stator

Abstract

The invention relates to a stator (1) having a plurality of circumferentially arranged stator grooves (2) which extend axially through the stator (1) and in which a plurality of electrical conductors (3) in the form of hairpins (8, 9, 10, 11) are provided so as to form a stator winding (4) having radially adjacent winding layers (5), wherein the electrical conductors (3) comprise the following types of hairpins (8, 9, 10, 11): standard hairpins (8), the free ends of which positioned in a winding head (12) are designed so as to establish an electrical contact between an even winding layer (5) and an odd winding layer (5); layer-changing pins (9), the free ends of which positioned in a winding head (12) are designed so as to establish an electrical contact between an odd winding layer (5) and an odd winding layer (5) lying radially thereunder; inverter pins (10), the free ends of which positioned in a winding head (12) are designed so as to establish an electrical contact in order to reverse the current direction; I-pins (11) which are positioned neither on the innermost nor on the outermost winding layer (5); and at least one HV terminal (6) which is provided on the hairpin head side (13) and is connected to end wires (7) of the stator winding (4), the end wires (7) being situated in central winding layers (5) of the stator (1), and the inverter pins (10) being situated both in an innermost winding layer (5) and in an outermost winding layer (5).

Description

[0001] stator

[0002] The present invention relates to a stator with a plurality of circumferentially arranged stator slots extending axially through the stator, in which several electrical conductors designed as hairpins are arranged to form a stator winding with radially adjacent winding layers.

[0003] Various stator winding designs for electrical machines are known in the art, particularly those with distributed windings such as hairpin or wave windings. While these windings offer advantages in terms of power and efficiency, they also present significant disadvantages and challenges that affect the design and operation of the electrical machines. A key aspect in the design of stators with distributed windings is the size of the high-voltage (HV) terminal. A large HV terminal introduces several problems. First, material costs are high because long copper busbars are required to make the electrical connections within the stator winding. Second, the long length of the copper busbars leads to increased winding resistance, which reduces the efficiency of the electrical machine and causes energy losses.Third, the low stiffness and high mass of the long copper busbars make the stator winding susceptible to mechanical vibrations, which can lead to mechanical damage and a reduced winding lifespan. Fourth, a large HV terminal requires more space within the machine, making the overall design bulkier and heavier, and complicating the integration of the machine into various applications.

[0004] Another disadvantage of conventional stator windings is the dependence of the HV terminal circumference on the number of pole pairs. By default, the circumference of the HV terminal corresponds to the circumference of the I-pins of the winding. This rule states that the circumference of the I-pin is 360° divided by the number of pole pairs. A winding with eight poles (four pole pairs) thus has an I-pin circumference of 90°. With six poles (three pole pairs), the circumference is 120°. A small number of pole pairs therefore increases the circumference of the terminal wires, which further exacerbates the aforementioned problems. The design of the HV terminal for stators with distributed windings is particularly complex when the circumference of the terminal wires is very wide. This situation occurs especially with a small number of pole pairs. The number of pole pairs also affects the rotor speed: A rotor with half the number of pole pairs rotates twice as fast.Therefore, it would be advantageous to reduce the diameter of the terminal wires without changing the number of pole pairs in order to minimize the aforementioned problems.

[0005] Documents US2021006115A and US2020149169A show stators with hairpin windings that also exhibit the aforementioned challenges.

[0006] The object of the invention is therefore to provide a stator that avoids or at least reduces the problems known from the prior art.

[0007] This problem is solved by a stator with a plurality of circumferentially arranged stator slots extending axially through the stator, in which several electrical conductors designed as hairpins are arranged to form a stator winding with radially adjacent winding layers, wherein the electrical conductors comprise the following types of hairpins:

[0008] • Standard hairpins whose free ends, positioned in a winding head, are designed to enable electrical contact from an even winding layer to an odd winding layer;

[0009] • Layer change pins, whose free ends positioned in a winding head are designed to enable electrical contact from an odd winding layer to a radially below it; • Inverter pins, whose free ends positioned in a winding head are designed to enable electrical contact for reversing the current direction;

[0010] • I-pins that are neither located on the innermost nor on the outermost winding layer; and at least one HV terminal located on the hairpin head side, which is connected to end wires of the stator winding, wherein the end wires are located in middle winding layers of the stator, and the inverter pins are located in both an innermost winding layer and an outermost winding layer.

[0011] This allows for the realization of a stator where the design of the high-voltage terminal can be significantly simplified and made more compact. By arranging the end wires in the middle winding layers, the circumference of the high-voltage terminal is reduced, resulting in less material usage and thus cost savings. Furthermore, the winding resistance is reduced because the length of the copper busbars is minimized. This increases the efficiency of the stator winding and reduces its sensitivity to vibrations.

[0012] First, the individual elements of the claimed subject matter of the invention are explained in the order in which they are mentioned in the claim set, and subsequently, particularly preferred embodiments of the subject matter of the invention are described.

[0013] Electrical conductors

[0014] For the purposes of this patent application, an electrical conductor is an electrical component used to conduct and transmit electric current. An electrical conductor is preferably made of a material with high electrical conductivity, such as copper or aluminum.

[0015] In the context of this invention, the conductors are designed as hairpins that are inserted into the stator slots to form an efficient and compact stator winding. The hairpins used as conductors are preferably designed to be anchored in the stator slots and to ensure a stable mechanical connection.

[0016] Copper is the preferred material for the electrical conductors because its excellent electrical conductivity and good workability make it ideally suited for this application. Copper conductors have low electrical losses and are mechanically stable. Aluminum can also be used as a conductor material. Aluminum is lighter than copper, which reduces the overall weight of the stator. Although aluminum has lower conductivity than copper, this can be compensated for by using larger cross-sections.

[0017] The conductors can be manufactured in various shapes and cross-sections. Round conductor cross-sections are easy to produce and offer good mechanical stability. Rectangular conductor cross-sections can be advantageously used for a more compact winding, as they make better use of the available space in the stator slots. Profiled conductors can meet special requirements for cooling and mechanical integration.

[0018] Preferably, the conductors are insulated to prevent short circuits between adjacent windings and to ensure electrical safety. Insulation can be achieved by a coating or sheathing made of suitable insulating material, such as enamel or plastic.

[0019] Stator winding

[0020] For the purposes of this patent application, a stator winding is an arrangement of several electrical conductors configured as hairpins, arranged in a plurality of radially adjacent winding layers within the stator slots of a stator. The stator winding serves, in particular, to generate a magnetic field when energized, which, in interaction with the rotor, produces a torque and thus enables the drive of the machine.

[0021] The stator winding consists of a plurality of electrical conductors, which are advantageously configured as hairpins (e.g., standard hairpins, layer change pins, inverter pins, and I-pins). These hairpins are preferably shaped such that their free ends are positioned in a winding head, which enables electrical contact between different winding layers.

[0022] The stator winding can be implemented in various configurations with different numbers of winding layers. For example, it is conceivable that the stator winding comprises four, six, or eight winding layers. A stator winding with four winding layers offers several specific advantages. The fewer number of winding layers reduces manufacturing complexity, resulting in lower production costs. The simpler design allows for faster and more efficient winding production. Furthermore, heat dissipation is more effective with fewer winding layers because the thermal resistance is lower and heat can be more easily transferred to the environment. This leads to improved thermal stability of the stator winding. In addition, the mechanical stress on each winding layer is lower, which increases the reliability and robustness of the winding.

[0023] A stator winding with six layers offers a balanced combination of packing density and heat dissipation. The higher number of layers compared to a four-layer winding allows for a greater quantity of copper wire, increasing the electrical performance and efficiency of the stator winding. At the same time, heat dissipation remains sufficiently effective to prevent overheating. Distributing the electrical conductors across six layers enables a more uniform current distribution and reduces local hotspots, thus improving the thermal stability and reliability of the winding.

[0024] A stator winding with eight winding layers offers the highest packing density and therefore the greatest electrical performance among the configurations mentioned. This configuration allows for the use of a maximum amount of copper wire, resulting in increased current density and improved magnetic flux characteristics. The high packing density maximizes the power output of the electric machine and improves its efficiency.

[0025] Although heat dissipation is more challenging with a higher number of winding layers, this can be compensated for by suitable cooling methods and materials. The eight winding layers allow for fine-tuning of the winding geometry, which optimizes electromagnetic efficiency and reduces harmonic losses. Furthermore, the uniform distribution of mechanical stresses across the eight winding layers provides high mechanical stability and reliability of the winding.

[0026]

[0027] For the purposes of this patent application, a winding layer is a specific layer within a stator winding in which the electrical conductors, in particular hairpins, are arranged. Each winding layer extends radially over a specific position within the stator and can be either straight or coiled. The winding layers are radially adjacent to each other and together form the entire stator winding, which is responsible for generating the electromagnetic field.

[0028] The winding layers play a central role in generating the electromagnetic field in the stator. The arrangement and connection of the hairpins in the winding layers creates a magnetic field that interacts with the rotor, thus enabling its rotation. The correct positioning and connection of the hairpins in the various winding layers is crucial for the motor's functionality and performance.

[0029] The winding layers can be configured as straight windings, helical windings, or differentiated windings. Straight windings are linear and are preferred for applications requiring high mechanical stability and ease of manufacture. Helical windings have a spiral or otherwise coiled structure and offer the advantage of a more uniform magnetic field distribution. They are advantageous for applications requiring high efficiency and uniform field distribution. Differentiated windings combine various types of hairpins within one and / or multiple winding layers to achieve specific electrical and magnetic properties. This configuration is particularly advantageous for customized applications where specific performance parameters need to be optimized.

[0030] HV terminal

[0031] For the purposes of this patent application, an HV terminal is a high-voltage terminal used for the electrical connection of the stator winding to external power sources or electrical circuits. It is an electrical component that organizes the electrical connection of the stator winding's end wires and enables efficient and safe current flow.

[0032] The HV terminal is designed to accommodate and connect multiple end wires of the stator winding. These end wires are advantageously extensions of the electrical conductors, configured as hairpins.

[0033] The main function of the HV terminal is therefore to electrically connect the end wires of the stator winding and to direct the current flow to the corresponding external components. This is advantageously achieved by an arrangement of busbars and / or terminals that receive and secure the end wires.

[0034] The HV terminal advantageously consists of an insulating base plate on which several busbars and / or terminals are mounted. These busbars are arranged to accommodate the end wires of the stator winding and ensure a secure electrical connection. The busbars can be made of conductive material such as copper or aluminum and are preferably provided with an insulating coating to prevent short circuits.

[0035] Preferably, the high-voltage terminal can comprise four busbars, three of which are for the phases and one for the neutral point. The busbars for the phases are arranged radially outwards, and the busbar for the neutral point is arranged radially inwards. This arrangement enables a compact and space-saving design of the high-voltage terminal and ensures that heat generation is distributed evenly.

[0036] The HV terminal can also be designed in a modular style, with individual modules for different phases or functions. These modules can be added or removed as needed to increase the flexibility and adaptability of the HV terminal. This design is particularly advantageous for applications requiring different configurations or expansions. End wires

[0037] For the purposes of this patent application, end wires are the sections of electrical conductors arranged in the winding heads of the stator and used for the electrical connection of the windings to each other and to external connections, such as high-voltage terminals. These end wires advantageously extend axially from the respective winding head to enable easy assembly and reliable electrical contact. The end wires can be designed as extensions of the hairpins.

[0038] Standard hairpin

[0039] For the purposes of this patent application, standard hairpins are to be understood as electrical conductors arranged in stator slots, transitioning from an even winding layer to an odd winding layer or vice versa. These standard hairpins are designed such that their free ends, positioned in a winding head, enable electrical contact between two adjacent winding layers.

[0040] The standard hairpin design essentially comprises two electrically connected sections extending axially through the stator slot, and two ends positioned in one of the winding heads. The ends are shaped to establish a reliable electrical connection between adjacent winding layers. These connections are preferably made by welding or brazing to ensure a durable and stable electrical contact.

[0041] Advantageously, standard hairpins can be manufactured from conductive materials such as copper or aluminum to ensure high electrical conductivity. The surface of the hairpins can be additionally coated or insulated to prevent corrosion and improve electrical insulation. Preferred embodiments of standard hairpins include various geometric shapes and sizes that can be adapted to the specific requirements of the stator winding. One possible embodiment is the use of round or rectangular cross-sections, which can be selected depending on space requirements and winding configuration. Another conceivable embodiment is the integration of cooling channels or other thermal management structures to improve heat dissipation within the winding and reduce the operating temperature of the electric machine.

[0042]

[0043] For the purposes of this patent application, position change pins are electrical conductors that are arranged in stator slots and are designed to provide electrical contact between an odd winding layer and a radially below it odd winding layer.

[0044] The layer change pins are formed from an electrically conductive material, preferably copper. Layer change pins can also be provided with additional insulating layers to prevent short circuits and increase electrical safety. Their free ends are arranged in a winding head and designed to establish a reliable electrical connection between the winding layers. These pins thus traverse different winding layers, enabling the transfer of electric current from an odd-numbered winding layer to an underlying odd-numbered winding layer.

[0045] Preferred embodiments of the position change pins include various geometric shapes and sizes that can be adapted to the specific requirements of the stator winding. One possible embodiment is the use of round or rectangular cross-sections, which can be selected depending on space requirements and winding configuration. These cross-sections allow for optimal adaptation to the available space within the stator slots and ensure efficient electrical contact. Another advantageous embodiment is the integration of cooling channels or other thermal management structures into the position change pins. These cooling channels improve heat dissipation within the winding and help to reduce the operating temperature of the electric machine. By reducing the operating temperature, the service life of the winding is extended and the overall performance of the machine is increased.

[0046] Inverter pins, as defined in this patent application, are electrical conductors in the form of hairpins used to reverse the current direction in the stator winding. The inverter pins are designed such that their free ends, positioned in a winding head, create an electrical contact to reverse the current direction. This means that the inverter pins change the current flow in the winding by directing the current in the opposite direction.

[0047] The inverter pins are made of a conductive material, preferably copper, and are shaped to fit into the stator slots. They are typically designed to extend axially through the stator. The inverter pins feature a specific design for their ends, which are located in the winding heads. These ends are shaped to create a secure and reliable electrical connection that directs the current in the opposite direction.

[0048] Preferred embodiments of the inverter pins include various geometric shapes and sizes that can be adapted to the specific requirements of the stator winding. One possible embodiment is the use of round or rectangular cross-sections, which can be selected depending on space requirements and winding configuration. These cross-sections allow for optimal adaptation to the available space within the stator slots and ensure efficient electrical contact. Another advantageous embodiment is the integration of cooling channels or other thermal management structures into the inverter pins. These cooling channels improve heat dissipation within the winding and help to reduce the operating temperature of the electric machine. By reducing the operating temperature, the service life of the winding is extended and the overall performance of the machine is increased.

[0049] I-Pins

[0050] For the purposes of this patent application, I-pins are electrical conductors positioned as interface wires within the stator winding. Unlike U-shaped hairpins, I-pins are straight, with their ends positioned at different winding head ends. I-pins serve to electrically connect different winding layers of the stator.

[0051] Preferred embodiments of the I-pins include various geometric shapes and sizes that can be adapted to the specific requirements of the stator winding. One possible embodiment is the use of round or rectangular cross-sections, which can be selected depending on space requirements and winding configuration. These cross-sections allow for optimal adaptation to the available space within the stator slots and ensure efficient electrical contact. Another advantageous embodiment is the integration of cooling channels or other thermal management structures into the I-pins. These cooling channels improve heat dissipation within the winding and help to reduce the operating temperature of the electric machine. By reducing the operating temperature, the service life of the winding is extended and the overall performance of the machine is increased.

[0052] Advantageous embodiments of the invention

[0053] According to an advantageous embodiment of the invention, the end wires of the stator winding can be formed by the I-pins. This reduces the complexity of the winding and simplifies the manufacture of the stator. Since the I-pins are located neither on the innermost nor on the outermost winding layer, a uniform distribution of the electrical conductors in the middle winding layers is achieved. This can also contribute to improved mechanical stability and a more uniform heat distribution within the stator.

[0054] The object of the invention can also be achieved by a stator with a plurality of circumferentially arranged stator slots extending axially through the stator, in which several electrical conductors designed as hairpins are arranged to form a stator winding with radially adjacent winding layers, wherein the electrical conductors comprise the following types of hairpins: • Standard hairpins, the free ends of which are positioned in a winding head and are designed to provide electrical contact from an even winding layer to an odd winding layer;

[0055] • Layer change pins, whose free ends positioned in a winding head are designed to enable electrical contact from an odd winding layer to a radially below it; • Inverter pins, whose free ends positioned in a winding head are designed to enable electrical contact for reversing the current direction;

[0056] and at least one HV terminal arranged on the twist side, which is connected to end wires of the stator winding, wherein the end wires are formed from extensions of standard hairpins, inverter pins or layer change pins and are arranged in adjacent winding layers, and the end wires are arranged in adjacent winding layers and the inverter pins are arranged in both the innermost winding layer and the outermost winding layer.

[0057] This stator design offers the advantage that the hairpin extensions can be arranged in adjacent winding layers, enabling efficient and compact winding. Positioning the end wires in adjacent winding layers increases mechanical stability and improves the electrical connection between the windings. Furthermore, this arrangement reduces the size of the high-voltage terminal, resulting in less material usage and lower costs. Winding resistance is reduced because the length of the copper busbars is minimized, increasing the efficiency of the stator winding and decreasing its sensitivity to vibrations.

[0058] Furthermore, according to another advantageous embodiment of the invention, at least one of the end wires, preferably a plurality of end wires, may have a post-bend in the radial direction towards a radially adjacent winding. These post-bends facilitate the design of the HV terminal and allow for a more compact arrangement of the end wires. This leads to a further reduction in material usage and manufacturing costs. In addition, this measure can also reduce the mechanical stress on the end wires.

[0059] According to a further particularly preferred embodiment of the invention, the HV terminal can be configured for a neutral point connection, comprising four busbars, wherein three busbars are provided for the phases and one busbar for the neutral point, and the busbars for the phases are arranged radially outwards and the busbar for the neutral point radially inwards. The arrangement of the busbars for the phases radially outwards and the busbar for the neutral point radially inwards ensures a compact and space-saving design. This reduces the required installation space and improves the mechanical stability of the HV terminal. Furthermore, heat generation is distributed more evenly.

[0060] Furthermore, the invention can also be further developed such that the HV terminal is configured for a delta connection. This type of connection enables flexible and efficient use of the stator winding by balancing different phase currents and ensuring a uniform power output. The delta connection reduces the need for additional circuits and components, which lowers the overall cost and complexity of the electrical machine.

[0061] In a preferred embodiment of the invention, the stator can also have six or fewer poles, thereby realizing several technical and economic advantages. Firstly, using a stator with six or fewer poles increases the rotor speed, as the rotor completes two revolutions per pole pair. This leads to a higher power density and efficiency of the electric machine. Furthermore, reducing the number of pole pairs allows for a more compact stator design, which reduces the required installation space and facilitates integration into various applications. The simpler design and lower number of poles also reduce manufacturing costs and material usage, resulting in economic benefits. The invention will now be explained in more detail with reference to figures, without limiting the general concept of the invention.

[0062] It shows:

[0063] Figure 1 shows a first embodiment of a stator winding in a perspective view,

[0064] Figure 2 shows a perspective detail view of the end wires of the first embodiment of the stator winding from Figure 1.

[0065] Figure 3 shows an HV terminal mounted on the end wires from Figure 2 in a perspective view.

[0066] Figure 4 shows a top view of the end wire area of ​​the first embodiment of the stator winding,

[0067] Figure 5 shows a slot layout and wiring diagram of the first embodiment of the stator winding,

[0068] Figure 6 shows a second embodiment of a stator winding in a first perspective view,

[0069] Figure 7 shows a second embodiment of a stator winding in a second perspective view,

[0070] Figure 8 shows a top view of the end wire area of ​​the second embodiment of the stator winding.

[0071] Figure 9 shows a slot layout and wiring diagram of the second embodiment of the stator winding, Figure 10 shows a standard hairpin, a position change pin, an inverter pin and an I-pin, each in a perspective view.

[0072] Figure 11 shows a wound stator of an electric machine in a cross-sectional view,

[0073] Figure 12 shows a third embodiment of a stator winding in a perspective view,

[0074] Figure 13 shows a slot layout and wiring diagram of the third embodiment of the stator winding.

[0075] Figures 1-4 show a stator winding 4 for a stator 1 with a plurality of circumferentially arranged stator slots 2 extending axially through the stator 1, as also sketched in Figure 11. Several electrical conductors 3, configured as hairpins 8, 9, 10, 11, are arranged in the stator slots 2 to form the stator winding 4 with radially adjacent winding layers 5.

[0076] In the first embodiment of the stator winding 4 shown, the electrical conductors 3 comprise the following types of hairpins 8, 9, 10, 11: standard hairpins 8, whose free ends, positioned in a winding head 12, are configured to provide electrical contact from an even winding layer 5 to an odd winding layer 5; layer change pins 9, whose free ends, positioned in a winding head 12, are configured to provide electrical contact from an odd winding layer 5 to a radially below it odd winding layer 5; inverter pins 10, whose free ends, positioned in a winding head 12, are configured to provide electrical contact for reversing the current direction; and I-pins 11, which are not located on either the innermost or the outermost winding layer 5.

[0077] Furthermore, the stator winding 4 has an HV terminal 6 arranged on the hairpin head side 13, which is connected to end wires 7 of the stator winding 4, as can be clearly seen in Figure 3. In Figure 2, the area of ​​the end wires 7 is shown without the HV terminal 6. In the embodiment shown, a plurality of end wires 7 have a post-bend in the radial direction towards a radially adjacent winding length 5. This post-bend allows the busbars 21, 22, 23 provided for the phases to be arranged only radially outwards.

[0078] Figure 3 further shows that the HV terminal 6 is configured for a star point connection, comprising four busbars 21, 22, 23, 24, wherein three busbars 21, 22, 23 are provided for the phases and one busbar 24 for the star point, and the busbars 21, 22, 23 for the phases are arranged radially outside and the busbar 24 for the star point is arranged radially inside.

[0079] The end wires 7 are arranged in the middle winding layers 5 of the stator 1, while the inverter pins 10 are positioned in both an innermost winding layer 5 and an outermost winding layer 5. This can be clearly seen in Figure 4.

[0080] Figures 1-4 also show that the end wires 7 of the stator winding 4 are formed by the I-pins 11.

[0081] In the first embodiment of the stator winding 4, the HV terminal 6 is arranged on the hairpin head side 13 of the stator 1. This embodiment includes various types of hairpins, namely standard hairpins 8, shift pins 9, inverter pins 10, and I-pins 11.

[0082] The standard hairpins 8 have free ends positioned in a winding head 12, configured to provide electrical contact from an even winding layer 5 to an odd winding layer 5. Layer change pins 9 have free ends positioned in a winding head 12, configured to provide electrical contact from an odd winding layer 5 to a radially below it, odd winding layer 5. Inverter pins 10 have free ends positioned in a winding head 12, configured to provide electrical contact for reversing the current direction. The I-pins 11 are arranged so that they are not located on either the first or the last winding layer 5. Preferably, the I-pins 11 can be located on the second and third winding layers 5 in a stator with four winding layers 5.In a stator with six winding layers 5, the I-pins 11 can be arranged on the second and third winding layer 5 or on the fourth and fifth winding layer 5. In a stator with eight winding layers 5, the I-pins 11 can be positioned on the second and third, fourth and fifth, or sixth and seventh winding layer 5.

[0083] The inverter pins 10 are arranged in both the innermost and the outermost winding layer 5.

[0084] This first embodiment enables a compact and efficient design of the HV terminal 6 by positioning the end wires 7 in the middle winding layers 5. This reduces the size of the HV terminal 6 and decreases material usage and manufacturing costs. At the same time, the winding resistance is minimized, which increases the efficiency of the stator winding 4 and reduces its sensitivity to vibrations.

[0085] The slot layout plan in Figure 5 clearly shows that the end wires 7 are arranged in the middle winding layers 5 of the stator 1, and

[0086] The inverter pins 10 are arranged in both an innermost winding layer 5 and an outermost winding layer 5. In the illustrated embodiment, the stator 1 has 48 stator slots 2, each filled with four electrical conductors 3. In the embodiment shown in Figure 5, stator slots 1-6 and 7-12 are equipped with inverter pins 10. The end wires 7 are positioned in stator slots 7-12. In this embodiment, the HV terminal 6 is arranged on the insertion side of the stator winding 4.

[0087] Figures 6-8 show an alternative embodiment of a stator winding 4 in which the electrical conductors 3 comprise the following types of hairpins 8, 9, 10: standard hairpins 8, layer-change pins 9, and inverter pins 10. Standard hairpins 8 have free ends positioned in a winding head 12, configured to provide electrical contact from an even winding layer 5 to an odd winding layer 5. Layer-change pins 9 have free ends positioned in a winding head 12, configured to provide electrical contact from an odd winding layer 5 to a radially below it, also an odd winding layer 5. Inverter pins 10 have free ends positioned in a winding head 12, configured to provide electrical contact for reversing the current direction.

[0088] On the twist side 14 an HV terminal 6 is arranged, which is connected to end wires 7 of the stator winding 4, wherein the end wires 11 are formed from extensions of standard hairpins 8, inverter pins 10 or layer change pins 9 and are arranged in adjacent winding layers 5.

[0089] The inverter pins 10 are arranged in both the innermost winding layer 5 and the outermost winding layer 5.

[0090] In this second embodiment of the invention, the HV terminal 6 is thus arranged on the twist side 14 of the stator 1. This embodiment includes various types of hairpins, namely standard hairpins 8, shift pins 9, and inverter pins 10. Unlike in the first embodiment of Figures 1-4, no I-pins 11 are used.

[0091] The standard hairpins 8 have free ends positioned in a winding head 12, configured to provide electrical contact from an even winding layer 5 to an odd winding layer 5. Layer change pins 9 have free ends positioned in a winding head 12, configured to provide electrical contact from an odd winding layer 5 to a radially below it, odd winding layer 5. Inverter pins 10 have free ends positioned in a winding head 12, configured to provide electrical contact for reversing the current direction. The end wires 7 consist of extensions of the standard hairpins 8, inverter pins 10, or layer change pins 9 and are arranged in adjacent winding layers 5. In a stator with four winding layers 5, the end wires 7 can, for example, be positioned in layers 1 and 2, 2 and 3, or 3 and 4.In a stator with six winding layers 5, the end wires 7 can be positioned in layers 1 and 2, 2 and 3, 3 and 4, 4 and 5 or 5 and 6.

[0092] The inverter pins 10 are arranged in both the innermost and outermost winding layers 5. This arrangement of the inverter pins 10 ensures effective current reversal. It may be advantageous to bend the middle end wires 7 to simplify the design of the HV terminal 6. These bends allow for a more compact arrangement of the end wires 7 and facilitate integration into the stator winding 4.

[0093] This second embodiment of a stator winding 4 also enables an efficient and compact design of the HV terminal 6 by positioning the end wires 7 in the adjacent winding layers 5. This reduces the size of the HV terminal 6 and decreases material usage and manufacturing costs. At the same time, the winding resistance is minimized, which increases the efficiency of the stator winding 4 and reduces its sensitivity to vibrations.

[0094] Figure 9 shows a slot layout plan for an embodiment of the stator 1, in which the HV terminal 6 is arranged on the twist side of the stator winding 4.

[0095] Figures 12 and 13 illustrate a third embodiment of a stator winding in a perspective view and a slot layout and wiring diagram, respectively. Figure 12 shows that—unlike in the previously discussed embodiments of the stator winding 4—the position change pins 9 are not only arranged locally near the inverter pins 10, but are used radially inwards and radially outwards, which is clearly evident in Figures 12 and 13. The invention is not limited to the embodiments shown in the figures. The preceding description should therefore be considered explanatory rather than limiting. The following claims are to be understood as meaning that a named feature is present in at least one embodiment of the invention. This does not preclude the presence of further features.If the patent claims and the preceding description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a hierarchy. List of reference symbols.

[0096] 1 Stator

[0097] 2 stator slots

[0098] 3 conductors

[0099] 4 Stator winding

[0100] 5 layers of wrapping

[0101] 6 HV terminal

[0102] 7 end wires

[0103] 8 Standard Hairpin

[0104] 9 Position change pin

[0105] 10 Inverter pin

[0106] 11 I-Pin

[0107] 12 winding head

[0108] 13 Hairpin head side

[0109] 14 twist page

[0110] 21 busbar

[0111] 22 busbar

[0112] 23 busbar

[0113] 24 busbar

[0114] 23 electric machine

[0115] 24 Rotor

Claims

Claims 1. Stator (1 ) with a plurality of circumferentially arranged stator slots (2) extending axially through the stator (1), in which several electrical conductors (3) designed as hairpins (8,9,10,11) are arranged to form a stator winding (4) with radially adjacent winding layers (5), wherein the electrical conductors (3) comprise the following types of hairpins (8,9,10,11): • Standard hairpins (8) whose free ends, positioned in a winding head (12), are designed to provide electrical contact from an even winding layer (5) to an odd winding layer (5); • Layer change pins (9) whose free ends, positioned in a winding head (12), are designed to enable electrical contact from an odd winding layer (5) to a radially below odd winding layer (5); • Inverter pins (10) whose free ends, positioned in a winding head (12), are designed to provide electrical contact for reversing the current direction; • I-pins (11) that are not located on either the innermost or the outermost winding layer (5); and at least one HV terminal (6) arranged on the hairpin head side (13), which is connected to end wires (7) of the stator winding (4), characterized by the fact that the end wires (7) are arranged in middle winding layers (5) of the stator (1), and the inverter pins (10) are arranged in both an innermost winding layer (5) and an outermost winding layer (5).

2. Stator (1) according to claim 1 , characterized by the fact that the end wires (7) of the stator winding (4) are formed by the I-pins (11).

3. Stator (1 ) with a plurality of circumferentially arranged stator slots (2) extending axially through the stator (1), in which several electrical conductors (3) designed as hairpins (8,9,10) are arranged to form a stator winding (4) with radially adjacent winding layers (5), wherein the electrical conductors (3) comprise the following types of hairpins (8,9,10): • Standard hairpins (8) whose free ends, positioned in a winding head (12), are designed to provide electrical contact from an even winding layer (5) to an odd winding layer (5); • Layer change pins (9) whose free ends, positioned in a winding head (12), are designed to enable electrical contact from an odd winding layer (5) to a radially below odd winding layer (5); • Inverter pins (10) whose free ends, positioned in a winding head (12), are designed to provide electrical contact for reversing the current direction; as well as at least one HV terminal (6) arranged on the twist side (14) which is connected to end wires (7) of the stator winding (4), wherein the end wires (11) are formed from extensions of standard hairpins (8), inverter pins (10) or layer change pins (9) and are arranged in adjacent winding layers (5), and the end wires (11) are arranged in adjacent winding layers (5) and the inverter pins (10) are arranged in both the innermost winding layer (5) and the outermost winding layer (5).

4. Stator (1) according to any one of the preceding claims, characterized by the fact that at least one of the end wires (7), preferably a plurality of end wires (7), has a post-bending in the radial direction towards a radially adjacent winding layer (5).

5. Stator (1) according to any one of the preceding claims, characterized by the fact that the HV terminal (6) is configured for a star point connection, comprising four busbars (21 ,22,23,24), wherein three busbars (21 ,22,23) are provided for the phases and one busbar (24) for the star point, and the busbars (21 ,22,23) for the phases are arranged radially outside and the busbar (24) for the star point is arranged radially inside.

6. Stator (1 ) according to any one of the preceding claims 1-4, characterized by the fact that the HV terminal (6) is configured for a delta connection.

7. Stator (1) according to any one of the preceding claims, characterized by the fact that the stator (1) has six or fewer poles.

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