Cooling of a wound stator of an electric machine

Abstract

Proposed is a stator (1) of an electric machine (2), said stator having a stator axis (3) and comprising a stator laminated core (4) in which there are formed stator teeth (5), which proceed from a stator yoke (7), and interposed stator grooves (6). Here, the stator grooves (6) are closed by a groove closure means (20) at the groove slots (6s) at the stator tooth ends averted from the yoke. A conductor bundle (10) comprising one or more conductors (9) is provided in each of the stator grooves (6) in order to form an electrical stator winding (11), and a groove gap (12) is thus created which forms a groove gap channel (13) extending in the axial direction. A cooling fluid, which is optionally in liquid form, can thus flow through the groove gap channel as a groove cooling path. Furthermore, a radial supply path (15) is formed in the stator laminated core and supplies cooling fluid to the groove gap channels of a plurality of stator grooves (6), and an at least ring-segment-shaped distributor channel (16) is formed in the stator laminated core (4). Said distributor channel (16) is formed between the groove closure means (20) and the tooth ends as viewed in the radial direction.

Description

[0001] Description

[0002] title

[0003] COOLING A WOUND 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 of an electrical machine is already known from DE102019113785 A1, which has a stator axis and a stator lamination stack. Stator teeth and stator slots located between the stator teeth are formed on the stator lamination stack. The stator lamination stack comprises a stator yoke connecting the stator teeth. The stator slots have slot slots formed between the tooth ends facing away from the yoke. A single conductor or a conductor bundle comprising several conductors, in particular a stack of flat wire conductors, is provided in each of the stator slots to form an electrical stator winding. Between the slot 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. A cooling fluid, in particular oil, can flow through the slot gap channel along a slot cooling path.

[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 supply of the cooling fluid into the slot gap channels is simplified. The manufacturing costs for the stator are thereby reduced.

[0009] This is achieved according to the invention in that at least one supply path is formed in the stator laminated core, which opens into a plurality of the stator slots for the supply of cooling fluid from a plurality of slot cooling paths, and in that an annular or partially annular distribution channel is formed in the stator laminated core, which is formed in the radial direction with respect to the stator axis between a slot closure device for closing the slot slots and the tooth ends of the stator teeth facing away from the yoke and opens into a plurality of the stator slots as part of a supply path. In this way, the distribution channel is created as an annular or partially annular gap on a circumference facing away from the stator yoke. The distribution channel therefore has an annular or partially annular extension in the circumferential direction.

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

[0011] It is very advantageous if the distribution channel is formed in at least one, in particular several, special laminations of the stator laminated core and extends in the circumferential direction, with the at least one special lamination being arranged between a first sub-package and a second sub-package of the stator laminated core. This allows the distribution channel to be easily created in at least one special lamination, for example, in a stack of special laminations, between two sub-packages of the stator laminated core.

[0012] It is particularly advantageous if the respective special lamella for forming the distribution channel has lamella teeth that are shortened in the radial direction compared to the other sheet metal lamellas, in particular with a shortened tooth tip or no tooth tip at all. In this way, the distribution channel is formed at the shortened tooth ends of the lamella teeth of the respective special lamella.

[0013] It is particularly advantageous if at least one yoke channel is provided in the stator yoke, extending axially relative to the stator axis, from which a radial channel branches off in at least one of the special laminations, extending radially relative to the stator axis through one of the stator teeth and opening into the distribution channel. The yoke channel can be easily manufactured in the stator core. The radial channel formed in at least one of the special laminations simply creates a flow connection between the yoke channel and the distribution channel.

[0014] It is further advantageous if the yoke channel is designed as a through-channel for the passage of a fastening screw for attaching the stator laminated core to a housing, wherein the yoke channel is formed in the gap between the through-channel and the fastening screw, in particular in a groove-shaped channel recess of the yoke channel. In this way, the supply path can be formed in a through-opening that often already exists in the stator laminated core.

[0015] It is also advantageous if the stator core has several circumferentially spaced yoke channels designed as through-channels, as well as several radial channels branching off from one of the yoke channels. This allows sufficient cooling fluid to be supplied to the slot gap channels, thus achieving highly effective direct conductor cooling.

[0016] According to an advantageous embodiment, the slot closure device can be provided on the tooth ends of the stator teeth facing away from the yoke for at least partial arrangement in the air gap, i.e. in the radial direction outside the slot slots, and / or can be formed at least partially in the slot slots of the stator slots.

[0017] It is advantageous if two slot cooling paths running in opposite directions are provided in the respective stator slot, which exit as a free jet at the ends of the respective stator slot via a slot outlet, in particular in the slot head or in the slot base of the stator slot. In this way, an annular distributor for distributing the cooling fluid into the slot gap channels and / or an annular collector for collecting the cooling fluid exiting from the slot gap channels can be dispensed with on the end faces of the stator laminated core. Such annular distributors would require a sealing of a stator chamber from a rotor chamber of the electric machine, for example by means of a sleeve or a can. Furthermore, the flow connection of the slot gap channels according to the invention enables a lower pressure in the respective slot cooling path, so that the requirements for sealing the slot gap channels are reduced.In addition, the pressure loss in the respective slot cooling path is reduced because the respective slot cooling path does not run over the entire length, but only over an axial section of the respective stator slot.

[0018] It is also advantageous if several support points are formed in the stator slots, spaced apart from one another in the axial direction relative to the stator axis, for clamping the conductor or conductor bundle located in the respective stator slot. The support points are each formed by twisting individual or multiple laminations of the stator core, in particular by a group or multiple groups of laminations. The support points allow the slot gap channel in each stator slot to be reproducibly adjusted and stably maintained.

[0019] It is further advantageous if the respective slot cooling path is at least narrowed at the support points, with a bypass being provided at each support point to direct the cooling fluid past the respective narrowed support point. The bypasses of the respective stator slot, starting from the inlet into the respective stator slot, are formed alternately in the slot base or the slot head along the respective slot cooling path. In this way, the flow through the slot gap channels is meandering, or the slot cooling paths run in a meandering pattern, whereby the conductors in the stator slots are cooled more evenly, thus improving stator cooling.

[0020] The invention further relates to an electrical machine with a stator according to the invention.

[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 shows a stator of an electrical machine with a supply path according to the invention for supplying cooling fluid to a direct conductor cooling system, Fig.2 shows a section of the stator along the line II-II in Fig.1,

[0025] Fig.3 a section of the stator along the line lll-lll in Fig.1 ,

[0026] Fig.4 is a partial view according to Fig.3 with a distribution channel according to the invention,

[0027] Fig.5 shows a section through one of the stator slots of the stator with a conductor bundle mounted according to the invention in one of the stator slots at several support points,

[0028] Fig.6 the stator lamination stack according to Fig.5 with twisted laminations to form the

[0029] Support points,

[0030] Fig.7 shows a section through one of the stator slots of the stator with a conductor bundle mounted according to the invention in one of the stator slots at several support points,

[0031] Fig.8 is a section through the stator slot of the stator along the line VIII-VIII in Fig.7 and Fig.9 is a section through the stator slot of the stator along the line IX-IX in Fig.7.

[0032] Description of the embodiment

[0033] Fig.1 shows a stator of an electrical machine with a supply path according to the invention for supplying cooling fluid to a direct conductor cooling system.

[0034] The stator 1 of an electrical machine 2 according to the invention comprises a stator axis 3 and a stator laminated core 4 extending around the stator axis 3. The stator laminated core 4 is designed as a stack of laminated laminations 8.

[0035] Fig.2 shows a section of the stator along the line ll-ll in Fig.1 .

[0036] Stator teeth 5 and stator slots 6 located between the stator teeth 5 are formed on the stator laminated core 4. The stator laminated core 4 also includes an annular stator yoke 7 connecting the stator teeth 5. The stator slots 6 extend in the radial direction relative to the stator axis 3 between a slot base 6g and a slot head 6h and have slot slots 6s formed between tooth ends 5e facing away from the yoke. The tooth ends 5e facing away from the yoke are, of course, understood to mean the tooth ends facing away from the stator yoke 7.

[0037] In the stator slots 6 extending in the axial direction with respect to the stator axis 3, a single conductor 9 or a conductor bundle 10 comprising several conductors 9, in particular a stack of flat wire conductors, can be provided to form an electrical stator winding 11.

[0038] Between the slot flanks 6f of the respective stator slot 6 and the conductor 9 or conductor bundle 10 arranged in the stator slot 6, at least one slot gap 12 is provided, which forms a slot gap channel 13 extending in the axial direction, through which a cooling fluid, in particular oil, can flow along a slot cooling path 14.

[0039] Fig. 3 shows a section of the stator along the line I 11-I 1 in Fig. 1. Fig. 4 shows a partial view according to Fig. 3 with a distribution channel according to the invention. According to the invention, at least one supply path 15 is formed in the stator laminated core 4, which opens into a plurality of the stator slots 6 for the supply of cooling fluid from a plurality of slot cooling paths 14. Furthermore, according to the invention, an annular or partially annular distribution channel 16 is formed in the stator laminated core 4, which is formed in the radial direction between a slot closing device 20 for closing the slot slots 6s and the tooth ends 6e of the stator teeth 6 facing away from the yoke and opens into a plurality of the stator slots 6 as part of a supply path 15.

[0040] The distribution channel 16 is formed in at least one, in particular several, special laminations 21 of the stator laminated core 4 and extends in the circumferential direction. The at least one special lamination 21 is arranged between a first sub-package 4.1 and a second sub-package 4.2 of the stator laminated core 4.

[0041] To form the distribution channel 16, the respective special lamella 21 has lamella teeth 21 z which are shortened in the radial direction compared to the other sheet metal lamellas and which in particular have a shortened tooth head or no tooth head.

[0042] In the stator yoke 7, at least one yoke channel 17 extending in the axial direction is provided as part of a supply path 15.

[0043] From the respective yoke channel 17, in the region of the at least one special lamination 21, a radial channel 18 branches off in the radial direction relative to the stator axis 3, which radial channel 18 runs through one of the stator teeth 5, 21z in the at least one special lamination 21 and opens into the distribution channel 18. The distribution channel 18 opens into the respective stator slots 6 in a central region of the stator laminated core 4 via the respective slot slots 6s.

[0044] The radial channel 18 is, for example, a slot-shaped cutout in the respective special lamella 21.

[0045] According to the embodiment, several special laminations 21 are provided as a stack in the stator laminated core 4, in each of which the distribution channel 16 and the radial channel 18 are formed.

[0046] According to Fig. 1, the yoke channel 17 is designed as a through-channel for the passage of a fastening screw 22 for fastening the stator laminated core 2 to a housing 23. The yoke channel 17 is designed in a gap between the through-channel 17 and the fastening screw 22, in particular in a groove-shaped channel recess 26 of the through-channel 17. The stator yoke 7 can have, on its circumference facing away from the stator teeth 5, a plurality of projections or bulges projecting in the radial direction, which are to be regarded as part of the stator yoke 7, wherein the through-channel 17 can be designed at least in sections in this projection or bulge.

[0047] According to the exemplary embodiment, a plurality of yoke channels 17 are provided in the stator laminated core 4, which are spaced apart from one another in the circumferential direction and designed as through-channels.

[0048] The slot closure device 20 is provided on the tooth ends 5e of the stator teeth 5 facing away from the yoke and can be arranged at least partially in the air gap between the stator 1 and a rotor of the electric machine 2 and / or at least partially in the slot slots 6s of the stator slots 6. The slot closure device 20 can, for example, be a stator sleeve for closing the slot slots 6s.

[0049] Fig.5 shows a section through one of the stator slots of the stator with a conductor bundle mounted according to the invention in one of the stator slots at several support points.

[0050] Fig.6 shows the stator laminated core according to Fig.5 with twisted laminations to form the support points.

[0051] In the stator slots 6, a plurality of support points 28 are formed, spaced apart from one another in the axial direction with respect to the stator axis 3, for clamping the conductor 9 or conductor bundle 10 located in the respective stator slot 6. The support points 28 can, for example, be formed by twisting individual or multiple laminations 8 of the stator laminated core 4. To form the support points 28, at least one group 30 of laminations 8 is twisted in the stator laminated core 4. According to the exemplary embodiment, a plurality of groups 30 or stacks 30 of laminations 8 in the stator laminated core 4 are twisted opposite one another by a twist angle t|) about the stator axis 3.

[0052] Fig. 7 shows a section through one of the stator slots of the stator with a conductor bundle mounted according to the invention at several support points in one of the stator slots. Two slot cooling paths 14 are provided in the respective stator slot 6, extending in opposite directions from the respective opening into the stator slot 6. These cooling paths exit as a free jet at the ends of the respective stator slot 6 via a slot outlet, in particular in the slot head 6h or the slot base 6g of the stator slot 6.

[0053] Fig.8 shows a section through the stator slot of the stator along the line VIII-VIII in Fig.7.

[0054] The view according to Fig. 8 shows a section between the support points 28 according to the invention. Between the support points 28 according to the invention, the conductor 9 or the conductor bundle 10 of the respective stator slot 6 are mounted in a freely suspended manner, i.e., without contact with the stator core 4. As a result, the slot gap 12 and the slot gap channel 13 are formed in the stator slot 6.

[0055] Fig. 9 shows a section through the stator slot of the stator along the line IX-IX in Fig. 7. Fig. 9 also shows a section through one of the support points 28.

[0056] The conductor 9 or the conductor bundle 10 of the respective stator slot 6 is in contact with the stator laminated core 4 at the support points 28, and only at the support points 28.

[0057] The respective slot cooling path 14 is at least narrowed at the support points 28. Therefore, a bypass 29 is provided at each support point 28 to direct the cooling fluid past the respective narrowed support point 28. Starting from the inlet into the respective stator slot 6, the bypasses 29 of the respective stator slot 6 can be formed alternately in the slot base 6g or the slot head 6h along the respective slot cooling path 14, in particular to form meandering slot cooling paths 14.

Claims

Claims 1 . Stator of an electrical machine (2) with a stator axis (3) and with a stator core (4) on which stator teeth (5) and stator slots (6) located between the stator teeth (5) are formed and which comprises a stator yoke (7) connecting the stator teeth (5), wherein the stator slots (6) have slot slots (6s) formed between tooth ends (5e) facing away from the yoke, wherein a single conductor (9) or a conductor bundle (10) comprising several conductors (9), in particular a stack of flat wire conductors, is provided in each of the stator slots (6) to form an electrical stator winding (11), wherein at least one slot gap (12) is provided between the slot flanks (6f) of the respective stator slot (6) and the conductor (9) or conductor bundle (10) arranged in the stator slot (6), which forms a slot gap channel (13) extending in the axial direction and extending along a Groove cooling path (14) through which a cooling fluid, in particular oil, can flow, characterized in that - at least one supply path (15) is formed in the stator laminated core (4), which opens into several of the stator slots (6) for supplying cooling fluid from several slot cooling paths (14), - an annular or partially annular distribution channel (16) is formed in the stator laminated core (4), which is formed in the radial direction with respect to the stator axis (3) between a slot closure device (20) for closing the slot slots (6s) and the tooth ends (5e) of the stator teeth (5) facing away from the yoke and opens into several of the stator slots (6) as part of a supply path (15).

2. Stator according to claim 1, characterized in that the distribution channel (16) is designed in at least one, in particular several, special lamellae (21) of the stator laminated core (4) and runs in the circumferential direction, wherein the at least one special lamella (21) is arranged between a first partial core (4.1) and a second partial core (4.2) of the stator laminated core (4).

3. Stator according to claim 2, characterized in that the respective special lamination (21) for forming the distribution channel (16) has lamination teeth (21 z) which are shortened in the radial direction compared to the other laminations (8), which in particular have a shortened tooth head or no tooth head.

4. Stator according to one of the preceding claims, characterized in that in the stator yoke (7) at least one yoke channel (17) running in the axial direction with respect to the stator axis (3) is provided, from which a radial channel (18) branches off in at least one of the special lamellas (21) running in the radial direction with respect to the stator axis (3) through one of the stator teeth (5) and opening into the distributor channel (16).

5. Stator according to claim 4, characterized in that the yoke channel (17) is designed as a through-channel for the passage of a fastening screw (22) for fastening the stator laminated core (4) to a housing (23), wherein the yoke channel (17) is formed in the gap between the through-channel and the fastening screw (22), in particular in a groove-shaped channel recess (26) of the through-channel (17).

6. Stator according to one of claims 4 or 5, characterized in that the stator laminated core (4) has a plurality of yoke channels (17) spaced apart from one another in the circumferential direction and designed as through channels.

7. Stator according to one of the preceding claims, characterized in that the slot closure device (20) is provided on the tooth ends (5e) of the stator teeth (5) facing away from the yoke for at least partial arrangement in the air gap and / or is formed at least partially in the slot slots (6s) of the stator slots (6).

8. Stator according to one of the preceding claims, characterized in that in the respective stator slot (6) two slot cooling paths (14) running in opposite directions are provided, which exit at the ends of the respective stator slot (6) via a slot outlet as a free jet, in particular in the slot head (6h) or in the slot base (6g) of the stator slot (6).

9. Stator according to one of the preceding claims, characterized in that in the stator slots (6) a plurality of support points (28) are formed which are spaced apart from one another in the axial direction with respect to the stator axis (3) for clamping the conductor (9) or conductor bundle (10) lying in the respective stator slot (6), wherein the support points (28) are each formed by the rotation of individual or several laminations (8) of the stator lamination stack (4), in particular by a group (30) or by several groups (30) of sheet metal lamellae (8).

10. Stator according to claim 9, characterized in that the respective slot cooling path (14) is at least narrowed at the support points (28), wherein a bypass (29) is provided at each of the support points (28) in order to guide the cooling fluid past the respective narrowed support point (28), wherein the bypasses (29) of the respective stator slot (6), starting from the inlet into the respective stator slot (6) along the respective slot cooling path (14), are formed alternately in the slot base (6g) or in the slot head (6h), in particular for forming meander-shaped slot cooling paths (14). 11 . Electrical machine with a stator (1) according to one of the preceding claims.

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