Stator with a nozzle opening assembly for an hv terminal cooling function; electric machine with stator

Abstract

The invention relates to a stator (1) for an electric machine (2) of a motor vehicle, comprising a stator main part (3), which is formed from a laminated core and which has axially extending slots (4), and a coil assembly, which is at least partly situated in the slots (4) and which forms winding heads (5) on axial sides of the stator main part (3). The stator main part (3) has multiple axially extending cooling channels (6) which are offset with respect to one another in the circumferential direction and which are open towards at least one end face (7) of the stator main part (3). The respective cooling channel (6) longitudinal portions of each pair of longitudinal portions adjoining one another in the circumferential direction are connected to one another via a connecting channel (9) which is introduced into a distributor plate (8), the connecting channel (9) being connected to at least two directly axially emerging nozzle openings (10) of a nozzle plate (11). The invention also relates to an electric machine (2) comprising a stator (1).

Description

[0001] Stator with nozzle opening arrangement for HV terminal cooling; electric machine with stator

[0002] The invention relates to a stator for an electric machine of a motor vehicle with a stator base body formed from a laminated core with axially extending slots, and a coil arrangement arranged at least partially in the slots, which forms winding heads on axial sides of the stator base body, wherein the stator base body has several axially extending cooling channels offset from one another in the circumferential direction, which are open to at least one end face of the stator base body.

[0003] The prior art is disclosed in German patent application DE 10 2019 111 340 A1. This document discloses the construction of a stator and a method for manufacturing a stator. It discloses the use of a connection element comprising several busbars and a star busbar. The connection element has several contact points for the busbars as well as several contact points for the star busbar. The connection element surrounds the winding ends of the winding head. A bending comb positioned on the connection element bends the winding ends to the contact points of the connection element, thus making electrical contact with them.

[0004] The prior art also includes publication CN 106 849 393 A, which discloses a stator core for a vehicle generator. This stator core can improve the cooling efficiency of a stator during power generation and is easy to manufacture. The stator core is formed from stacked thin plates; the thin plates comprise magnetic yokes and a plurality of teeth; the multiple teeth are separated from one another at defined intervals on one side of the magnetic yokes; the thin plates comprise first thin plates and second thin plates, with heat dissipation ridges formed on the other sides of the first thin plates corresponding to the teeth; and no heat dissipation ridges formed on the other sides of the second thin plates corresponding to the teeth.

[0005] Also known is publication CN 117 013 723 A. This publication concerns the technical field of engine cooling. The publication discloses a structure for oil cooling a motor stator, comprising a shell, a stator core, and stator windings, wherein the stator core and the stator windings are arranged in the shell, and the stator windings are located on both sides of the stator core; an oil inlet opening is formed in the radial central surface of the shell; the stator iron core comprises a plurality of stamped iron core laminations, which are axially distributed and arranged symmetrically relative to the radial central surface of the shell; the stamped iron core laminations are combined to form a concave annular oil channel; the stamped iron core laminations are provided with axial through-openings, and the axial through-openings, the concave annular oil channel, and the oil inlet opening are sequentially connected.The shell has a simple structure and low production costs; oil is directed to the center of the stator iron core, flows in a circle around the diameter of the stator iron core, and is sprayed onto the stator windings on both sides of the stator iron core. The oil supply method and cooling effect are uniform due to the structural design and the combined application of stamped iron core sheets in some models. Furthermore, welding is carried out by means of the continuous weld bead arranged on the stamped iron core sheet, resulting in high weld strength and low costs.

[0006] Further prior art of the applicant exists in the field of the technical invention. This includes the merging of two connecting channels to form a fluid guide channel that is in fluidic communication with a nozzle opening.

[0007] The prior art reveals a lack of efficient cooling strategies for wetting the winding heads, particularly the winding ends. The winding ends have an axial distance from the stator body and a radial projection towards the winding heads. This means the winding ends represent a section with a larger diameter than the section defined by the stator heads. Supplying cooling fluid to this larger diameter section / windings is therefore problematic.

[0008] The winding ends on this diameter are considered inadequate. The windings on the larger diameter cannot currently be cooled, or only inadequately.

[0009] The present invention aims to achieve an improvement over the prior art. Known disadvantages are to be eliminated or at least reduced.

[0010] In a stator as presented above, this is achieved according to the invention by connecting two longitudinal sections of the cooling channels that are adjacent to each other in the circumferential direction via a connecting channel inserted in a distributor plate, wherein the connecting channel is connected to at least two nozzle openings that exit directly axially.

[0011] In other words, the invention relates to a nozzle arrangement for stator cooling. Included in the nozzle arrangement is at least one additional nozzle opening arranged / positioned radially further outwards, which is specifically designed for high-voltage terminal cooling (HV terminal cooling).

[0012] By having at least one additional nozzle opening positioned radially further outwards, it is possible to spray the cooling fluid (e.g., cooling oil) onto the outermost windings, i.e., onto the windings and winding ends with a larger diameter. This makes it possible to spray the cooling fluid over the winding heads and into the area of ​​the winding ends.

[0013] The nozzle arrangement offers the advantage of improved cooling of the area around the high-voltage terminal, including the star rail with the winding ends and weld points. This improved cooling enables energy- and power-efficient operation of the stator and the electric motor in motor vehicles. Furthermore, the improved cooling allows for an increase in the stator's service life while conserving resources.

[0014] Advantageous embodiments are claimed in the dependent claims and are explained in more detail below.

[0015] In the context of the explanation of the embodiments, the directional specifications refer to the stator as disclosed and thus to the electric machine. The radial direction is in the radial direction of the stator base body. The tangential / circumferential direction is defined in the direction of the circumference of the stator base body. The axial direction is implicitly in the axial direction of the stator / electric machine.

[0016] It has proven advantageous if at least two nozzle openings are assigned to a groove and are spaced apart from each other in the circumferential direction.

[0017] Due to the increased number and spacing of the nozzle openings in the circumferential direction, it is advantageously possible, with regard to the arrangement options and the uniformity of the oil wetting of the windings, to position the nozzle openings around the grooves.

[0018] The at least two nozzle openings can advantageously be positioned circumferentially to the right and left of the grooves. This advantageous embodiment preferably achieves the effect of improved accessibility to the winding heads and a preferably distributed, i.e., uniform, wetting of the winding heads.

[0019] Furthermore, it is advantageous if the at least two nozzle openings are radially spaced apart from each other.

[0020] The radial spacing of the nozzle openings advantageously allows for uniform wetting by ensuring that, with the same exit angle of the cooling fluid, areas of the winding heads and / or winding ends that are axially further apart from the end faces of the stator body can be wetted at the nozzle opening. Preferably, the winding ends on the star rail or weld points can also be wetted with cooling fluid in this way to facilitate heat dissipation. The cooling fluid is preferably sprayable through the windings.

[0021] By varying the outlet angle and / or outlet velocity of the cooling fluid, further control over the wetting of the windings can be advantageously achieved. This preferably results in increased cooling efficiency and power efficiency of the stator.

[0022] Furthermore, it is advantageous if at least the two nozzle openings have different diameters.

[0023] By using nozzles with preferably different diameters, it is advantageously possible, with regard to cooling and resource efficiency, to vary the amount of cooling fluid exiting the machine depending on the requirements of the windings.

[0024] By providing preferably at least one nozzle opening with a larger diameter, it is advantageously possible to discharge any residual dirt through the larger nozzle opening. The larger diameter also prevents clogging of the nozzle openings, thus improving ease of maintenance.

[0025] The at least one nozzle opening with the preferably larger diameter is preferably provided in combination with preferably two nozzle openings with preferably smaller diameters. The nozzle opening with the preferably larger diameter is preferably located radially further outwards than the two nozzle openings with the smaller, preferably equal, diameters. This arrangement offers further advantages with regard to the removal of residual dirt. To achieve the aforementioned technical effect, an embodiment of the smaller nozzle openings with a diameter of preferably 0.7 mm and the larger nozzle openings with a diameter of preferably 1.0 mm has proven advantageous. Clogging of the nozzles by residual dirt is thus avoided.

[0026] It has proven advantageous if the connecting channels are designed in a roof- or web-like profile.

[0027] The roof- or web-like design of the connecting channels advantageously allows the cooling fluid supply to be adapted to the arrangement of the nozzle openings. Bridge- or U- / horseshoe-shaped designs of the connecting channels for the flow of the cooling fluid to the nozzle openings are also conceivable.

[0028] The number of nozzle openings supplied with cooling fluid via the connecting channels is variable. Design configurations with two, three, four, or a plurality of nozzle openings are conceivable and advantageous.

[0029] Furthermore, it is advantageous if the nozzle openings are designed as nozzle bores.

[0030] By designing the nozzle openings as nozzle bores, they can be integrated into the nozzle plate in a way that is advantageous from both a manufacturing and cost perspective. This allows the nozzle plates to be easily manufactured in series production using standard tooling.

[0031] Furthermore, it is advantageous if the nozzle openings are arranged with a radial or axial distance between 4 mm and 10 mm. Spacing the nozzles within this range of 4 mm to 10 mm achieves a distribution of nozzle openings / nozzle arrangement that is beneficial for the homogeneity of the oil wetting / uniformity of the cooling fluid distribution.

[0032] Furthermore, it is advantageous if the nozzle plate is designed with at least two sections with different nozzle arrangements.

[0033] By varying the nozzle arrangement section by section, it is possible to adapt the nozzle arrangement to the local cooling requirements of different areas of the stator. This is advantageous with regard to the resource efficiency of the cooling fluid and preferably results in increased sustainability.

[0034] It is also advantageous if the nozzle openings and connection channels are located in the area of ​​the high-voltage terminal.

[0035] By arranging the nozzle openings and connecting channels as disclosed in the area of ​​the high-voltage terminal (HV terminal), it can be advantageously cooled and its power efficiency can be advantageously improved.

[0036] Furthermore, an electric machine with a stator and a rotor that can be rotated relative to the stator is disclosed.

[0037] The electric machine preferably incorporates the technical advantages realized by the stator according to the disclosure. As a result, a significantly increased power efficiency and service life are achievable.

[0038] The invention is explained in more detail below with the aid of a drawing. A first embodiment of the stator according to the invention is shown. It illustrates:

[0039] Fig. 1 is a schematic representation of a first embodiment of the stator according to the disclosure in a two-dimensional view, Fig. 2 is a perspectively distorted section II from Fig. 1 in an enlarged detail view with a partially transparent nozzle plate with translucent cooling channels and connecting channels,

[0040] Fig. 3 shows an enlarged section III from Fig. 2 of a distributor plate with cooling channels and connecting channels after removal of the nozzle plate.

[0041] Fig. 4 shows a schematic partial representation of the front face of a stator base body in a top view.

[0042] Fig. 5 shows a schematic partial representation of a stator body with winding heads and winding ends in a side view.

[0043] Fig. 6 shows a schematic representation of a section VI of a nozzle plate of the stator according to the disclosure in Fig. 1 in a two-dimensional view,

[0044] Fig. 7 is a schematic representation of a section VII of the nozzle plate from Fig. 6 in an enlarged detail view,

[0045] Fig. 8 is a schematic representation of section VIII of the nozzle plate from Fig. 6 in an enlarged detail view with diameters for nozzle openings shown,

[0046] Fig. 9 shows a schematic representation of a first embodiment of a nozzle arrangement of the stator according to the disclosure in Fig. 1 in a two-dimensional, semi-transparent view,

[0047] Fig. 10 shows a schematic representation of a second embodiment of a nozzle arrangement of a stator according to the disclosure in a two-dimensional, semi-transparent view; Fig. 11 shows a schematic representation of a third embodiment of a nozzle arrangement of a stator according to the disclosure in a two-dimensional, semi-transparent view.

[0048] Fig. 12 shows a schematic representation of a fourth embodiment of a nozzle arrangement of a stator according to the disclosure in a two-dimensional, semi-transparent view,

[0049] Fig. 13 shows a schematic representation of a fifth embodiment of a nozzle arrangement of a stator according to the disclosure in a two-dimensional, semi-transparent view.

[0050] Fig. 14 shows a schematic representation of a sixth embodiment of a nozzle arrangement of a stator according to the disclosure in a two-dimensional, semi-transparent view.

[0051] The figures are purely schematic and serve only to illustrate the invention. The same elements are identified by the same reference numerals. The features of the individual embodiments may be mutually complementary or interchangeable.

[0052] Fig. 1 shows a stator 1 according to the disclosure in a first embodiment for an electric machine 2 of a motor vehicle. The stator 1 has a stator base body 3 with axially extending slots 4. A coil arrangement is provided at least partially in the slots 4, which forms winding heads 5 on the axial side of the stator base body 3.

[0053] The stator base body 3 further comprises several axially extending cooling channels 6, offset from one another in the circumferential direction and not visible in Fig. 1. As can be seen in Fig. 2, the cooling channels 6 are preferably arranged radially below the nozzle openings 10. The cooling channels 6 are open towards at least one end face 7 of the stator base body 3. Two longitudinal sections of the cooling channels 6 adjacent to each other in the circumferential direction are connected to one another via a connecting channel 9 incorporated in a distributor plate 8 (see Fig. 2) to ensure the transport of the cooling fluid to the nozzle openings 10.

[0054] The connecting channel 9 is in turn connected to at least two axially protruding nozzle openings W of a nozzle plate 11. The arrangement of the nozzle openings 10 in the nozzle plate 11 according to Fig. 1 in the area of ​​a high-voltage terminal 12 (HV terminals) preferably differs from that in the remaining area of ​​the nozzle plate 11.

[0055] The windings / winding heads 5 comprise a plurality of conductors, the ends of which, i.e., the conductor ends of the winding wire / winding ends 13, are preferably connected via contact points to the high-voltage terminal 12, i.e., to a power supply. This arrangement makes it particularly clear that a significant amount of waste heat is generated in the area of ​​the high-voltage terminal 12.

[0056] Due to the required higher cooling capacity, nozzle openings 10 are arranged on different diameters 14 of the nozzle plate 11 and thus at different distances from the slots 4 / the winding heads 5.

[0057] This nozzle opening arrangement, characterized by different radial and / or axial distances, is located in a first sub-region of the nozzle plate 11 with a first nozzle opening arrangement 15. This first sub-region with a first nozzle opening arrangement 15 is preferably located in the area of ​​the high-voltage terminal 12. The subsequent sub-region of the nozzle plate 11 constitutes a second sub-region with a second nozzle opening arrangement 16.

[0058] Fig. 2 shows a perspectively distorted section II from Fig. 1 in an enlarged detail view with a partially transparent nozzle plate 11 with translucent cooling channels 6 and connecting channels 9. The high-voltage terminal 12 from Fig. 1 has been removed so that the first 15 and the second 16 sub-areas with the first and second nozzle opening arrangements are visible.

[0059] Fig. 3 shows an enlarged section III from Fig. 2 of a distributor plate 8 with cooling channels 6 and connecting channels 9 after removal of the nozzle plate 11. Shown are a roof-shaped (center and left in the plane of the figure) and a groove-shaped (right in the plane of the figure) embodiment of the connecting channel 9.

[0060] Fig. 4 shows a schematic partial view of the end face 7 of a stator body 3 in a top view. The grooves 4 of the inner diameter of the stator 1, in which the coil assembly is guided, are shown translucently. Winding heads 5 and the winding ends 13 are shown on the end face 7.

[0061] Fig. 5 shows a schematic partial representation of a stator base body 3 with winding heads 5 and winding ends 13 in a side view.

[0062] Fig. 6 shows a schematic representation of a section of a nozzle plate 11 of the stator 1 according to the disclosure as shown in Fig. 1 in a two-dimensional view.

[0063] The nozzle plate 11 is provided with grooves 4 arranged in the radially inner region of the nozzle plate 11. The nozzle plate 11 is divided circumferentially into the first sub-region with the first nozzle opening arrangement 15 and the second sub-region with the second nozzle opening arrangement 16. The first sub-region with the first nozzle opening arrangement 15 extends circumferentially over the stator-side section of the high-voltage terminal 12. The high-voltage terminal 12 is shown in Fig. 1.

[0064] The second area preferably extends over the remaining section of the nozzle plate 11 that is not attributable to the first area. The nozzle opening arrangement of the first 15 and the second 16 sub-areas differ. The nozzle opening arrangement in the first sub-area 15 is preferably configured to bring about increased wetting of the winding wires, i.e., winding heads 5 and winding ends 13, of the stator 1 according to the disclosure with cooling fluid and thereby increased heat dissipation.

[0065] Fig. 7 shows a schematic representation of section VII of the nozzle plate from Fig. 6 in an enlarged detail view. Extending beyond Fig. 6, the different diameters of the nozzle openings 10 in the first section of the nozzle opening arrangement 15 (left in the direction of the figure) and in the second section of the nozzle opening arrangement 16 (right in the direction of the figure) are shown. The nozzle openings 10 are preferably designed as nozzle bores. It is also conceivable, in accordance with the stator 1 as disclosed, that the nozzle openings 11 in the first section of the nozzle opening arrangement 15 have different diameters.

[0066] Fig. 8 shows a schematic representation of section VIII of the nozzle plate from Fig. 6 in an enlarged detail view with the diameters for the nozzle openings indicated. Beyond Fig. 6 and Fig. 7, it can be seen that the nozzle openings 11 in the first part of the nozzle opening arrangement 15 are arranged at different radial distances from the grooves 4. This means that the nozzle openings 11 are arranged on different diameters 14 of the stator base body 3.

[0067] Fig. 9 shows a schematic representation of a first embodiment of a nozzle arrangement of a stator 1 according to the disclosure in a two-dimensional, semi-transparent view. Shown are two nozzle openings 10 of a nozzle plate 11 with grooves 4 and the openings of two cooling channels 6 in a groove-shaped, translucent connecting channel 9 of a distributor plate 8. The nozzle openings 10 are arranged on a diameter.

[0068] Fig. 10 shows a schematic representation of a second embodiment of a nozzle arrangement of a stator 1 according to the disclosure in a two-dimensional, semi-transparent view. Shown are three nozzle openings 10 of a nozzle plate 11 with grooves 4 and the openings of two cooling channels 6 in a groove-shaped, translucent connecting channel 9 of a distributor plate 8. The nozzle openings 10 are arranged on two different diameters.

[0069] Fig. 11 shows a schematic representation of a third embodiment of a nozzle arrangement of a stator 1 according to the disclosure in a two-dimensional, semi-transparent view. Shown are three nozzle openings 10 of a nozzle plate 11 with grooves 4 and the openings of two cooling channels 6 in a pitched, translucent connecting channel 9 of a distributor plate 8. The nozzle openings 10 are arranged on two different diameters.

[0070] Fig. 12 shows a schematic representation of a fourth embodiment of a nozzle arrangement of a stator 1 according to the disclosure in a two-dimensional, semi-transparent view. Shown are three nozzle openings 10 of a nozzle plate 11 with grooves 4 and the openings of two cooling channels 6 in a pitched, translucent connecting channel 9 of a distributor plate 8. The nozzle openings 10 are arranged on three different diameters.

[0071] Fig. 13 shows a schematic representation of a fifth embodiment of a nozzle arrangement of a stator 1 according to the disclosure in a two-dimensional, semi-transparent view. Shown are three nozzle openings 10 of a nozzle plate 11 with grooves 4 and the openings of two cooling channels 6 in a web-like, translucent connecting channel 9 of a distributor plate 8. The nozzle openings 10 are arranged on two different diameters. Fig. 14 shows a schematic representation of a sixth embodiment of a nozzle arrangement of a stator 1 according to the disclosure in a two-dimensional, semi-transparent view. Shown are four nozzle openings 10 of a nozzle plate 11 with grooves 4 and the openings of two cooling channels 6 in a web-like, translucent connecting channel 9 of a distributor plate 8. The nozzle openings 10 are arranged on three different diameters.

[0072] List of reference signs

[0073] stator

[0074] Electric machine

[0075] Stator base body

[0076] Nut

[0077] winding head

[0078] Cooling channel

[0079] Front

[0080] Distributor plate

[0081] Connection channel

[0082] Nozzle opening

[0083] Nozzle plate

[0084] High-voltage terminal / HV terminal

[0085] Conductor ends / winding ends

[0086] diameter

[0087] First section of the nozzle plate / nozzle arrangement in the area of ​​the

[0088] High-voltage terminals / first nozzle assembly

[0089] Second section of the nozzle plate / second nozzle arrangement

Claims

Patent claims 1. Stator (1) for an electric machine (2) of a motor vehicle, comprising a stator base body (3) formed from a laminated core with axially extending slots (4), and a coil arrangement arranged at least partially in the slots (4), which forms winding heads (5) towards the axial side of the stator base body (3), wherein the stator base body (3) has several axially extending cooling channels (6) offset from one another in the circumferential direction, which are open to at least one end face (7) of the stator base body (3), wherein two longitudinal sections of the cooling channels (6) adjacent to each other in the circumferential direction are connected to one another via a connecting channel (9) provided in a distributor plate (8), which connecting channel (9) is connected to at least two nozzle openings (10) of a nozzle plate (11) that directly exit axially.

2. Stator (1 ) according to claim 1 , characterized in that the at least two nozzle openings (10) are spaced apart from each other in the circumferential direction.

3. Stator (1 ) according to one of claims 1 to 2, characterized in that the at least two nozzle openings (10) are radially spaced apart from each other.

4. Stator (1 ) according to one of claims 1 to 3, characterized in that the at least two nozzle openings (10) are designed with different diameters.

5. Stator (1 ) according to one of claims 1 to 4, characterized in that the connecting channels (9) are designed in a roof or web profile manner.

6. Stator (1 ) according to one of claims 1 to 5, characterized in that the nozzle openings (10) are designed as nozzle bores.

7. Stator (1) according to one of claims 1 to 6, characterized in that the nozzle openings (10) are spaced radially or axially apart. are set up with 4 mm and 10 mm spacing relative to each other.

8. Stator (1 ) according to one of claims 1 to 7, characterized in that the nozzle plate (11 ) is designed with at least two sections of different nozzle arrangements.

9. Stator (1 ) according to one of claims 1 to 8, characterized in that the nozzle openings (10) and connecting channels (9) are arranged in the area of ​​a high-voltage terminal (12).

10. Electric machine (2) with a stator (1) according to one of the preceding claims and a rotor rotatable relative to the stator (1).

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