Stator for an electric machine
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-21
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026051417_13082026_PF_FP_ABST
Abstract
Description
[0001] R. 419838-2
[0002] 1
[0003] Description
[0004] title
[0005] Stator of an electric machine
[0006] State of the art
[0007] The invention relates to a stator of an electrical machine according to the preamble of the main claim.
[0008] A stator of an electric machine is already known from CN118353183 A, comprising a stator body extending around a stator axis, in particular a stator lamination stack, on which stator teeth and stator slots located between the stator teeth are formed, and which includes a stator yoke connecting the stator teeth, wherein the stator teeth have tooth heads facing away from the stator yoke, wherein the stator slots each have a slot bottom facing the stator yoke, wherein in each stator slot a conductor bundle comprising several conductors, in particular a stack of flat wire conductors, for forming an electrical stator winding, and each slot provides an electrically insulating spacer extending in the axial direction with respect to the stator axis, which establishes a distance between the conductor bundle and slot walls of the respective stator slot and forms at least one slot gap between at least one of the slot walls and the conductor bundle.which extends in an axial direction and is permeable to a cooling fluid as a slot gap channel along a slot cooling path, wherein the respective spacer element has flank recesses on flank sides facing the tooth flanks of the respective stator slot to form a slot gap channel.
[0009] Advantages of the invention
[0010] 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 radially innermost conductors of the stator winding is improved in the stator slots by providing an innermost slot gap channel radially within each of the radially innermost conductors. R. 419838-2
[0011] 2
[0012] This is achieved according to the invention by exposing the radially innermost conductor on a narrow side of the respective spacer element facing away from the groove base, at least partially, by at least one narrow-side recess, in particular an elongated hole or a pair of elongated holes, to form an innermost groove gap channel, and by directly connecting the tooth heads of adjacent stator teeth via tooth bridges to radially delimit the innermost groove gap channels.
[0013] The tooth bridges also achieve a seal or quasi-seal of the stator slots, especially the innermost slot channels, radially inwards towards an air gap. The stator slots are thus closed radially inwards towards the air gap by the tooth bridges.
[0014] 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.
[0015] It is particularly advantageous if at least one narrow-side recess and, in particular, the flank recesses of the respective spacer element towards the ends of the respective stator slot are each bounded by an end sleeve of the spacer element, which is, in particular, completely closed. In this way, the stator slots, especially their slot cooling paths, can be sealed or quasi-sealed at the ends, so that no or substantially no cooling fluid escapes directly from the ends of the stator slots. The stator winding can be fixed, in particular clamped, to the end sleeves of the spacer elements.
[0016] It is highly advantageous if the tooth bridges are spaced at least section by section along the respective narrow-side recess of the respective spacer element in the radial direction to the radially innermost conductor of the respective stator slot, in order to enlarge the innermost slot gap channels. In this way, a slot-shaped bridge channel is created in the respective stator slot radially inside the narrow-side recess and radially outside the respective tooth bridge between the adjacent tooth tips as part of the innermost slot gap channel. The bridge channels further improve the cooling of the radially innermost conductors of the stator winding. Furthermore, this results in the tooth bridges being spaced along a partial length. R. 419838-2
[0017] 3
[0018] The respective stator groove becomes radially narrower, thereby reducing the stray fluxes flowing over the tooth bridges.
[0019] According to an alternative design, the tooth bridges can also be arranged along the respective stator groove without a radial distance to the respective spacer element.
[0020] Furthermore, it is advantageous if the toothed bridge of the respective stator slot projects radially at the ends of the stator slot towards the respective end sleeve, particularly up to the end sleeve. In this way, the stator slots, especially the sections of the innermost slot gap channels formed in the stator lamination stack, can be sealed or quasi-sealed at the ends, so that no or substantially no cooling fluid escapes directly from the stator slots at their ends.
[0021] It is highly advantageous if the tooth bridges of the end lamellae of the stator body are radially taller than the tooth bridges of the other lamellae of the stator body, particularly if they have a higher radial height at the tooth tips. This allows for a simple sealing or quasi-sealing of the ends of the stator slots by the end lamellae of the stator body.
[0022] Furthermore, it is advantageous if the two end sleeves of the respective spacer element are connected to each other on at least one narrow side, and in particular on both narrow sides, by a longitudinal strip or a U-shaped longitudinal profile. This increases the mechanical stiffness of the spacers, allowing them to be inserted more easily into the stator slots in the axial direction.
[0023] According to an advantageous embodiment, two cooling channels extending in opposite directions are provided in the respective stator groove. These channels run in at least one narrow-side recess of the respective narrow side and, in particular, in a pair of flank recesses in the respective flank side of the respective spacer element. In this way, the cooling fluid can be guided through the stator groove with minimal pressure loss. R. 419838-2
[0024] 4
[0025] It is also advantageous if a central sleeve is formed on the respective spacer element in the axial direction between the two end sleeves, which is either completely closed or interrupted in the circumferential direction by a narrow-side recess. The central sleeve of the respective spacer element can hydraulically separate the cooling paths in the stator slot on the same side, particularly the flank and / or narrow side, of the spacer element, which run in opposite directions, thus achieving more uniform direct cooling of the conductors in the stator slot. Furthermore, the central sleeve can increase the stiffness of the spacer element, so that the spacers can be inserted more easily into the stator slots in the axial direction. The stator winding can be fixed, in particular clamped, to the central sleeves of the spacers.
[0026] It is further advantageous if the respective spacer element is a folded body made of insulating paper, comprising a central strip, on each of the long side edges of which a tooth-flank-side flank strip is angled, wherein an end strip is angled on a side edge facing away from the central strip of at least one flank strip, in particular of both flank strips, wherein the central strip and the at least one end strip of the respective spacer element are arranged opposite each other in the radial direction with respect to the stator axis. In this way, the spacer elements can be manufactured very simply and cost-effectively.
[0027] In an advantageous embodiment, two overlapping end strips or two buttressed end strips can be provided on the narrow side of the spacer element opposite the central strip.
[0028] Furthermore, it is advantageous if at least one narrow-side recess, in particular an elongated hole or a pair of elongated holes, is formed on a narrow side of the respective spacer element facing the bottom of the slot to create an outermost slot gap channel. In this way, the cooling of the radially outermost conductors of the stator winding can be improved in the stator slots by providing an outermost slot gap channel radially outside each of the radially outermost conductors.
[0029] It is further advantageous if the groove base is at least partially aligned along the respective narrow-side recess of the respective spacer element to R. 419838-2
[0030] 5
[0031] The outermost slot channel is set back by increasing its size. This further improves the cooling of the radially outermost conductors of the stator winding within the stator slots.
[0032] Advantageously, the respective spacer element can be formed from expandable insulating paper, wherein the expandable insulating paper comprises an expandable material that is particularly suitable for fixing the stator winding in the stator slot by expansion and that is particularly thermally activatable. In this way, the stator winding can be fixed at support points in the stator slots. The support points can be formed at the end sleeves and, if present, additionally at the center sleeves of the spacer elements.
[0033] 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.
[0034] drawing
[0035] An embodiment of the invention is shown in simplified form in the drawing and explained in more detail in the following description.
[0036] They show:
[0037] Fig. 1 shows a stator of an electrical machine according to the invention.
[0038] Fig. 2 shows a sectional view through one of the stator slots of the stator according to Fig. 1 with a spacer element according to the invention located in the stator slot, Fig. 3 shows the sectional view according to Fig. 2 with the stator winding hidden, Fig. 4 shows a cross-section through several stator slots along a line IV-IV in Fig. 2,
[0039] Fig. 5A shows an embodiment of the spacer element according to Fig. 2 and Fig. 3, Fig. 5B shows a development of the spacer element according to Fig. 5.
[0040] Fig. 5C shows an alternative development of the spacer element and
[0041] Fig. 6 shows a cross-section through several stator slots along a line Vl-Vl in Fig. 2.R. 419838-2
[0042] 6
[0043] Description of the exemplary embodiment
[0044] Fig. 1 shows a stator of an electric machine according to the invention.
[0045] The stator 1 of an electric machine 2 comprises a stator body 4 extending around a stator axis 3, in particular a stator laminated core, on which stator teeth 5 and stator slots 6 located between the stator teeth 5 are formed, and which has a stator yoke 10 connecting the stator teeth 5. A stator winding 14 runs in the stator slots 6.
[0046] Fig. 2 shows a sectional view through one of the stator slots of the stator according to Fig. 1 with a spacer element according to the invention located in the stator slot.
[0047] The electric machine 2 additionally comprises a rotor 30 and an air gap 31 formed between the stator 1 and the rotor 30.
[0048] In each of the stator slots 6, a conductor bundle 12 comprising several conductors 11, in particular a stack of flat wire conductors, is provided for forming the electrical stator winding 14 and each provides an electrically insulating spacer element 15 extending in the axial direction with respect to the stator axis 3.
[0049] The respective spacer element 15 encloses the respective conductor bundle 12 at least partially. The spacer element 15 establishes a distance between the conductor bundle 12 and the slot walls 6w of the respective stator slot 6 and forms at least one slot gap between at least one of the slot walls 6w and the conductor bundle 12, which extends in the axial direction and is accessible as a slot gap channel 16 along a slot cooling path 17 through which a cooling fluid, in particular oil, can flow.
[0050] According to Fig. 2, the stator slots 6 can be supplied with cooling fluid via at least one supply path 18 running through the stator body 4. The respective supply path 18 opens, for example, into the respective stator slot 6 in a central section of the slot viewed in the axial direction, particularly in the axial center of the slot. At the ends of the stator slots 6, the cooling medium can be discharged from the stator slots 6 and from the stator body 4 via at least one outlet path 19 running through the stator body 4. R. 419838-2
[0051] 7
[0052] Fig. 3 shows the sectional view according to Fig. 2 with the stator winding hidden.
[0053] Fig. 4 shows a cross-section through several stator slots along a line IV-IV in Fig. 2.
[0054] According to Fig. 2 to Fig. 4, each spacer element 15 has flank recesses 20 on flank sides 15W facing the tooth flanks 5f of the respective stator slot 6 to form a slot gap channel 16.
[0055] According to Fig. 4, the stator teeth 5 have tooth heads 5h facing away from the stator yoke 10. The stator grooves 6 each have a groove base 7 facing the stator yoke 10.
[0056] According to the invention, it is provided that on a narrow side 15N of the respective spacer element 15 facing away from the groove base 7, the conductor 11i radially innermost with respect to the stator axis 3 is exposed at least partially by at least one narrow-side recess 21, in particular an elongated hole or a pair of elongated holes, to form an innermost groove gap channel 16i (Figs. 3 and 4). The elongated hole is understood to be, in particular, a recess with a longitudinal extent.
[0057] According to the embodiment, the respective narrow-side recess 21 of the respective spacer element 15 extends exclusively to the respective narrow side 15N.
[0058] Furthermore, according to the invention, the tooth heads 5h of adjacent stator teeth 5, in particular of all stator teeth 5, are directly connected via tooth bridges 5b for radially limiting the innermost groove gap channels 16i (Fig. 4). The tooth bridges 5b face away from the stator yoke 10, lie on an inner circumference of the stator body 4 and face the air gap 31.
[0059] According to Fig. 3, the at least one narrow-side recess 21 and, in particular, the flank recesses 21 of the respective spacer element 15 towards the ends of the respective stator groove 6 are each limited by an end sleeve 15s of the spacer element 15, which is in particular completely closed.
[0060] According to the embodiment shown in Fig. 4, the tooth bridges 5b can be enlarged, at least section by section, along the respective narrow-side recess 21 of the respective spacer element 15 in radial direction to enlarge the innermost groove gap channels 16i. 419838-2
[0061] 8
[0062] The direction relative to the stator axis 3 is spaced from the radially innermost conductor 11 i of the respective stator groove 6. This creates a groove-shaped bridge channel 22 in the respective stator groove 6, radially inside the narrow-side recess 21 and radially outside the respective tooth bridge 5b between the adjacent tooth heads 5h, as part of the innermost groove gap channel 16i. Along the groove-shaped bridge channels 22, the tooth bridges 5b have, for example, a lower height in the radial direction than the tooth heads 5h.
[0063] At the ends of the respective stator groove 6, the respective tooth bridge 5b can project radially on the side facing the stator groove 6 in the direction of the respective end sleeve 15s of the respective spacer element 15 to axially close the respective bridge channel 22, in particular up to the end sleeve 15s.
[0064] The innermost groove gap channels 16i can also be expressly formed only by the narrow-side recesses 21 in the spacer elements 15, with the tooth bridges 5b arranged along the respective stator groove 6 without radial distance to the respective spacer element 15.
[0065] On a narrow side 15N of the respective spacer element 15 facing the groove base 7, at least one narrow-side recess 21, in particular an elongated hole or a pair of elongated holes, can be formed to create an outermost groove gap channel 16a. To enlarge the outermost groove gap channel 16a, the groove base 7 can be recessed at least section by section along the respective narrow-side recess 21 of the respective spacer element 15, forming a base channel 23.
[0066] According to Fig. 3, two groove cooling paths 17 running in opposite directions are provided in the respective stator groove 6, which run in the at least one narrow side recess 21 of the respective narrow side 15N and in particular in a pair of flank recesses 20 in the respective flank side 15W of the respective spacer element 15.
[0067] Fig. 5A shows an embodiment of the spacer element according to Fig. 2 and Fig. 3.
[0068] According to the exemplary embodiment, the two end sleeves 15s of the respective spacer element 15 are formed on at least one narrow side 15N, in particular on both sides. 419838-2
[0069] 9
[0070] Narrow sides 15N, each connected to each other via a longitudinal strip 15L or a U-shaped longitudinal profile 15L.
[0071] At the respective spacer element 15, a central sleeve 15t can be formed in the axial direction between the two end sleeves 15s, which can be completely closed or interrupted in the circumferential direction by a narrow-side recess 21.
[0072] The respective spacer element 15 is, for example, a folded body made from insulating paper. Insulating paper is understood to be a conventional electrically insulating sheet insulating material for electrical machines. The insulating paper can, for example, be a laminate. The respective spacer element 15 can, in particular, be formed from expandable insulating paper comprising an expandable material. The expandable material of the expandable insulating paper is particularly suitable for fixing the stator winding 14 in the stator slot 6 by expansion and is, in particular, thermally activatable.
[0073] Fig. 5B shows a development of the spacer element according to Fig. 5A.
[0074] According to Fig. 5B, each spacer element 15 comprises a central strip 15m, on the long side edges of which a tooth flank-side flank strip 15f is angled.
[0075] An end strip 15e can be angled on a side edge of at least one flank strip 15f, in particular on both flank strips 15f, facing away from the central strip 15m. The central strip 15m and the at least one end strip 15e of the respective spacer element 15 can be arranged opposite each other in the respective stator groove 6 in a radial direction with respect to the stator axis 3.
[0076] The flank strips 15m, for example, have a strip height that corresponds to the radial height of the stator slots 6, in particular essentially corresponds to the radial height of the stator slots 6. The center strips 15m and the end strips 15e, for example, each have a strip height that corresponds to the width of the stator slots 6, in particular essentially corresponds to the width of the stator slots 6. R. 419838-2
[0077] 10
[0078] On the narrow side 15N of the respective spacer element 15 opposite the central strip 15m, two overlapping end strips 15e or alternatively, in a manner not shown, two buttressed end strips 15e can be provided according to Fig. 5A.
[0079] The narrow-side recess 21 can be formed in the central strip 15m according to Fig. 5B and / or in the at least one end strip 15e, in particular in both end strips 15e, of the respective spacer element 15 according to Fig. 5C.
[0080] According to Fig. 5C, an open narrow-side recess 21 is formed in each of the two end strips 15e of the respective spacer element 15. For this embodiment with two open narrow-side recesses 21, it is provided that the two end strips 15e of the respective spacer element 15, when folded, are buttressed opposite each other in the area of the end sleeves 15s and together form a closed narrow-side recess 21 between the two end sleeves 15s.
[0081] Fig. 6 shows a cross-section through several stator slots along a line Vl-Vl in Fig. 2.
[0082] To achieve axial closure of the respective bridge canal 22, the dental bridges 5b can be closed by end lamellae L e of the stator body 4 compared to the tooth bridges 5b of the remaining lamellae L of the stator body 4 be radially higher, in particular have the radial height h of the tooth heads 5h.
Claims
R. 419838-2 11 Claims 1. Stator of an electric machine (2) with a stator body (4) extending around a stator axis, in particular a stator laminated core, 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 teeth have tooth heads facing away from the stator yoke, wherein the stator slots (6) each have a slot base (7) facing the stator yoke (10), wherein a conductor bundle (12) comprising several conductors (11), in particular a stack of flat wire conductors, for forming an electrical stator winding (14) and an electrically insulating spacer element (15) extending in the axial direction with respect to the stator axis (3) is provided in each of the stator slots (6).which establishes a distance between the conductor bundle (12) and slot walls (6w) of the respective stator slot (6) and forms at least one slot gap between at least one of the slot walls (6w) and the conductor bundle (12), which extends in the axial direction and is permeable to a cooling fluid as a slot gap channel (16) along a slot cooling path (17), wherein the respective spacer element (15) has flank recesses (20) on flank sides (15W) facing the tooth flanks (5f) of the respective stator slot (6) for forming a slot gap channel (16), characterized in that, - on a narrow side (15N) of the respective spacer element (15) facing away from the groove base (7) the radially innermost conductor (11 i) is exposed at least sectionally by at least one narrow-side recess (21), in particular an elongated hole or a pair of elongated holes, to form an innermost groove gap channel (16i), - the tooth heads (5h) of adjacent stator teeth (5) are directly connected via tooth bridges (5b) to radially limit the innermost groove gap channels (16i).
2. Stator according to claim 1, characterized in that the at least one narrow-side recess (21) and, in particular, the flank recesses (20) of the respective spacer element (15) towards the ends of the respective stator groove (6) are each limited by an end sleeve (15s) of the spacer element (15), in particular a circumferentially closed one. R. 419838-2 12 3. Stator according to one of the preceding claims, characterized in that the tooth bridges (5b) are arranged along the respective stator groove (6) without radial distance to the respective spacer element (15).
4. Stator according to one of the preceding claims, characterized in that the tooth bridges (5b) are spaced at least sectionally along the respective narrow-side recess (21) of the respective spacer element (15) in a radial direction to the respective radially innermost conductor (11 i) of the respective stator slot (6) to enlarge the innermost slot channels (16i).
5. Stator according to claim 4, characterized in that the tooth bridge (5b) of the respective stator groove (6) projects radially at the ends of the stator groove (6) in the direction of the respective end sleeve (15s), in particular up to the end sleeve (15s).
6. Stator according to claim 5, characterized in that the tooth bridges (5b) are formed by end lamellae (L e ) of the stator body (4) are radially higher than the tooth bridges (5b) of the other lamellae (L) of the stator body (4), in particular having a radial height (h) of the tooth heads (5h).
7. Stator according to one of claims 2 to 6, characterized in that the two end sleeves (15s) of the respective spacer element (15) are connected to each other on at least one narrow side (15N), in particular on both narrow sides (15N), via a longitudinal strip (15L) or a U-shaped longitudinal profile (15L).
8. Stator according to one of the preceding claims, characterized in that two groove cooling paths (17) extending in opposite directions are provided in the respective stator groove (6), which run in the at least one narrow-side recess (21) of the respective narrow side (15N) and in particular in a pair of flank recesses (20) in the respective flank side (15W) of the respective spacer element (15).
9. Stator according to one of claims 2 to 8, characterized in that a central sleeve (15t) is formed on the respective spacer element (15) in the axial direction between the two end sleeves (15s), which is circumferentially closed or interrupted in the circumferential direction by a narrow-side recess (21). R. 419838-2 13 10. Stator according to one of the preceding claims, characterized in that the respective spacer element (15) is a folded body made of insulating paper, comprising a central strip (15m) at each of whose long side edges a tooth flank-side flank strip (15f) is angled, wherein an end strip (15e) is angled at a side edge of at least one flank strip (15f), in particular of both flank strips (15f), facing away from the central strip (15m), wherein the central strip (15m) and the at least one end strip (15e) of the respective spacer element (15) are arranged opposite each other in a radial direction with respect to the stator axis (3).
11. Stator according to claim 10, characterized in that on the narrow side (15N) of the spacer element (15) opposite the central strip (15m) two overlapping end strips (15e) or two butt-jointed end strips (15e) are provided.
12. Stator according to one of the preceding claims, characterized in that at least one narrow-side recess (21), in particular an elongated hole or a pair of elongated holes, is formed on a narrow side (15N) of the respective spacer element (15) facing the base of the groove (7) to form an outermost groove gap channel (16a).
13. Stator according to claim 12, characterized in that the groove base (7) is recessed at least section by section along the respective narrow side recess (21) of the respective spacer element (15) to enlarge the outermost groove gap channel (16a).
14. Stator according to one of the preceding claims, characterized in that the respective spacer element (15) is formed from an expandable insulating paper, wherein the expandable insulating paper comprises an expandable material which is particularly suitable for fixing the stator winding (14) in the stator slot (6) by expansion and which is particularly thermally activatable.
15. Electric machine (2) with a stator (1) according to one of the preceding claims, with a rotor (30) and with an air gap (31) formed between the stator (1) and the rotor (30).