cooling fluid.

[0033] In an advantageous embodiment, a chamber for introducing or collecting cooling fluid from a corresponding channel is then axially positioned at at least one channel, preferably also engaging with at least one stator section.

[0034] In principle, the stator can be used in any application.

[0035] In particular, the stator is used in motors, where the stator interacts with the corresponding rotor.

[0036] Furthermore, it goes without saying that, in addition to the method used to manufacture the stator, the stator manufactured in this way also falls within the scope of this invention.

[0037] Other important features and advantages of the invention will become apparent from the description of the dependent claims, the drawings, and the related drawings with reference to the drawings.

[0038] It goes without saying that, without departing from the scope of the invention, the features described above and those to be described below can be used not only in the combinations given separately, but also in other combinations or individually. Attached Figure Description

[0039] Preferred embodiments of the invention are shown in the accompanying drawings and explained in more detail in the following description, wherein the same reference numerals denote the same or similar or functionally identical parts.

[0040] They are shown schematically respectively:

[0041] Figure 1 A top view of the stator is shown.

[0042] Figure 2 An isometric view is shown during stator manufacturing.

[0043] Figure 3 It shows in Figure 1 The section through the stator, denoted by III.

[0044] Figure 4 An example of another embodiment is shown. Figure 3 The view. Detailed Implementation

[0045] Stator 1 (i.e., for example) Figures 1 to 4 The stator shown includes at least two stator segments 2, which are arranged adjacent to and connected to each other in the circumferential direction 3 to form a stator 1. In the illustrated embodiment, the stator 1 has a plurality of such stator segments 2, which are arranged adjacent to and connected to each other in the circumferential direction 3. For this purpose, as Figure 2As shown in the diagram, the individual stator sections 2 are arranged close to each other in the circumferential direction and then connected to each other, for example, by means of material fitting, especially by welding. (As shown in the diagram...) Figures 2 to 4 Specifically, it can be seen that the corresponding stator section 2 includes a coil winding 4, which is mounted on a carrier 5 of the stator section 2, which is also referred to below as carrier tooth 5. As can be seen from... Figure 2 It can be seen that the stator 1 therefore has the shape of a hollow cylinder as a whole, in which the coil winding 4 of the stator section 2 is arranged between the inner yoke 6 and the outer yoke 7. Here, the corresponding carrier teeth 5 have corresponding sections of the inner yoke 6 and the outer yoke 7. Therefore, the stator 1 extends in the circumferential direction 3 and in the axial direction 9. The corresponding coil winding 4 has two outer sides 8 that are opposite to each other in the circumferential direction 3. Therefore, in the stator 1, the outer sides 8 of the stator drive 2 that are adjacent to each other in the circumferential direction 3 are arranged opposite each other.

[0046] Figure 3 A cross-section extending in the axial direction 9 through the stator 1 is shown, which cross-section is in Figure 1 The Chinese character is represented by III.

[0047] from Figure 3 It can be learned that at least two advantageously corresponding stator sections 2 of the stator section 2, before being arranged close to each other in the circumferential direction 3, each have at least one wall portion 10, such that the walls 10 of the at least two stator sections 2 that are adjacent to each other in the circumferential direction together define a cavity 11 for forming a flow-through channel 12. Here, such walls 10 are respectively installed on the side of at least two coil windings 4 that are opposite to each other in the stator 1, away from the associated carrier teeth 5 in the circumferential direction 3, and then, in order to manufacture the stator 1, the stator sections 2 are arranged and connected to each other accordingly in the circumferential direction 3. Thus, the corresponding walls 10 form half of the associated channel 12 in the stator 1. Here, the manufacturing of the stator 1, especially the connection of the stator sections 2, is carried out such that the corresponding channel 12 is fluid-tight relative to the coil windings 4. Here, in the illustrated embodiment, all stator sections 2 are provided with such walls 10. Figure 3 and Figure 4 As can be seen from this, here, this wall portion 10 is installed at the corresponding stator section 2 on the side of the corresponding coil winding 4 facing away from the associated carrier tooth 5 in the circumferential direction. For example, from... Figure 3 and Figure 4 It can also be seen that, in the illustrated embodiment, stator section 2 is manufactured and configured as the same component 13. Here, for better understanding, in Figure 1 and Figure 2 The wall portion 10 is not shown in the diagram.

[0048] As from Figure 3and Figure 4 As can be seen from the illustration, the wall portion 10 in the illustrated embodiment is not directly mounted on the outer side 8 of the associated coil winding 4. In the illustrated embodiment, a protective layer 14 is provided between the outer side 8 and the corresponding wall portion 10, wherein, in the illustrated embodiment, the protective layer 14 surrounds the entire coil winding 4. The wall portion 10 is mounted on the protective layer 14. Here, the protective layer 14 and the wall portion 10 are mounted separately by injection molding. Advantageously, the coil winding 4 is encapsulated and cast using the protective layer 14. Furthermore, it is advantageous to spray the wall portion 10 onto the protective layer 14.

[0049] Particularly preferably, the protective layer 14 is a thermosetting plastic. Due to the low viscosity of thermosetting plastics, the encapsulation and casting of the coil winding 4 using the thermosetting plastic constituting the protective layer 14 can be performed with a smaller injection volume, thereby avoiding or at least reducing cavitation in the coil winding 4, while simultaneously fixing and defining the geometry of the coil winding 4. This allows the wall portion 10 to be injected with a larger injection volume and higher pressure, and thus more quickly, enabling the manufacturing of the corresponding stator section 2 to be performed faster overall and with greater synchronization without damaging the coil winding 4. Particularly preferably, the wall portion 10 is a thermoplastic plastic. This achieves low-cost, simple, and rapid installation of the wall portion 10.

[0050] As from Figure 3 and Figure 4 As can be seen from this, in this embodiment, the channel 12 is axially open, and thus open in the axial direction 9. In the illustrated embodiment, the channel 12 is axially open on one side only. The axial opening 15 formed by the corresponding channel 12 allows cooling fluid (not shown) to be introduced into or drawn out of the corresponding channel 12.

[0051] exist Figure 4 In the embodiment shown, the stator 1 is provided with a chamber 16, which is axially mounted at the channel 12 and fluidly connected thereto, so that during operation, cooling fluid can flow into or out of the corresponding channel 12 via the chamber 16.

[0052] Therefore, stator 1 can be manufactured simply and at low cost, with the cooling device of stator 1 integrated into the manufacturing of stator section 2. Furthermore, this method improves the cooling of coil winding 4, thereby increasing the power density of stator 1.

Claims

1. Method for producing a stator (1) having at least two stator segments (2) which follow one another in a circumferential direction (3) and are connected to one another, - wherein the respective stator segment (2) has a carrier tooth (5) on which a coil winding (4) is mounted, such that the respective coil winding (4) has two outer sides (8) which face away from one another in the circumferential direction (3), - wherein, in order to produce the stator (1), the stator segments (2) are arranged one after the other in the circumferential direction (3) such that the outer sides (8) of the coil windings (4) which follow one another are arranged opposite one another in the circumferential direction (3), - wherein an electrically insulating wall (10) is respectively mounted on the side of at least two coil windings (4) which face away from the associated carrier tooth (5) in the circumferential direction (3) opposite one another, such that between the opposite outer sides (8) there is provided the associated two walls (10), - the stator segments (2) are subsequently arranged one after the other in the circumferential direction (3) such that the associated walls (10) respectively form a channel (12), - the stator segments (2) are connected to one another such that the respective channel (12) is fluid-tightly sealed with respect to the coil winding (4).

2. Method according to claim 1, characterized in that at least one of the walls (10) is produced by injection moulding.

3. Method according to claim 2, characterized in that a thermoplastic is produced as a wall (10) by injection moulding.

4. Method according to one of claims 1 to 3, characterized in that - a protective layer (14) is mounted on the outer side (8) of at least one of the coil windings (4), - the wall (10) is mounted on the protective layer (14).

5. Method according to claim 4, characterized in that the protective layer (14) is mounted on the entire coil winding (4).

6. Method according to claim 4, characterized in that the coil winding (4) is overmoulded with the protective layer (14).

7. Method according to claim 5, characterized in that a thermoset is mounted as a protective layer (14) on the coil winding (4).

8. Method according to one of claims 1 to 3, characterized in that at least two of the at least two stator segments (2) are produced as identical parts (13).

9. Method according to one of claims 1 to 3, characterized in that - at least one of the at least one channel (12) is produced in an open manner in an axial direction (9), - a chamber (16) is subsequently arranged axially at the channel (12), which chamber serves for introducing cooling fluid into the channel (12) and / or collecting cooling fluid from the channel (12).

10. Stator (1) having a plurality of stator segments (2) which follow one another in a circumferential direction (3), wherein the stator (1) is produced according to the method of one of claims 1 to 9.

11. Stator according to claim 10, characterized in that the stator (1) is a stator for an electric machine.

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