Stator of an electrical machine

Abstract

A stator (1) of an electromachine (2) comprising a stator stacked core (5), wherein stator slots (7) are formed in the stator stacked core (5), and a conductor bundle (10) is provided in each stator slot (7) to form an electrical stator coil (11), and a slot gap (12) is formed between the side surface (7f) of each stator slot (7) and each conductor bundle (10), and the slot gap (12) forms a slot gap path (13) within each stator slot (7). In a stator (1), the slot gap (13) is formed such that a coolant can pass through it along the slot cooling path (14), and the stator slots (7) extend radially between the slot bottom (7g) and the slot slit (7s), respectively, and the slot slit (7s) is closed by a stator sealing sleeve (15), and the stator sealing sleeve (15) has a radial projection (16) on the outside, and the radial projection (16) reaches into the slot slit (7s) radially, - The stator (1) is characterized in that the radial projection (16) of the stator sealing sleeve (15) is a slot slit sealing portion that seals or narrows a portion of each slot slit (7s) for the sake of the slot cooling path (14), - the stator sealing sleeve (15) has multiple slot slit sealing portions (16) formed for each slot slit (7s), - slot slit passages (17) are formed between adjacent slot slit sealing portions (16) of the same slot slit (7s), and - the slot slit sealing portions (16) are formed in a groove shape.

Description

Technical Field

[0001] The present invention starts from a stator based on the field of claim 1.

Background Art

[0002] The stator of an electric machine is already known from DE102020126408A1 and DE102020119110A1, and includes a stator axis and a stator laminated core. The stator laminated core is formed with stator teeth and stator slots between the stator teeth. The stator laminated core includes a number of thin sheet metals. In each stator slot, there is provided a conductor bundle containing only one conductor or a plurality of conductors, especially a stack of flat rectangular conductors, for forming an electric stator coil. A slot gap is formed between the side surface of each stator slot and the conductor or conductor bundle arranged in the stator slot. The slot gap forms a slot gap path that extends axially with respect to the stator axis within each stator slot. The slot gap path can be flowed through by a refrigerant, especially oil, along the slot cooling path. The stator slot extends between a slot bottom and a slot slit in the radial direction with respect to the stator axis. The slot slit of the stator slot is closed by a slot cap formed as a stator sealing sleeve. The stator sealing sleeve has a radially protruding portion on the outer side facing the stator laminated core. The radially protruding portion reaches into the slot slit in the radial direction and extends axially. This stator sealing sleeve has a supplementary stiffening rib for pressing the stator sealing sleeve against the inner diameter of the stator. The supplementary stiffening rib is formed continuously in the axial direction.

Summary of the Invention

[0003] Advantages of the Present Invention In contrast, the stator according to the present invention having the features of claim 1 has the advantage that the stator sealing sleeve contributes to the emergence of a serpentine slot cooling path and improves the cooling of the stator by improved flow control. In particular, the conductor bundles in each slot gap path along the cooling path are cooled more uniformly.

[0004] This is achieved by the present invention by the following: - The radial projection of the stator sealing sleeve is a slot slit sealing portion that seals or narrows each slot slit in a portion of its length for the sake of the slot cooling path, and - The stator sealing sleeve has multiple slot slit sealing portions formed for each slot slit of the stator, spaced apart from each other in the axial direction relative to the stator axis, and these slot slit sealing portions extend particularly to the conductor or conductor bundle. - Between adjacent slot slit sealing portions of the same slot slit, a slot slit passage is formed for changing the direction of the slot cooling path. - The slot slit sealing portion of the stator sealing sleeve is formed in a groove shape.

[0005] The groove-shaped slot slit sealing portion enables the inexpensive manufacture of the stator sealing sleeve according to the present invention. The measures described in the dependent claims enable advantageous modifications and improvements to the stator presented in claim 1 of the electromachine.

[0006] According to one advantageous embodiment, the slot slit passage of the stator sealing sleeve may be formed as an interrupted groove or as a groove with a reduced groove height. The stator sealing sleeve has a sealing pattern for each slot slit, including at least one slot slit sealing portion and at least one slot slit passage, wherein a first sealing pattern is defined for a first set of slot slits and a second sealing pattern is defined for a second set of slot slits, the second sealing pattern having one slot slit sealing portion in an axial position where the first sealing pattern has one slot slit passage, and it is particularly advantageous when the slot slit sealing portions of both sealing patterns overlap, especially when viewed in the axial direction. In this way, the bypasses in the first set of stator slots are located radially opposite to the second set of stator slots, so that the meandering slot cooling paths in the first set of stator slots run radially opposite to the second set of stator slots. That is, in an axial position where one bypass is formed in the slot bottom in the first set of stator slots, there is one bypass in the slot slit in the second set of stator slots.

[0007] Furthermore, multiple support points are formed within each stator slot, spaced apart from each other axially with respect to the stator axis, to support the conductor or conductor bundle within each stator slot. In this case, the cooling path of each slot is narrowed at least at the support points, and a bypass is provided at each support point to guide the coolant to pass alongside each narrowed support point. These bypasses of each stator slot are formed alternately at the bottom of the slot or within the slot slit along the axial extension of each stator slot to form a meandering cooling path, and it is advantageous for the bypasses within the slot slit, which serve as slot slit passages, to be provided in the stator sealing sleeve. In this way, the gap between slots can flow from end to end, and the bypasses within the slot slits, which serve as slot slit passages, are formed in the stator sealing sleeve. To avoid linear flow through the slot slits, which is unfavorable for cooling, slot slit sealing sections are formed within the slot slits between the support points.

[0008] It is highly advantageous if the support points are formed by the twisting of at least two thin sheets of metal in each of the stator laminated cores at a specific twist angle around the stator axis. In this way, the support points can be manufactured particularly easily. Above all, this solution does not require any special thin sheets within the stator laminated core.

[0009] It is also advantageous when the stator sealing sleeve is fixedly coupled to the stator by deformation, particularly thermal deformation, especially by the extrusion of the stator sealing sleeve material into the slot slits. This allows for the creation of a very thin stator sealing sleeve, which only slightly enlarges the voids in the electromechanical system, thereby potentially achieving higher electromechanical performance. Furthermore, the sealing of the slot slits is improved by the material extrusion.

[0010] Furthermore, it is advantageous if the stator sealing sleeve is manufactured from a material containing thermoplastics, particularly thermoplastic composites, and especially fiber-reinforced composites. This allows for the manufacture of the stator sealing sleeve by thermal deformation.

[0011] Furthermore, it is advantageous that the stator sealing sleeve is manufactured from a raw material to be deformed, which is a smooth tube, particularly an extruded sleeve, attached to the stator laminated core by bonding air (Fuegeluft) and subsequently expanded. Alternatively, the raw material can be a flat material strip, particularly made of organosheet, which is formed along the circumferential surface of the stator teeth facing the gaps to form a sleeve shape, particularly with the ends of the flat material strip overlapping, and in the slot slit region, particularly by roller burnishing (Rollieren) to form it into the slot slit of the stator laminated core. This achieves the inexpensive manufacture of stator sealing sleeves for mass production.

[0012] Furthermore, the present invention relates to a method for forming a stator sealing sleeve on the stator of an electromachine, comprising the following steps: a. A step of preparing a completed stator including a stator laminated core and stator coils, b. The step of arranging the raw material for creating the stator sealing sleeve along the circumferential surface of the stator teeth of the stator laminated core that faces the void, c. A stator sealing sleeve is formed by deforming the raw material using at least one deformation tool, particularly by roller burnishing or expansion, particularly by thermal deformation, more specifically by applying the raw material to the circumferential surface of the stator teeth facing the gap, and in particular by extruding the raw material into the slot slit. d. Step of creating a groove within the stator sealing sleeve in order to form a slot slit sealing portion. This includes methods.

[0013] This method has the advantage of eliminating the need for press-fitting of the stator sealing sleeve. This means the stator sealing sleeve does not need to have the high rigidity required for press-fitting. Instead, the raw material is fixedly formed along the stator by deformation.

[0014] Furthermore, the present invention relates to an electromachine equipped with a stator according to the present invention. One exemplary embodiment of the present invention is shown in a simplified manner in the drawings and will be described in detail in the following description. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view of an electromachine equipped with a stator and rotor according to the present invention. [Figure 2] This is a cross-sectional view of one of the stator slots of the stator, along line AA in Figure 1. [Figure 3] This is a cross-sectional view of one of the stator slots of the stator, along line BB in Figure 1. [Figure 4] This is a cross-sectional view of one of the stator slots of the stator, along line CC in Figure 1. [Figure 5] Figure 1 shows a cross-sectional view of the inner circumferential surface of the stator and the stator sealing sleeve according to the present invention mounted on this inner circumferential surface. [Modes for carrying out the invention]

[0016] Figure 1 shows a cross-section of an electromachine equipped with a stator and rotor according to the present invention. The stator 1 of the electromachine 2 has a stator shaft 3 and includes a stator laminated core 5, which has stator teeth 6 and stator slots 7 between the stator teeth 6, and the stator laminated core 5 includes a number of thin sheets 8. Within each stator slot 7 is provided a conductor bundle 10 containing one or more electrical conductors 9, particularly a stack of flat wire conductors, to form an electrical stator coil 11. A single electrical conductor 9 is, for example, enameled wire. A slot gap 12 is formed between the side surface 7f of each stator slot 7 and the conductor 9 or conductor bundle 10 located within the stator slot 7, and the slot gap 12 forms a slot gap passage 13 that extends axially with respect to the stator shaft 3 within each stator slot 7, and the slot gap passage 13 is permeable to a coolant, particularly oil, along a slot cooling path 14, which is formed particularly on both sides of the conductor 9 or conductor bundle 10. The stator slot 7 extends radially between the slot bottom 7g and the slot slit 7s with respect to the stator shaft 3. The slot slit 7s of the stator slot 7 is closed by a sleeve-shaped slot cap, which is fitted to the circumferential surface of the stator teeth 6 facing the gap, and is hereafter referred to as the stator sealing sleeve 15. The stator sealing sleeve 15 has a radial projection 16 on its outer side facing the stator laminated core 5, and the radial projection 16 reaches into the slot slit 7s in the radial direction and extends axially.

[0017] According to the present invention, the radially protruding portion 16 of the stator sealing sleeve 15 is a slot slit blocking portion 16 that blocks or narrows each slot slit 7s in some sections for the slot cooling path 14. A plurality of slot slit blocking portions 16 that are axially spaced apart from each other with respect to the stator axis 3 are formed on the stator sealing sleeve 15 for each slot slit 7s of the stator 1, and this slot slit blocking portion 16 reaches, in particular, the conductor 9 or the conductor bundle 10. Between adjacent slot slit blocking portions 16 of the same slot slit 7s, a slot slit passage 17 is formed for changing the direction of the slot cooling path 14 so as to return in the direction of the slot bottom 7g. That is, the slot slit blocking portion 16 of the stator sealing sleeve 15 helps to control the flow of the slot cooling path 14. A meandering orbit, in particular, is defined in the slot cooling path 14.

[0018] In the stator slot 7, for example, a plurality of support points 18 that are axially spaced apart from each other with respect to the stator axis 3 are formed in each stator slot 7 to support the conductor 9 or the conductor bundle 10 in each stator slot 7. Each slot cooling path 14 is at least narrowed at the support point 18. Therefore, one bypass 19 is provided at each support point 18, whereby the refrigerant is guided to pass by the side of each narrowed support point 18. The bypass 19 of each stator slot 7 is formed alternately along the axial extension of each stator slot 7 to form a meandering slot cooling path 14, either in the slot bottom 7g or in the slot slit 7s. The bypass 19 in the slot slit 7s as the slot slit passage 17 is formed on the stator sealing sleeve 15.

[0019] As shown in FIG. 1, the bypass 19 is formed, for example, alternately from one of the support points 18 to the next support point 18, either in the slot bottom 7g or in the slot slit 7s. The support point 18 can be formed, for example, by the twist of at least two thin metal plates 8 of the stator laminated core at a specific twist angle centered on the stator axis 3.

[0020] The stator sealing sleeve 15 has, in the axial direction, sleeve end sections 15e protruding beyond both end faces of the stator laminated core 5, and the wall thickness of the sleeve end sections 15e is formed, for example, larger than the minimum wall thickness within the intermediate section of the stator sealing sleeve 15 between the sleeve end sections 15e.

[0021] The electric machine 2 includes a stator space 25 for the arrangement and cooling of the stator 1 of the electric machine and a rotor space 26 for the arrangement of the rotor 27. The stator sealing sleeve 15 is provided to seal the rotor space 26 from the stator space 25. The electric machine 2 has two bearing pedestals 28 for supporting the rotor 27. A ring neck section 29 is fixed or integrally formed on each bearing pedestal 28. A sleeve packing 30 is provided between the ring neck section 27 of each bearing pedestal 28 and each sleeve end section 15e of the stator sealing sleeve 15.

[0022] At each end face of the stator 1, a stator cooling space 31 for accommodating each coil end of the stator coils 11 is formed. The stator slots 7 can be flowed through along the slot cooling path 14 from one of both stator cooling spaces 31 into the other stator cooling space 31.

[0023] FIG. 2 shows a cross section along line A - A of FIG. 1 of one of the stator slots of the stator. According to the invention, the slot slit blocking section 16 of the stator sealing sleeve 15 is formed in a groove shape. The groove-shaped slot slit passage 17 of the stator sealing sleeve 15 can be formed, for example, as an interruption of the groove or as a groove with a reduced groove height.

[0024] A plurality of grooves 16 for each slot slit 7s are formed shorter in the axial direction than the lamination length of the stator laminated core 5, different from the reinforcing ribs from the prior art. The cross-section of the stator slot 7 of the stator 1 along line AA is one cross-section of the support location 18. A bypass 19 for bypassing the support location 18 is provided as a recess in each thin sheet metal 8 at the slot bottom 7g in the cross-section based on Figure 2. The bypass 19 at the slot bottom 7g can be formed, for example, within the slot bottom 7g or within the tooth surface 7f at the root of the stator tooth 6. A groove-shaped slot slit sealing portion 16 is provided within the slot slit 7s in the cross-section based on Figure 2. In other words, a support location 18 with a slot slit sealing portion 16 has one bypass 19 within the slot bottom 7g.

[0025] Figure 3 shows a cross-section of one of the stator slots of the stator, along line BB in Figure 1. The cross-section of the stator slot 7 of the stator 1 along line BB is located between the axial directions of the two support points 18. Therefore, no bypass 19 is provided in either the slot bottom 7g or within the slot slit 7s. Thus, the stator sealing sleeve 15 in the cross-section shown in Figure 3 has a groove-shaped slot slit sealing portion 16.

[0026] Figure 4 shows a cross-section of one of the stator slots of the stator, along line CC in Figure 1. The cross-section of the stator slot 7 of stator 1 along line CC is another cross-section of the support location 18. A bypass 19 for bypassing the support location 18 is provided within the slot slit 7s in the cross-section based on Figure 4, and therefore the stator sealing sleeve 15 has a slot slit passage 17 at this axial position. No bypass 19 is provided at the slot bottom 7f.

[0027] Figure 5 shows a cross-sectional view of the inner circumferential surface of the stator based on Figure 1 and the stator sealing sleeve according to the present invention attached to this inner circumferential surface. The stator sealing sleeve 15 has a sealing pattern 20 for each slot slit 7s, which includes at least one slot slit sealing portion 16 and at least one slot slit passage 17. For the stator laminated core 5, a first sealing pattern 20.1 is defined for a first set 21 of slot slits 7s, and a second sealing pattern 20.2 is defined for a second set 22 of slot slits 7s, wherein the second sealing pattern 20.2 has one slot slit sealing portion 16 in the axial position where the first sealing pattern 20.1 has one slot slit passage 17. The slot slit sealing portions 16 of both sealing patterns 20.1 and 20.2 may overlap, for example, when viewed axially. The first set 21 of slot slits 7s and the second set 22 of slot slits 7s contain the same number of slot slits 7s.

[0028] According to the present invention, the stator sealing sleeve 15 is manufactured by deformation, particularly thermal deformation, thereby permanently bonding to the stator laminated core 5, for example, in a way that it cannot be removed without destruction. For this purpose, the material of the stator sealing sleeve 15 is extruded into the slot slit 7s as shown in Figure 4. At this time, rib-shaped thickness-increasing portions 32 are formed within the slot slit 7s.

[0029] The stator sealing sleeve 15 is manufactured, for example, from a material containing a thermoplastic substance, in particular from a thermoplastic composite material, and especially from a fiber-reinforced composite material. The stator sealing sleeve 15 is manufactured from a raw material to be deformed, which, according to an exemplary first embodiment, may be a smooth tube and is attached to the stator laminated core 5 by joining air and subsequently expanded. The smooth tube may be, for example, an extruded tube or an extruded sleeve. The raw material may, according to an exemplary second embodiment, be a flat material strip, which is formed along the circumferential surface of the stator teeth 6 facing the gaps in order to form a sleeve shape, with both ends of the flat material strip overlapping in particular, and in the region of the slot slit 7s, it is formed into the slot slit 7s of the stator laminated core 5, particularly by roller burnishing. The flat material strip may be, for example, a so-called organosheet.

[0030] The following steps are specified for forming the stator sealing sleeve 15 on the stator 1. In the first step, a completed stator is prepared, including a stator stacked core 5 and stator coils 11 positioned within the stator stacked core 5.

[0031] In the subsequent second step, the raw material for creating the stator sealing sleeve 15 is arranged along the circumferential surface of the stator teeth 6 of the stator laminated core 5 that faces the void. In a further third step, the raw material is deformed, particularly by thermal deformation, for example, by roller burnishing of a flat material strip or expansion of a smooth tube. This deformation is carried out using at least one deformation tool, so that the raw material is pressed against the circumferential surface of the stator teeth 6 facing the gap, and in particular, so that the material of the raw material is pressed into the slot slit 7s as shown in Figure 4. At this time, rib-like thickness-increasing portions 32 are created within the slot slit 7s. Furthermore, grooves are created in the stator sealing sleeve 15 to form the slot slit sealing portion 16, and these grooves may have been created in another step or already during the deformation of the raw material as described above. During this grooving, depressions are created on the circumferential surface of the stator sealing sleeve 15, as is evident in Figures 2 and 3.

[0032] Due to thermal deformation, the deformation tool and / or the unworked piece before deformation may be heated.

Claims

1. A stator (1) of an electromachine (2) comprising a stator shaft (3) and a stator laminated core (5), wherein the stator laminated core (5) has stator teeth (6) and stator slots (7) between the stator teeth (6), the stator laminated core (5) comprises a number of thin sheet metal (8), and each stator slot (7) is provided with a conductor bundle (10) containing one or more conductors (9), particularly a stack of flat wire conductors, for forming an electrical stator coil (11), and a slot gap (12) is formed between the side surface (7f) of each stator slot (7) and the conductor (9) or conductor bundle (10) arranged within the stator slot (7), and the slot gap (12) is within each stator slot (7) In a stator (1), a slot gap passage (13) is formed that extends axially with respect to the stator shaft (3), the slot gap passage (13) is permeable to a coolant, particularly oil, along a slot cooling path (14), the stator slot (7) extends radially with respect to the stator shaft (3) between a slot bottom (7g) and a slot slit (7s), the slot slit (7s) of the stator slot (7) is closed by a slot cap formed as a stator sealing sleeve (15), the stator sealing sleeve (15) has a radial projection (16) on the outside facing the stator laminated core (5), the radial projection (16) reaches radially into the slot slit (7s) and extends axially, - The radial projection (16) of the stator sealing sleeve (15) is a slot slit sealing portion that seals or narrows each of the slot slits (7s) in a portion of its length for the sake of the slot cooling path (14), - The stator sealing sleeve (15) has a plurality of slot slit sealing portions (16) formed in each slot slit (7s) of the stator (1), which are spaced apart from each other in the axial direction, and the slot slit sealing portions (16) in particular reach the conductor (9) or the conductor bundle (10), - Between adjacent slot slit sealing portions (16) of the same slot slit (7s), a slot slit passage (17) is formed for changing the direction of the slot cooling path (14). - A stator (1) characterized in that the slot slit sealing portion (16) of the stator sealing sleeve (15) is formed in a groove shape.

2. The stator according to claim 1, characterized in that the slot slit passage (17) of the stator sealing sleeve (15) is formed as an interrupted portion of a groove or as a groove having a reduced groove height.

3. The stator according to claim 1 or 2, wherein the stator sealing sleeve (15) has a sealing pattern (20) for each slot slit (7s) including at least one slot slit sealing portion (16) and at least one slot slit passage (17), wherein a first set (21) of slot slits (7s) is defined by a first sealing pattern (20.1), and a second set (22) of slot slits (7s) is defined by a second sealing pattern (20.2), wherein the second sealing pattern (20.2) has one slot slit sealing portion (16) in an axial position where the first sealing pattern (20.1) has one slot slit passage (17), and the slot slit sealing portions (16) of both sealing patterns (20.1, 20.2) overlap, in particular, when viewed in the axial direction.

4. A stator according to any one of claims 1 to 3, characterized in that a plurality of support locations (18) are formed within each stator slot (7), spaced apart from each other in the axial direction with respect to the stator shaft (3), to support the conductor (9) or conductor bundle (10) located within each stator slot (7), wherein each slot cooling path (14) is at least narrowed at the support locations (18), and in this regard, one bypass (19) is provided at each support location (18), thereby guiding the refrigerant to pass beside each of the narrowed support locations (18), and the bypasses (19) of each stator slot (7) are formed alternately along the axial extension of each stator slot (7) at the slot bottom (7g) or within the slot slit (7s) to form a meandering slot cooling path (14), and the bypasses (19) within the slot slit (7s) as a slot slit passage (17) are provided in the stator sealing sleeve (15).

5. The stator according to claim 4, characterized in that the support portion (18) is formed by the twisting of at least two thin sheet metals (8) of each of the stator laminated cores (5) at a specific twist angle around the stator axis (3).

6. The stator according to any one of claims 1 to 5, characterized in that the stator sealing sleeve (15) is fixedly coupled to the stator (1) by deformation, particularly thermal deformation, and in particular by the material of the stator sealing sleeve (15) being extruded into the slot slit (7s).

7. The stator according to any one of claims 1 to 6, characterized in that the stator sealing sleeve (15) is made from a material containing a thermoplastic substance, in particular from a thermoplastic composite material, and in particular from a fiber-reinforced composite material.

8. The stator sealing sleeve (15) is manufactured from a raw product to be deformed, and the raw product is a. A smooth tube, particularly an extruded sleeve, which is attached to the stator laminated core (5) by joining air and subsequently expanded. b. A stator according to any one of claims 1 to 7, characterized in that it is a flat material strip made of organosheet, which is formed along the circumferential surface of the stator teeth (6) facing the gap in order to form a sleeve shape, in particular the ends of the flat material strip overlap, and in the region of the slot slit (7s), in particular by roller burnishing, it is formed into the slot slit (7s) of the stator laminated core (5).

9. A method for forming a stator sealing sleeve (15) on a stator (1) according to any one of claims 1 to 8, a. A step of preparing a completed stator (1) including a stator stacked core (5) and stator coils (11), b. The step of arranging the unprocessed material for creating the stator sealing sleeve (15) along the circumferential surface of the stator teeth (6) of the stator laminated core (5) that faces the void, c. The stator sealing sleeve (15) is formed by deforming the raw product using at least one deformation tool, particularly by roller burnishing or expansion, particularly by thermal deformation, more specifically by applying the raw product to the circumferential surface of the stator teeth (6) facing the gap, and in particular by extruding the material of the raw product into the slot slit (7s), d. A method comprising the step of generating a groove within the stator sealing sleeve (15) in order to form the slot slit sealing portion (16).

10. An electric machine comprising a stator according to any one of claims 1 to 8.

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