Stator of an electric machine

Abstract

The invention relates to a stator of an electric machine (2) comprising a laminated core (3) which comprises laminations (4) and on which stator teeth (5) and stator slots (6) lying between the stator teeth (5) are formed, said laminated core extending about a stator axis (7), wherein a respective conductor bundle (9) of a stator winding (10) runs in each stator slot (6), and sleeves (11) are provided in the stator slots (6) of the laminated core (3), said sleeves at least partly surrounding the conductor bundle (9) of each stator slot (6). The invention is characterized in that - the material for producing each sleeve (11) is an expandable material, in particular a thermally expandable material, and - the conductor bundles (9) are locally clamped in the stator slots (6) as a result of an expansion of the sleeves (11), thereby forming clamping points (12).

Description

[0001] Description

[0002] title

[0003] Stator of an electrical machine

[0004] State of the art

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

[0006] A stator for an electrical machine is already known from DE102021204202 A1, comprising a stator core comprising laminations, on which stator teeth and stator slots located between the stator teeth are formed, and which extends around a stator axis. A conductor bundle of a stator winding runs in each of the stator slots. Sleeves are provided in the stator slots of the stator core, which at least partially enclose the conductor bundle of the respective stator slot. In the stator core, laminations are twisted relative to one another to locally clamp and thus fix the conductor bundles at the clamping points. The sleeves serve to protect the conductor bundles from mechanical damage caused by the twisted laminations.

[0007] Advantages of the invention

[0008] The stator of an electrical machine according to the invention with the characterizing features of the main claim has the advantage that the twisting of the laminations in the stator package can be omitted and instead the sleeves clamp the conductor bundles.

[0009] This is achieved according to the invention in that the material for producing the respective sleeve is an expandable, in particular thermally expandable material and in that the conductor bundles are clamped locally in the stator slots due to an expansion of the sleeves, forming clamping points.

[0010] The measures listed in the subclaims enable advantageous refinements and improvements to the stator of an electrical machine specified in the main claim. It is particularly advantageous if at least one collar, in particular two to four collars, is provided per stator slot, with a clamping point being formed in each respective stator slot for each collar. In this way, each conductor bundle located in one of the stator slots is secured at at least one clamping point. If there are two or more clamping points per stator slot, the conductor bundle of the respective stator slot can be mounted so as to be freely suspended between two clamping points, i.e., without contact with the stator core.

[0011] It is also advantageous if the sleeves are each designed to be continuous or interrupted in the circumferential direction, whereby an interruption in the respective sleeve can be formed by a sleeve slit between the circumferential ends of the sleeve or by an overlap of two circumferential ends of the sleeve. In this way, the sleeve can be manufactured particularly cost-effectively and joined particularly easily. A sleeve slit makes it particularly easy to create a bypass.

[0012] It is very advantageous if the sleeves are formed or manufactured from an expandable insulation paper or laminate. This allows the sleeves to be manufactured easily and cost-effectively.

[0013] It is also advantageous if at least one of the sleeves has at least one collar that is angled relative to a slot section of the sleeve and supported axially on one of the stator teeth. In this way, the sleeves can be fixed in the stator core, allowing the conductor bundles of the stator winding to be easily inserted axially into the stator slots and moved through the sleeves with as little friction as possible.

[0014] According to an advantageous embodiment, the respective collar of the respective sleeve is formed on a flank side facing a tooth flank of the respective stator slot and / or on a narrow side connecting the flank sides.

[0015] It is also advantageous if the stator core comprises at least one special lamination whose groove contours are set back relative to the other laminations to form a space for accommodating the collar of the respective sleeve. Alternatively, the collar of the respective sleeve can also be clamped between laminations of the stator core. In this way, the collars of the sleeves are accommodated in an additional space in the stator core or clamped between the laminations. The sleeves are thereby secured in the stator core.

[0016] It is advantageous if a cooling medium, particularly oil, can flow through each of the stator slots along a meandering cooling path. This allows the conductor bundles of the stator winding to be cooled directly.

[0017] It is also advantageous if the conductor bundles running in the stator slots extend outside the sleeves at a distance from the tooth flanks of the respective stator slots, thereby forming slot gap channels in the stator slots through which the cooling medium can flow, forming part of the cooling path. In this way, the conductor bundles of the stator winding can be cooled directly.

[0018] It is further advantageous if groove-shaped or slot-shaped bypasses are designed on the sleeves to bypass the pinching points. These bypasses are formed, in particular, by the sleeve slots and are provided, in particular, on the narrow sides of the sleeves. The expanded sleeves or pinching points can narrow or close the slot gap channels formed in the stator slots. The bypasses formed on the sleeves therefore serve to guide the cooling path past the pinching points or sleeves with the lowest possible pressure loss.

[0019] It is also advantageous if the stator slots are closed in a radial direction away from the stator yoke relative to the stator axis, in particular by means of a stator sleeve. In this way, the stator slots are sealed in the radial direction relative to the air gap.

[0020] The invention further relates to an electrical machine with a stator according to the invention and in particular with a rotor. The invention additionally relates to a method for producing the stator according to the invention, comprising the steps: a. providing stator sub-packets, conductor bundles for forming a stator winding, and expandable, in particular thermally expandable, sleeves; b. inserting the sleeves into the stator slots of at least one of the stator sub-packets; c. stacking the stator sub-packets to form a stator pack; d. pushing the conductor bundles into the stator slots of the stator pack, wherein the conductor bundles are pushed through the sleeves, in particular with play; e. expanding the sleeves, in particular by means of heat, for locally clamping the conductor bundles in the stator slots.

[0021] drawing

[0022] An embodiment of the invention is shown in simplified form in the drawing and explained in more detail in the following description.

[0023] They show:

[0024] Fig.1 a stator of an electrical machine,

[0025] Fig.2 is a sectional view through one of the stator slots of the stator according to Fig.1 with a conductor bundle mounted in the stator slot by means of expanded sleeves according to the invention,

[0026] Fig.3 the sectional view according to Fig.2 before expansion of the cuffs according to the invention,

[0027] Fig.4 one of the cuffs according to the invention according to Fig.2 and Fig.3,

[0028] Fig.5 is a further sectional view through one of the stator slots of the stator,

[0029] Fig.6 a sectional view along the line VI-VI in Fig.5 and

[0030] Fig.7 is a sectional view along the line VI I- VI I in Fig.5.

[0031] Description of the embodiment

[0032] Fig. 1 shows a stator of an electrical machine. The stator 1 of an electrical machine 2 according to the invention has a stator core 3 comprising laminations 4, on which stator teeth 5 and stator slots 6 located between the stator teeth 5 are formed, and which extends around a stator axis 7. The stator teeth 5 are connected to one another via a stator yoke 8 running in the circumferential direction. The stator slots 6 can, for example, have slot slots 6s on a side facing away from the stator yoke 8. A conductor bundle 9 of a stator winding 10 runs in each of the stator slots 6. The conductor bundle 9 is formed, for example, by a stack of conductors 19, which are designed in particular as flat wires.

[0033] Fig.2 shows a sectional view through one of the stator slots of the stator according to Fig.1 with a conductor bundle which is mounted in the stator slot by means of expanded sleeves according to the invention.

[0034] Sleeves 11 are provided in the stator slots 6 of the stator core 3, which at least partially enclose the conductor bundle 9 of the respective stator slot 6, for example, in a sleeve-like configuration. The sleeves 11 can be electrically insulating. The sleeves 11 have a slot section 11s that is configured to correspond to the shape of the stator slots 6, in particular, trapezoidal, rectangular, sleeve-shaped, partially trapezoidal, partially rectangular, or U-shaped in cross-section.

[0035] According to the invention, the material for producing the respective sleeve 11 is an expandable, in particular thermally expandable material, and the conductor bundles 9 are clamped locally in the stator slots 6 due to an expansion of the sleeves 11, forming clamping points 12.

[0036] According to the exemplary embodiment, the sleeves 11 are formed from a thermally expandable insulating paper or laminate. The material of the respective sleeve 11 can, for example, contain expandable microcapsules.

[0037] At least one sleeve 11, in particular two to four sleeves 11, is provided per stator slot 6. Figures 2 and 3 show, by way of example, three sleeves 11 per stator slot 6. A clamping point 12 is formed in each stator slot 6 for each sleeve 11. Figure 3 shows the sectional view according to Figure 2 before expansion of the sleeves according to the invention.

[0038] Before the expansion of the sleeve 11, there is a clearance between the respective sleeve 11 and the respective conductor bundle 9, which allows a smooth insertion or insertion of the conductor bundle 9 into the respective stator slot 6 and a smooth passage through the respective sleeve 11.

[0039] Fig.4 shows one of the cuffs according to the invention according to Fig.2 and Fig.3.

[0040] The sleeves 11 can be either continuous or interrupted in the circumferential direction. An interruption in the respective sleeve 11 can be formed by a sleeve slot 14 between the circumferential ends of the sleeve 11 or by an overlap of two circumferential ends of the sleeve 11. The sleeve 11 according to the embodiment in Fig. 4 is interrupted by a sleeve slot 14.

[0041] The respective sleeve 11 can have at least one collar 15, which is angled relative to the groove section 11s of the sleeve 11 and supported on one of the stator teeth 7 in the axial direction relative to the stator axis 7. The collar 15 of the respective sleeve 11 can be formed on a flank side 16 facing a tooth flank 5f of the respective stator groove 6 and / or on a narrow side 17 connecting the flank sides 16.

[0042] The stator core may further comprise at least one special lamination 18, the groove contours of which are set back relative to the remaining laminations 4 to form a space for receiving the collar 15 of the respective sleeve 11. Alternatively, the collar 15 of the respective sleeve 11 may be clamped between laminations 4 of the stator core 3.

[0043] Fig.5 shows a further sectional view through one of the stator slots of the stator according to the invention.

[0044] In Fig.5, four sleeves 11 per stator slot 6 are shown as an example.

[0045] A cooling medium, in particular oil, can flow through each of the stator slots 6 along a particularly meandering cooling path 20. For this purpose, at least one supply path 21 can be formed in the stator core 3, which is provided for supplying the cooling medium to the cooling paths 20 and opens into the stator slots 6 via a slot inlet 22. Starting from the respective slot inlet 22, two cooling paths 20 running in opposite directions can be provided in the respective stator slot 6, which exit as a free jet at the ends of the respective stator slot 6 via a slot outlet 23. Alternatively, the stator slots 6 can be flowed through continuously from one of the end faces of the stator core 3 to the other end face.

[0046] According to Fig.2, the conductor bundles 9 running in the stator slots 6 run outside the sleeves 11 at a distance from the tooth flanks 5f of the respective stator slot 6, whereby slot gap channels 24 are formed in the stator slots 6, which are part of the respective cooling path 20 in the respective stator slot 6.

[0047] The expanded sleeves 11 or pinching points 12 can locally narrow or close the slot gap channels 24 formed in the stator slots 6. To bypass the pinching points 12, groove-shaped or slot-shaped bypasses 25 can be formed on the sleeves 11, which are formed in particular by the sleeve slots 14 and are provided in particular on narrow sides of the sleeves 11. To create a meandering cooling path 20, the bypasses 25 can be arranged alternately on the narrow side of the respective sleeves 11 facing the stator yoke 8 or the narrow side facing away from the stator yoke 8, as shown in Fig. 6 and Fig. 7. This can be achieved with identical sleeves 11 by rotating the sleeves 11 by 180 degrees. For this purpose, the sleeves 11 are mounted in such a way that the sleeve slot 14 is either facing the stator yoke 8 or facing away from the stator yoke 8.

[0048] The stator slots 6 are closed in a radial direction away from the stator yoke 8 with respect to the stator axis 7, for example by means of a stator sleeve 26.

[0049] The electrical machine 2 comprises, for example, a housing 30, the stator 1 according to the invention arranged in the housing 30, and a rotor 32. A so-called air gap 33 is formed between the stator 1 and the rotor 32. The following steps are provided for producing the stator 1 according to the invention: a. Providing stator sub-packets 13, conductor bundles 9 for forming the stator winding 10, and expandable, in particular thermally expandable, sleeves 11, b. Inserting the sleeves 11 into the stator slots 6 of at least one of the stator sub-packets 13, c. Stacking the stator sub-packets 13 to form a stator pack 3, d. Pushing the conductor bundles 9 into the stator slots 6 of the stator pack 3, the conductor bundles 9 being pushed through the sleeves 11 with play, e. Expanding the sleeves 11, in particular by means of heat, for locally clamping the conductor bundles 9 in the stator slots 6.

[0050] The sleeves 11 have a sleeve length L in the axial direction with respect to the stator axis 7, which is shorter than the height H of one of the stator sub-packets 13, so that the slot gap channels 24 for direct cooling of the conductors 19 of the respective conductor bundle 9 are formed in the stator slots 6.

Claims

Claims 1. Stator of an electrical machine (2) with a stator core (3) comprising laminations (4), on which stator teeth (5) and stator slots (6) located between the stator teeth (5) are formed and which extends around a stator axis (7), wherein a conductor bundle (9) of a stator winding (10) runs in each of the stator slots (6), wherein sleeves (11) are provided in the stator slots (6) of the stator core (3) which at least partially enclose the conductor bundle (9) of the respective stator slot (6), characterized in that the material for producing the respective sleeve (11) is an expandable, in particular thermally expandable material, the conductor bundles (9) are clamped locally in the stator slots (6) due to an expansion of the sleeves (11), forming clamping points (12).

2. Stator according to claim 1, characterized in that at least one sleeve (11), in particular two to four sleeves (11), is provided for each stator slot (6), wherein in the respective stator slot (6) per sleeve (11) a clamping point (12) is formed.

3. Stator according to one of the preceding claims, characterized in that the sleeves (11) are each designed to be closed or interrupted in the circumferential direction, wherein an interruption of the respective sleeve (11) can be formed by a sleeve slot (14) between circumferential ends of the sleeve (11) or by an overlap of two circumferential ends of the sleeve (11).

4. Stator according to one of the preceding claims, characterized in that the sleeves (11) are formed from a thermally expandable insulating paper or laminate.

5. Stator according to one of the preceding claims, characterized in that at least one of the sleeves (11) has at least one collar (15) which is angled relative to a groove section (11 s) of the sleeve (11) and is supported on one of the stator teeth (5) in the axial direction.

6. Stator according to claim 5, characterized in that the collar (15) of the respective sleeve (11) is formed on a flank side (16) facing a tooth flank (5f) of the respective stator groove (6) and / or on a narrow side (17) connecting the flank sides (16).

7. Stator according to one of claims 5 or 6, characterized in that the stator core (3) comprises at least one special lamination (18), the groove contours of which are set back with respect to the other laminations (4) to form a construction space for receiving the collar (15) of the respective sleeve (11), and / or that the collar (15) of the respective sleeve (11) is clamped between laminations (4) of the stator core (3).

8. Stator according to one of the preceding claims, characterized in that the stator slots (6) can each be flowed through by a cooling medium, in particular oil, along a particularly meander-shaped cooling path (20).

9. Stator according to claim 8, characterized in that the conductor bundles (9) running in the stator slots (6) run outside the sleeves (11) at a distance from the tooth flanks (5f) of the respective stator slot (6), whereby slot gap channels (24) are formed in the stator slots (6).

10. Stator according to one of the preceding claims, characterized in that groove-shaped or slot-shaped bypasses (25) are designed to bypass the clamping points (12) on the sleeves (11) and are formed in particular by the sleeve slots (14) and in particular on narrow sides (17) of the cuffs (11) are provided.

11. Stator according to one of the preceding claims, characterized in that the stator slots (6) are closed in a radial direction facing away from the stator yoke (8) with respect to the stator axis (7), in particular by means of a stator sleeve (26).

12. Electrical machine with a stator (1) according to one of the preceding claims and in particular with a rotor (32).

13. A method for producing the stator (1) according to one of claims 1 to 11, comprising the steps: a. Providing stator sub-packets (13), conductor bundles (9) for forming a stator winding (10) and expandable, in particular thermally expandable, sleeves (11), b. Inserting the sleeves (11) into the stator slots (6) of at least one of the stator sub-packets (13), c. Stacking the stator sub-packets (13) to form a stator pack (3), d. Pushing the conductor bundles (9) into the stator slots (6) of the stator pack (3), wherein the conductor bundles (9) are pushed through the sleeves (11), in particular with play, e. Expanding the sleeves (11), in particular by means of heat, for locally clamping the conductor bundles (9) in the stator slots (6).

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