Machine arrangement and motor vehicle

Abstract

An electrical machine arrangement (1) comprising two coaxially arranged electrical machines (2, 3), each having a rotor (4, 5) and a stator (37, 38), wherein the rotor (4, 5) of each electrical machine (2, 3) is rotatable independently of the rotor (4, 5) of the other electrical machine (2, 3), wherein the rotors (4, 5) have a common axis of rotation (8) extending in the axial direction of the machine arrangement (1), wherein the stators (37, 38) each have a stator body (9, 10) and at least one winding (31, 32) with winding heads (11, 12) projecting axially on both sides beyond the respective stator body (9, 10), wherein the facing winding heads (12) of the electrical machines (2, 3) overlap in the radial direction (35), wherein the distance (D) between the stator bodies (9, 10) in the axial direction is smaller than the sum of the lengths (L1,L2) of the two opposing winding heads (12) of the electrical machines (2, 3) in the axial direction, such that the winding heads (12) interlock in an axial section (A) of the machine arrangement (1), characterized in that the windings (31, 32) of the electrical machines (2, 3) are hairpin windings (31, 32) with a plurality of hairpin wires, wherein at least some wire ends (13, 14) of the hairpin wires of the respective electrical machine (2, 3) are welded together in pairs within the axial section (A) of the machine arrangement (1), wherein in at least one section plane (17) perpendicular to the axial direction in the axial section (A) in the circumferential direction (36) wire ends (13) of the winding (31) or of one of the windings (31, 32) of a first of the electrical machines (2) and wire ends (14) of the winding (32) or one of the windings (31, 32) of a second of the electrical machines (3) are arranged.

Description

[0001] The invention relates to an electrical machine arrangement comprising two coaxially arranged electrical machines, each having a rotor and a stator, wherein the rotor of the respective electrical machine is rotatable independently of the rotor of the other electrical machine, wherein the rotors have a common axis of rotation extending in the axial direction of the machine arrangement, wherein the stators each have a stator body and at least one winding with winding heads protruding in the axial direction on both sides beyond the respective stator body, wherein the mutually facing winding heads of the electrical machines overlap in the radial direction, wherein the distance between the stator bodies in the axial direction is smaller than the sum of the lengths of the two mutually facing winding heads of the electrical machines in the axial direction, so that the winding heads engage with one another in an axial section of the machine arrangement.The invention also relates to a motor vehicle.

[0002] In electric vehicles and hybrid vehicles, it is common practice to install two electric motors on one axle, each driving one wheel on the axle. Each of the two wheels is thus driven by a separate electric motor, allowing the rotational speed of each wheel to be individually adjusted to the driving situation and providing more power than if both wheels were operated by just one electric motor. If both electric motors are arranged so that their rotors are coaxial with each other, this is referred to as an axle-twin-coaxial arrangement (ATA drive for short).

[0003] The publication DE 10 2020 122 246 A1 shows such an ATA drive with two electric motors, whose coaxially arranged rotors are housed in a common housing and each drives an output shaft. However, the arrangement of the electric motors takes up a lot of space, especially in the axial direction, which is due, among other things, to the size of the stator winding heads.

[0004] Especially in the development of modern and increasingly complex motor vehicles with increasing number or complexity of components, the installation space requirement represents a particularly critical factor. It is therefore desirable to provide all necessary components, including electrical machines, in the smallest possible installation space in a compact manner.

[0005] The document DE 11 2006 001 432 B4 discloses a drive device for a hybrid vehicle with two coaxial electric motors whose stator windings overlap in the axial direction.

[0006] The subsequently published document DE 10 2021 124 127 A1 discloses coaxial electric drive machines, wherein a first rotor shaft extends axially into a second rotor shaft.

[0007] In the hybrid drive according to the document DE 101 54 147 C1, two electric machines are used, with parts of the hybrid drive being nested axially within each other.

[0008] Therefore, the object of the present invention is to reduce the installation space requirement of two coaxially arranged electrical machines, or of an axle twin coaxial drive.

[0009] To achieve this object, in an electrical machine arrangement of the type mentioned at the outset, it is provided according to the invention that the windings of the electrical machines are hairpin windings with a multiplicity of hairpin wires, wherein at least some wire ends of the hairpin wires of the respective electrical machine are welded to one another in pairs within the axial section of the machine arrangement, wherein in at least one sectional plane perpendicular to the axial direction in the axial section, wire ends of the winding or of one of the windings of a first of the electrical machines and wire ends of the winding or of one of the windings of a second of the electrical machines are arranged alternately in the circumferential direction.

[0010] This allows the winding heads to be arranged very compactly, allowing the stators and rotors of the two electric machines to be positioned closer together in the axial direction. This saves installation space.

[0011] This creates an axial section in which the two facing winding heads engage with each other, while simultaneously overlapping in the radial direction. In other words, a part of a first of the two facing winding heads engages in the axial direction with the free spaces of a second of the facing winding heads. This allows installation space to be saved in the axial direction compared to a conventional arrangement of the winding heads, in which the winding heads are located in separate installation spaces and the spaces between the installation spaces remain unused. In the motor vehicle or in other devices incorporating the machine arrangement, the saved installation space can be made available for other components, such as the suspension, the chassis, a subframe or a shock absorber. Alternatively, it can also be used to reduce the track width of the vehicle and thus adapt cornering behavior.

[0012] Furthermore, the size of the housing housing both electric motors can be reduced, requiring less material and reducing the weight of the vehicle or device. In terms of efficiency and range, weight reduction, in addition to the space savings, is also highly significant for modern motor vehicles.

[0013] The described electrical machine arrangement can form an ATA drive and comprises two electrical machines, each with a rotor and a stator arranged coaxially along a common axis of rotation. Both rotors rotate about the same axis of rotation, making the machine arrangement particularly suitable for driving two wheels on one axle of a motor vehicle. The electrical machines can be, for example, three-phase synchronous machines, in particular permanent-magnet synchronous machines, or three-phase asynchronous machines.

[0014] The facing winding overhangs of both electrical machines can be ring-shaped, with the winding overhangs each having an inner and an outer diameter that can be at least substantially the same for both electrical machines. Thus, the intermeshing winding overhangs can overlap in the radial direction. Additionally or alternatively, the stator bodies of both electrical machines can each have an inner and an outer diameter that are at least substantially the same for both electrical machines. At least substantially the same diameters are understood to mean diameters whose magnitude differs from one another by no more than 10%.

[0015] Both stator bodies can have a cross-section running in the axial direction that is identical for the stator bodies of both electrical machines. In particular, both stator bodies and / or winding heads can be of identical construction.

[0016] In the electrical machines according to the invention, the windings of the electrical machines are hairpin windings with a plurality of hairpin wires, wherein at least some wire ends of the hairpin wires of the respective electrical machine are welded together in pairs within the axial section of the machine arrangement. Hairpin wires are wires that can be made of copper, for example, and are bent approximately into a U-shape and, in particular, are electrically insulated from the outside. The hairpin wires are inserted into the stator body, whereupon the wire ends of the unbent side are bent and then welded in pairs. This creates a winding head with bent hairpin wires on one side of the stator body and a winding head with welded hairpin wires on the other side, the so-called welding side.

[0017] Depending on the design of the winding heads, a free space may be available between the welded wire ends, which can be used to arrange the wire ends of two welding-side winding heads in an interlocking manner. The electrical machines can be arranged coaxially so that the two welding-side winding heads are opposite each other. If the wire ends of the two winding heads are arranged so that they can engage in the free space of the other winding head in the axial direction, the winding heads can be arranged with axial overlap. This can reduce the installation space required for both winding heads in the axial direction.

[0018] According to the invention, in at least one sectional plane perpendicular to the axial direction in the axial section, wire ends of the winding or of one of the windings of a first of the electrical machines and wire ends of the winding or of one of the windings of a second of the electrical machines are arranged alternately in the circumferential direction. In other words, the wire ends of the two stators can interlock such that they alternate in the circumferential direction, i.e., are arranged alternately. Such an arrangement enables an identical design of the two stators, including their windings. The standardization thus enabled can simplify the manufacture of the stators and reduce effort and costs.

[0019] The interlocking wire ends can run straight in the axial direction in the axial section. Alternatively, wire ends that are not axially aligned and / or bent can interlock.

[0020] The welded wire ends of each stator can be distributed in at least one sectional plane perpendicular to the axial direction in a radial region on concentric circles of multiple diameters. For example, in one sectional plane, wire ends of the winding or one of the windings of a first electrical machine and wire ends of the winding or one of the windings of a second electrical machine can be arranged alternately on three or more circles extending concentrically around the common rotation axis, each in the circumferential direction of the winding heads.

[0021] For the electrical machine arrangement, an embodiment is particularly preferred in which each stator body has the same number of slots evenly distributed in the circumferential direction of the respective stator body for accommodating at least one conductor section of the respective winding or of one of the respective windings. The slots of one of the stator bodies are offset from one another in the circumferential direction by an angle that deviates by less than 20% or less than 10% from the quotient of 180° and the number of slots. The number of slots is the number of slots in one of the two stator bodies.

[0022] This facilitates the meshing of the welding-side winding heads, as no adjustment of the bending pattern of the winding heads is required. With identical winding patterns, such a rotation of the slots of one of the two stator bodies or stators results in a circumferential offset of the wire ends by the same angle. The wire ends are then positioned circumferentially at the gaps between the wire ends of the other stator and can be inserted into them axially. Both stators can have the same winding pattern, allowing the use of a standard winding pattern.

[0023] For example, if both stator bodies each have 54 slots, this would mean that the slots of the two stator bodies would have to be offset from each other in the circumferential direction of the winding heads by an angle of approximately 3.33°. The angular range can vary depending on the size of the welded wire ends and the number of slots in the stator body. If the welded wire ends take up less space in the circumferential direction or if the stator bodies have a relatively small number of slots, a larger angular range may be possible in which the slots of the stator bodies can be offset from each other in the circumferential direction to enable the wire ends on the welding side to mesh. Conversely, wire ends that take up more space in the circumferential direction and stator bodies with a high number of slots can result in the angular range becoming smaller.

[0024] Since potential differences can occur between the intermeshing angle heads of both electrical machines, a particularly preferred embodiment of the electrical machine arrangement provides for an insulating element to be arranged between the intermeshing winding heads of the electrical machine. In this way, the two intermeshing winding heads can be electrically insulated from one another. Despite possible potential differences, the intermeshing winding heads can thus be arranged in a space-saving manner. A so-called phase insulation can be used as the insulating element. This can be, for example, an insulating tape or a part made of insulating plastic. Additionally or alternatively, an insulating layer can also be produced, for example, by dipping the winding heads into an insulating medium and then curing it.With sufficiently strong insulation, the winding heads, especially the wire ends of the winding heads, can be arranged spatially close to one another.

[0025] Due to the interlocking of the welding-side winding overhangs, mounting the rotor shafts of both electrical machines between the two rotors on at least one stator of the electrical machines or a housing is difficult or cumbersome. In a preferred embodiment of the invention, it can therefore be provided that the rotor of one of the electrical machines or a rotor shaft connected in a rotationally fixed manner to this rotor and the rotor of the other electrical machine or a further rotor shaft connected in a rotationally fixed manner to this rotor are mounted on one another by at least one pivot bearing so as to be rotatable about the axis of rotation. By mounting the rotor shafts on one another, a bearing projecting outwards beyond the rotor shafts in the radial direction can be avoided. At the same time, the mounting of the rotor shafts on one another can be designed to be compact.

[0026] With regard to the bearing arrangement of the two rotor shafts, it is advantageous if one of the rotors or the rotor shaft of one of the rotors is designed, at least in part, particularly in the axial section, as a hollow shaft into which a shaft journal of the other rotor or the rotor shaft of the other rotor engages. This structural design allows an annular gap to be created between the two rotor shafts, which can be used to support the two rotor shafts relative to each other.

[0027] The hollow shaft section and / or the shaft journal can extend in the axial direction over an axial region of the respective rotor shaft. The axial region of each rotor shaft can, for example, begin at the end faces of the respective stator body or on the welding side outside the respective stator body and extend towards the other electrical machine. Alternatively, it is also possible for the hollow shaft section to extend in the axial direction into the interior of the rotor of the respective electrical machine. The hollow shaft section and the shaft journal can also extend over any axial region between the rotors of the two electrical machines or can also be arranged within one of the rotors.Advantageously, the hollow shaft section projects beyond the axial section of the intermeshing wire ends of both winding heads in the direction of the other electrical machine or in both directions and does not project into the rotor of the other electrical machine.

[0028] Alternatively, the two rotor shafts can be guided to each other only in sections in the circumferential direction. Furthermore, the rotor shafts can be mounted on each other in such a way that each rotor shaft can rotate independently of the other rotor shaft.

[0029] Furthermore, it is particularly preferred for at least one bearing to be arranged or formed between the hollow shaft and the shaft journal, supporting the hollow shaft and the shaft journal so as to be rotatable about the axis of rotation. The annular gap between the hollow shaft and the shaft journal can advantageously be used to arrange bearings, thereby enabling the two rotor shafts to be mounted very compactly against one another. For example, one or more ball bearings, rolling bearings and / or needle bearings can be arranged in the annular gap between the hollow shaft and the shaft journal. By using rolling bearings in an X or O arrangement, the two rotor shafts can absorb forces not only in the radial direction but also in the axial direction thanks to the bearings. Furthermore, it is also conceivable for an axial bearing to be installed between the base of the hollow shaft and the end face of the shaft journal to absorb axial forces.In contrast to ball and roller bearings, the use of one or more needle bearings can save installation space in the radial direction due to their narrow design.

[0030] Alternatively, it is possible that the inner surface of the hollow shaft and the outer surface of the shaft journal are each a sliding surface, and the rotor shafts are supported on each other by these sliding surfaces or a plain bearing.

[0031] Because the shaft journal engages the hollow shaft, a bearing arrangement can be created that counteracts any tilting of the hollow shaft and the shaft journal, or of the two rotor shafts, relative to each other, or prevents this completely by arranging several bearings spaced axially apart. Bearing arrangements using plain bearings or sliding surfaces can counteract tilting of the rotor shafts relative to each other particularly effectively.

[0032] In order to keep the required installation space for the electrical machine arrangement compact, the electrical machines can be accommodated in a common housing, with at least one bearing that rotatably supports the respective rotor shaft on the housing of each electrical machine being arranged between the housing and the rotor shaft or a respective rotor shaft that is firmly connected to the respective rotor. The common housing can save installation space and material. In combination with the previously described mounting of the two rotor shafts against one another, the additional bearings of the rotor shafts on the housing can provide complete mounting of the rotor shafts that is secured against tilting. A common housing for both electrical machines can also reduce manufacturing costs.The shared housing can also provide additional functionality, such as cooling cores for cooling the electrical machines and / or control electronics for controlling the electrical machines. Furthermore, the shared housing can also facilitate the installation of the electrical machine assembly in the motor vehicle, which offers an economic advantage.

[0033] In addition to the electrical machine assembly described above, the invention relates to a motor vehicle comprising at least one electrical machine assembly according to the invention. The previous statements regarding the electrical machine assembly also apply to the motor vehicle. The motor vehicle can, in particular, be a fully electrically powered motor vehicle.

[0034] In an advantageous embodiment of the invention, it can be provided that two wheels of an axle of the motor vehicle can be driven separately from one another by one of the electric machines of the machine arrangement. The electric machine arrangement can be installed on only one axle of the motor vehicle. Alternatively, an electric machine arrangement can be installed on each of the axles of the motor vehicle. Further advantageous embodiments of the invention emerge from the following exemplary embodiments, which are described with reference to

[0035] The figures are schematic representations and show: Fig. 1 shows an embodiment of an electrical machine arrangement according to the invention with intermeshing winding heads; Fig. 2 a detailed view of a section of the stators of the electrical machine arrangement from Fig. 1 in rolled up state; Fig. 3 a detailed view of the winding heads in section plane III - III of the Fig. 2; and Fig. 4 an embodiment of a motor vehicle according to the invention with an embodiment of an electrical machine arrangement according to the invention.

[0036] Fig. Figure 1 shows a schematic diagram of an electrical machine arrangement 1 with a first electrical machine 2 and a second electrical machine 3, as a sectional view. Both electrical machines 2, 3 each have a rotor 4, 5 and a rotor shaft 6, 7 connected in a rotationally fixed manner to the respective rotor 4, 5. The rotors 4, 5 and the rotor shafts 6, 7 are arranged coaxially with one another along a common rotation axis 8.

[0037] The stators 37, 38 of both electrical machines 2, 3 each have a stator body 9, 10. The electrical machine arrangement 1 shown as an example represents an axle twin coaxial drive (ATA drive), wherein the stators 37, 38 of the two electrical machines 2, 3 are identical in construction and their stator bodies 9, 10 are offset by a distance D in the axial direction.

[0038] Hairpin windings 31, 32 are incorporated into each of the stators 37, 38, forming winding heads 11, 12 that project axially beyond the stator bodies 9, 10 on both sides. The winding heads 11, each of which is oriented laterally outward, are formed by the bent sections of the hairpin wires. In contrast, the wire ends 13, 14 of the hairpin wires of the respective windings 31, 32, which are welded together in pairs, are arranged on the opposite winding heads 12, as can be seen particularly in the schematic representation of the windings 31, 32 in Fig. 2. The winding heads 12 each protrude in the axial direction by a length L1, L2 beyond their respective stator bodies 9, 10.

[0039] Fig. 2 additionally shows a section of the stators 37, 38 of both electrical machines 2, 3, viewed from their inside in a rolled-up state. The respective windings 31, 32 of the stators 37, 38 can be seen. Of the stator bodies 9, 10 themselves, only their stator teeth 33, 34, which delimit the slots 15, 16, can be seen. These teeth extend inward in the radial direction 35 between the hairpin wires or the sections of the windings 31, 32 extending through the slots 15, 16, since the rest of the respective stator body 9, 10 is concealed by the respective winding 31, 32, which is shown only in abstract form.

[0040] Both stator bodies 9, 10 have the same number of slots 15, 16 evenly distributed in the circumferential direction 36 of the respective stator body 9, 10 for receiving the windings 31, 32. Furthermore, the wire ends 13, 14 of the opposite winding heads 12 form in the radial direction 35, i.e. perpendicular to the image plane of the Fig. 2, rows (see Fig. 3).

[0041] A rotation of one of the two stator bodies 9, 10 around the common rotation axis 8 results in the winding heads 12, in particular the rows of wire ends 13, 14 extending in the radial direction 35, being rotated in the same way relative to one another. The resulting arrangement of the wire ends 13, 14 is shown in Fig. 3. With the same structure of the windings 31, 32 in the two stators 37, 38, the positions of radial rows of wire ends 13 of the winding overhang 12 of one of the stators 37 coincide with a respective gap between corresponding rows of wire ends 14 of the winding overhang 12 of the other stator 38, whereby the winding overhangs 12 of both electrical machines 2, 3 can be pushed into one another in the axial direction.

[0042] This results in the Fig. 2, in which in the axial section A and in the radial area R (see Fig. 1) In the circumferential direction 36 of the winding heads 12, wire ends 13 of the first stator 37 and wire ends 14 of the second stator 38 are arranged alternately next to one another. As a result, the distance D between the mutually facing end faces of both stator bodies 9, 10 in the axial direction is smaller than the sum of the lengths L1, L2 of the two mutually facing winding heads 12 of the electrical machines 2, 3 in the axial direction.

[0043] By interlocking the winding heads 12, the installation space required for the electrical machine assembly 1 can be reduced in the axial direction. The two winding heads 12 are, so to speak, pushed into one another in the axial direction, thereby saving installation space compared to conventional ATA drives.

[0044] In Fig. 3, the angle W by which the slots 15, 16 of the two stator bodies 9, 10 are rotated relative to each other is clearly visible due to the resulting twisted wire ends 13, 14. The view shown shows the intermeshing winding heads 12 of both electrical machines 2, 3 in the sectional plane 17. Each wire end 13, 14 is welded to another wire end 13, 14 of the same winding head 12. Thus, for example, in Fig. 3 the two wire ends 13 are welded together and the two wire ends 14 are welded together.

[0045] The angle W between the wire ends 13, 14 results from the mutually rotated slots 15, 16 of the respective stator bodies 9, 10 and can be calculated as the quotient of 180° and the number of slots 15, 16 of one of the two stator bodies 9, 10.

[0046] In Fig. 3 further shows that an insulating element 18 is arranged between the wire ends 13, 14 and thus between the winding heads 12. Since potential differences can occur between the two intermeshing winding heads 12, i.e., the wire ends 13, 14, of the electrical machines 2, 3, electrical insulation or additional insulation of the wire ends 13, 14 is provided by the insulating element 18. The insulating element 18 can, for example, be an insulating tape or a part made of insulating plastic. The insulating element 18 can extend in the axial direction over the entire axial section A to ensure sufficient insulation of the winding heads 12 from one another.

[0047] On Fig. Returning to Figure 1, this shows that the electrical machine arrangement 1 is arranged in a housing 19. The rotor shafts 6, 7 connected to the respective rotors 4, 5 of the two electrical machines 2, 3 are rotatably mounted on one another about the common axis of rotation 8 by a pivot bearing 20. In the exemplary embodiment, the pivot bearing is formed in that the rotor shaft 7 is designed as a hollow shaft 21 in an axial region. In addition, the second rotor shaft 6 is designed as a shaft journal 22 in an axial region, which engages in the section of the rotor shaft 7 designed as a hollow shaft 21.

[0048] This axial engagement creates an annular gap 23 between the hollow shaft 21 and the shaft journal 22, which accommodates the bearings 24. The two bearings 24 between the hollow shaft 21 and the shaft journal 22 support the two rotor shafts 6, 7 so that they can rotate around the common rotation axis 8.

[0049] The two bearings 24 primarily serve to absorb radial forces. If necessary, it is also possible to provide an additional axial bearing between the bottom of the hollow shaft 21 and the end face of the shaft journal 22 in order to also absorb forces acting on the rotor shafts 6, 7 in the axial direction. The fact that the hollow shaft 21 and the shaft journal 22 mesh with each other for support and that two bearings 24 offset in the axial direction are provided counteracts tilting of the two rotor shafts 6, 7.

[0050] In addition, each rotor shaft 6, 7 is rotatably mounted on the housing 19 by means of a bearing 25. Both rotor shafts 6, 7 can thus rotate independently of one another about the common axis of rotation 8, whereby the design of the pivot bearing 20 by means of the hollow shaft 21 and the shaft journal 22 ensures a compact mounting of the two rotor shafts 6, 7 to one another. By means of a pivot bearing 20 designed in this way, additional mounting of the rotor shafts 6, 7 in the axial section A or between the stators 37, 38 on the rotationally fixed stator bodies 9, 10 or on the housing 19 can be avoided. Such bearings would require a large amount of installation space, would conflict with a compact design of the electrical machine arrangement 1, and could under certain circumstances disrupt the field distribution in the stators 37, 38.

[0051] Ball bearings or roller bearings can be used as bearing 24. It is also recommended, as described in the Fig. 1, the use of axially offset bearings 24, in particular roller bearings in an X or O arrangement, is possible in order to also absorb forces acting in the axial direction on the two rotor shafts 6, 7. If the annular gap 23 is very narrow in the radial direction 35, one or more needle bearings can be provided, for example, to support the two rotor shafts 6, 7 against one another. In addition, ball or roller bearings, preferably in an X or O arrangement, can also be installed as bearings 25 between the rotor shafts 6, 7 and the housing 19.

[0052] Alternatively, the pivot bearing 20 can also be implemented without a bearing 24 and with sliding surfaces on the rotor shafts 6, 7 or the inner surface of the hollow shaft 21 and the outer surface of the shaft journal 22. The use of a plain bearing in the annular gap 23 is also conceivable. Regardless of the bearing variant, a particularly high degree of stability against tilting of the two rotor shafts 6, 7 can be achieved by sliding the two rotor shafts 6, 7 against each other.

[0053] The Fig. 4 schematically shows a motor vehicle 26 with the electrical machine arrangement 1 from Fig. 1 to Fig.3 on a rear axle 27 of the motor vehicle 26. The two independently rotatable rotor shafts 6, 7 are each connected directly or indirectly to one of the wheels 28 of the rear axle 27 in a torque-transmitting manner. For example, it is possible for the rotor shafts 6, 7 of the electric motors 2, 3 to be indirectly connected to the wheels 28 via a transmission and an additional output shaft.

[0054] The electric machine arrangement 1 can alternatively or additionally also be provided on a front axle 29 of the motor vehicle 26 in order to drive the two wheels 30 on the front axle 29 independently of one another. Because each of the two electric machines 2, 3 of the electric machine arrangement 1 can drive a wheel 28, 30 independently of the other electric machine 2, 3, the speed of each wheel 28, 30 can be individually adapted to the driving situation of the motor vehicle 26.

[0055] The electrical machine arrangement 1 with intermeshing winding heads 12 of the electrical machines 2, 3 results in installation space savings in the axial direction of the electrical machine arrangement 1. The housing 19 of the electrical machine arrangement 1 can be made smaller and thus lighter and more compact. The achieved weight savings can reduce the overall weight of the motor vehicle 26 and thus increase its efficiency. Furthermore, due to the installation space savings in the axial direction, more room is available for the suspension, chassis, shock absorbers or other components, which represents a significant improvement over conventional drives with electrical machines 2, 3, in particular ATA drives. Alternatively, the track width of the respective axle 27, 29 can be reduced with the electrical machine arrangement 1.

Claims

[1] Electrical machine arrangement (1), comprising two coaxially arranged electrical machines (2, 3), each having a rotor (4, 5) and a stator (37, 38), wherein the rotor (4, 5) of the respective electrical machine (2, 3) is rotatable independently of the rotor (4, 5) of the other electrical machine (2, 3), wherein the rotors (4, 5) have a common axis of rotation (8) extending in the axial direction of the machine arrangement (1), wherein the stators (37, 38) each have a stator body (9, 10) and at least one winding (31, 32) with winding heads (11, 12) projecting in the axial direction on both sides beyond the respective stator body (9, 10), wherein the mutually facing winding heads (12) of the electrical machines (2, 3) overlap in the radial direction (35), wherein the distance (D) between the stator bodies (9, 10) in the axial direction is smaller than the sum of the lengths (L1,L2) of the two mutually facing winding heads (12) of the electrical machines (2, 3) in the axial direction, so that the winding heads (12) engage with each other in an axial section (A) of the machine arrangement (1), , characterized by in that the windings (31, 32) of the electrical machines (2, 3) are hairpin windings (31, 32) with a multiplicity of hairpin wires, wherein at least some wire ends (13, 14) of the hairpin wires of the respective electrical machine (2, 3) are welded to one another in pairs within the axial section (A) of the machine arrangement (1), wherein in at least one sectional plane (17) perpendicular to the axial direction in the axial section (A) in the circumferential direction (36) wire ends (13) of the winding (31) or of one of the windings (31, 32) of a first of the electrical machines (2) and wire ends (14) of the winding (32) or of one of the windings (31, 32) of a second of the electrical machines (3) are arranged alternately. [2] Electrical machine arrangement (1) according to claim 1, characterized by in that each stator body (9, 10) has an equal number of slots (15, 16) evenly distributed in the circumferential direction (36) of the respective stator body (9, 10) for receiving at least one conductor section of the respective winding (31, 32) or of one of the respective windings (31, 32), wherein the slots (15, 16) of one of the stator bodies (9, 10) are offset from one another in the circumferential direction (36) by an angle (W) which deviates by less than 20% or less than 10% from the quotient of 180° and the number of slots. [3] Electrical machine arrangement (1) according to one of the preceding claims, characterized by that an insulating element (18) is arranged between the intermeshing winding heads (12) of the electrical machines (2, 3). [4] Electrical machine arrangement (1) according to one of the preceding claims, characterized by that the rotor (4, 5) of one of the electrical machines (2, 3) or a rotor shaft (6, 7) connected in a rotationally fixed manner to this rotor (4, 5) and the rotor (4, 5) of the other electrical machine (2, 3) or a further rotor shaft (6, 7) connected in a rotationally fixed manner to this rotor (4, 5) are mounted on one another by at least one rotary bearing (20) so as to be rotatable about the rotation axis (8). [5] Electrical machine arrangement (1) according to claim 4, characterized by that one of the rotors (4, 5) or the rotor shaft (6, 7) of one of the rotors (4, 5) is designed at least in sections as a hollow shaft (21) into which a shaft journal (22) of the respective other rotor (4, 5) or of the rotor shaft (6, 7) of the respective other rotor (4, 5) engages. [6] Electrical machine arrangement (1) according to claim 5, characterized bythat one of the rotors (4, 5) or the rotor shaft (6, 7) of one of the rotors (4, 5) is designed in the axial section (A) as the hollow shaft (21) into which the shaft journal (22) of the other rotor (4, 5) or the rotor shaft (6, 7) of the other rotor (4, 5) engages. [7] Electrical machine arrangement (1) according to claim 5 or 6, characterized by that between the hollow shaft (21) and the shaft journal (22) at least one bearing (24) is arranged or formed which supports the hollow shaft (21) and the shaft journal (22) rotatably about the rotation axis (8). [8] Electrical machine arrangement (1) according to one of the preceding claims, characterized bythat the electrical machines (2, 3) are accommodated in a common housing (19), wherein between the housing (19) and the or a respective rotor shaft (6, 7) fixedly connected to the respective rotor (4, 5) of each electrical machine (2, 3) at least one bearing (25) is arranged in each case, which supports the respective rotor shaft (6, 7) rotatably on the housing (19). [9] Motor vehicle (26) comprising at least one electrical machine arrangement (1) according to one of the preceding claims. [10] Motor vehicle (26) according to claim 9, characterized by that two wheels (28, 30) of an axle (27, 29) of the motor vehicle (26) can be driven separately from one another by one of the electrical machines (2, 3) of the machine arrangement (1).

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