Cooling channels for motor winding heads

Abstract

The present disclosure relates to a cooling channel for a motor winding end, wherein the cooling channel is designed with at least one inlet (25) and at least one outlet (26) for guiding a cooling fluid, and is designed to be annular for being arranged around the winding end, wherein the cooling channel has a plurality of partitions (31; 32) which are arranged so as to form parallel sub-channels between the at least one inlet (25) and the at least one outlet (26), wherein with respect to the cooling channel, the inlet (25) is arranged radially outside, and the outlet (26) is arranged radially inside, and vice versa.

Description

Technical Field

[0001] The present disclosure relates to a cooling channel for an over-winding of an electric machine and a stator comprising such a cooling channel. Background Art

[0002] The term "electric machine" is mainly understood to mean an electric motor or generator comprising a stator and a rotor, wherein the rotor is rotatably supported relative to the stator around a common central axis. The stator comprises a stator laminated core and a current-carrying winding. The winding is preferably arranged in grooves of the stator laminated core, which are distributed on the circumference and extend in the axial direction. The winding forms a plurality of coils / half coils, wherein the coil / half coil comprises two conductive sections extending in different grooves and two / one connecting sections connecting these conductive sections at the end side of the stator laminated core. Only the winding portion extending axially in the groove affects the torque magnitude; it is also referred to as the effective length. In contrast, the winding portion that electrically connects the effective length of the front end of the laminated core has no effect on the torque magnitude; this portion axially located outside the laminated core is also referred to as the winding end. The winding end can therefore be regarded as the portion of the winding that extends axially out of the stator laminated core.

[0003] A plurality of conductor sections can be placed in the recess (multilayer system).

[0004] As the temperature rises, the efficiency of electric machines, in particular traction motors of electric vehicles, decreases, so as is known, the electric machines are cooled by means of a cooling fluid. This is achieved, for example, by cooling sleeves / cooling channels or cooling jackets through which water flows, which indirectly cool the stator or its stator casing. Indirect cooling means that the cooling fluid is not in direct contact with the heat source. In order to increase the efficiency, it is also known to directly cool the winding heads. Dielectric oil is usually used for this, which is pumped through the winding heads.

[0005] US 2017 310 189 describes a winding end cooling device in the form of a cooling cap for an electric motor.

[0006] DE 10 2015 220 112 A1 describes a covering unit for an overwinding of an electric machine, wherein the covering unit has cooling channels extending in the circumferential direction of the stator.

[0007] Furthermore, it is known that the winding can also be assembled from strip conductors which can be inserted or embedded in grooves of the laminated core. The strip conductors are connected in pairs to form half coils. This can be done directly, for example by bending the strip conductors together and directly welding them, or indirectly, for example by connecting pieces (synonymous: end connectors) that bridge the gap between two strip conductors.

[0008] The strip conductor can be one-piece (solid conductor) or multi-piece (wire strands) and can be designed, for example, in the form of hairpins (hairpin conductors, Hairpins) or I-shaped (I-shaped pin conductors, I-Pins). The strip conductor can also be configured specifically as a molded and twisted wire strand.

[0009] By means of winding ends, segmented conductors or strip conductors arranged inside the stator are interconnected with one another at their ends in a predetermined pattern.

[0010] For directly interconnected strip conductors, such as hairpin windings, the winding ends can be cooled without any problems by adding cooling hoods. For winding ends equipped with interconnecting tabs, direct cooling is difficult to implement, since the individual interconnecting tabs must be held by means of retaining elements. In particular, for mobile applications, where strong vibrations occur, the secure holding of the interconnecting tabs is endangered. Therefore, interconnecting tabs for mobile applications are usually placed directly on top of each other and cast in resin. This ensures that the electrical contact is not interrupted due to fatigue fractures at the welding points, for example caused by vibrations, but it brings disadvantages in cooling the winding ends. Summary of the invention

[0011] It is therefore an object of the present disclosure to provide direct and improved cooling of an electric machine or its winding overhangs, in particular winding overhangs equipped with interconnecting webs.

[0012] To this end, according to the present disclosure, a cooling channel according to the present invention is pre-set. Specifically, a cooling channel for a winding end of an electric machine is provided, wherein the cooling channel is designed with at least one inlet and at least one outlet for guiding a cooling fluid, and is designed to be annular for being arranged around the winding end. The cooling channel has a plurality of baffles, which are arranged so that parallel sub-channels are formed between at least one inlet and at least one outlet, wherein the inlet is arranged radially outside and the outlet is arranged radially inside with reference to the cooling channel, or the inlet is arranged radially inside and the outlet is arranged radially outside. The advantage of this is that a defined channel is formed by means of the baffles and the flow of the cooling fluid thus describes a defined path. It is thereby ensured that all segmented conductors are cooled, preferably all segmented conductors are cooled to the same extent, and the efficiency of the electric machine is thereby improved. Hot spots caused by uneven distribution of the cooling medium can be avoided or reduced. Similarly, the defined cooling channel allows a technically advantageous design of the flow. This can affect, for example, the reduction or increase of the vortex of the cooling flow, and / or the decrease or increase of the cooling flow rate, and / or the reduction or increase of the cooling flow rate. This makes it possible to improve the cooling of the winding head.

[0013] Parallel sub-channels should be understood as parallel circuits of fluids rather than geometrical parallelism of the sub-channels.

[0014] The spacers also allow or are preferably designed to serve as a fixation or retention of the interconnecting plates of the winding ends. Here, one or more interconnecting plates are arranged or retained in a predetermined position between the spacers and prevented from sliding or displacement. This ensures the electrical contact between the interconnecting plates and the strip conductors of the stator and prevents interruptions, for example under vibrations.

[0015] The fluid flow preferably flows from the radial outside to the radial inside. Thus, the fluid outlet can optionally be integrated with a cooling outlet of a hollow rotor shaft through which the cooling fluid flows.

[0016] Preferably, the inlet and / or outlet are each designed as an annular gap, wherein the inlet and outlet are separated from each other by an annular covering section of the cooling channel. The advantage of this preferred embodiment is that a uniform and constant inflow and outflow of cooling fluid for the winding head can be achieved.

[0017] Preferably, at least a portion of the plurality of webs are arranged radially and form radial webs. Here, the webs form a plane parallel to the central axis of the stator. This has the advantage that the interconnecting webs can be separated individually and held securely. This is particularly the case if the interconnecting webs are formed by an arc and two radial webs, and the webs are respectively arranged between two webs.

[0018] It is also advantageous if at least a portion of the plurality of partitions is designed as an arc and is arranged concentrically with one another, in particular in groups. This is particularly advantageous for the interconnecting sheets if they have interconnecting arcs or are designed as arcs. Thus, the interconnecting sheets can be arranged and held in a predetermined position.

[0019] Furthermore, advantageously, at least a portion of the plurality of partitions has and / or forms insulating rings which are arranged concentrically and parallel to one another (in a geometric sense). These insulating rings can be understood as annular plate-shaped base plates for interconnecting the plates and are arranged in particular perpendicular to the center axis of the stator or horizontally. Likewise, the partitions can alternatively have a conical outer circumference. The conical outer circumference helps to separate the different interconnection planes from one another fluidically and / or electrically and helps to maintain the interconnection plates.

[0020] In order to form channels around the interconnecting sheets, radial baffles, arcuate baffles and / or horizontal baffles (also called insulating rings) can be arranged perpendicular to each other all or at least partially. This helps to bring more mechanical stability to the cooling channels and provide a more orderly flow path for the cooling fluid.

[0021] In order to fix or hold the interconnecting sheet in the partition, the partition has fixing elements, in particular clamping elements or projections. These fixing elements allow the cooling channel to be used for interconnecting sheets of different shapes or thicknesses and thus to be configured more flexibly. In addition, the cooling fluid can flow unhindered through the interval or space created by the fixing elements between the partition and the interconnecting sheet and cool the interconnecting sheet better.

[0022] Alternatively, the interconnecting sheet can also be positioned loosely, ie with clearance, in the spacer. This provides clearance for establishing an electrical connection between the interconnecting sheet and the strip conductor. This reduces tolerance dependency.

[0023] The plurality of webs are preferably formed from an elastic and / or electrically insulating material. As a result, in particular, structural tolerances can be better compensated and the cooling channel can be mounted on the winding head more easily overall.

[0024] The partitions can be connected to one another in the form of a tongue-and-groove joint in order to seal the cooling channel or parts of the cooling channel. Alternatively or additionally, the partitions can have a sealing means, such as a sealing lip, for example, in order to fluidically seal the contacting partitions. The sealing means can be designed as a separate component, such as an O-ring, or as an injection-molded component of a multi-component partition. In particular, the sealing means can be provided between horizontally stacked partitions or insulating rings.

[0025] In a further advantageous embodiment, the cooling channel is designed in one piece or in multiple pieces. A multiple-piece channel allows the entire design to be configured flexibly as required; thus, the number of webs and / or outer walls can be adapted to the winding head and can be varied.

[0026] It is also advantageous if the cooling channel has a sealing element, in particular a sealing mat, as a bottom part and the stator cooling housing as an outer side wall. This particular embodiment shows that existing parts of the stator can be used for the cooling channel and thus no additional components are required for the channel.

[0027] According to the present disclosure, a stator with a cooling channel according to the present invention is provided. The stator, which is provided in particular for an electric motor, is designed with a plurality of strip conductors, wherein the stator has at least one cooling channel according to the present disclosure and the partitions of the cooling channel are arranged between at least a portion of the strip conductors. In this embodiment, the strip conductors extend into the cooling channel and are electrically connected to interconnecting sheets arranged in the cooling channel. In another embodiment, the interconnecting sheets can protrude from the cooling channel and be electrically connected to the strip conductors outside the cooling channel.

[0028] Preferably, the stator has a plurality of interconnecting sheets corresponding to or corresponding to the strip conductors.

[0029] In addition, according to the present disclosure, a motor including the cooling channel according to the present disclosure or including the stator as disclosed above is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described below relate to preferred embodiments of the cooling channel according to the present disclosure and the stator according to the present disclosure, wherein these drawings should not be considered as limiting, but are mainly used to illustrate the present disclosure. Elements with the same reference numerals in different drawings are the same, and therefore, the description of the elements in the drawings is valid for the elements with the same reference numerals or the same numbers in other drawings.

[0031] In the attached picture:

[0032] Figure 1 shows a perspective view of a stator including assembled windings;

[0033] Figure 2 Shown according to Figure 1 A side view of a stator;

[0034] Figure 3 Shown is the Figure 1 and Figure 2 The basic form of stator winding end cooling device.

[0035] Figure 4a shows the interconnect plane according to Figure 3 The cross section of half of the stator;

[0036] Figure 4b The different annular regions are shown according to Figure 3 Schematic top view of half a stator.

[0037] Figure 5a Based on Figure 5b The stepped cross section shows an embodiment of a variant according to Figure 3 A top view of a stator including only radial partitions.

[0038] Figure 5b Shown along Figure 5a A cross section of the shaft of the stator of FIG. 1 , illustrating a view into the cooling channel and its interior;

[0039] FIG. 6a shows a second embodiment variant according to FIG. 6b in a stepped cross section. Figure 3 A top view of a stator comprising interconnected planes and interconnected sheet groups connected in parallel in a fluidic manner;

[0040] FIG6 b shows a cross section along the axis of the stator of FIG6 a , illustrating the view looking into the cooling channel and into its interior;

[0041] Figure 7Shown according to Figure 3 A top view of a stator for a design in which the fluid flows only in the groove area (including radial baffles, without strip conductors, interconnecting sheets and cooling channels);

[0042] Figure 8a and Figure 8b A perspective view of a covering unit is shown, which is used according to Figure 7 The winding ends of the stator;

[0043] Figure 9a An exploded view of an insulating ring including cooling channels interconnecting the sheet packs is shown in another embodiment variant for use only in the bridging region, which is used for the fluid flow according to Figure 3 Design scheme of stator winding end cooling device;

[0044] Figure 9b Shows Figure 9a A top view of the insulating ring shown in ;

[0045] Fig.10a and Fig.10b A perspective view of an assembled insulating ring from a cooling channel without interconnecting webs is shown in each case according to a preferred embodiment variant. Figure 3 A stator winding end cooling device;

[0046] Fig.11 Shown according to Fig.10a Or Fig.10b An assembled insulating ring including an interconnecting piece;

[0047] Fig.12a and Figure 12b Shown according to Fig.10a Or Fig.10b An assembled insulating ring including a cover unit or a top cover;

[0048] Fig.13 A stator according to a preferred embodiment variant is shown, comprising a cooling channel according to the present disclosure, with fluid flows indicated;

[0049] Fig.14 shows a longitudinal section through the upper part of a stator according to this preferred embodiment variant, in particular its winding head including the cooling channel according to the disclosure, wherein the fluid flow is marked;

[0050] Fig.15 An exploded view of a stator according to the present disclosure according to this preferred embodiment variant is shown, which includes two winding ends and a cooling channel; and

[0051] Fig.16Four different configuration variations of the baffles within the cooling channels with the interconnecting sheets disposed therein are shown.

[0052] Fig.17 A construction variant for arranging the retaining element on the partition is shown.

[0053] Fig.18 A variant of a top cover is shown which comprises a widened inlet opening. DETAILED DESCRIPTION

[0054] Figure 1 and Figure 2 A stator comprising windings assembled from strip conductors and interconnecting sheets is shown.

[0055] Figure 1 The stator 1 is shown to include a cylindrical stator housing or stator laminated core 2, wherein elongated stator strip conductors 6 are arranged concentrically around the axis of the stator or stator housing in corresponding grooves or recesses of the stator housing 2. At the ends of the stator 1, starting from the upper side or the lower side of the stator housing 2, a first winding head (on the A side) and a second winding head 4 (on the B side) are respectively provided. The two winding heads 3, 4 each have an interconnection plane 5 formed by interconnection plates 9. Here, the interconnection plates 9 respectively connect two strip conductors 6 extending from the stator housing 2 into the winding heads 3, 4. The winding head 4 differs from the winding head 3 in that an interconnection plane 7 including three phase connections 8 is additionally incorporated into the winding head 4. The interconnection plates 9 are arc-shaped strip conductors, which include additional strip conductors extending radially to the stator axis, and whose function is to electrically connect the strip conductors 6 in pairs. Here, the strip conductors 6 are connected to each other in a predetermined pattern, and the distance and number of interconnecting pieces 9 designed as strip conductors between the strip conductors 6 connected in pairs are therefore predetermined. The winding ends 3 and 4 are designed to be annular or cylindrical and are mainly formed by interconnection planes 5 arranged concentrically and parallel to each other. The phase connection 8 in the marked interconnection plane 7 consists of three contacts and is preferably used for three-phase AC connection. The strip conductors 6 are designed so that they extend to specific interconnection planes 5 in the winding ends 3 and the winding ends 4. As a result, these strip conductors 6 are assigned to the same or different interconnection planes 5 and thus to specific interconnection pieces 9 to achieve a specific interconnection pattern.

[0056] Figure 2 Shows Figure 11 . The first winding head 3 has four interconnection planes 5, while the second winding head 4 has four interconnection planes 5 and one interconnection plane 7 including the phase connection 8. The interconnection planes 5 and 7 are arranged perpendicular to the central axis 23 of the stator 1, while the strip conductors 6 are arranged parallel to this axis. The central axis 23 describes the axis of a rotor (not shown) which can be inserted into the stator 1 and is used at the same time to describe the geometrical properties of the individual elements of the stator 1, such as the stator housing 2, the strip conductors 6, the interconnection planes 5, etc., and to relate them to each other.

[0057] Figure 3 and Figure 4a , Figure 4b A basic variant is shown for Figure 1 Or Figure 2 The stator winding end cooling device comprises an annular gap-shaped fluid inlet 25 and an annular gap-shaped fluid outlet 26.

[0058] Figure 3 A cross section through the stator 1 along the center axis 23 is shown, wherein compared to Figure 1 and Figure 2 , the stator 1 shown here additionally has a cylindrical cooling housing / cooling sleeve 20. The cooling housing 20 is integral and has thread-like cooling ribs 44 in its central outer section, over which a cooling fluid such as water can flow, and has an outer ring 28 on both end sections. The stator casing 2 lies on the inside against the cooling housing 20 and has essentially the same length as this section. The stator can be cooled indirectly, i.e. without direct fluid contact, by means of the cooling housing.

[0059] The winding ends have direct cooling, i.e. a cooling fluid such as dielectric oil can be guided through the winding ends. The two winding ends 3 and 4 are located in two outer rings 28 formed by a cooling housing. The winding ends 3 and 4 or their outermost interconnection plane 5 are protected from probing into the housing 20 by an annular covering unit or cover ring 21 with an inner ring 22. The cover ring 21 forms an annular gap 25 with the outer ring 28 as an inlet for the cooling fluid. The cover ring 21 and the inner ring 22 together form an annular gap 26 as an outlet for the cooling fluid. Therefore, the two winding ends 3 and 4 each have an annular cover 21 with an inner ring 22 as a cover for the interconnection plane 5 or 7 relative to the outside. From the cross section of the stator 1, it can be clearly seen that the strip conductors 6 and 6a are designed concentrically around the center axis 23 of the stator 1. Here, the strip conductors 6 and 6a are located in pairs in the same groove of the stator housing 2. Compared to the strip conductors 6 arranged outside, the strip conductors 6a arranged inside or closer to the axis 23 are longer and preferably reach the outermost interconnection plane of the winding ends 3 and 4. The housing 20 is at least partially formed of metal to achieve a better cooling effect of the cooling fluid and the remaining elements of the stator 1.

[0060] Figure 4a Shown according to Figure 3 AA in FIG. 1 , wherein in particular the strip conductors 6 which are connected in pairs by interconnecting webs and are located between the inner ring 22 and the outer ring 28 can be seen.

[0061] Figure 4b Four annular areas or rings are schematically shown, which are formed according to Figure 3 Or Figure 4a Between the outer ring 28 and the inner ring 22 of the stator. The annular region is introduced for ease of reference so that it can be used as a reference in the following text. The areas inside and outside the annular gaps 25, 26 for the inflow or outflow of the cooling fluid are shown here. The annular region 30 shows the area in which the arc-shaped part of the interconnecting sheet 9 extends. This area can be referred to as the bridging area 30. The annular region 29 shows the annular area in which the strip conductors 6; 6a are arranged in the stator grooves and connected to the interconnecting sheet 9. This area can also be referred to as the groove area 29 or the connection area 29.

[0062] In the following, through Figure 5a , Figure 5b In other words, Figure 6a and Figure 6b implement the Figure 3 Two different variants of winding end cooling.

[0063] Figure 5a , Figure 5bA first embodiment of a winding head cooling device with only radially arranged webs 31 is shown. The winding consists of strip conductors 6, 6a (not shown in FIG. 6a ) arranged in two layers in grooves of the laminated core 2 and connected by interconnecting webs 9 (only shown in a preliminary manner) arranged in multiple layers. The interconnecting webs 9 are held by or in the circumferentially regularly arranged retaining tabs / positioning clips 31a. The positioning clips simultaneously form radial webs 31. Due to the radially extended positioning clips, the interconnecting webs 9 of the individual interconnection planes 5 are not fluidly separated from one another in the horizontal direction.

[0064] The cooling fluid is introduced into the winding head completely uniformly over the entire height of the winding head via the annular gap 25, is deflected in the direction of the central axis 23 by means of the radial webs 31, and then leaves the winding head via the partially interrupted annular gap 26. As a result, identical interconnecting sheet sections are subjected to virtually identical application of cooling medium and thus to virtually identical cooling.

[0065] Figure 5a The partial cross section shows in detail the Figure 5b The cross section BB in is similar to Figure 3 The stator of FIG. 1 shows a covering element 21 on the one hand and a vertically arranged partition 31 of a cooling channel on the other hand. The covering element 21 or the top cover is arranged on the upper side of the cooling channel. The inner ring 22 and the outer ring 28 form the lateral boundary of the cooling channel. Next to the inner ring 22 and the top cover 21, vertically arranged partitions 31 are arranged radially. An annular gap 25 is formed between the cover ring 21 and the outer ring 28 as an inlet for the cooling fluid. An annular gap 26 is formed between the cover ring 21 and the inner ring 22 as an outlet, wherein the inner annular gap 26 is interrupted by the web of the covering part 21. The partition 31 is designed to be radially and in particular axially symmetrical with respect to the center axis 23. A channel is formed by means of the partition 31 and the top cover 21, which can cause a laminar fluid flow between the annular gap 25 and the annular gap 26.

[0066] Figure 5b Shown along Figure 5a A cross section of the shaft of the stator of FIG. 2 illustrates the view into the cooling channel and its interior. The cover ring 21 is arranged on the winding end or on its uppermost interconnection plane 5. An annular gap flow outlet 26 is formed between the inner ring 22 and the cover ring 21. An annular gap flow inlet 25 is formed between the outer ring 28 and the cover ring 21. For this purpose, corresponding arrows describing the flow stream are marked on the left side of the cross section. Figure 5a The vertical partition 31 can be seen in Figure 5b 2 shows the webs arranged perpendicularly to the center axis 23. The connection points to the interconnecting strips 9, at which the two elements are connected to one another, can be clearly seen next to the strip conductors 6 and 6a.

[0067] Figures 6a and 6b show a diagram similar to Figure 3 A second embodiment of the present invention comprises a double parallel cooling channel for the winding ends. The individual interconnection planes 5 are separated by horizontal insulating plates 32, on which the interconnection plates 9 are positioned. In each interconnection plane 5, the interconnection plates are combined into interconnection plate groups 40, wherein the individual interconnection plate groups are separated from each other by radial partitions 42. The cooling fluid flowing in or out through the annular gaps 25 or 26 is brought into a track along the longitudinal axis of the interconnection plates by means of the arc-shaped partitions 34, 35.

[0068] FIG. 6a shows in detail in a partial cross section (compare section BB in FIG. 6b ) Figure 3 1 shows a top view of a stator 1 showing, on the one hand, the cover element 21 and, on the other hand, the interconnection plane including the interconnecting webs 9. Furthermore, in this case, the radially designed webs 31 are not visible, but the arc-shaped inner and outer walls 34 and 35 are visible. On the left side, radial elements or webs can be seen between the inner ring 22 and the cover element 21, which fix the ring 22 to the cover 21 and are arranged in the region of the annular gap flow outlet 26. Between the inlet region 43 and the outlet region 36 in the cooling channel, a separate fluid flow is formed between the mentioned walls. As can be seen from the top view of the stator 1, the interconnecting webs 9 are arranged in groups of five 40 in the annular sectors formed by the radial webs 42. The inlet region 43 can be designed as a throttling element, advantageously as a bore in the outer wall 35, in order to achieve a uniform flow distribution between the different groups 40.

[0069] 6b shows a cross section along the axis of the stator 1 of FIG. 6a, which illustrates the view into the cooling channel and its interior. The strip conductors 6 and 6a can again be identified, which are connected to the interconnecting sheet 9. The fluid flow is also marked on the left side, which flows from the annular gap inlet 25, through the cooling channel, to the annular gap outlet 26. The cooling channel itself is annular and is mainly formed by the cover ring 21, the inner ring 22, the outer ring 28 and the lowest insulating ring 32.

[0070] Figure 7 and Figure 8a , Figure 8b A possible design of a groove region 29 for a stator 1 according to an embodiment of the disclosure is shown, wherein radial partitions of the cooling channels according to the disclosure are formed only in the groove region 29. The design of the fluid channels in the region of the bridging region can be varied.

[0071] Figure 7A top view of a stator 1 is shown, which comprises a housing 20, an outer ring 28 and an inner ring 22, but without strip conductors. Similar to the previous examples, interconnecting sheets 9 are arranged in the end face region of the stator laminated core 2 to form an assembled winding. The radial webs 31 are designed integrally with the inner ring.

[0072] Figure 8a and Figure 8b A perspective view of a cover unit 21 for stator winding ends is shown, comprising an integrally connected inner ring 22, radially arranged partitions 31 and an annular gap flow outlet 26. The cover unit has an annular projection containing an O-ring. In the installed state, the projection separates the inlet flow area from the outlet flow area, see Fig.13 .

[0073] Figure 9a , Figure 9b , Fig.10a , Fig.10b and Fig.11 A design possibility for a bridging region 30 according to an embodiment of the present disclosure is shown. Here, the individual interconnecting sheets 9 are accommodated in an insulating plate or insulating ring 32 and separated from each other by arc-shaped partitions 41, so that a well-defined cooling channel is formed for each individual interconnecting sheet 9. This ensures that each interconnecting sheet has a comparable cooling efficiency.

[0074] Figure 9a An exploded view of an insulating ring 32 of a cooling channel is shown in detail, comprising an interconnection plane 5 consisting of three interconnection sheet groups 40 each of five interconnection sheets 9, which can be arranged on the insulating ring 32 or horizontal partitions 32, in particular in prefabricated grooves or gaps. The insulating ring 32 has three fluid inlets 38, i.e., each interconnection sheet group has its own inlet, and two fluid outlets 39 for each interconnection sheet, i.e., each interconnection sheet group 40 has ten outlets, while the insulating ring 32 has thirty outlets 39. All outlets 39 point to the center of the ring 32. In order to arrange the interconnection sheets 9 appropriately in the corresponding interconnection sheet groups 40, intermediate plates 41 are provided between the interconnection sheets 9 or on the insulating ring 32, which intermediate plates form the grooves. In addition, the interconnection sheet groups 40 are separated from each other by radial intermediate plates 42. Thereby, the fluid flow can be divided into parallel partial flows for each interconnecting sheet group, and each partial flow is additionally divided into further parallel partial flows respectively for half of the interconnecting sheets.

[0075] Figure 9b Shows Figure 9a3 shows a top view of the insulating ring 32. In this figure, in order to better illustrate the channels or grooves formed by the intermediate plates 41, no interconnecting plates 9 are arranged. Each groove is connected to the outside through a triangular inlet extending from the inlet area 38 to the inner wall 34 and can be supplied with cooling fluid. The cooling fluid flowing in through the inlet area 38 can flow out from ten different outlets 39 in the direction of the central axis 23. This applies to each annular sector of the ring 32 or to each interconnecting plate group 40 of the interconnecting plane 5. However, instead of a continuous inlet area 38, the intermediate plates 41 and the outer wall 35 can also be designed as non-interrupted and can each have radial boreholes as fluid inlets. By arranging the boreholes, a pressure drop can be set in a targeted manner on each inlet area, for example a pressure drop of 100 mbar on the outer wall and a pressure drop of 10 mbar on each intermediate plate. In particular, during horizontal operation of the stator, an uneven distribution of the cooling fluid on multiple interconnecting plate groups 40 and / or multiple interconnecting planes 5 can be achieved.

[0076] Fig.10a and Fig.10b A perspective view of an assembled insulating ring 32 from a cooling channel without interconnecting webs is shown in each case. Four insulating rings 32 arranged one above the other each have three inlets 38 and thirty outlets 39.

[0077] Fig.11 Shown according to Fig.10a Or Fig.10b The assembled insulating ring 32 includes the interconnecting sheet 9.

[0078] Fig.12a and Figure 12b Finally, it is shown Figure 9a , Figure 9b , Fig.10a , Fig.10b and Fig.11 ,as well as Figure 7 and Figure 8a , Figure 8b Combinations of design possibilities shown in . Fig.10a Or Fig.10b The assembled insulating ring 32 is preset to have a configuration similar to Figure 8a and Figure 8b The cover unit or cover 21. The cover unit 21 is equipped with an inner ring 22 and vertical partitions 31. In both cases, the interconnecting sheets used cannot be identified.

[0079] Figures 13 to 15 A preferred embodiment of a stator cooling device comprising cooling channels according to the present disclosure is shown.

[0080] Fig.13A perspective view of a stator 1 is shown, which includes a cooling channel according to the present disclosure, and the fluid flow is indicated. The stator 1 is designed with a cooling housing 20 and cooling ribs or turns 44. On the upper side, a cover unit 21 can be seen, which includes an inner ring 22, which forms an annular gap inlet 25 and an annular gap outlet 26 in combination with an outer ring of the cooling housing 20.

[0081] Fig.14 A longitudinal section through the upper part of the stator 1, in particular a winding head including a cooling channel according to the present disclosure, is shown, wherein the fluid flow is marked on the right side. Compared to the stator described above, this embodiment is equipped with a fluid housing 48. The fluid housing 48 has a cylindrical outer wall 50 and an annular cover plate 51, such as a bearing cover. The outer wall 50 is directly adjacent to the cooling housing 20. The cover plate 51 is fixed to the outer wall 50 and has a plurality of openings for fluid inflow and an opening for fluid outflow and the rotor. The fluid inflow is directed to the cover unit 21 and presses it downward or on the stator housing 2. The cover unit 21 is supported axially displaceably. The cover unit is separated from the inflow area and the outflow area by an annular protrusion including an O-ring with an edge. Through the design of the individual inflow and fluid passage, in particular in the inflow to the interconnected sheet group, the flow resistance of the cooling fluid can be set within a wide range, so that the pressing pressure of the cover unit can be adjusted, for example in the range of 150 to 250 mbar. By means of the enlarged cross section along the longitudinal axis or center axis 23 of the stator 1, the stator housing 2 with the strip conductors 6 and 6a, the winding ends with the various interconnecting webs 9, the insulating ring 32 of the cover unit 21 with the inner ring 22 and the annular gaps 25 and 26 for inflow and outflow formed thereby can be clearly seen. The webs 9 and the conductors 6, 6a are fixed to one another at the contacts 33, in particular welded to one another.

[0082] This results in a multiplicity of parallel fluid flows in total. The individual interconnection planes are fluidically connected in parallel via the annular gap inflow openings. The individual interconnection plates or interconnection half plates are fluidically connected in parallel via the insulating plates.

[0083] Fig.15An exploded view of a stator 1 according to the present disclosure is shown, which includes two winding ends 3 and 4 and cooling channels. The stator 1 is equipped with a stator housing 2, in which a groove or groove area 29 is formed inside, and strip conductors 6 and 6a are arranged concentrically around a central axis 23. On one side, a winding end 3 is arranged to connect the strip conductors 6 and 6a at one end to a corresponding interconnecting sheet 9. On the other side of the stator housing 2, a further winding end 4 is arranged, which differs from the first winding end 3 in that it has an additional interconnecting plane 7 including a phase connection 8. The two winding ends 3 and 4 are arranged one on top of another by means of a sealing gasket 45, an adapter 47, four interconnecting planes 5 including corresponding interconnecting sheets 9 or three interconnecting sheet groups 40 in each case. A cover element 21 is provided as a closure element, which has an inner ring 22 and vertically arranged radial partitions 31.

[0084] Fig.16 Four different construction variants of the insulating ring 32, in particular of its intermediate plate 41, in the cooling channel, wherein the cooling channel comprises an interconnecting sheet 9 arranged therein. The intermediate plate 41 and the insulating ring 32 may have retaining elements 46 in the form of bumps or the like. In example a), the element 46 is formed on the intermediate plate 41. In example b), the element 46 is arranged on the intermediate plate 41 and on the lower side of the ring 32. In example c), the element 46 is formed simultaneously on the lower side of the upper ring 32 and on the lower side of the upper ring 32. In example d), the element 46 is molded on both intermediate plates and on the upper and lower sides of the upper or lower insulating ring 32, wherein the lateral elements 46 and the top / bottom elements 46 are not at the same height, but are formed alternately along the longitudinal axis of the interconnecting sheet 9, see example 46. Fig.17 .

[0085] Fig.17 Schematically and partially shown is an interconnecting sheet 9 held between two spacers 41. Here, the interconnecting sheet is held by staggered projections 46. By means of the projections 46, the interconnecting sheet 9 can be mounted, wherein the interconnecting sheet is bent and firmly clamped.

[0086] Fig.18 A variant of a stator according to the present disclosure is shown in a top view, which includes a cover part 17 with a widened inlet opening 25'. The widened inlet opening 25' is designed as a recess in the cover 21. The inlet opening 25' is arranged on the stator from above, wherein the stator is operated in a horizontal arrangement. Gravity acts accordingly from top to bottom in the drawing plane. As a result, a uniform fluid supply can be achieved over the entire stator circumference. In particular, the flow resistance can be reduced at the injection point in the upper area of ​​the winding end. As a result, uneven fluid distribution, which is caused, for example, by the antechamber of the winding end (between the cover 21 and the housing cover 51, see Fig.14) and the uneven pressure distribution due to the hydrostatic pressure. Advantageously, a uniform cooling of the entire winding head can be achieved even at very low pressures and / or very small volume flows.

[0087] At low fluid pressures, the fluid first accumulates at the lowest point of the antechamber. There, the fluid cannot flow out as quickly as it was when it was fed in, due to the high flow resistance of the annular gap. The fluid level in the antechamber rises accordingly to the height of the widened inlet opening 25'. From there, the fluid can enter the annular gap 25 located behind it practically without flow resistance, where it flows uniformly, for example, along the outer circumference of the insulating plate 32 and flows through the single inlet opening 38 to the interconnecting sheet group 40 or the interconnecting sheet 9, see Figure 12b The fluid inlet to the antechamber can be arranged at any desired position.

[0088] Reference numerals list

[0089] 1 Stator

[0090] 2 Stator housing or stator laminated core

[0091] 3 A side winding end

[0092] 4 B side winding end

[0093] 5 Interconnection plane

[0094] 6 Strip conductor

[0095] 6a Strip conductor

[0096] 7 Interconnection plane including phase connections

[0097] 8 Phase Connector

[0098] 9 Interconnection Sheets / End Face Connectors

[0099] 20 Cooling housing / cooling sleeve

[0100] 21 Top cover

[0101] 22 Inner Ring

[0102] 23 Center axis

[0103] 25 Annular gap inlet

[0104] 25' widened inflow opening

[0105] 26 Annular gap outflow

[0106] 28 Outer Ring

[0107] 29 Groove area / connection area

[0108] 30 Crossover area

[0109] 31 Partition (vertical)

[0110] 32. Partition (horizontal) or insulating ring / insulating plate

[0111] 33 Contacts / weld points between strip conductors and interconnecting plates

[0112] 34 Partition, curved inner wall

[0113] 35 Partition, curved outer wall

[0114] 36 Exit Area

[0115] 37 Top cover

[0116] 38 Entrance

[0117] 39 Exit

[0118] 40 Interconnection Sheet Group

[0119] 41 Panels

[0120] 42. Spacers between interconnected sheet groups

[0121] 43 Entrance Area

[0122] 44 turns / cooling fins

[0123] 45 Gasket

[0124] 46 Bump / Retaining element

[0125] 47 Adapter / Adapter Ring

[0126] 48 Fluid Housing

[0127] 50 Outer wall of fluid housing

[0128] 51 Cover plate for fluid housing.

Claims

1. A cooling channel for an end winding of an electric machine, wherein the cooling channel is designed with at least one inlet (25) and at least one outlet (26) for guiding a cooling fluid, and is designed in a ring shape for being arranged around the end winding, It is characterized in that The cooling channel has a plurality of partitions, and the partitions are arranged so as to form parallel sub-channels between at least one of the inlet ports (25) and at least one of the outlet ports (26), wherein with reference to the cooling channel, the inlet port (25) is arranged radially outside and the outlet port (26) is arranged radially inside, or the inlet port is arranged radially inside and the outlet port is arranged radially outside, wherein at least a portion of the plurality of partitions are arranged radially and form radial partitions (31).

2. The cooling channel according to claim 1, It is characterized in that The inlet (25) and / or the outlet (26) are designed as an annular gap, wherein the inlet and the outlet are separated from each other by an annular cover element (21) of the cooling channel.

3. The cooling channel according to claim 1 or 2, It is characterized in that At least a portion of the plurality of partitions is designed to be in an arc shape.

4. The cooling channel according to claim 1 or 2, It is characterized in that At least a portion of the plurality of partitions has insulating rings (32) which are arranged concentrically and in parallel with each other.

5. The cooling channel according to claim 4, It is characterized in that The radial partition plate (31) and the insulating ring (32) are arranged perpendicular to each other.

6. The cooling channel according to claim 1 or 2, It is characterized in that The partition has a fixing element (46).

7. The cooling channel according to claim 1 or 2, It is characterized in that The plurality of partitions are formed of elastic material.

8. The cooling channel according to claim 1 or 2, It is characterized in that The cooling channel is designed in multiple parts.

9. The cooling channel according to claim 8, It is characterized in that The cooling channel has a sealing gasket (45) as a bottom part and a stator cooling housing (20) as an outer side wall.

10. The cooling channel according to claim 3, It is characterized in that At least a portion of the plurality of partitions is designed to be in an arc shape and are arranged concentrically with each other in groups.

11. The cooling channel according to claim 6, It is characterized in that The fixing element (46) is a clamping element or a projection.

12. A stator (1) comprising a plurality of strip conductors (6, 6a), wherein the stator (1) has at least one cooling channel according to any one of claims 1 to 11, and partitions of the cooling channel are arranged between at least a portion of the strip conductors (6, 6a).

13. The stator (1) according to claim 12, It is characterized in that The stator (1) has interconnecting plates (9) of a number corresponding to the number of the strip conductors (6, 6a).

14. The stator (1) according to claim 12, It is characterized in that The stator (1) is used for an electric motor.

15. An electric machine comprising a cooling channel according to any one of claims 1 to 11 or a stator (1) according to any one of claims 12 to 14.

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