DE102022130168A1 - End plate for a stator laminated core - Google Patents

Abstract

The invention relates to an end plate for a laminated core of a stator of an electrical machine, having an annular contour which extends between a laminated core side and a winding head side of the end plate, and on the laminated core side a plurality of radial guide recesses which are spaced apart from one another in the circumferential direction of the annular contour and which are each designed to guide a coolant flow from a coolant axial channel of the laminated core arranged further inside on the stator to a coolant outlet arranged further outside on the end plate.

Description

The invention relates to an end plate for a laminated core of a stator of an electrical machine and a stator for an electrical drive machine in a motor vehicle.

If the necessary cooling of the stator in an electric drive machine for a motor vehicle takes place via cooling channels close to the slot, a number of challenges arise in connection with the coolant guidance beyond the laminated core to the winding heads and with the assembly of the stator.

With regard to the coolant supply, the challenge is to ensure that the winding heads are sufficiently and evenly wetted with coolant spray. In known solutions, this is achieved using a complicated arrangement of variously punched individual sheets in the assembly of the sheet stack. Such a solution implies a massive increase in the complexity of the punching process and a corresponding increase in costs.

In terms of production, it is problematic that every winding slot in which enamelled copper wire and slot insulation paper are located must be filled with drip resin to at least a certain extent. This ensures that the conductors remain insulated from one another on the one hand and cannot become acoustically noticeable on the other. However, this drip process on the laminated core can lead to deposits of drip resin on the front side. This is problematic with the known use of additional axial coolant channels close to the winding slot (also known as near the slot) through which a coolant is supposed to flow during operation, because the deposits - or in the worst case even a drip resin seal - hinder or prevent the required circulation of the coolant to the winding heads and thus impair cooling.

Against this background, it is an object of the invention to improve cooling of the winding heads of a stator, in particular for an electric drive machine of a motor vehicle.

Each of the independent claims defines with its features an object that solves this problem. The dependent claims relate to advantageous developments of the invention.

According to one aspect, an end plate for a laminated core of a stator of an electric drive machine, in particular in a motor vehicle, is disclosed.

The end plate has a ring contour with a ring wall thickness which extends between a laminated core side - i.e. a side which is designed to face the laminated core - and a winding head side - i.e. a side which is designed to face a winding head of the stator - of the end plate.

Furthermore, the end plate has a plurality of radial guide recesses, which are spaced apart from one another in the circumferential direction, on the laminated core side of the ring wall thickness, which are each designed, in particular in cooperation with a side wall of an outer sheet of the laminated core, to guide a coolant flow from a coolant axial channel of the laminated core arranged radially further inside on the stator to a coolant outlet arranged radially further outside on the end plate and directed towards the winding head side.

By guiding the coolant radially outwards on the end plate, wetting of the entire winding head, in particular from the radial outside, can be ensured even in the case of axial coolant channels close to the groove, which can be arranged, for example, at an overlapping radial position with the winding grooves

In addition, by designing the coolant outlets on a separately designed end plate (instead of on the laminated core itself), the risk of accidentally clogging the coolant outlets with the drip resin used to fill the winding slots away from the respective winding is reduced.

Furthermore, the design of coolant outlet nozzles in the sheets of the laminated core itself has a negative effect on the electromagnetic properties of the laminated core, so that their formation on the end plate instead has a beneficial effect.

According to a further aspect, a stator for an electric drive machine in a motor vehicle is disclosed. The stator has a laminated core with a plurality of winding slots and a plurality of coolant axial channels, which are arranged in the circumferential direction between the winding slots. On both sides of the laminated core, the stator has a stator winding head, starting from the respective axial ends of the winding slots. On both sides of the laminated core, an end plate is arranged in accordance with an embodiment of the invention.

The invention is based, among other things, on the consideration that the front openings of the cooling channels near the groove look out of the laminated core or are aligned in a number of ways in an unfavourable way with regard to their position. The representation of spray holes in the outer sheets of the laminated core is very complex and cannot be represented electromagnetically without losses. As described at the beginning, the automated trickling process is also difficult to carry out in such a way that the openings are reliably glued. Spray nozzles punched into the laminated core have a negative electromagnetic effect and thus cause a deterioration in the active length. This results in a deterioration in the performance-related relative weight of the stator.

The invention is based, among other things, on the idea of providing an end plate on both sides of the laminated core, which is designed, for example, as a cooling medium transfer plate.

The end plate solves the problems described for stators cooled with oil close to the groove by directing the cooling medium flow radially outwards to a larger radius, for example to be transferred to a separate winding head cooling module or sprayed out. This also prevents the openings of the axial channels from becoming blocked when the stator is dripped and any masking required to protect the openings can be applied more easily. This is because the openings of the channels are then no longer in the immediate vicinity of the drip resin nozzle.

Steel, for example, can be considered as a material for the transfer sheet because, like the sheets of the laminated core, it can be attached to the laminated core with baking varnish. In addition, a step in the housing can ensure that the transfer sheet is pressed onto the stator. The end plate is then designed in such a way that there is no deterioration in the air and creepage distance between the copper (Cu) conductors of the winding heads and the laminated core, so that the winding head dimensions do not deteriorate despite the installation of the end plate.

Alternatively, a dielectric plastic material (e.g. PA6 or PA12) can be used as a material, for example if it is not possible to package the transfer contour with the rest of the laminated core at the same time. Such an end plate could be made in one piece if glued before stator production, or in several parts if later screwed onto the laminated core after stator production, in order to take into account the undercut of the radial oil channels behind the conductors. A plastic end plate can then have a high-temperature-resistant hard component for the transfer geometry and a high-temperature-resistant soft component for the sealing surface to the laminated core, and can be manufactured using a multi-component injection molding process, for example. It can be screwed on, for example, using countersunk screws that do not protrude in the contour.

According to one embodiment, the radial guide recesses are spaced apart from one another in accordance with a positioning of the coolant axial channels, in particular evenly. The coolant can thus be guided axially outward directly from an axial end of each coolant axial channel.

According to one embodiment, each radial guide recess or two or more radial guide recesses are assigned a coolant outlet. In the first alternative embodiment, the coolant that has flowed through a specific coolant axial channel can cool the assigned part of the winding head at the corresponding handling position. In the second alternative embodiment, the coolant can still be sprayed out effectively even under unfavorable pressure conditions because fewer outlets have to be served. With a separate coolant outlet for each coolant axial channel, the pump pressure required would be very high, which would reduce the efficiency of the machine. If the pressure were kept the same, only a trickle would come out of the holes and end up in the air gap. For this reason, it is necessary to reduce the number of openings. To make matters worse, the smaller the holes are punched, the shorter the service life of the punching tools. Many small holes have to be weighed against fewer, larger holes.

According to one embodiment, the coolant outlet is designed as a spray nozzle, which is particularly designed to wet the winding heads with coolant and/or is directed towards the winding heads. In this embodiment, the winding head can be sufficiently sprayed or wetted with coolant due to the suitable design of the coolant outlet(s). The oil channels on the laminated core side can either be led into a single collection volume or into several collection volumes (number less than the number of oil channels).

According to an alternative embodiment, the coolant outlet is designed as a coolant interface to a winding head cooling module, which is designed for the appropriate distribution of the coolant to the winding head. In this embodiment, a further coolant guide is provided downstream of the end plate, and in particular downstream of the coolant outlets, which is designed in such a way that the title head can be optimally wetted with coolant or as required.

According to one embodiment, a coolant outlet arranged further down in the installation position of the stator is designed with a smaller cross-section than a coolant outlet arranged further up. Coolant outlet. This can compensate for the effect of gravity in the distribution of the coolant to the individual coolant outlets and/or the fact that upper parts of the winding head are cooled exclusively by the coolant sprayed there, while our parts of the winding head can also be cooled by the coolant that runs off the upper parts.

According to one embodiment, the end plate comprises a steel material. In particular, it is made of a steel material. In particular, the end plate comprises a dielectric layer that completely surrounds the contour of the end plate or only on the winding head side.

According to an alternative embodiment, the end plate is made of at least one plastic material, in particular a dielectric one. This means that the end plate can easily be arranged axially between the laminated core and the winding head, in particular on the teeth between the slots, without causing problems with clearance and creepage distances. An axial extension of the stator is not necessary for this. With a suitable design, the end plate can then even contribute to electrical insulation of the laminated core and the center head from one another, so that an axial shortening of the stator may even be an option.

In particular, the end plate is designed as a multi-component component with a hard component to form the radial guide recesses and the ring contour, and with a soft component to form a sealing surface for the laminated core. In this way, an end plate can be manufactured in a known, and therefore simple and inexpensive, manner that meets both the structural requirements and the sealing requirements for the coolant guide.

According to one embodiment, several seals are provided, particularly as a soft component, which are spaced apart from one another in the circumferential direction of the ring contour and are formed around one or more radial guide recesses. This makes it easier to form a reliable seal than with a single seal running along the entire circumference of the ring contour.

According to one embodiment, at least one recess is arranged in the circumferential direction between two radial guide recesses, so that the radial guide recesses are delimited by a remaining web, along the extension of which the end plate has the full ring wall thickness. The end plate can thus be designed with the lowest possible dead weight.

According to one embodiment, the end plate is formed from two or more, in particular six, in particular identically formed, peripheral parts, which can be assembled in such a way that they form an end plate running in the circumferential direction. An end plate composed of several components can be noted more easily - especially after the windings have been inserted into the winding slots. This ensures optimized cooling of both winding heads and enables undercut positioning of the component between the conductor tracks, for example after the windings have been inserted.

According to one embodiment, the end plates are baked to the laminated core using a baking varnish, either completely or in a way that is sufficiently coolant-tight for the specific application, particularly in a baking process that is carried out together with the baking of the sheets of the laminated core. Additionally or alternatively, the dripping process can be designed in such a way that the dripping resin itself also contributes to the tightness of the system. The capillary effect of the minimally spaced individual sheets can be exploited, since the dripping resin is used in the positions required for this anyway due to the system. This makes the stator particularly easy to manufacture - particularly with very few steps.

According to an alternative embodiment, the radial guide recesses on the laminated core side of the end plates are delimited with an elastic plastic component and clamped, in particular screwed, to the laminated core in such a way that the respective radial guide recess and the associated side of the laminated core delimit a radial guide in a coolant-tight manner. In this way, the end plate can be made entirely from a dialectical plastic - for example as a 2-component component - so that the stator can be designed to be optimized electromagnetically and, if necessary, also in terms of its axial dimension.

One way to assemble stators is using a hairpin twist method.

1. (i) Hairpinherstellung: dabei wird der typischerweise bereits lackierte Kupferflachdraht kontinuierlich abgewickelt und gerichtet, eventuell mehrstufig, um Restkrümmungen und Eigenspannungen zu reduzieren. Da normalerweise in einem späteren Prozessschritt die Kupferenden der einzelnen Hairpins miteinander verschweißt werden, kann nach dem Richtvorgang eine partielle Abisolation des Hairpin-Drahts erfolgen, entweden laserbasierte oder mechanisch. In Abhängigkeit von der gewünschten Hairpin-Geometrie wird der Hairpin-Draht mithilfe eines Schneidprozesses abgelängt und gebogen. Die Reihenfolge von Biege- und Ablängoperation kann hierbei variieren. Hairpins werden in die gewünschte, ggf. dreidimensionale, Geometrie umgeformt. Dieser Prozess erfolgt entweder einstufig mithilfe spezieller CNC-Biegeanlagen oder mehrstufig mit Gesenkbiegen und Schwenkbiegen.
2. (ii) Montage und Twisten: da eine Direktmontage der Hairpins in das Blechpaket durch Überdeckungen der Wickelkopfgeometrie limitiert ist und ein prozesssicheres Einstecken in die Statorbaugruppe gewährleistet sein muss, werden die Hairpins meist in einer sogenannten Montagesonne vormontiert. In Abhängigkeit des Wickelschemas erfolgt die Anordnung der einzelnen Pins in der Vormontage. Ein Hairpin-Stator verfügt typischerweise über wenigstens drei, meist bis zu 21 oder mehr, verschiedene Hairpin-Geometrien. Parallel zur Vormontage wird in die Statornuten Isolationspapier eingeführt. Dies dient der Trennung von Wicklungssystem und Erdpotential des Blechpakets.

A hairpin twist process (also called hairpin process chain) is an indirect process for winding production, especially in stators of drive machines. Due to the massive conductor cross-section, the geometry of the hairpins is adjusted before the assembly process for inserting the plug-in coils into the laminated core. In contrast, In addition to conventional stator production (with its winding-based assembly processes), a forming-based assembly process is used. A typical hairpin process chain usually has several higher-level process steps:

1. (i) Hairpin production: the flat copper wire, which is typically already painted, is continuously unwound and straightened, possibly in several stages, to reduce residual curvature and residual stresses. Since the copper ends of the individual hairpins are normally welded together in a later process step, the hairpin wire can be partially stripped after the straightening process, either laser-based or mechanically. Depending on the desired hairpin geometry, the hairpin wire is cut to length and bent using a cutting process. The order of bending and cutting operations can vary. Hairpins are formed into the desired, possibly three-dimensional, geometry. This process is carried out either in one stage using special CNC bending machines or in several stages using die bending and swivel bending.
2. (ii) Assembly and twisting: since direct assembly of the hairpins into the laminated core is limited by overlaps of the winding head geometry and reliable insertion into the stator assembly must be ensured, the hairpins are usually pre-assembled in a so-called assembly sun. The arrangement of the individual pins takes place in the pre-assembly depending on the winding pattern. A hairpin stator typically has at least three, usually up to 21 or more, different hairpin geometries. In parallel with the pre-assembly, insulation paper is inserted into the stator slots. This serves to separate the winding system and the ground potential of the laminated core.

After the hairpins have been fully pre-assembled, the entire hairpin basket (also called the hairpin nest) is inserted axially into the sheet stack using a multiple gripping system. Due to very small tolerances, hairpins are sometimes chamfered during the cutting process - positioning holders are also used if necessary. Depending on the winding pattern, the hairpin ends are interlaced against each other in each layer. This process is also known as the twist process. In addition to the rotational movement, the assembly tool also moves in an axial direction. To ensure axial access for a setting tool, the hairpin ends must be radially exposed in a preparatory step. The crucial point in the subsequent production step of twisting is when the wires begin to bend axially from the face of the sheet stack. If the bending is done too early, the slot insulation paper can tear, the LuK distances are not met, and damage can be expected. In order to initiate the bending radius at the correct point, the collar support fingers are advanced radially and the bend is initiated at their shoulder.

Therefore, when twisting the hairpins, so-called collar support fingers are used, which ensure that the correct twist radius is introduced at the correct location on each hairpin radially between the conductors. These support fingers are designed differently depending on the system supplier, but in use they combine the radial feed and the axial support of the bending forces in the sheet metal package.

(iii) Welding and wiring: adjacent hairpin ends are now contacted with each other according to the circuit diagram. A laser welding process is usually used for this, which melts the hairpin ends and connects them together in a material-tight manner. During the welding process, attention should be paid to homogeneous weld seam geometries and to minimizing the thermal input into the hairpins. In order to be able to pursue reproducible welding strategies, a particular challenge lies in creating a consistent initial welding situation. Height and lateral offset of the hairpin ends to each other can cause welding errors. To counteract this, correction processes are sometimes used depending on the tolerances of upstream processes.

(iv) Rendering of a hairpin stator: to realize phase jumps and the winding connection, interconnection elements such as contact rings, plug-in bridges, connection terminals or jumpers are then connected to the welded hairpin ends. This process is usually also carried out using a laser welding process.

Secondary insulation: after wiring, the final step is to insulate the welded copper ends and, if necessary, impregnate the stator. The copper ends are usually insulated by powder coating or the application of casting resins, for example polyurethane-based. For casting, impregnation, trickling or full casting processes are typically used. Impregnation can be carried out in a similar way to impregnation processes in the manufacture of conventionally wound stators. Impregnation serves to protect against thermal, electrical, ambient and mechanical influences. Dipping or trickling processes are also usually used for impregnation.

In hairpin twist processes, frontal elevations on the sheet stack, which extend beyond the magnetic active length, the handling ability in production and hinder the hairpin twist process.

According to one embodiment, the collar support fingers are formed on the end plate, in particular integrally therewith, and solve the manufacturing problem during twisting by means of a geometry analogous to the collar support fingers, contained on the front side of the laminated core, for example deep-drawn, which then remains on the stator.

The coolant-carrying part is manufactured using a 2K injection molding process so that the twisting results in axial compression with the sheet metal package, which ensures that the coolant is tight. The challenge in designing the seal is to take into account the springback of the wires after twisting and the thermal expansion of the various materials used.

• Die Geometrie ist gemäß einer Ausführung so ausgeführt, dass es zu keiner Verschlechterung in der Luft- und Kriechstrecke zwischen dem Cu-Leiter der Wicklung einerseits und andererseits dem Blechpaket kommt, wodurch sich die Wickelkopfabmessungen nicht verschlechtern.

According to one design, the coolant-carrying part of the geometry is designed in such a way that the ducts on the laminated core side are brought together in such a way that they can be guided radially further outwards towards the winding head at a suitable position:

• According to one embodiment, the geometry is designed in such a way that there is no deterioration in the clearance and creepage distance between the Cu conductor of the winding on the one hand and the laminated core on the other hand, which means that the winding head dimensions do not deteriorate.

According to one embodiment, the end plate has a collar support finger on a circumferential region, in particular on a circumferential position, of one, several or all of the radial guide recesses, which extends radially inwards, in particular starting from the ring contour, in particular further than a radial position of one or more coolant axial channels. In other words, according to one embodiment, the end plate has a collar support finger on a circumferential position of each winding slot, which extends radially along part or all of a radial extension of the winding slots of the stator, in particular starting from the ring contour. When twisting the hairpins, collar support fingers are used, which ensure radially between the conductors that the correct twist radius is introduced at the correct location of each hairpin.

According to one design, the collar support finger(s) is/are made from the material of a hard component of a 2-component injection-molded component. The end plate is thus manufactured in such a way that the twisting results in axial compression on both sides with the sheet metal package, which ensures oil tightness. The hairpins are pulled slightly towards the switching ring side during the twisting process, which is why the A side is constricted. Therefore, different forms of the collar support finger contour are provided on the star ring on the A and B sides.

The A-side contour has a shape that already takes into account the machine forming of the hairpin roofs, the B-side contour takes into account the twisting process.

According to one embodiment, the collar support finger(s) is/are arranged within an axial area of the ring wall thickness. The collar support fingers integrated into the geometry solve the manufacturing problem during twisting by means of a geometry analogous to the collar support fingers, which then remains on the stator.

According to one embodiment, the collar support finger(s) has/have, in particular each, a support projection which extends on the winding head side with respect to a central axis of the circular contour of the end plate beyond the axial extent of the ring contour. In this way, the hairpins can be twisted at a predetermined distance from the laminated core, in particular without damaging the slot insulation paper.

According to one embodiment, the support projection has a rounded roof-like support surface, which in particular runs radially and/or covers part of a fictitious plane of the ring contour. In this way, the hairpins can be bent on the support surface and/or supported after bending.

• 1 zeigt einen Stator mit zwei Endscheiben gemäß einer ersten beispielhaften Ausführung der Erfindung.
• 2 zeigt einen Ausschnitt des Stators der 1.
• 3 zeigt einen teilweise geschnittenen Ausschnitt einer der Endscheiben des Stators der 1.
• 4 zeigt eine Schnittansicht des Stators der 1.
• 5 zeigt eine Ansicht des Stator der 1 ohne die Wicklungen.
• 6 zeigt in 6A die Wickelkopfseite und in 6B die Blechpaketseite einer der Endscheiben des Stators der 1.
• 7 zeigt einen Ausschnitt einer alternativ gemäß einer zweiten beispielhaften Ausführung im Stator der 1 einsetzbaren Endscheibe mit einer Mehrzahl von längeren Kragenstützfingern sowie einer als Elastomerdichtung ausgebildeten Umlaufdichtung.
• 8 zeigt in 8A die Blechpaketseite und in 8B die Wickelkopfseite der alternativen Endscheibe aus 7.
• 9 zeigt einen Stator mit zwei unterschiedlichen Endscheiben gemäß einer dritten beispielhaften Ausführung der Erfindung (an der „A“-Seite der elektrischen Antriebsmaschine) bzw. einer vierten beispielhaften Ausführung der Erfindung (an der „B“-Seite der elektrischen Antriebsmaschine) in einer Seitenansicht.
• 10 zeigt den Stator der 9 in einer Schrägansicht auf die „B“-Seite.
• 11 zeigt die Endscheibe gemäß der dritten beispielhaften Ausführung der Erfindung (an der „A“-Seite der elektrischen Antriebsmaschine) in einer schrägen Frontalansicht.
• 12 zeigt die Endscheibe gemäß der dritten beispielhaften Ausführung der Erfindung in einer Frontalansicht.
• Fig: 13 a/b verdeutlicht den Unterschied in den Stützvorsprüngen der Endscheibe gemäß der dritten beispielhaften Ausführung und der vierten beispielhaften Ausführung
• 14 zeigt die Endscheibe gemäß der dritten beispielhaften Ausführung der Erfindung in einer Rückansicht auf die Radialführungsausnehmungen und auf mehrere als Elastomerdichtung ausgebildete Einzeldichtungen von Radialführungsausnehmungen.
• 15 a/b zeigt in unterschiedlichen Ansichten eine für sich abgedichtete radial Führung Ausnehmung der Endscheibe aus 14.

Further advantages and possible applications of the invention will become apparent from the following description in conjunction with the figures:

• 1 shows a stator with two end plates according to a first exemplary embodiment of the invention.
• 2 shows a section of the stator of the 1 .
• 3 shows a partially cut section of one of the end plates of the stator of the 1 .
• 4 shows a sectional view of the stator of the 1 .
• 5 shows a view of the stator of the 1 without the windings.
• 6 shows in 6A the winding head side and in 6B the laminated core side of one of the end plates of the stator of the 1 .
• 7 shows a section of an alternative according to a second exemplary embodiment in the stator of the 1 insertable end plate with a plurality of longer collar support fingers and a circumferential seal designed as an elastomer seal.
• 8th shows in 8A the sheet metal package side and in 8B the winding head side of the alternative end plate 7 .
• 9 shows a stator with two different end plates according to a third exemplary embodiment of the invention (on the “A” side of the electric drive machine) or a fourth exemplary embodiment of the invention (on the “B” side of the electric drive machine) in a side view.
• 10 shows the stator of the 9 in an oblique view of the “B” side.
• 11 shows the end plate according to the third exemplary embodiment of the invention (on the “A” side of the electric drive machine) in an oblique frontal view.
• 12 shows the end plate according to the third exemplary embodiment of the invention in a front view.
• Fig: 13 a/b illustrates the difference in the support projections of the end plate according to the third exemplary embodiment and the fourth exemplary embodiment
• 14 shows the end plate according to the third exemplary embodiment of the invention in a rear view of the radial guide recesses and of several individual seals of radial guide recesses designed as elastomer seals.
• 15 a /b shows in different views a sealed radial guide recess of the end plate made of 14 .

1 shows a stator 1 for an electric drive machine in a motor vehicle. The stator 1 has a laminated core 2 with several winding slots 4 and several coolant axial channels 6, which are arranged in the circumferential direction U between the winding slots 4. On both sides of the laminated core 2, the stator 1 has a stator winding head 8.1 and 8.2, respectively, starting from the respective axial ends of the winding slots. On both sides of the laminated core 2, an end plate 10 is arranged in accordance with an embodiment of the invention.

Each of the two end disks 10 has a ring contour 12 with a ring wall thickness X_R, which extends between a laminated core side P and a winding head side D of the end disk 10.

Furthermore, the end plate 10 has a plurality of radial guide recesses 14 on the laminated core side P, which are spaced apart from one another in the circumferential direction U and which are each designed, in cooperation with a side wall of an outer sheet of the laminated core 2, to guide a coolant flow F from a coolant axial channel 16 of the laminated core 2, arranged further inside on the stator 1 in the radial direction R, to a coolant outlet 18 arranged radially further outside on the end plate 10 and directed towards the winding head side D and thus towards one of the stator winding heads 8.1 or 8.2.

The geometry and function of the end plate 10 in general and in particular of the radial guide recesses 14 is particularly 3 and 4 and 6B clearly visible.

By guiding the coolant radially outwards on the end plate, wetting of the entire winding head from the radial outside can be ensured even in the case of axial coolant channels close to the groove.

The enlarged section of the 1 in 2 It can be seen that in the exemplary embodiment the radial guide recesses 14 begin radially so far inward that their radially inner ends enable an alignment and/or fixing of the end plate 10 in the circumferential direction U to be determined.

In the example of 1 to 6 Thus, areas of the end plate are already formed which extend radially inwards. Nevertheless, these areas are not yet formed so far radially inwards that they can be used as collar support fingers 120 (cf. 7 and 8th ) in the hairpin twist process. Another exemplary embodiment of an end plate 110 with such collar support fingers 120 is shown in the 7 and 8th shown and explained in the corresponding figure descriptions.

• Die Radialführungsausnehmungen 14 sind an den Umfangspositionen der Kühlmittelaxialkanäle 16 angeordnet, und dementsprechend in Umfangsrichtung gleichmäßig voneinander beabstandet. So kann von einem axialen Ende eines jeden Kühlmittelaxialkanals unmittelbar das Kühlmittel axial außen geführt werden.

The various views of the first exemplary embodiment of the invention in 3 , 4 , 5 and 6 Further features and advantages can be found here:

• The radial guide recesses 14 are arranged at the circumferential positions of the coolant axial channels 16 and are accordingly evenly spaced from one another in the circumferential direction. The coolant can thus be guided axially outwards directly from one axial end of each coolant axial channel.

In addition, each radial guide recess 14 is assigned a coolant outlet 18. Therefore, the coolant that has flowed through a specific coolant axial channel can cool the associated part of the winding head at the corresponding handling position.

In the exemplary embodiment, each of the coolant outlets 18 is designed to wet the winding heads with coolant and is directed towards the winding heads so that the coolant can spray out there.

In the exemplary embodiment, the end plate 10 is designed as a dielectric plastic component, manufactured using a 2-component injection molding process. A hard component made of a heat-resistant plastic is provided, which, among other things, together with a side surface of the outermost sheet of the laminated core 2, delimits the radial guide recesses 14. In addition, a soft or elastic component made of another heat-resistant plastic is provided, which seals the contact surfaces between the end plate 10 and the laminated core 2.

This means that the end plate can be easily arranged axially between the laminated core 2 and the winding head 8 without causing problems with clearance and creepage distances. An axial extension of the stator 1 is not necessary for this.

In 7 and 8th In different views, an end plate 110 is shown, which additionally has fully formed collar support fingers 120. In addition, the geometry of the radial guide recesses 114 and the coolant outlets 118 is different from the other embodiment of the 1 to 6 , but without any fundamental functional differences between the two versions.

A collar support finger 120 is provided on a circumferential area of each of the radial guide recesses 114, which extends radially inward from the ring contour 12 further than the winding slots 4 of the stator 1. The circumferential extension of the collar support fingers is designed such that each finger 120 precisely covers the circumferential space between two winding slots 4, so that the collar support finger 120 can optimally serve to support the hairpin curvature.

The collar support fingers 120 are formed with the material of a hard component of a 2-component injection-molded component and are manufactured in such a way that the twisting results in axial compression with the laminated core, which contributes to the coolant tightness. In the exemplary embodiment shown, a single circumferential seal 115 is provided on the ring contour 12 radially inside the radial guide recesses 114 for the sealing effect. The circumferential seal 115 is formed with the (in particular elastomer) material of a soft component of the 2-component injection-molded component.

In 9 a stator 201 is shown with a first end plate 210 according to a third exemplary embodiment of the invention on the "A" side of the electric drive machine and a second end plate 310 according to a fourth exemplary embodiment of the invention on the "B" side of the electric drive machine.

The collar support fingers 220 and 320 of the two end disks 210 and 310 each have a support projection 222 and 322, respectively, which extends on the winding head side D beyond the axial extent of the ring contour 12. The support projections 222 and 322 each have a rounded, roof-like support surface 224 and 226, respectively.

• Die Hairpins werden während des Twistprozesses noch etwas in Richtung Schaltringseite gezogen, weshalb sich die „A“-Seite einschnürt. Daher sind „A“- und „B“-seitig auch unterschiedliche Ausprägungen der Kragenstützfingerkontur am Sternring vorgesehen.

The end plates 210 and 310 differ in the longitudinal extension (along the longitudinal axis L) of a respective support projection 222 or 322 and the design of a respective associated support surface 224 or 324. The differences in design and function are particularly evident in the 13 refer to:

• During the twisting process, the hairpins are pulled slightly towards the switching ring side, which is why the "A" side is constricted. Therefore, different forms of the collar support finger contour on the star ring are provided on the "A" and "B" sides.

The "A"-side contour has a shape that already takes into account the machine-forming of the hairpin roofs; therefore, the support projections 222 are axially longer with an axial extension L_A and the support surfaces 224 are rounded like a roof so that the roofs can form and/or rest on them. The "B"-side contour takes into account the twisting process, so that the support projections 322 are axially shorter with an axial extension L_B.

In 10 is the stator 201 of the 9 shown in an oblique view of the "B" side. In this view it is clear that the coolant outlets 318 of the end plate 310 (and also the coolant outlets 218 of the end plate 210 on the "A" side, which are not visible here) are designed as circular recesses - and relatively small in order to support a high injection pressure.

In 11 the end plate 210 on the "A" side of the electric drive machine is shown in an oblique frontal view. In particular, the collar support fingers 220 with the support projections 222 and the shape of the support surfaces 224 are clearly visible.

In 12 the end plate 210 is shown in a frontal view. In this view, the radially outer wave shape of the ring contour 212 is particularly clear, which serves to save material at the circumferential positions where no coolant guide is required.

In 14 the end plate 210 is shown in a rear view so that the radial guide recesses 214 can be seen. Each of the radial guide recesses 214, which are spaced apart from one another in the circumferential direction, is designed as a radial guide recess 214 with a circumferential individual seal 215 for guiding coolant from two adjacent coolant axial channels to the coolant outlet 218, wherein the respective individual seal 215 is designed only to seal this one radial guide recess 214 and is made of a softer sealing plastic (for example in the sense of a 2K component; in particular of an elastomer material).

In 15 a /b shows in different views a sealed radial guide recess 214 of the end plate 210 made of 14 shown enlarged.

LIST OF REFERENCE SYMBOLS

1, 201

stator

2

Sheet metal package

4

Winding slots

6

Coolant axial channels

8.1, 8.2

Stator winding head

10, 110, 210, 310

End plate

12, 212

Ring contour

14, 114, 214

Radial guide recesses

16

Coolant axial channel

18, 118, 218, 318

Coolant outlet

115

Circulating seal

120, 220, 320

Collar support fingers

215

Single seal

222, 322

Support projection

224, 324

Support surface

A

A-side of the electric drive machine

B

B-side of the electric drive machine

D

Winding head side

F

Coolant foot

P

Sheet metal package side

R

Radial direction

U

Circumferential direction

X_R

Ring wall thickness

L_A, L_B

Axial extensions

Claims (18)

End plate (10, 110, 210, 310) for a laminated core (2) of a stator (1, 201) of an electrical machine, comprising - an annular contour (12) which extends between a laminated core side (P) and a winding head side (D) of the end plate, - on the laminated core side a plurality of radial guide recesses (14, 114, 214) which are spaced apart from one another in the circumferential direction (U) of the annular contour and which are each designed to guide a coolant flow (F) from a coolant axial channel (16) of the laminated core arranged further inside on the stator in the radial direction (R) to a coolant outlet (18, 118, 218, 318) arranged radially further outside on the end plate to the winding head side (D). End plate according to Claim 1 , characterized in that the radial guide recesses are spaced from one another in accordance with a positioning of the coolant axial channels, in particular uniformly. End plate according to one of the preceding claims, characterized in that each radial guide recess or two or more radial guide recesses are jointly assigned a coolant outlet. End plate according to one of the preceding claims, characterized in that the coolant outlet is designed as a spray nozzle. End plate according to one of the preceding claims, characterized in that a coolant outlet arranged further down is designed with a smaller cross-section than a coolant outlet arranged further up. End plate according to one of the preceding claims, comprising a steel material and/or at least one plastic material. End plate according to one of the preceding claims, designed as a multi-component component with a hard component for forming the radial guide recesses and the ring contour, and with one or more soft components for forming a seal (115, 215), in particular with a sealing surface, for the laminated core. End plate according to one of the preceding claims, characterized in that a plurality of seals (215) are provided which are spaced apart from one another in the circumferential direction of the ring contour and are formed circumferentially around one or more radial guide recesses. End plate according to one of the preceding claims, formed from two or more, in particular six, in particular identically formed, peripheral parts. End plate according to one of the preceding claims, characterized by a collar support finger (120, 220, 320) which extends radially inward on a peripheral region of one, several or all radial guide recesses. End plate according to one of the preceding claims, characterized by a respective collar support finger which extends radially along a part or all of a radial extension of the winding slots (4) of the stator, at a circumferential position of each winding slot. End plate according to one of the preceding Claims 10 or 11 , characterized in that the collar support finger(s) are formed with the material of a hard component of a 2-component injection-molded component. End plate according to one of the preceding Claims 10 until 12 , characterized in that the collar support finger(s) are arranged within an axial region (X_R) of the radial guide recesses (14). End plate according to one of the preceding Claims 10 until 13 , characterized in that the collar support finger(s) have a support projection (222, 322) which extends on the winding head side beyond the axial extent of the ring contour. End plate according to Claim 14 , characterized in that the support projection has a rounded roof-like support surface (224, 324). Stator (1, 201) for an electric drive machine in a motor vehicle, comprising - a laminated core (2) with a plurality of winding slots (4) and coolant axial channels (16) which are arranged in the circumferential direction (U) between the winding slots, - a stator winding head (8.1, 8.2) on both sides of the laminated core, starting from the respective axial ends of the winding slots, characterized by an end disk (10, 110, 210, 310) according to one of the preceding claims on both sides of the laminated core. Stator according to Claim 16 , characterized in that the end plates are baked to the laminated core in a coolant-tight manner by means of a baking varnish. Stator according to Claim 16 , characterized in that the radial guide recesses on the laminated core side (P) of the end plates are delimited with an elastic plastic component and clamped to the laminated core.

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