Stator of an electric machine

Abstract

The invention relates to a stator of an electric machine having a stator body on which stator teeth and stator grooves are formed and which comprises a stator yoke, wherein the stator grooves each have a first groove base facing the stator yoke and a second groove base, wherein a respective conductor or conductor bundle comprising multiple conductors is provided in the stator grooves to form a stator winding, wherein a respective spacer element is provided in the stator grooves, which forms at least one groove gap through which, as a groove gap channel, a cooling fluid can flow along a groove cooling path, wherein the spacer element comprises a central strip, on the long side edges of which a respective wing strip is angled, forming a respective folded edge, wherein flank recesses for forming a groove gap channel are formed in the wing strips of the respective spacer element, characterized in that - at least one axial group (20p) of flank recesses (20) and at least one radial separating web (15r) are formed in each wing strip (15f) of the respective spacer element (15), - the separating webs (15r) in both wing strips (15f) of the respective spacer element (15) form a central sleeve (15t) which is in particular circumferentially closed or has in particular a slot (13) in particular in one of the groove bases (7, 8).

Description

[0001] R. 416243-3

[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 shaft and a stator body, 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. The stator slots each have a first slot base facing the stator yoke and a second slot base opposite the first slot base. A conductor or a bundle of conductors, in particular a stack of flat wire conductors, is provided in each stator slot to form an electrical stator winding. Furthermore, an electrically insulating spacer extending axially with respect to the stator shaft is arranged in each stator slot, maintaining a distance between the conductor or the bundle of conductors.The spacer element is positioned between the conductor bundle and the groove walls, particularly the tooth flanks, of the respective stator groove and forms at least one groove gap between the groove walls, particularly the tooth flanks, and the conductor or conductor bundle. This gap extends axially and is designed as a groove gap channel through which a cooling fluid can flow along a groove cooling path. The spacer element is a folded body made of insulating paper, comprising a central strip located at the first or second groove base. A wing strip is angled at each of the long side edges of this central strip, forming a fold edge. Flank recesses are formed in the wing strips of the respective spacer element to form a groove gap channel.In one of the two wing strips of the respective spacer element, at least one axial pair of flank recesses arranged one behind the other in the axial direction is arranged, the flank recesses of which are separated from each other by a radial separating web extending radially with respect to the stator axis. R. 416243-3.

[0009] 2

[0010] The spacer element allows for direct conductor cooling through the recesses on its flanks. Depending on the design, the stator winding may not be fixed in the stator slots, or not sufficiently so.

[0011] Advantages of the invention

[0012] 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 fixing of the stator winding in the stator slots is improved. This is achieved, according to a first aspect of the invention, by forming at least one axial group, in particular one axial pair, of flank recesses and at least one radial separating web in each wing strip of the respective spacer element.

[0013] According to a second aspect of the invention, the separating webs in both wing strips of the respective spacer element form a central sleeve, which is in particular closed all around or has a slot, especially at one of the groove bases. Because the central sleeve is closed all around or has at most a slot, especially at one of the groove bases, it can be ensured that each conductor of the stator groove is sufficiently clamped between the tooth flanks from both sides. If the central sleeve is closed all around, the adjacent flank recesses of an axial group are hydraulically separated, i.e., not flow-connected, thereby achieving more uniform direct cooling of the conductors in the stator groove.

[0014] According to the invention, the central sleeve of the respective spacer element can form an additional support point for clamping or fixing the stator winding. Since the stator winding oscillates with a reduced amplitude due to the additional support point, the fill factor in the stator slots can be increased, thereby achieving higher efficiency and a higher maximum power output of the electric machine.

[0015] 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.

[0016] According to an advantageous first clamping solution, the respective spacer element can be folded from a thermally expandable insulating paper for expansion of the spacer element to fix the stator winding in the stator slot. R. 416243-3

[0017] 3

[0018] According to an alternative second clamping solution, several laminations of the stator body can be twisted around the stator axis in the axial area of ​​the center sleeves and, for example, also in the axial area of ​​the end sleeves of the spacers to fix the stator winding in the stator slots. According to this second clamping solution, the twisted laminations press down on the stator winding via the center sleeves and, for example, also via the end sleeves, clamping it locally.

[0019] It is particularly advantageous if four sleeve sections projecting radially from the central strip are provided at the ends of each spacer element. These sleeve sections are arranged in pairs opposite each other and form two end sleeves, each of which is completely closed or has a slot, located particularly at the bottom of the first slot. This improves the fixation of the stator winding in the stator slots, as it ensures that each conductor of the stator slot is sufficiently clamped between the tooth flanks from both sides, even within the end sleeves.

[0020] It is also advantageous if the respective end sleeve of the respective spacer element is connected to the central sleeve via a longitudinal profile extending in the axial direction, which is arranged on a narrow side of the spacer element, particularly one facing the central strip, and / or is particularly U-shaped or strip-shaped. This increases the stiffness of the respective spacer element, allowing it to be inserted more easily into the stator slot in the axial direction.

[0021] According to an advantageous first variant, the flank recesses of the respective spacer element can be open in a radial direction.

[0022] In a further advantageous second variant, the flank recesses of the respective spacer element can be closed in the radial direction. This further increases the stiffness of the spacer element, allowing it to be inserted more easily into the stator slot in the axial direction.

[0023] It is very advantageous if, according to the second variant, the respective end sleeve of the respective spacer element is connected to the central sleeve via a longitudinal profile extending in the axial direction, which is arranged on a narrow side of the spacer element, particularly one facing away from the central strip, and / or is particularly U-shaped. In this way, the flank recesses in R. 416243-3

[0024] 4. The radial direction must be closed. In the first variant, for example, the longitudinal profiles on the narrow side of the spacer element facing away from the center strip are omitted.

[0025] Furthermore, it is advantageous if, according to the second variant, the end sleeves and the center sleeve of the respective spacer element are completely closed. In this way, the stator winding can be optimally fixed in the sleeves.

[0026] It is further advantageous if at least one of the two radial separating webs of the central sleeve of the respective spacer element is designed to guide the flow of the cooling fluid from a recess inlet to an axially spaced recess outlet of the respective flank recess, in particular if it has at least one guide ramp extending at an oblique angle to the axial direction, and especially if it has two guide ramps leading to both flank recesses. In this way, uniform cooling within the respective flank recess can be achieved.

[0027] Furthermore, it is advantageous if at least one of the two radial separating webs of the central sleeve of the respective spacer element has a longitudinal axis that runs at an oblique angle to the axial direction. In this way, a single recess inlet, extending radially across the radial separating web in a tooth flank of the respective stator groove, can supply cooling fluid to two flank recesses separated by a radial separating web.

[0028] It is further advantageous if at least one, and in particular both, wing strips of the respective spacer element have several radially arranged axial groups of flank recesses. This allows the cooling fluid to be guided even more effectively in the respective flank recess.

[0029] It is very advantageous if at least one bead is formed on a narrow side of the respective spacer element, particularly in the central strip, which extends in the axial direction and projects, in particular, away from or towards the conductor bundle. In this way, the stiffness of the respective spacer element can be further increased. The bead of the spacer element can, in particular, be arranged in a slot of the stator groove, which is located between R. 416243-3.

[0030] 5 adjacent tooth ends, especially between adjacent tooth heads, the stator teeth are formed.

[0031] It is further advantageous if at least one of the wing strips of the respective spacer element has a curved pre-mark that extends in the axial direction and is curved towards or away from the conductor or conductor bundle. This further increases the stiffness of the respective spacer element. A curved pre-mark in the wing strip that is curved towards the conductor or conductor bundle has the advantage that the spacer element can be inserted more easily into the stator slot.

[0032] The respective spacer element can advantageously have at least one support collar at an axial end for axially abutting the spacer element against an end face of the stator body, which is folded towards an outer surface of the spacer element, in particular by at least 90 degrees. In this way, a stop is formed on the spacer element, so that the spacer element is brought into a defined position when axially inserted into the stator slot.

[0033] In an advantageous embodiment, the respective spacer element can have at least one insertion collar at its other end, which projects axially and, by forming an insertion ramp, facilitates the insertion of the spacer element into a stator slot. In this way, the respective spacer element can be more easily inserted into the respective stator slot.

[0034] In an advantageous embodiment, the ends of the two wing strips of the respective spacer element facing away from the central strip can lie, at least partially, on a narrow side of the spacer element, particularly at the bottom of the first groove, and overlap there. In this way, the central strip of the spacer element can lie at the groove slot, so that the spacer element can seal or quasi-seal the groove slot towards the air gap, thus preventing or minimizing the passage of cooling fluid from the stator groove into the air gap. Alternatively, the two overlapping wing strips of the spacer element can also lie at the bottom of the second groove. R. 416243-3

[0035] 6

[0036] 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.

[0037] drawing

[0038] Exemplary embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description.

[0039] They show:

[0040] Fig. 1 shows a stator of an electrical machine according to the invention.

[0041] 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.

[0042] Fig. 3 shows a cross-section through one of the stator slots along the line III-III in Fig. 2,

[0043] Fig. 4A shows a first embodiment of the spacer element according to the invention as shown in Fig. 2.

[0044] Fig. 4B shows a development of the first embodiment according to Fig. 4A,

[0045] Fig. 5A shows a second embodiment of the spacer element according to the invention as shown in Fig. 2.

[0046] Fig. 5B shows a development of the second embodiment according to Fig. 5A,

[0047] Fig. 6A shows a third embodiment of the spacer element according to the invention as shown in Fig. 2.

[0048] Fig. 6B shows a development of the third embodiment according to Fig. 6A,

[0049] Fig. 7A shows a fourth embodiment of the spacer element according to the invention as shown in Fig. 2.

[0050] Fig. 7B shows a development of the fourth embodiment according to Fig. 7A,

[0051] Fig. 8A shows a fifth embodiment of the spacer element according to the invention as shown in Fig. 2.

[0052] Fig. 8B shows a development of the fifth embodiment according to Fig. 8A and

[0053] Fig. 9 shows an alternative cross-sectional shape of the spacer element according to the invention.

[0054] Description of the exemplary implementations

[0055] Fig. 1 shows a stator of an electric machine according to the invention. R. 416243-3

[0056] 7

[0057] The stator 1 of an electric machine 2 according to the invention has a stator shaft 3 and comprises a stator body 4, in particular a stator laminated core, on which stator teeth 5 and stator grooves 6 lying between the stator teeth 5 are formed and which has a stator yoke 10 connecting the stator teeth 5.

[0058] The electric machine 2 also includes a rotor 30 (Fig. 2). An air gap 31 is formed between the stator 1 and the rotor 30.

[0059] 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 lying in the stator slot in the second embodiment.

[0060] In each of the stator slots 6, a 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.

[0061] Furthermore, an electrically insulating spacer element 15 extending axially with respect to the stator axis 3 is inserted in each of the stator slots 6, which establishes a distance between the conductor 11 or conductor bundle 12 and slot walls, in particular tooth flanks 5f, of the respective stator slot 6 and forms at least one slot gap 16 between the slot walls, in particular tooth flanks 5f, and the conductor 11 or conductor bundle 12, which extends axially with respect to the stator axis 3 and can be used as a slot gap channel along a slot cooling path 17 through which a cooling fluid, in particular oil, can flow.

[0062] The respective spacer element 15 is a folded body made from insulating paper. Insulating paper refers to a conventional electrically insulating sheet insulating material for electrical machines. The insulating paper can, for example, be a laminate.

[0063] The respective spacer element 15 can, for example, have a length in the axial direction that corresponds at least to the length of the stator slots 6.

[0064] Fig. 3 shows a cross-section through one of the stator slots along line I11-I12 in Fig. 2. R. 416243-3

[0065] 8

[0066] The stator grooves 6 each have a first groove base 7 facing the stator yoke 10 and, in particular, a second groove base 8 arranged opposite the first groove base 7. A slot 9 can be formed at the second groove base 8 between adjacent tooth ends of the stator teeth 5, especially tooth tips. In this case, the second groove base 8 can, for example, be formed by two inner surfaces of two adjacent tooth tips facing the respective stator groove 6. Alternatively, adjacent tooth ends of the stator teeth can also be connected by a sheet metal web or a tooth bridge (not shown), so that the stator grooves 6 do not have a slot and are closed radially inwards, i.e., towards the air gap 31. In this case, the second groove base 8 is formed by an inner surface of the respective tooth bridge or sheet metal web.

[0067] The respective spacing element 15 comprises a central strip 15m lying on the first or second groove base 7,8, on whose long side edges a wing strip 15f is angled, forming a fold edge in each case.

[0068] In the wing strips 15f of the respective spacer element 15, flank recesses 20 are formed to create a groove channel. At least in one of the two wing strips 15f of the respective spacer element 15, at least one axial group 20p, in particular an axial pair, of flank recesses 20 arranged one behind the other in the axial direction is arranged, the flank recesses 20 of which are each separated from one another by a radial separating web 15r extending in the radial direction with respect to the stator axis.

[0069] The ends of the two wing strips 15f of the respective spacer element 15 facing away from the central strip 15m lie along the axial extent of the spacer element 15, at least partially, and in particular at least at fully closed end sleeves 15s and a fully closed central sleeve 15t, on a narrow side of the spacer element 15, particularly at the base of the first groove 7, and can overlap on this narrow side as shown in Fig. 3. Alternatively, the ends of the two wing strips 15f of the respective spacer element 15 facing away from the central strip 15m can be arranged side by side along a slot or connected to each other along a butt joint. R. 416243-3

[0070] 9

[0071] At the transition from the respective tooth flank 5f to the first groove base 7, the two wing strips 15f of the respective spacer element 15 each have a folding edge.

[0072] Fig. 4A shows a first embodiment of the spacer element according to Fig. 2. Fig. 4B shows a development of the first embodiment according to Fig. 4A.

[0073] According to a first aspect, the invention provides that in each wing strip 15f of the respective spacer element 15 at least one axial group 20p, in particular an axial pair, of flank recesses 20 and at least one radial separating web 15r is formed.

[0074] According to a second aspect, the invention provides that the separating webs 15r in both wing strips 15f of the respective spacer element 15 form a central sleeve 15t, which is in particular completely closed or in particular has a slot 13 in particular at one of the groove bases 7,8.

[0075] Following an initial clamping solution, it can be provided that the respective spacer element 15 is folded from expandable insulating paper in order to expand the spacer element 15, in particular the end sleeves 15s and the center sleeve 15t, to fix the stator winding 14 in the stator slot 6. The expandable insulating paper of the respective spacer element 15 comprises or contains an expandable material, which is in particular thermally activatable.

[0076] According to an alternative, second clamping solution (not shown), several laminations of the stator body 4 can be twisted around the stator axis 3 in the axial region of the central sleeves 15t and / or in the axial region of the end sleeves 15s of the spacer elements 15 of the stator body 4 to fix the stator winding 14 in the stator slots 6, for example as in Figure 1 of DE102021207920 A1. According to the second clamping solution, the twisted laminations press on the stator winding 14 via the central sleeves 15t and / or the end sleeves 15s.

[0077] At the axial ends of each spacer element 15, four sleeve sections 15k projecting radially from the central strip 15m are provided, which are arranged in pairs opposite each other and form two end sleeves 15s, each of which is completely closed or, according to Figures 4A and 4B, each has a slot 13 R. 416243-3

[0078] 10. The respective slot 13 can, for example, be located at the first groove base 7. The respective center sleeve 15 of a spacer element 15 lies between the end sleeves 15s of the spacer element 15, in particular in the middle between the end sleeves 15s of the spacer element 15.

[0079] The end sleeves 15s of the respective spacer element 15 lie at least partially in the respective stator groove 6 for sealing the stator groove 6, in particular at one end of the respective stator groove 6.

[0080] The respective end sleeve 15s of the respective spacer element 15 is connected to the central sleeve 15t via a longitudinal profile 15L extending in the axial direction, which is arranged on a narrow side of the spacer element 15, particularly one facing the central strip 15m, and / or is particularly U-shaped or strip-shaped. The central strip 15m is part of this longitudinal profile 15L.

[0081] According to the first embodiment and a first variant, the flank recesses 20 of the respective spacer element 15 are open in a radial direction away from the central strip 15m. According to the remaining embodiments in Figs. 5 to 8 and a second variant, the flank recesses of the respective spacer element are closed in the radial direction.

[0082] Each flank recess 20 is associated with a recess inlet 21 and a recess outlet 22, as shown in Fig. 2. These are each formed on a tooth flank 5f of the respective stator groove 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 a central groove section of the respective stator groove 6, in particular in the axial center of the groove. Two groove cooling paths 17 extending in opposite directions are provided in the respective stator groove 6. These originate from a recess inlet 21 and extend in opposite directions to the ends of the stator groove 6. The respective recess outlet 22 can, for example, be flow-connected to an outlet opening 33 in an end disk 34 of the stator body 4 via an outlet path 19 running through the stator body 4. R. 416243-3

[0083] 11

[0084] At least one of the two radial separating webs 15r of the central sleeve 15t of the respective spacer element 15 is designed, according to Figs. 4A and 4B, to guide the flow of the cooling fluid from a recess inlet 21 to an axially spaced recess outlet 22 of the respective flank recess 20. In particular, the radial separating web 15r has at least one guide ramp 23 extending at an oblique angle α to the axial direction. According to Figs. 4A and 4B, the radial separating web 15r has two guide ramps 23 facing both flank recesses 20. The radial separating web 15r is thus, for example, cup-shaped or triangular. The guide ramp 23 can be, for example, straight, curved, arched, or arcuate.

[0085] The central strip 15m of the respective spacing element 15 has a strip height that corresponds to the circumferentially measured width of the stator slots 6, in particular essentially corresponds to the width of the stator slots 6.

[0086] The respective spacer element 15 can have at least one tab-shaped support collar 28 at an axial end, i.e. at one of the end sleeves 15s, which is folded towards an outside of the spacer element 15, in particular by at least 90 degrees, and is provided for stopping the spacer element 15 against an end face of the stator body 4.

[0087] Fig. 5A shows a second embodiment of the spacer element according to the invention as shown in Fig. 2. Fig. 5B shows a development of the second embodiment as shown in Fig. 5A.

[0088] In the embodiments with radially closed flank recesses 20 (second variant), the respective end sleeve 15s of the respective spacer element 15 is connected to the central sleeve 15t via a longitudinal profile 15L extending in the axial direction. This profile is arranged on a narrow side of the spacer element 15, particularly one facing away from the central strip 15m, and / or is U-shaped. According to the first variant, this longitudinal profile 15L is, for example, not provided on the narrow side of the spacer element 15 facing away from the central strip 15m. R. 416243-3

[0089] 12

[0090] In the embodiments with radially closed flank recesses 20 according to Fig. 5 to Fig. 8 (second variant), the end sleeves 15s and the middle sleeve 15t of the respective spacer element 15 are, for example, completely closed.

[0091] According to Fig. 5A and Fig. 5B, the flank recesses 20 of the respective spacer element 15 are, for example, rectangular, in particular parallelogram-shaped or trapezoidal. The flank recesses 20 of an axial pair 20p of the respective spacer element 15 can be mirror-symmetrical to a lamellar plane of the stator body 4.

[0092] The flank recesses 20 are designed, for example, such that each conductor 11 in the respective stator slot 6 is exposed section by section on both sides by the flank recesses 20 for direct conductor cooling.

[0093] The other end of the spacer element 15, which is turned away from the one end with the support collar 28, can have at least a tab-shaped insertion collar 29 which projects in the axial direction and facilitates the insertion of the spacer element 15 into a stator groove 6 by forming an insertion ramp.

[0094] Fig. 6A shows a third embodiment of the spacer element according to the invention as shown in Fig. 2. Fig. 6B shows a development of the third embodiment as shown in Fig. 6A.

[0095] According to the third embodiment (second variant), the flank recesses 20 of the spacer element 15 are rectangular, and the radial separating webs 15r are also rectangular. The flank recesses 20 of an axial pair 20p of the respective spacer element 15 can be mirror-symmetrical to a lamellar plane of the stator body 4.

[0096] Fig. 7A shows a fourth embodiment of the spacer element according to the invention according to Fig. 2. Fig. 7B shows a development of the fourth embodiment according to Fig. 7A.

[0097] According to the fourth embodiment (second variant), several R. 416243-3 are present in at least one, in particular both, wing strips 15f of the respective spacer element 15.

[0098] 13 radially arranged axial groups 20p, for example axial pairs, of flank recesses 20 are provided.

[0099] The flank recesses 20 of the spacer element 15 are, for example, rectangular or oblong. The flank recesses 20 of an axial pair 20p of the respective spacer element 15 can be mirror-symmetrical to a lamellar plane of the stator body 4.

[0100] Fig. 8A shows a fifth embodiment of the spacer element according to the invention according to Fig. 2. Fig. 8B shows a development of the fifth embodiment according to Fig. 8A.

[0101] According to the fifth embodiment (second variant), at least one of the two radial separating webs 15r of the central sleeve 15t of the respective spacer element 15 has a longitudinal axis 27 which runs at an oblique angle β to the axial direction.

[0102] In one of the flank recesses 20 of the respective wing strip 15f of the respective spacer element 15, the recess inlet 21 can open radially inwards, and in another flank recess 20 of the flank strip 15f of the spacer element 15, it can open further radially outwards into the respective flank recess 20. In one of the flank recesses 20 of the respective flank strip 15f of the respective spacer element 15, the recess inlet 21 and the recess outlet 22 are both located radially inwards or both radially outwards, so that the flank recess 20 has a projection 40 at an edge section located between the recess inlet 21 and the recess outlet 22 for radial flow deflection in order to achieve uniform cooling in the flank recess 20 in the radial direction.

[0103] Fig. 9 shows an alternative cross-sectional shape of the spacer element according to the invention compared to Fig. 3.

[0104] On one narrow side of the respective spacer element 15, particularly in the central strip 15m, at least one groove 24 can be formed, extending in the axial direction and projecting, in particular, away from or towards the conductor 11 or conductor bundle 12. R. 416243-3

[0105] - 14 -

[0106] Furthermore, at least one of the two, in particular both, wing strips 15f of the respective spacer element 15 can have a curved pre-embossing 26 which extends in the axial direction and is curved towards the conductor 11 or conductor bundle 12 or away from the conductor 11 or conductor bundle 12.

Claims

R. 416243-3 15 Claims 1. Stator of an electric machine (2) with a stator shaft (3) and with a stator body (4), in particular a stator laminate stack, 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) each have a first slot base (7) facing the stator yoke (10) and a second slot base (8) opposite the first slot base (7), wherein a conductor (11) or a conductor bundle (12) comprising several conductors (11), in particular a stack of flat wire conductors, is provided in each of the stator slots (6) to form an electrical stator winding (14), wherein an electrically insulating spacer element (15) extending in the axial direction with respect to the stator shaft (3) is provided in each of the stator slots (6), which maintains a distance between the conductor (11) or conductor bundle (12) and groove walls, especially tooth flanks (5f),the respective stator groove (6) and forms at least one groove gap (16) between the groove walls, in particular tooth flanks (5f), and the conductor (11) or conductor bundle (12), which extends in the axial direction and can be permeated by a cooling fluid as a groove gap channel along a groove cooling path (17), wherein the spacer element (15) is a folded body made of insulating paper, comprising a central strip (15m) located at the first or second groove base (7, 8), on the long side edges of which a wing strip (15f) is angled, each forming a folded edge, wherein flank recesses (20) are formed in the wing strips (15f) of the respective spacer element (15) to form a groove gap channel, wherein at least in one of the two wing strips (15f) of the respective spacer element (15) at least one axial group (20p) of flank recesses arranged one behind the other in the axial direction (20) is ordered,whose flank recesses (20) are each separated from each other by a radial separating web (15r) extending in a radial direction with respect to the stator axis (3), characterized in that, - in each wing strip (15f) of the respective spacer element (15) at least one axial group (20p), in particular an axial pair, of flank recesses (20) and at least one radial separating web (15r) is formed, R. 416243-3 16 - the separating webs (15r) in both wing strips (15f) of the respective spacer element (15) form a central sleeve (15t) which is in particular completely closed or in particular has a slot (13) in particular at one of the groove bases (7,8).

2. Stator according to claim 1, characterized in that a. the respective spacer element (15) is folded from an expandable insulating paper for the expansion of the spacer element (15) to fix the stator winding (14) in the stator slot (6), or b. several laminations of the stator body (4) in the axial area of ​​the central sleeves (15t) and / or end sleeves (15s) of the spacer elements (15) are twisted around the stator axis (3) to fix the stator winding to the central sleeves (15t) and / or end sleeves (15s).

3. Stator according to one of the preceding claims, characterized in that four sleeve sections (15k) projecting radially from the central strip (15m) are provided at the ends of the respective spacer element (15), which are opposite each other in pairs and form two end sleeves (15s), each of which is fully closed or each has a slot (13), in particular at the first groove base (7).

4. Stator according to claim 3, characterized in that the respective end sleeve (15s) of the respective spacer element (15) is connected to the central sleeve (15t) via a longitudinal profile (15L) extending in an axial direction, which is arranged on a narrow side of the spacer element (15) facing in particular the central strip (15m) and / or is in particular U-shaped or strip-shaped.

5. Stator according to one of the preceding claims, characterized in that the flank recesses (20) of the respective spacer element (15) are open in a radial direction.

6. Stator according to one of claims 1 to 4, characterized in that the flank recesses (20) of the respective spacer element (15) are closed in the radial direction. R. 416243-3 17 7. Stator according to one of claims 3 to 6, characterized in that the respective end sleeve (15s) of the respective spacer element (15) is connected to the central sleeve (15t) via a longitudinal profile (15L) extending in an axial direction, which is arranged on a narrow side of the spacer element (15) facing away from the central strip (15m) and / or is in particular U-shaped.

8. Stator according to claim 7, characterized in that the end sleeves (15s) and the middle sleeve (15t) of the respective spacer element (15) are fully enclosed.

9. Stator according to one of the preceding claims, characterized in that at least one of the two radial separating webs (15r) of the central sleeve (15t) of the respective spacer element (15) is designed for guiding the flow of the cooling fluid from a recess inlet (21) to an axially spaced recess outlet (22) of the respective flank recess (20), in particular having at least one guide ramp (23) extending at an oblique angle (a) to the axial direction, and especially having two guide ramps (23) towards both flank recesses (20).

10. Stator according to one of the preceding claims, characterized in that at least one of the two radial separating webs (15r) of the central sleeve (15t) of the respective spacer element (15) has a longitudinal extension axis (27) which runs at an oblique angle (β) to the axial direction.

11. Stator according to one of the preceding claims, characterized in that several radially arranged axial groups (20p) are provided in at least one, in particular both, wing strips (15f) of the respective spacer element (15).

12. Stator according to one of the preceding claims, characterized in that at least one groove (24) is formed on a narrow side of the respective spacer element (15), in particular in the central strip (15m), which extends in the axial direction and in particular projects away from the conductor (11) or conductor bundle (12) or in particular towards the conductor (11) or conductor bundle (12). R. 416243-3 18 13. Stator according to one of the preceding claims, characterized in that at least one of the wing strips (15f) of the respective spacer element (15) has a curved pre-embossing (26) which extends in the axial direction and is curved towards the conductor (11) or conductor bundle (12) or away from the conductor (11) or conductor bundle (12).

14. Stator according to one of the preceding claims, characterized in that the respective spacer element (15) has at least one support collar (28) at an axial end, which is folded towards an outside of the spacer element (15) and is provided for axially stopping the spacer element (15) against an end face of the stator body (4).

15. Stator according to one of the preceding claims, characterized in that the respective spacer element (15) has at least one insertion collar (29) at the other end, which projects in the axial direction and facilitates the insertion of the spacer element (15) into a stator groove (6) by forming an insertion ramp.

16. Stator according to one of the preceding claims, characterized in that the ends of the two wing strips (15f) of the respective spacer element (15) facing away from the central strip (15m) lie at least partially on a narrow side of the spacer element (15) located, in particular at the first groove base (7), and in particular overlap.

17. 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).

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