Stator of an electric machine

Abstract

The invention relates to a stator of an electric machine (2), the stator comprising: a laminated core (3) which comprises core laminations (8) and on which stator teeth (4) and stator slots (5) lying between the stator teeth (4) are formed and which extends about a stator axis (7); and a stator winding (6) running in the stator slots (5), wherein at least one set (13) of at least two first partial lamination stacks (3.1) twisted in opposite directions is provided in the laminated core (3) in order to clamp the stator winding (6) at clamping locations (10) of the stator slots (5), wherein at least one of the first partial lamination stacks (3.1) of each set (13) is twisted about the stator axis (7) in one circumferential direction, and at least one other first partial lamination stack (3.1) of the set (13) is twisted in the opposite circumferential direction, wherein protective sleeves (11) are provided in the stator slots (5) of the laminated core (3) in the region of the twisted first partial lamination stacks (3.1), said protective sleeves protecting the stator winding (6) from being damaged by the twisted first partial lamination stacks (3.1) and being in particular electrically insulating, characterised in that at least one of the protective sleeves (11) has at least one collar (12) which is angled relative to a slot section (11.1) of the protective sleeve (11) and which is provided for axial support against one of the stator teeth (4) of one of the first partial lamination stacks (3.1).

Description

[0001] Description

[0002] title

[0003] Stator of an electric machine

[0004] State of the art

[0005] The invention relates to a stator of an electrical machine according to the preamble of the main claim.

[0006] A stator of an electrical machine is already known from DE102021204202 A1, comprising a stator core with laminations, on which stator teeth and stator slots located between the stator teeth are formed and which extends around a stator axis, and with a stator winding running in the stator slots, wherein at least one set of three oppositely twisted first stator sub-packs is provided in the stator core for clamping the stator winding at clamping points of the stator slots, wherein two of the first stator sub-packs of the respective set are twisted in one circumferential direction and the remaining first stator sub-pack of the set in the opposite direction around the stator axis, wherein protective sleeves are provided in the stator slots of the stator core in the area of ​​the twisted first stator sub-packs, which protect the stator winding from damage by the twisted first stator sub-packs.

[0007] Advantages of the invention

[0008] In contrast, the stator of the electric machine according to the invention, with the characterizing features of the main claim, has the advantage that the assembly of the protective sleeves is simplified by the fact that the protective sleeves can be inserted into the stator slots of a stator module or a set of stator module assemblies and are brought into a defined axial position and held there during insertion. This is achieved according to the invention by providing at least one of the protective sleeves with at least one collar which is provided for axial support on one of the stator teeth of one of the first stator module assemblies and is angled relative to a slot section of the protective sleeve.

[0009] Since the protective sleeves are securely fixed in the stator stack in the axial direction, the conductors or conductor bundles of the stator winding can be inserted and pushed through the protective sleeves with a small clearance fit or with an interference fit, so that a high slot fill factor in the stator slots can be achieved.

[0010] The measures listed in the dependent claims enable advantageous further developments and improvements of the stator of the electrical machine specified in the main claim.

[0011] According to an advantageous embodiment, the collar of the respective protective sleeve is formed on at least one flank side facing a tooth flank of the respective stator groove, and / or on a narrow side connecting the flank sides, for example as an angled tab. The collar of the respective protective sleeve can also be an annular or partially annular circumferential collar.

[0012] It is particularly advantageous if the first stator core assembly includes at least one end lamella on at least one of its two end faces, the groove contours of which are recessed relative to the other lamellae to create a space for receiving the collar of the respective protective sleeve. Alternatively or additionally, the collar of the respective protective sleeve can be clamped between lamellae of the stator core assembly. In this way, the protective sleeve is reliably fixed to the stator core assembly via the collar.

[0013] It is further advantageous if the collars of several, in particular all, protective sleeves of one of the first stator stacks or a set of first stator stacks are integrally connected to form a protective sleeve unit, wherein the protective sleeve unit has a lamellar section for connecting the protective sleeves, the lamellar section of the protective sleeve unit being formed in a plane between two laminations of the stator stack. This simplifies the assembly of the protective sleeves, as fewer parts need to be mounted on the stator stack.

[0014] It is highly advantageous if the respective protective sleeve extends axially in either one of the first stator assemblies of the respective set, according to a first variant, or in all first stator assemblies of the set, according to a second variant. The protective sleeves according to the first variant do not need to be deformed when the first stator assemblies are rotated. The protective sleeves according to the second variant must be able to accommodate deformation when the first stator assemblies are rotated, but have the advantage that fewer parts need to be mounted on the stator assembly. Furthermore, in the variant with recessed groove contours in the end laminations, less iron needs to be removed from the end laminations of the first stator assemblies.

[0015] Furthermore, it is advantageous if the protective sleeves are closed in the circumferential direction or interrupted by slots, with the slots being provided particularly on axially extending edges of the protective sleeves. Closed protective sleeves have the advantage of being very dimensionally stable and easy to install. Slotted protective sleeves have the advantage that the conductor bundles of the stator winding can be more easily inserted into or pushed through the protective sleeves, especially if the protective sleeves are manufactured with draft angles.

[0016] According to an advantageous embodiment, the groove section of the protective sleeves can be designed according to the shape of the stator grooves, in particular in cross-section trapezoidal, rectangular, sleeve-shaped, partially trapezoidal, partially rectangular or U-shaped.

[0017] Furthermore, it is advantageous if the material of the respective protective sleeve is a plastic, in particular an elastomer or thermoplastic elastomer, or a ceramic. In this way, the tooth flanks of the twisted first stator assemblies are covered with an electrically insulating material. The clamping forces are exerted on the stator winding via the protective sleeves. Using an elastic plastic for the protective sleeves prevents the conductors of the stator winding from being damaged at the clamping points by the clamping forces resulting from the twisting of the first stator assemblies.

[0018] Furthermore, it is advantageous if the stator slots are each permeable to a cooling medium, in particular oil, along a cooling path, with bypasses provided on the protective sleeves to circumvent the pinch points, particularly on one of the inner narrow sides of the protective sleeves, and especially on an inner narrow side facing the stator yoke or away from it. In this way, the cooling medium can be guided past the pinch points with minimal pressure loss.It is advantageous if the stator teeth are connected to each other via an annular stator yoke and each tooth has a tooth end facing away from the stator yoke, which is particularly designed as a tooth head. The stator slots between the respective tooth ends have slots formed by the tooth ends. A radially projecting web section is formed on a narrow side of the respective protective sleeve facing away from the stator yoke, extending into the respective slot and in an axial direction. In this way, a meandering flow pattern can be achieved in the slot channels of the stator slots. The web section locally closes the slot in the area of ​​a pinch point, so that the flow must bypass the respective pinch point via a bypass in the slot bottom. This results in better and / or more uniform cooling of the conductors of the stator winding.

[0019] It is further advantageous if at least one second stator sub-package is provided in the stator stack, which is arranged between first stator sub-packages of a set of first stator sub-packages and / or between two sets of first stator sub-packages and is oriented circumferentially such that the conductors of the stator winding in each stator slot of the second stator sub-package run along the stator slot at a distance from the two tooth flanks of the stator slot, thereby forming slot gap channels in the stator slots. In this way, the cooling medium can be guided through the stator slots with low pressure loss.

[0020] According to an advantageous embodiment, a set of first stator subsets can comprise exactly two first stator subsets, or exactly three first stator subsets, or at least three first stator subsets.

[0021] A stator sleeve can be provided on the inner diameter of the stator stack to seal the slotted grooves.

[0022] The invention further relates to an electric machine with a stator according to the invention. Drawing

[0023] Exemplary embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description.

[0024] They show:

[0025] Fig. 1 shows a sectional view of an electric machine with a stator and a rotor.

[0026] Fig. 2 shows a partial view of a stator according to Fig. 1 with several twisted first stator component packages, in whose stator grooves protective sleeves according to a first embodiment are provided according to the invention; Fig. 3 shows a single first stator component package according to Fig. 2 with protective sleeves according to a first embodiment.

[0027] Fig. 4 shows a partial view of a stator according to Fig. 1 with several first stator component packages that are still unspun, in whose stator slots protective sleeves according to a second embodiment are provided.

[0028] Fig. 5 shows a first variant of a protective sleeve according to the invention as shown in Figs. 2 to 4.

[0029] Fig. 6 shows a second variant of a protective sleeve according to the invention as shown in Figs. 2 to 4 and

[0030] Fig. 7 shows another view of the protective sleeve according to Fig. 5.

[0031] Description of the exemplary implementations

[0032] Fig. 1 shows a sectional view of an electric machine with a stator and a rotor.

[0033] The stator 1 of an electric machine 2 according to the invention comprises a stator core 3, on which stator teeth 4 and stator slots 5 located between the stator teeth 4 are formed, and which extends around a stator axis 7. The stator 1 also comprises a stator winding 6 running in the stator slots 5. The stator core 3 is formed from a stack of laminations 8, in particular sheet metal laminations. The stator teeth 4 are connected to each other via an annular stator yoke 9. The stator slots 5 each have a slot base 5g facing the stator yoke 9 and a slot 5s facing away from the slot base 5g and formed between the tooth ends 4e.

[0034] In each of the stator slots 5, a single conductor 15 or a bundle of conductors 29 comprising several conductors 15, in particular a stack of flat wire conductors, is provided to form the electrical stator winding 6.

[0035] The electric machine 2 additionally has a rotor 26 rotatable about the stator axis 7 and a housing 27. An air gap 28 is formed between the stator 1 and the rotor 26.

[0036] In the stator assembly 3, for example, at least one supply path 30 can be formed, which is provided for supplying the cooling medium to the cooling paths 17 and opens into the stator slots 5 via a slot inlet 5i. In the respective stator slot 5, starting from the respective slot inlet 5i, for example, two cooling paths 17 running in opposite directions and in particular meandering are provided, which exit at the ends of the respective stator slot 5 via a slot outlet 5a, for example as a free jet or liquid jet.

[0037] Alternatively, the two winding heads of the stator winding 6 can each be arranged in a winding head cooling chamber 31 of the housing 27 enclosed along the dashed lines, wherein the two winding head cooling chambers 31 are flow-connected to each other by means of the cooling paths 15 leading through the stator slots 6 and in particular meandering.

[0038] Fig. 2 shows a partial view of a stator according to Fig. 1 with several twisted first stator part packages, in whose stator grooves protective sleeves according to a first embodiment are provided.

[0039] In the stator assembly 3, at least one set 13 of at least two, in particular three, oppositely rotated first stator sub-assemblies 3.1 is provided for clamping the stator winding 6 at clamping points 10 of the stator slots 5. According to the exemplary embodiment, two sets 13 of three rotated first stator sub-assemblies 3.1 are provided. At least one of the first stator sub-assemblies 3.1 of the respective set 13 is rotated by an angle of rotation t|) in one circumferential direction and at least one other first stator sub-assembly 3.1 of the set 13 in the opposite direction, for example by the angle of rotation <|), about the stator axis 7. According to the exemplary embodiment, two first stator sub-assemblies 3.1 of the respective set 13 are rotated in one circumferential direction and one remaining first stator sub-assembly 3.1 of the set 13 is rotated in the opposite direction about the stator axis 7. For example, a set of first stator subsets 3.1 can consist of exactly two first stator subsets 3.1 or exactly three first stator sub-packages 3.1 or at least three first stator sub-packages 3.1, for example four first stator sub-packages 3.1.

[0040] The lamellae 8 of the respective first stator subpackage 3.1 are firmly connected to each other, in particular by gluing, stamping, welding or baking.

[0041] With a set 13 of first stator subsets 3.1, an axial support bearing area 14 can be formed in the stator stack 3. In each support bearing area 14 of the stator stack 3, the stator winding 6 is locally clamped in all stator slots 5 at the clamping points 10. The respective clamping point 10 is an axial area in the respective stator slot 5. According to the exemplary embodiment, several, for example two, three or four, support bearing areas 14 are provided in the stator stack 3, which are spaced apart from each other, for example in the axial direction.

[0042] Protective sleeves 11 are provided in the stator slots 5 of the stator stack 3 in the area of ​​the twisted first stator sub-stacks 3.1. These sleeves protect the stator winding 6 from damage caused by the twisted first stator sub-stacks 3.1 and are designed to be electrically insulating. For example, one protective sleeve according to the invention is provided as a separate component for each slot of a first stator sub-stack.

[0043] According to the invention, at least one of the protective sleeves 11 has at least one collar 12 which is angled relative to a groove section 11.1 of the protective sleeve 11. The collar 12 supports the protective sleeve 11 axially with respect to the stator axis 7 against one of the stator teeth 4 of one of the first stator subsets 3.1 and thereby determines the axial position of the protective sleeve 11 in the respective stator groove 5.

[0044] According to Figures 2 and 4, at least one second stator sub-package 3.2 can be provided in the stator stack 3.1, which is arranged between first stator sub-packages 3.1 of a set 13 of first stator sub-packages 3.1 and / or between two sets 13 of first stator sub-packages 3.1 and is oriented circumferentially such that the conductors 15 of the stator winding 6 run along each stator slot 5 of the second stator sub-package 3.2 at a distance from the two tooth flanks 4f of the stator slot 5, thereby forming slot gap channels 23 in the stator slots 5. The laminations 8 of the respective second stator sub-package 3.2 are, for example, firmly connected to one another, in particular by bonding, stamping, welding, or bonding.

[0045] The stator grooves 5 are each permeable to a cooling medium, in particular oil, along a cooling path 17, which is in particular meandering. Bypasses 24 can be provided on the protective sleeves 11 to circumvent the clamping points 10, in particular as a recess or notch on one of the inner narrow sides 22, especially on an inner narrow side 22 facing towards or away from the stator yoke 9.

[0046] A stator sleeve 25 can be provided on the inner diameter of the stator package 3 to seal the slot 5s.

[0047] Fig. 3 shows a single first stator component package according to Fig. 2 with protective sleeves according to the invention in a first embodiment.

[0048] According to the first embodiment, the respective protective sleeve 11 extends in the axial direction only in one of the first stator subsets 3.1 of a set 13.

[0049] The collar 12 of the respective protective sleeve 11 is formed on at least one flank side 21 which faces a tooth flank 4f of the respective stator groove 5, and / or on a narrow side 22 connecting the flank sides 21.

[0050] The respective first stator module 3.1 can, according to Figs. 2 and 3, have at least one end lamella 8e on at least one of its two end faces, the groove contours of which are recessed relative to the other lamellae 8 to form a space for receiving the collar 12 of the respective protective sleeve 11. Additionally, the collar 12 of the respective protective sleeve 11 can be clamped axially with respect to the stator axis 7 between lamellae 8 of the stator module 3. Fig. 4 shows a partial view of a stator according to Fig. 1 with several first stator module modules that are not yet twisted, in whose stator grooves protective sleeves according to a second embodiment are provided.

[0051] According to the second embodiment, the respective protective sleeve 11 extends in all first stator sub-packages 3.1 of the set 13, i.e., starting from collar 12 in the respective stator groove 5 over all first stator sub-packages 3.1 of the set 13.

[0052] According to a second embodiment, the collars 12 of several, in particular all, protective sleeves 11 of one of the first stator sub-packs 3.1 or of a set 13 of first stator sub-packs 3.1 can be integrally connected to form a protective sleeve unit 16. The protective sleeve unit 16 has a lamellar section 16.1 for connecting the protective sleeves 11. The lamellar section 16.1 of the protective sleeve unit 16 is arranged in a plane between two lamellae 8 of the stator stack 3.

[0053] The groove sections 11.1 of the protective sleeves 11 can be closed in the circumferential direction according to Fig. 5 or interrupted by slots 18 according to Fig. 6. For example, slots 18 are provided on axially extending edges 19 of the groove sections 11.1 of the protective sleeves 11 according to Fig. 6.

[0054] The groove section 11.1 of the protective sleeves 11 is, for example, designed according to the shape of the stator grooves 5. Thus, the groove section 11.1 of the protective sleeves 11 can have a trapezoidal, rectangular, sleeve-shaped, partially trapezoidal, partially rectangular, or U-shaped cross-section.

[0055] The protective sleeves 11 can be made of plastic, in particular an elastomer or a thermoplastic elastomer, or of ceramic.

[0056] Fig. 7 shows another view of the protective sleeve according to Fig. 5.

[0057] The protective sleeves 11 can have a radially projecting web section 20 on a narrow side 22 facing away from the stator yoke 9, which extends into the respective usable slot 5s and in an axial direction.

Claims

Claims 1. Stator of an electric machine (2) comprising a stator core (3) comprising laminations (8), on which stator teeth (4) and stator slots (5) located between the stator teeth (4) are formed and which extends around a stator axis (7), and with a stator winding (6) running in the stator slots (5), wherein at least one set (13), in particular two sets (13), of at least two, in particular three, oppositely twisted first stator sub-cores (3.1) are provided in the stator core (3) for clamping the stator winding (6) at clamping points (10) of the stator slots (5), wherein at least one, in particular two, of the first stator sub-cores (3.1) of the respective set (13) are twisted in one circumferential direction and at least one other first stator sub-core (3.1) of the set (13) is twisted in the opposite direction around the stator axis (7), wherein in the stator slots (5) of the Stator stack (3) in the area of ​​the twisted first stator sub-stacks (3.1) Protective sleeves (11) are provided which protect the stator winding (6) from damage by the twisted first stator sub-packages (3.1) and are in particular electrically insulating, characterized in that at least one of the protective sleeves (11) has at least one collar (12) which is angled relative to a groove section (11.1) of the protective sleeve (11) and is provided for axial support on one of the stator teeth (4) of one of the first stator sub-packages (3.1).

2. Stator according to claim 1, characterized in that the collar (12) of the respective protective sleeve (11) is formed on at least one flank side (21) which faces a tooth flank (4f) of the respective stator groove (5), and / or on a narrow side (22) connecting the flank sides (21).

3. Stator according to one of the preceding claims, characterized in that the respective first stator component stack (3.1) comprises at least one end lamella (8e) on at least one of the two end faces, the groove contours of which are recessed relative to the other lamellae (8) to form a space for receiving the collar (12) of the respective protective sleeve (11), and / or that the collar (12) of the respective protective sleeve (11) is clamped between lamellae (8) of the stator stack (3).

4. Stator according to one of the preceding claims, characterized in that the collars (12) of several, in particular all, protective sleeves (11) of one of the first stator sub-packages (3.1) or of a set (13) of first stator sub-packages (3.1) are integrally connected to form a protective sleeve unit (16), wherein the protective sleeve unit (16) has a lamellar section (16.1) for connecting the protective sleeves (11), wherein the lamellar section (16.1) of the protective sleeve unit (16) is formed in a plane between two lamellae (8) of the stator stack (3).

5. Stator according to one of the preceding claims, characterized in that the respective protective sleeve (11) extends in the axial direction only in one of the first stator sub-packages (3.1) of the respective set (13) or in all first stator sub-packages (3.1) of the set (13).

6. Stator according to one of the preceding claims, characterized in that the protective sleeves (11) are closed in the circumferential direction or are interrupted by slots (18), wherein the slots (18) are provided in particular on axially extending edges (19) of the protective sleeves (11).

7. Stator according to one of the preceding claims, characterized in that the groove section (11.1) of the protective sleeves (11) is designed according to the shape of the stator grooves (5), in particular in cross-section trapezoidal, rectangular, sleeve-shaped, partially trapezoidal, partially rectangular or U-shaped.

8. Stator according to one of the preceding claims, characterized in that the material of the respective protective sleeve (11) is a plastic, in particular an elastomer or thermoplastic elastomer, or a ceramic.

9. Stator according to one of the preceding claims, characterized in that the stator teeth (4) are connected to each other via an annular stator yoke (9) and each has a tooth end (4e) facing away from the stator yoke (9), which is in particular designed as a tooth head, wherein the stator grooves (5) have slot slots (5s) formed between the respective tooth ends (4e), wherein a radially projecting web section (20) is formed on a narrow side (22) of the respective protective sleeve (11) facing away from the stator yoke (9), which extends into the respective usable slot (5s) and in an axial direction 10. Stator according to claim 9, characterized in that the stator grooves (5) are each permeable to a cooling medium, in particular oil, along a cooling path (17), wherein bypasses (24) are provided on the protective sleeves (11) to bypass the clamping points (10), in particular on one of the inner narrow sides (22) of the protective sleeves (11), especially in particular on an inner narrow side (22) facing towards or away from the stator yoke (9).

11. Stator according to one of the preceding claims, characterized in that at least one second stator sub-package (3.2) is provided in the stator stack (3), which is arranged between first stator sub-packages (3.1) of a set (13) of first stator sub-packages (3.1) and / or between two sets (13) of first stator sub-packages (3.1) and is oriented circumferentially such that the conductors (15) of the stator winding (6) run along the stator slot (5) in each stator groove (5) of the second stator sub-package (3.2) at a distance from the two tooth flanks (4f) of the stator groove (5), thereby forming slot gap channels (23) in the stator grooves (5).

12. Stator according to one of the preceding claims, characterized in that a set (13) of first stator sub-packages (3.1) comprises exactly two first stator sub-packages (3.1) or exactly three first stator sub-packages (3.1) or at least three first stator sub-packages (3.1).

13. Electric machine (2) with a stator (1) according to one of the preceding claims.

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