Stator of an electric machine

Abstract

Stator of an electric machine (2) with a stator shaft (3) and a stator body (4) comprising, in particular, a stator lamination stack (8), on which stator teeth (5) and stator slots (6) are formed and which includes a stator yoke (10), wherein the stator slots (6) have a slot base (7), wherein a single conductor (11) or a conductor bundle (12) comprising several conductors (11) is provided in each of the stator slots (6) to form a stator winding (14), wherein at least one slot gap channel is formed between the tooth flanks (5f) of the respective stator slot (6) and the conductor (11) or conductor bundle (12) arranged in the stator slot (6), which can be permeated by a cooling fluid along a slot cooling path (17), characterized by the fact that - the stator body (4) has at least one end face an end disk device (40) comprising several outlet openings (41) arranged along the circumferential direction for spraying a layer (14L) of a winding head (14K) of the stator winding (14) and several outlet connections (42) for connecting the outlet openings (41) to one or more of the slot cooling paths (17), - the outlet openings (41) are arranged in disc teeth (40t) or in a disc yoke (40y) of the respective end disc device (40).

Description

State of the art

[0001] The invention relates to a stator of an electrical machine according to the preamble of the main claim.

[0002] A stator for an electric machine is already known from DE102019113785 A1, which has a stator body, in particular comprising a stator lamination stack, with a stator axis on which stator teeth and stator slots located between the stator teeth are formed, and which includes a stator yoke connecting the stator teeth. The stator slots have a slot bottom facing the stator yoke. In each stator slot, a single conductor or a conductor bundle comprising several conductors, in particular a stack of flat wire conductors, is provided to form an electrical stator winding. Between the tooth flanks of the respective stator slot and the conductor or conductor bundle arranged in the stator slot, at least one slot gap is provided, which forms a slot gap channel extending in the axial direction with respect to the stator axis, through which a cooling fluid can flow along a slot cooling path. In this way, direct conductor cooling is achieved. Advantages of the invention

[0003] In contrast, the stator of an electric machine according to the invention, with the characterizing features of the main claim, has the advantage that the cooling of the stator is improved by directing the cooling fluid downstream of the conductor direct cooling to one of the layers of at least one winding head of the stator winding for winding head cooling. In particular, the winding head cooling is improved when the cooling fluid is directed to the outermost layer of the winding head.

[0004] This is achieved according to the invention by the stator body having an end disk device on at least one end face, and in particular on both end faces, which comprises several outlet openings arranged along the circumferential direction for spraying a layer of a winding head of the stator winding and several outlet connections for connecting the outlet openings to one or more of the slot cooling paths. According to the invention, the outlet openings are arranged in disk teeth or in a disk yoke of the respective end disk device, in particular in the disk yoke between two adjacent stator slots and / or in particular in the disk yoke at a radial distance from the slot bottom of the stator slots.

[0005] The design according to the invention provides many degrees of freedom for the development of optimal winding head cooling, in particular with regard to the arrangement and design of the outlet openings.

[0006] The radial spacing of the outlet openings from the groove base allows for a radial distance between the outlet openings and the winding head, resulting in a free jet of cooling fluid directed towards the winding head at each outlet opening. The respective free jet is easily adjustable at the end plate assembly, particularly with regard to its impact position on the conductors of the winding head and / or its jet velocity.

[0007] The measures listed in the dependent claims enable advantageous further developments and improvements of the stator of an electrical machine specified in the main claim.

[0008] It is particularly advantageous if the end disk assembly has groove recesses that are provided axially for the passage of conductors of the stator winding and, in the radial direction with respect to the stator axis, open via a groove base outlet into a yoke channel extending within the disk yoke to form one of the outlet connections. This allows the outlet connections to be formed easily. Furthermore, effective winding head cooling can be achieved.

[0009] The yoke channels of the end plate assembly can be separated from each other. This allows the cooling flow in each stator slot to be individually adjustable. For example, different or the same flow rates can be set in the stator slots.

[0010] According to the exemplary embodiments, in an end-disc device, several yoke channels from several adjacent groove recesses are advantageously connected to a circumferentially extending collecting channel, which leads into at least one of the outlet openings. In this way, more uniform winding head cooling in the circumferential direction can be achieved.

[0011] It is further advantageous if the end-disc assembly has at least two separate collecting channels arranged one behind the other in the circumferential direction, each extending along a partial circumference of the disc yoke's inner circumference. This allows the collecting areas to be hydraulically decoupled from one another, enabling the respective winding head to be cooled to varying degrees in different circumferential areas associated with the collecting channels. Furthermore, a larger contact area of ​​the end-disc assembly on the stator lamination stack can be achieved, allowing for better pressure against the stator lamination stack and improved sealing against it.

[0012] According to an advantageous first embodiment, the end plate device can be a single disc and / or a plastic part, in particular an injection-molded part. In this way, the end plate device can be manufactured simply and cost-effectively.

[0013] Advantageously, the outlet connections and outlet openings can be formed on the same disc. This makes the end disc assembly simple and cost-effective to manufacture.

[0014] It is also advantageous if the outlet connections according to the first embodiment are designed as groove-shaped recesses on a rear side of the end disk device facing the stator lamination stack.

[0015] Furthermore, it is advantageous if the groove recesses of the end disk assembly each have two tooth flanks, wherein at least one of the tooth flanks of the respective groove recess has a flank step extending radially with respect to the stator axis to form at least one radial flow connection to the respective groove bottom outlet. In this way, the cooling fluid can be guided within the respective stator groove from radially inside to the groove bottom outlet or to the outlet openings with minimal pressure loss.

[0016] According to an advantageous second embodiment, the end disk assembly can be multi-disc, and the outlet connections and outlet openings can be formed on different disks. In this way, the end disk assembly can be designed with sheet metal lamellae, so that it can be electromagnetically active and contribute to the torque generation of the electric machine.

[0017] Furthermore, it is advantageous if the end disk device according to the second embodiment comprises at least one groove outlet disk, on which the outlet connections are formed and which is in particular a sheet metal lamella, and at least one stator outlet disk, on which the outlet openings are formed and which is in particular a sheet metal lamella. In this way, the end disk device can be designed with sheet metal lamellae, so that the end disk device can be made electromagnetically active and contributes to the torque generation of the electric machine.

[0018] It is advantageous if the outlet connections in the respective grooved outlet disc are continuous in the axial direction and the respective collecting channel of the grooved outlet disc separates, along its circumferential extent, disc teeth formed between the groove recesses of the grooved outlet disc from a disc yoke of the grooved outlet disc. In this way, the outlet connections can be formed particularly easily in a sheet metal lamella.

[0019] Furthermore, it is advantageous if the groove recesses of the respective groove outlet disk are wider in the circumferential direction than the groove recesses of the stator laminations, in order to form at least one radial flow connection to the respective groove bottom outlet within the respective stator groove. In this way, the cooling fluid can be guided within the respective stator groove from the radial inside to the groove bottom outlet with minimal pressure loss.

[0020] It is further advantageous if two cooling channels running in opposite directions are provided in the respective stator slot, originating from a slot inlet in a central section of the slot (viewed axially) and extending in opposite directions to the ends of the stator slot. This allows the cooling channels to be traversed at a lower pressure, thus reducing the sealing requirements for the slot gap channels. Furthermore, the pressure drop in each cooling channel is reduced because the cooling channel does not extend over the entire length of the stator slot, but only over an axial portion.

[0021] Advantageously, a spacer element made of folded insulating paper can be provided in each of the stator slots. This spacer element comprises a central strip with a flank strip angled at each of its long side edges, facing one of the tooth flanks of the respective stator slot. The flank strips of the spacer element have recesses forming a slot cooling path. The insulating paper of the spacer element can be, in particular, an expandable, and especially a thermally expandable, insulating paper for fixing the stator winding to support points in the stator slot. The stator winding can be fixed in the stator slots by expanding the spacer elements. The support points are formed, in particular, on sleeve sections of the spacer elements.

[0022] Alternatively, the stator winding can be fixed to support points in the stator slot by twisting several laminations of the stator body, particularly the stator lamination stack, around the stator axis. In this way, the stator winding can be fixed by a mechanical process. The thermal process for expanding the spacers is eliminated.

[0023] It is also advantageous if the outlet openings of the end disk device each have an opening axis that runs axially or obliquely to the stator axis towards the winding head, and in particular is also aligned circumferentially. This allows the winding head cooling to be improved or optimized.

[0024] Additionally, it can be advantageous if the outlet openings of the end-disc assembly have different flow cross-sections, particularly with regard to size and shape. This allows for further improvement or optimization of the winding head cooling.

[0025] The invention further relates to an electric machine comprising a stator according to the invention, a rotor and an air gap formed between the stator and the rotor. drawing

[0026] Exemplary embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description.

[0027] They show: Fig. 1 a stator of an electric machine according to the invention with an end disk device according to the invention, Fig. 2 a sectional view through one of the stator slots of the stator after Fig. 1 for a first embodiment, Fig. 3 a cross-section through one of the stator slots along line III-III in Fig. 2, Fig. 4A a reverse side of the single-disc end disk device according to Fig. 2 according to the first embodiment, Fig. 4B a front side of the single-disc end disk assembly according to Fig. 2 according to the first embodiment, Fig. 5 a sectional view through one of the stator slots of the stator after Fig. 1 for a second embodiment, Fig. 6A a groove outlet disc of the multi-disc end disc device according to Fig. 5 according to the second embodiment, Fig. 6B a stator outlet disk of the multi-disc end disk device according to Fig. 5 according to the second embodiment. Description of the exemplary implementations

[0028] Fig. Figure 1 shows a stator of an electric machine according to the invention with an end disk device according to the invention.

[0029] The stator 1 of an electric machine 2 has a stator shaft 3 and a stator body 4 comprising in particular a stator lamination stack 8, on which stator teeth 5 and stator grooves 6 lying between the stator teeth 5 are formed and which includes a stator yoke 10 connecting the stator teeth 5.

[0030] The stator grooves 6 have a groove base 7 facing the stator yoke 10. A slot 9 can be formed between adjacent tooth ends of the stator teeth 5 of the stator body 4 facing away from the stator yoke 10. The tooth ends of the stator teeth 5 of the stator body 4 facing away from the stator yoke 10 can be tooth heads.

[0031] In each of the stator slots 6, a single conductor 11 or a bundle of conductors 12 comprising several conductors 11, in particular a stack of flat wire conductors, is provided to form an electrical stator winding 14.

[0032] Fig. Figure 2 shows a cross-sectional view through one of the stator slots of the stator. Fig. 1 for a first embodiment. Fig. Figure 3 shows a cross-section through one of the stator slots along line III-III in Fig. 2.

[0033] Between the tooth flanks 5f of the respective stator slot 6 and the conductor 11 or conductor bundle 12 arranged in the stator slot 6, at least one slot gap 16 is provided, which forms a slot gap channel extending in the axial direction with respect to the stator axis 3, which can be permeated by a cooling fluid, in particular oil, along a slot cooling path 17.

[0034] In each of the stator slots 6, a spacer element 15, folded from insulating paper, is provided. This spacer element comprises a central strip 15m, on the long side edges of which a flank strip 15f is angled, facing one of the tooth flanks 5f of the respective stator slot 6. Flank recesses 20 are formed in the flank strips 15f of the respective spacer element 15 to form a slot gap channel. The insulating paper of the respective spacer element 15 is, in particular, an expandable insulating paper, which, through expansion, which is particularly thermally activatable, achieves fixation of the stator winding 14 at support points in the stator slot 6. The support points are formed, in particular, on sleeve sections 15s of the spacer elements 15.

[0035] In at least one of the flank strips 15f, according to Fig. 2 and Fig. 3 in particular in both flank strips 15f of the respective spacer element 15 a group, in particular a pair, of flank recesses 20 arranged one behind the other in the axial direction can be formed, between which a radial separating web 15r extends in the radial direction.

[0036] Each flank recess 20 is according to Fig. 2 a recess inlet 21 and a recess outlet 22 are assigned, each formed on a tooth flank 5f of the respective stator slot 6. The respective recess inlet 21 can be supplied with cooling fluid via a supply path 18 running through the stator body 4 and is formed in the axially central slot section of the respective stator slot 6, in particular in an axial slot center.

[0037] In the respective stator groove 6, two groove cooling paths 17 extending in opposite directions are provided, which originate from a groove inlet in a central groove section seen in the axial direction, in particular the recess inlet 21, and extend via at least one flank recess 20 in the opposite direction to the ends of the stator groove 6.

[0038] As an alternative to expanding the spacer elements 15, several lamellae of the stator body 4, in particular of the stator lamination stack 8, can be twisted around the stator axis 3 to fix the stator winding 14 at support points of the stator slots 6.

[0039] Fig. Figure 4A shows a reverse side of the single-disc end disk assembly according to Fig. 2 according to the first embodiment. Fig. Figure 4B shows a front view of the single-disc end disk assembly according to Fig. 2 according to the first embodiment.

[0040] According to the invention, the stator body 4 has an end-disc device 40 on at least one end face, comprising several outlet openings 41 arranged along the circumferential direction for spraying a layer 14L of a winding head 14K of the stator winding 14 and several outlet connections 42 for connecting the outlet openings 41 to one or more of the slot cooling paths 16 of one or more stator slots 6. The outlet openings 41 can be configured according to Fig. 4A in a disk yoke 40y and / or in the disk teeth 40t (not shown) of the respective end disk assembly 40. When the outlet openings 41 are arranged in the disk yoke 40y, the outlet openings 41 can in particular be arranged between two adjacent stator slots 6 in the region of a radial extension of a disk tooth 40t and / or in particular at a radial distance A from the slot base 7 of the stator slots 6.

[0041] The outlet openings 41 of the end disk device 40 can be opened according to Fig. 2 each have an opening axis 41a which runs in the axial direction or obliquely to the stator axis 3, and in particular is additionally aligned in the circumferential direction. The outlet openings 41 of the end disk device 40 arranged along the circumferential direction can have different flow cross-sections.

[0042] The end disk device 40 has groove recesses 43 which are provided in the axial direction with respect to the stator axis 3 for the passage of conductors 11 of the stator winding 14 and in the radial direction with respect to the stator axis 3 for the formation of one of the outlet connections 42, each opening via a groove base outlet 44 into a yoke channel 45 which extends in the disk yoke 40y and leads into at least one of the outlet openings 41.

[0043] The yoke channels 45 of the end plate assembly 40 can be separated from each other according to a variant not shown. Alternatively, in an end plate assembly 40 according to Fig. 4A Several yoke channels 45 from several adjacent groove recesses 43 are flow-connected to a circumferentially extending collecting channel 46, each of which leads into at least one of the outlet openings 41. The respective collecting channel 46 is arranged radially outside the groove recesses 43.

[0044] After Fig. 4A The end disc assembly 40 has at least two separate collecting channels 46, which are arranged one behind the other in the circumferential direction and each run along the inner circumference of the disc yoke 40y over a partial circumference. The inner circumference of the disc yoke 40y faces the groove recesses 43. A channel separation 47 is provided between adjacent channel ends of adjacent collecting channels 46, which according to Fig. 4A a partition and after Fig. 6A is a disc tooth 40t.

[0045] According to the first embodiment, the end disc assembly 40 is, for example, designed as a single disc. The end disc assembly 40 can, for example, be a plastic part, in particular an injection-molded part. According to the first embodiment, the outlet connections 42 and the outlet openings 41 of the respective end disc assembly 40 are formed on the same disc.

[0046] The outlet connections 42 of the respective end disk device 40 are designed as groove-shaped recesses on a rear side of the end disk device 40 facing the stator lamination stack 8.

[0047] The groove recesses 43 of the end disk device 40 each have two tooth flanks 43f facing the tooth flanks 5f of the respective stator groove 6. On at least one of the tooth flanks 43f of the respective groove recess 43, for example, a flank step 48 extending radially with respect to the stator axis 3 is formed to create at least one radial flow connection to the respective groove bottom outlet 44.

[0048] The end disc assembly 40 has, in addition to the disc yoke 40y, an inner yoke 40i connecting the disc teeth 40t. In the radial direction between the disc yoke 40y and the inner yoke 40i are the ring-shaped groove recesses 43 and the disc teeth 40t located between the groove recesses 43.

[0049] A seal can be provided between the end disk assembly 40 and the stator lamination stack 8. The respective end disk assembly 40 can, for example, be attached to the stator lamination stack 8 or to a housing of the electric machine.

[0050] Fig. Figure 5 shows a cross-sectional view through one of the stator slots of the stator. Fig. 1 for a second embodiment.

[0051] According to the second embodiment, the end disk device 40 is multi-disc, wherein the outlet connections 42 and the outlet openings 41 are formed on different disks.

[0052] Fig. Figure 6A shows a groove outlet disc of the multi-disc end disc device according to Fig. 5 according to the second embodiment. Fig. Figure 6B shows a stator outlet disk of the multi-disc end disk arrangement according to Fig. 5 according to the second embodiment.

[0053] The multi-disc end disk device 40 comprises at least one groove outlet disk 50, on which the outlet connections 42 are formed and which is in particular a sheet metal lamella, and at least one stator outlet disk 60, on which the outlet openings 41 are formed and which is in particular a sheet metal lamella.

[0054] The outlet connections 42 in the respective groove outlet disc 50 are continuous in the axial direction, for example, by being punched out. The respective collecting channel 46 of the groove outlet disc 50 separates, along its circumferential extent, disc teeth 50t, which are formed between the groove recesses 43 of the groove outlet disc 50, from a disc yoke 50y of the groove outlet disc 50. In addition to the disc yoke 50y, the groove outlet disc 50 has an inner yoke 50i connecting the disc teeth 50t. Some of the disc teeth 50t of the groove outlet disc 50 are attached to the disc yoke 50y. For example, all disc teeth 50t are attached to the inner yoke 50i of the groove outlet disc 50.

[0055] The groove recesses 43 of the respective groove outlet disc 50 are wider in the circumferential direction than the groove recesses 43 of the sheet metal lamellae of the stator lamination stack 8 in order to form at least one radial flow connection to the respective groove bottom outlet 44 in the respective stator groove 6.

[0056] The stator outlet disk 60 comprises disk teeth 60t formed between the groove recesses 43 of the stator outlet disk 60, and a disk yoke 60y connecting the disk teeth 60t. According to the exemplary embodiment, the outlet openings 41 are provided in the disk yoke 60y, for example, each with a radial distance A to the groove base 7 of the stator grooves 6 and, for example, each between two groove recesses 43 in the region of a radial extension of a disk tooth 60t.

[0057] The groove recesses 43 of the respective stator outlet disk 60 are narrower in the circumferential direction than the groove recesses 43 of the groove outlet disk 50, in particular they have the same width in the circumferential direction as the groove recesses 43 of sheet metal lamellae of the stator lamination stack 8. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102019113785 A1

[0002]

Claims

[1] Stator of an electric machine (2) with a stator shaft (3) and a stator body (4) comprising, in particular, a stator lamination stack (8), on which stator teeth (5) and stator slots (6) located between the stator teeth (5) are formed and which comprises a stator yoke (10) connecting the stator teeth (5), wherein the stator slots (6) have a slot base (7) facing the stator yoke (10), wherein in each of the stator slots (6) a single conductor (11) or a conductor bundle (12) comprising several conductors (11), in particular a stack of flat wire conductors, is provided to form an electrical stator winding (14), wherein between the tooth flanks (5f) of the respective stator slot (6) and the conductor (11) arranged in the stator slot (6)conductor bundle (12) at least one slot gap (16) is provided which forms a slot gap channel extending in the axial direction with respect to the stator axis (3) and through which a cooling fluid can flow along a slot cooling path (17). characterized by , that - the stator body (4) has at least one end face an end disk device (40) comprising several outlet openings (41) arranged along the circumferential direction for spraying at least one layer (14L) of a winding head (14K) of the stator winding (14) and several outlet connections (42) for connecting the outlet openings (41) to one or more of the slot cooling paths (17), - the outlet openings (41) are arranged in disc teeth (40t) or in a disc yoke (40y) of the respective end disc device (40), in particular in the disc yoke (40y) between two adjacent stator slots (6) and / or in particular in the disc yoke (40y) with a radial distance (A) to the slot base (7) of the stator slots (6). [2] Stator according to claim 1, characterized by , that the end disk device (40) has slot recesses (43) which are provided in the axial direction for the passage of conductors (11) of the stator winding (14) and which open in the radial direction with respect to the stator axis (3) to form one of the outlet connections (42) via a slot base outlet (44) into a yoke channel (45) which extends in the disk yoke (40y) and leads into at least one of the outlet openings (41). [3] Stator according to claim 2, characterized by , that the yoke channels (45) of the end disk device (40) are separated from each other. [4] Stator according to claim 2, characterized by , that in an end disk device (40) several yoke channels (45) from several adjacent groove recesses (43) are flow-connected to a circumferentially extending collecting channel (46) which leads into at least one of the outlet openings (41). [5] Stator according to claim 4, characterized by , that the end disk device (40) has at least two separate collecting channels (46) arranged one behind the other in the circumferential direction and each extending along the inner circumference of the disk yoke (40y) over a partial circumference. [6] Stator according to any one of the preceding claims, characterized by that the end disk device (40) is single-disc and / or a plastic part, in particular an injection-molded part. [7] Stator according to any one of the preceding claims, characterized by, that the outlet connections (42) and the outlet openings (41) of the end disk device (40) are formed on the same disk. [8] Stator according to claim 7, characterized by , that the outlet connections (42) are formed as groove-shaped recesses on a rear side of the end disk assembly (40) facing the stator lamination stack (8). [9] Stator according to any one of claims 6 to 8, characterized by , that the groove recesses (43) of the end disk device (40) each have two tooth flanks (43f), wherein at least one of the tooth flanks (43f) of the respective groove recess (43) has a flank step (48) extending in a radial direction with respect to the stator axis (3) to form at least one radial flow connection to the respective groove bottom outlet (44). [10] Stator according to any one of claims 1 to 5, characterized by, that the end disk assembly (40) is multi-disc and that the outlet connections (42) and the outlet openings (41) are formed on different disks (50, 60). [11] Stator according to claim 10, characterized by , that the multi-disc end disk device (40) comprises at least one groove outlet disk (50) on which the outlet connections (42) are formed and which is in particular a sheet metal lamella, and at least one stator outlet disk (60) on which the outlet openings (41) are formed and which is in particular a sheet metal lamella. [12] Stator according to claim 11, characterized by, that the outlet connections (42) in the respective groove outlet disc (50) are formed continuously in the axial direction and that the respective collecting channel (46) of the groove outlet disc (50) separates disc teeth (50t) formed between the groove recesses (43) of the groove outlet disc (50) along its circumferential extent from a disc yoke (50y) of the groove outlet disc (50). [13] Stator according to one of claims 11 and 12, characterized by , that the groove recesses (43) of the respective groove outlet disk (50) are wider in the circumferential direction than groove recesses of sheet metal lamellae of the stator lamination stack (8) in order to form at least a radial flow connection to the respective groove bottom outlet (44) in the respective stator groove (6). [14] Stator according to any one of the preceding claims, characterized by, that in the respective stator slot (6) two slot cooling paths (17) extending in opposite directions are provided, which originate from a slot inlet in a central slot section seen in the axial direction and extend in opposite directions to the ends of the stator slot (6). [15] Stator according to any one of the preceding claims, characterized by, that in each of the stator slots (6) a spacer element (15) folded from insulating paper is provided, comprising a central strip (15m) on the long side edges of which a flank strip (15f) is angled, which faces one of the tooth flanks (5f) of the respective stator slot (6), wherein flank recesses (20) are formed in the flank strips (15f) of the respective spacer element (15) to form a slot cooling path (17), wherein the insulating paper of the respective spacer element (15) is in particular an expandable insulating paper for fixing the stator winding (14) to support points of the stator slot (6). [16] Stator according to any one of claims 1 to 14 characterized by , that to fix the stator winding (14) to support points of the stator slot (6) several lamellae of the stator body (4) are twisted around the stator axis (3). [17] Stator according to any one of the preceding claims, characterized by, that the outlet openings (41) of the end disk device (40) each have an opening axis (41a) which runs in the axial direction or obliquely to the stator axis (3), and in particular is additionally aligned in the circumferential direction. [18] Stator according to any one of the preceding claims, characterized by , that the outlet openings (41) of the end disk device (40) have different flow cross-sections. [19] Electric machine (2) comprising a stator (1) according to one of the preceding claims, comprising a rotor (30) and comprising an air gap (31) formed between the stator (1) and the rotor (3).

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