Rotor comprising coils, slot-closure wedges, and axial cooling channels

Abstract

The invention relates to a rotor assembly (1) comprising: - a rotor body (2) which forms a plurality of slots (3) in the axial direction for receiving a winding (4), - a plurality of rotor poles (5) which are formed in the radial direction between in each case two of the slots (3), - a plurality of windings (4) which extend in the slots (3) and surround the rotor poles (5), - a plurality of slot-closure elements (6) which close the slots (3) in the radial direction, and - at least one separating body (7) which is arranged in each of the slots (3) in the circumferential direction between two of the windings (4). The separating body (7) comprises a continuous cooling channel (8) which extends in the axial direction and through which a coolant can flow. The separating body (7) has a Y-shaped housing (9) with a Y-shaped cooling channel (8). A Y-shaped insert (19), around or through which the coolant can flow, is arranged in the cooling channel (8).

Description

[0001] P241214

[0002] - 1 -

[0003] Rotor arrangement

[0004] The present invention relates to a rotor arrangement comprising a rotor body which forms several slots in the axial direction for receiving a winding, rotor poles which are formed in the radial direction between each pair of the slots, windings which run in the slots and enclose the rotor poles, slot closure elements which close the slots in the radial direction, at least one separating body which is arranged in one of the slots in the circumferential direction between two of the windings, wherein the separating body comprises at least one continuous cooling channel extending in the axial direction through which a cooling medium can flow.

[0005] Electric motors are increasingly being used for propulsion in motor vehicles to create alternatives to combustion engines that require fossil fuels. Considerable efforts have already been made to improve the everyday usability of electric drives and to offer users the familiar driving comfort.

[0006] In the development of electric machines, particularly those intended for e-axles or hybrid modules, there is a persistent need to increase their power density and efficiency while simultaneously reducing manufacturing costs. In this context, it is also known to design these electric machines as separately excited synchronous machines (FSMs). A separately excited synchronous machine is a special type of synchronous machine in which the magnetic field in the rotor is generated not by permanent magnets, but by energized coils. These coils are often also referred to as field coils or excitation coils. To energize the coils in the rotating rotor, the current must be supplied via suitable transformers.

[0007] Due to the manufacturing process, gaps can form between each pair of excitation windings of a rotor. These gaps are filled, in particular, with support or separating elements that completely or largely fill them. Especially for high-speed applications, the separating elements P241214 ensure

[0008] - 2 - the windings of the excitation coils in the centrifugal field against unintentional movement. EP 1 494 335 B1 discloses corresponding separating elements between adjacent excitation coils.

[0009] Particularly with regard to increased power density and efficiency, it is necessary to cool the rotor during operation, especially in separately excited synchronous machines, and to dissipate thermal energy. Air-cooled rotors or fluid-cooled hollow shafts are known from the prior art. DE102018220810A1 discloses a fluid-cooled rotor for an electric machine as well as a separately excited synchronous machine with a directly or near-loss cooled rotor winding. A fluid-cooled hollow shaft with a conical wall is disclosed in EP3618241A1.

[0010] A common problem with these well-known rotor configurations is insufficient cooling of the windings and rotor poles, especially under high power demands. The thermal stress on the rotor components not only leads to reduced machine efficiency but also to increased wear and a shortened service life for the windings and other mechanical components. Conventional cooling channels are often not optimally positioned or designed, resulting in uneven distribution of the cooling medium. This can lead to so-called hotspots, areas where the temperature rises excessively, which in turn compromises the thermal stability of the rotor configuration.

[0011] Furthermore, conventional rotor designs often prove to be complex to manufacture, as many individual parts must be precisely manufactured and assembled. This leads to higher production costs and increased failure rates, especially if individual components loosen or wear out during operation. Moreover, many state-of-the-art rotor designs are limited in their mechanical stability because the windings are not adequately supported, which can lead to deformation at high speeds or under heavy loads. P241214

[0012] - 3 -

[0013] It can therefore be concluded that state-of-the-art rotor arrangements are often characterized by insufficient cooling capacity, complex and costly manufacturing, and limited mechanical stability. These disadvantages significantly reduce the efficiency, reliability, and service life of electrical machines and thus represent a need for improved rotor arrangements that address these problems.

[0014] The object of the invention is therefore to provide a rotor arrangement that avoids or at least reduces the problems known from the prior art.

[0015] This problem is solved by a rotor arrangement comprising a rotor body which forms several slots in the axial direction for receiving a winding, rotor poles which are formed in the radial direction between each pair of slots, windings which run in the slots and enclose the rotor poles, slot closure elements which close the slots in the radial direction, at least one separating body which is arranged in one of the slots in the circumferential direction between two of the windings, wherein the separating body comprises at least one continuous cooling channel extending in the axial direction through which a cooling medium can flow, wherein the separating body has a Y-shaped housing with a Y-shaped cooling channel, wherein a Y-shaped insert which can be surrounded and / or through which the cooling medium can flow is arranged in the cooling channel.

[0016] This rotor arrangement offers several advantages, including improved cooling performance. The Y-shaped housing, combined with a Y-shaped cooling channel and a Y-shaped insert, creates a larger surface area available for heat transfer. The insert within the cooling channel also helps increase turbulence in the cooling medium, significantly improving heat transfer efficiency. Furthermore, the special Y-shape ensures a uniform distribution of mechanical forces, providing radial support to the windings within the slots. This not only contributes to the stability and longevity of the windings but also simplifies component manufacturing, such as with the P241214.

[0017] - 4 -

[0018] The use of simple sheet metal stamping and bending parts reduces production costs.

[0019] Furthermore, the rotor arrangement according to the invention, due to its design, can not only meet the high requirements for tightness, but also structurally withstand the pressures of up to 100 bar induced by the rotational speed. This combination of strength and tightness is critical to ensure the long-term performance and reliability of the rotor arrangement.

[0020] First, the individual elements of the claimed invention are explained in the order in which they are mentioned in the claim set, and subsequently, particularly preferred embodiments of the invention are described.

[0021] For the purposes of this patent application, the separating element is formed in particular by the housing and the insert arranged therein. The housing of the separating element is Y-shaped and extends axially along the length of the groove in the rotor body. Inside the housing is a similarly Y-shaped insert, which is positioned so that the cooling medium can flow around or through it. Together, the housing and the insert form an integrated structure that serves as a separating element.

[0022] This combination of housing and insert serves a dual purpose. Firstly, it ensures the mechanical separation of the windings within the slots and stabilizes them radially. Secondly, the shape of the housing, in conjunction with the insert, creates a continuous cooling channel through which the cooling medium can flow to efficiently dissipate the generated heat. The Y-shape of the separator, particularly the insert, increases the surface area in contact with the cooling medium, thereby optimizing heat dissipation.

[0023] The housing thus forms the outer structure of the separator, while the insert influences the internal flow conditions and creates additional turbulence in the cooling medium. This design enables efficient P241214

[0024] - 5 - and uniform cooling of the rotor arrangement and simultaneously ensures the mechanical stability of the windings during operation.

[0025] The separating element is preferably made of one or more non-ferromagnetic materials so that the electromagnetic function of the rotor or the electric machine is not disturbed.

[0026] The separating body is preferably designed in the region of at least one of its axial ends on its inner wall such that a smooth inner contour is formed over an axial length, preferably up to 15 mm. This region may also have been post-processed, particularly by machining processes. A fluid inlet or outlet for the cooling medium is then inserted into this region. The fluid inlet or outlet can be bonded, welded, press-fitted, and / or positively engaged with the separating body. In a preferred embodiment, the fluid inlet and / or outlet is sealed to the separating body or the Y-shaped housing with a seal, for example, an O-ring seal.This results in the production of enclosed, sealed assemblies that are sealed against the cooling medium and are inserted between two rotor coils, but do not extend beyond the axial extent of the rotor coils, so that the axial length of the rotor is not significantly increased by these assemblies.

[0027] In a further, preferred embodiment of the invention, it can also be provided that the separating body has electrical insulation on at least section of its outer wall. The electrical insulation can, for example, be implemented as an electrically insulating coating. It is also conceivable that the electrical insulation is implemented as a separate component that is detachably or permanently connected to the separating body. This allows the separating body to be electrically isolated from current-carrying parts, in particular to prevent electrical contact between excitation coils or between the excitation coil and the vehicle, and thus to meet the requirements of high-voltage safety. A coating can be implemented, for example, by painting, overmolding, or an adhesive layer. For electrical insulation with limited requirements, see P241214.

[0028] - 6 -

[0029] Aluminum separators, for example, can also be anodized. In cases requiring high performance, they can be overmolded with plastic, coated with an alternative material, or covered with a film on the contact surfaces to the rotor coils. This ensures that no electrical short circuit occurs between excitation coils or between an excitation coil and the vehicle.

[0030] The separating body is preferably connected to a groove closure element that radially closes the groove and provides rotationally stable support for the supporting body. The groove closure element is preferably made of a non-ferromagnetic and non-electrically conductive material, e.g., plastic, so that the electromagnetic behavior of the machine is not affected and no additional eddy current losses occur in this component. The groove closure element can be manufactured by injection molding or extrusion and joined to the separating body by a form-fit or adhesive bond. Alternatively, the groove closure element can be directly injection-molded onto the separating body. In this case, it can be integrally bonded with a plastic overmolding of the separating body.

[0031] The invention can also be advantageously implemented in such a way that the groove closure element and the separating body are integrally connected.

[0032] The advantageous effect of this design lies in the fact that the integral connection allows the slot closure element and the separating body to be manufactured as a single component. This reduces the complexity of the rotor arrangement. A further advantage is that the integral connection provides a more stable component. The slot closure element and the separating body are preferably formed monolithically, for example, from aluminum or plastic.

[0033] According to a further preferred embodiment of the invention, the separating body may also comprise several cooling channels which are spaced apart from one another radially and / or circumferentially. The advantageous effect of this design is that it provides better heat dissipation and / or removal of heat loss. A further advantage lies in the fact that P241214

[0034] - 7 - more even heat dissipation and removal of heat loss is achieved through several spaced cooling channels.

[0035] Y-shaped case

[0036] For the purposes of this patent application, a Y-shaped housing is a structure that, in cross-sectional view, has a Y-like shape, with the cooling channel being defined by this shape. This housing comprises a base and two laterally extending arms that extend radially from the base. It serves to accommodate a winding in a rotor and simultaneously form a cooling channel through which a cooling medium flows. The Y-shaped cooling channel created by the internal structure of the housing enables improved distribution of the cooling medium and optimized cooling of adjacent windings and rotor poles.

[0037] The Y-shaped housing serves to mechanically support the windings while simultaneously ensuring efficient cooling of the windings and rotor poles. The Y-shape of the cooling channel creates a larger surface area for heat transfer, allowing for more efficient heat dissipation from the rotor. An insert, also Y-shaped, can be positioned within this cooling channel and is either surrounded or filtered by the cooling medium. This insert generates turbulence in the cooling medium, further enhancing heat transfer and ensuring uniform cooling.

[0038] The Y-shaped housing can be made of various materials. It is preferably made of metal, such as aluminum or steel, to ensure high strength, temperature resistance, and good thermal conductivity. These metal versions also allow for simple manufacturing using sheet metal stamping and bending techniques, which keeps production costs low. Alternatively, the Y-shaped housing can also be made of heat-resistant plastic, particularly in applications where weight savings or corrosion resistance are paramount. The Y-shaped housing can be joined to the other components of the rotor assembly by welding, P241214

[0039] - 8 -

[0040] Bonding or mechanical connections are made, with welding being preferred to ensure a tight and stable connection.

[0041] The arms of the Y-shaped housing can also be designed to extend radially to different distances, for example to ensure adapted cooling performance in different areas of the rotor.

[0042] Y-shaped insertion

[0043] For the purposes of this patent application, a Y-shaped insert is a component arranged within a Y-shaped cooling channel and designed to optimize the coolant flow within the channel. The Y-shaped insert follows the geometry of the cooling channel and preferably forms a structured surface in the axial direction, which directs the coolant flow in various directions to improve heat transfer. It can be completely surrounded or partially permeated by the coolant, thereby enabling increased turbulence and thus more efficient heat dissipation.

[0044] The Y-shaped insert preferably consists of a stable structure made of either metal or another thermally conductive material. Preferably, the insert can be manufactured from sheet metal by stamping, bending, or embossing, enabling cost-effective mass production. The Y-shaped structure creates additional surface area for the cooling medium to flow over, thus increasing the area available for heat exchange. Depending on the embodiment, the insert can be equipped with additional flow elements, such as knobby or cuboidal shapes, which further improve cooling performance by selectively influencing the coolant flow and increasing turbulence in the channel.

[0045] Possible embodiments of the Y-shaped insert include different materials and construction methods. Metallic inserts, especially those made of aluminum or copper, offer high thermal conductivity and strength, making them particularly suitable for applications with high thermal and mechanical demands. Alternatively, the insert can also be made of plastics with high thermal stability to save weight while also meeting P241214

[0046] - 9 - to ensure sufficient heat dissipation. Another embodiment involves manufacturing the Y-shaped insert as a one-piece, monolithic component, formed from the raw material in a single operation. This ensures high structural integrity and minimizes potential weak points. In other embodiments, the Y-shaped insert and the housing can be manufactured separately and subsequently joined together by a material bond, for example, by welding or bonding. Such connection methods ensure a permanent and robust integration of the insert into the cooling channel, which positively influences the function and service life of the entire rotor assembly.

[0047] For the purposes of this patent application, a flow element is a structural component arranged in a cooling channel that selectively influences the flow of the cooling medium to enable improved heat transfer. Through its geometry and positioning within the cooling channel, the flow element increases the turbulence of the flowing cooling medium, thereby increasing the contact area between the cooling medium and the heat-dissipating surfaces. The function of the flow element is therefore, in particular, to redirect or swirl the cooling medium within the cooling channel to improve heat transfer. This is achieved, for example, by the flow element locally increasing the flow velocity and thereby generating turbulence that allows for a more uniform distribution of the cooling medium.This targeted flow guidance avoids so-called hotspots, i.e. areas with increased thermal stress, and makes cooling more efficient, especially in the area of ​​the windings and rotor poles.

[0048] The flow elements are advantageously designed such that they are either integrally, and in particular monolithically, connected to the housing or insert, or are designed as separate components that can be connected to the housing or insert. In the monolithic design, the flow elements are an integral part of the Y-shaped housing or insert, which provides increased mechanical stability and P241214

[0049] - 10 - simplified manufacturing is possible. In the variant as separate components, the flow elements can preferably be connected to the housing or insert by welding or a material-bonded connection, which allows flexible adaptation to specific flow requirements.

[0050] Furthermore, according to another advantageous embodiment of the invention, it can be provided that a plurality of, and in particular all, flow elements are essentially identical. Standardizing the flow elements by making them essentially identical leads to significant economic and production-related advantages. The uniformity of the parts simplifies warehousing and logistics, as fewer different parts need to be kept in stock, unless the flow elements are already monolithically integrated with the housing or insert. This reduces the complexity of the production process and enables cost-effective mass production.

[0051] According to a further particularly preferred embodiment of the invention, the flow elements can be arranged in a grid-like pattern on the housing and / or insert. This arrangement enables maximum penetration of the cooling medium through the cooling channel(s), resulting in more efficient heat dissipation. The increased cooling capacity makes it possible to further reduce operating temperatures, thereby increasing the efficiency and performance of the motor. Furthermore, the improved cooling leads to a lower thermal load on the components, which extends their service life and increases the reliability of the rotor assembly.

[0052] Cooling medium

[0053] According to one embodiment, the cooling medium is a coolant. The advantage of this embodiment lies in the fact that coolants, compared to gases, have a higher heat capacity and higher thermal conductivity, thus enabling better heat dissipation and / or removal of heat loss. In particular, the coolant contains oil and / or water. P241214

[0054] - 11 -

[0055] For the purposes of this patent application, a rotor body is a mechanical structure of a rotor that serves as a support for the windings and rotor poles. The rotor body forms the "basic framework" of the rotor assembly and ensures that the mechanical and electromagnetic components are positioned precisely and stably relative to one another. Functionally, the rotor body serves to accommodate the windings in axial slots and to form the rotor poles in the radial direction. It ensures the mechanical stability of the rotor during operation and distributes the forces acting upon it, such as centrifugal forces, evenly. Furthermore, the rotor body supports the efficient cooling of the windings by providing the necessary space for the cooling channels and the cooling medium to effectively dissipate heat from the active components. According to one embodiment, the rotor body is designed as a laminated package to minimize eddy current losses within the rotor body.

[0056] The rotor body is preferably cylindrical or hollow cylindrical, with the slots for receiving the windings extending axially along the outer surface. These slots are arranged to optimally support the windings while simultaneously enabling a compact arrangement of the rotor poles. Slot closure elements are preferably located within the slots to secure the windings in position and protect them from mechanical damage. One or more separators are provided between the windings to offer additional stability and facilitate the effective flow of the cooling medium.

[0057] Advantageous embodiments of the invention

[0058] According to an advantageous embodiment of the invention, the Y-shaped housing may have flow elements projecting into the cooling channel, and / or the Y-shaped insert may have flow elements projecting into the cooling channel. Advantageously, the cooling performance can be further improved by integrating flow elements. These flow elements, which are attached to the housing and / or the insert, increase the turbulence of the cooling medium, which further intensifies heat transfer. With a suitable arrangement and design of the flow elements, this leads to optimized cooling, especially in thermally demanding environments.

[0059] - 12 - stressed areas. By appropriately arranging and designing the flow elements, a more uniform distribution of the cooling medium over the entire length of the cooling channel can also be achieved, thereby avoiding hotspots and increasing the overall efficiency of the rotor arrangement.

[0060] According to a further preferred embodiment of the invention, the flow elements of the housing and / or the flow elements of the insert can also have a knobby, cuboidal, and / or ellipsoidal shape. Designing the flow elements in knobby, cuboidal, or ellipsoidal shapes offers the advantage of generating different flow profiles in the cooling medium, thus optimizing heat dissipation at specific locations. With appropriate design and arrangement of the flow elements, this leads to improved heat transfer in areas with higher thermal stress. Furthermore, these geometric shapes increase the surface area within the cooling channel, further enhancing cooling performance.These elements can be easily manufactured, particularly using standard manufacturing techniques such as embossing and stamping, which keeps production costs low while ensuring the effectiveness of cooling.

[0061] The flow elements can advantageously be formed integrally, particularly monolithically, with the housing or insert. This design offers the significant advantage that the flow elements are an integral part of the Y-shaped housing or insert, thus eliminating the need for additional connecting elements or assembly steps. This simplifies the manufacturing of the rotor assembly, as fewer components are required, which in turn reduces production costs and assembly complexity. Furthermore, the monolithic design increases mechanical stability, as no weak points are created by connecting elements or joints.

[0062] Alternatively, the flow elements can also be connected to the housing or insert as separate components. This variant enables a P241214

[0063] - 13 - Greater flexibility in the design and adaptation of the flow elements to different cooling requirements. In particular, the flow elements can be easily replaced or modified as needed to optimize cooling performance for specific applications. This modular design offers the advantage that only the flow elements need to be replaced to meet different thermal requirements, without having to replace the entire housing or insert. The flow elements can be connected using mechanical connections, such as snap-fit ​​connections, or by material-bonding methods, such as resistance welding or adhesive bonding.

[0064] Furthermore, according to another advantageous embodiment of the invention, the Y-shaped housing can be closed at a first end face by a closure and / or the Y-shaped housing can be closed at a second end face by a closure. The closures at the end faces of the Y-shaped housing prevent the cooling medium from escaping, thus ensuring a closed cooling circuit. This has the advantage that the cooling of the rotor windings can be effectively controlled. The simple end-face access also simplifies assembly. The stability of the entire cooling system can also be optimized by welding the closures to both sides of the separating body. This measure makes it possible to withstand the high internal pressure loads without transmitting pressure forces to the surrounding structure.This makes it possible to operate the rotor at high speeds without compromising the integrity of the cooling system.

[0065] The closures on the end faces of the Y-shaped housing can be made of metal or plastic, allowing for flexible material selection depending on the specific application requirements. Metal closures offer the advantage of high strength and temperature resistance, making them particularly suitable for high-performance applications with high thermal loads. Plastic closures, on the other hand, are characterized by lower density and higher corrosion resistance, making them ideal for applications where weight savings or chemical resistance are required. P241214

[0066] - 14 -

[0067] Regardless of the material chosen, the closures can be sealed to the Y-shaped housing by welding, bonding, or a press fit. Welding, especially with metal closures, provides a durable and high-strength connection that remains stable even under high mechanical and thermal stresses. For plastic closures, bonding can be used, creating a reliable and tight seal without weakening the material through heat exposure. A press fit is another option, mechanically connecting the closures to the housing, allowing for quick and easy assembly. This method is particularly advantageous if future disassembly or maintenance of the rotor assembly is planned, as the closures can be easily detached and reattached.In all cases, the chosen connection method ensures that the cooling medium remains securely enclosed within the housing and that no leaks occur, thus guaranteeing the efficiency of the cooling circuit.

[0068] According to a further particularly preferred embodiment of the invention, a fluid inlet and / or a fluid outlet may be formed axially at a closure. The axial design of the fluid inlet and outlet improves the flow path of the cooling medium and ensures uniform cooling along the axial extent of the rotor assembly. The axial arrangement also facilitates the integration of the rotor assembly into existing cooling systems and simplifies installation and maintenance, as the cooling circuit can be integrated directly into the axial direction of the machine.

[0069] Furthermore, the invention can also be further developed in such a way that a fluid inlet is formed radially on the Y-shaped housing and / or a fluid outlet is formed radially on the Y-shaped housing. A significant advantage of the radial arrangement of the fluid inlet on the Y-shaped housing is that the housing can thus, for example, easily interact with a rotor shaft designed as a hollow shaft, which the P241214

[0070] - 15 -

[0071] The cooling medium is conveyed through the rotor. During operation, the centrifugal force generated by the rotation allows the cooling fluid to flow radially outwards, entering the housing through the radially oriented fluid inlet. This arrangement efficiently utilizes centrifugal force to propel the coolant flow without the need for additional pumps or complex piping. This mechanism offers several advantages: Firstly, cooling is enhanced by the direct use of centrifugal force, reducing energy consumption and the complexity of the cooling system. Secondly, the radial arrangement of the fluid inlet ensures optimal and uniform distribution of the cooling fluid within the rotor, thus reducing the thermal stress on the windings and rotor poles.Furthermore, this design facilitates the integration of the cooling circuit, as the fluid inlet is in a simple and robust connection with the hollow shaft, which simplifies assembly and maintenance.

[0072] In a preferred embodiment of the invention, the Y-shaped housing and / or the Y-shaped insert may also be formed from a stamped and bent sheet metal part. The use of stamped and bent sheet metal parts for the Y-shaped housing and the Y-shaped insert offers significant economic advantages. These components can be manufactured cost-effectively and in large quantities with high precision. This not only reduces production costs but also contributes to weight reduction, which improves the energy efficiency of the machine in which the rotor assembly is used. Furthermore, the use of sheet metal materials enables high dimensional stability and thermal conductivity, which increases the overall cooling capacity of the system.

[0073] It can also be advantageous to further develop the invention such that the flow elements of the housing and / or the flow elements of the insert are arranged equidistantly or unequally from one another. The equidistant or unequally arranged flow elements within the cooling channel allows for targeted adaptation of the flow conditions to the specific cooling requirements. This offers the advantage that cooling can be enhanced in areas subject to particularly high thermal stress. P241214

[0074] - 16 - while less critical zones can be operated with lower cooling capacity. This flexibility increases the efficiency of the cooling system and ensures that the rotor arrangement can be adapted to different operating conditions.

[0075] According to a further preferred embodiment of the invention, the flow elements of the housing can be in contact with the insert and / or the flow elements of the insert can be in contact with the housing. The contact of the flow elements of the housing with the insert, or vice versa, ensures improved mechanical stability of the entire cooling channel. This connection minimizes vibrations and mechanical deformations, which extends the service life of the cooling system. Furthermore, heat transfer between the components and the cooling medium is optimized, as the larger contact area enables more efficient heat dissipation. This leads to increased cooling performance and enhanced operational reliability of the rotor assembly.

[0076] Finally, the invention can also be advantageously implemented such that the flow elements of the housing are materially bonded to the insert and / or the flow elements of the insert are materially bonded to the housing, in particular by means of resistance welding or laser welding. The materially bonded connection of the flow elements by welding ensures an extremely stable and durable connection. This joining method ensures that no gaps or weak points arise between the components, which increases mechanical stability and enables continuous cooling without performance losses. Therefore, it is advantageous for the housing and the insert to form a solid connection in order to absorb the forces generated by operating pressures.This connection can preferably be made in the area of ​​the flow elements, particularly by methods such as resistance spot welding or laser welding, although a soldering process can alternatively be used in the area of ​​the flow elements. P241214.

[0077] - 17 -

[0078] The invention will now be explained in more detail with reference to figures, without limiting the general concept of the invention.

[0079] It shows:

[0080] Figure 1 shows a schematic section view of a rotor arrangement in a cross-sectional view.

[0081] Figure 2 shows a first embodiment of a separating body in a perspective view,

[0082] Figure 3 shows a first embodiment of a rotor arrangement in a

[0083] Exploded view,

[0084] Figure 4 shows a second embodiment of a separating body in a perspective view,

[0085] Figure 5 shows a third embodiment of a separating body in a perspective view,

[0086] Figure 6 shows an embodiment of a Y-shaped housing with cuboid flow elements in a perspective view.

[0087] Figure 7 shows an embodiment of a Y-shaped housing with ellipsoidal

[0088] Flow elements in a perspective view. P241214

[0089] - 18 -

[0090] Figure 1 shows a rotor assembly 1 comprising a rotor body 2 which forms several slots 3 in the axial direction for receiving a winding 4. Rotor poles 5 are formed radially between each pair of slots 3, and the windings 4 run in the slots 3 and enclose the rotor poles 5. This arrangement of the windings ensures uniform excitation of the rotor poles and optimizes the magnetic coupling between the rotor and stator, thus improving the efficiency of the electric machine.

[0091] Slot locking elements 6 close the slots 3 in a radial direction, thereby securely fixing the windings 4 and simultaneously absorbing mechanical loads, such as those caused by centrifugal forces at high speeds. These elements contribute to the structural integrity of the rotor and prevent the windings 4 from slipping during operation.

[0092] At least one separating element 7 is arranged circumferentially in one of the slots 3 between two of the windings 4. The separating element 7 fulfills a dual function: On the one hand, it serves as a mechanical barrier between the windings 4, thereby achieving improved mechanical stability. On the other hand, it plays a crucial role in cooling the rotor assembly 1, as it includes a continuous cooling channel 8 extending axially through which a cooling medium can flow. This cooling channel 8 enables the efficient dissipation of the heat generated during electrical excitation, which increases the thermal stability and service life of the windings 4.

[0093] The separator 7 has a Y-shaped housing 9 with a Y-shaped cooling channel 8 in which a Y-shaped insert 19 is arranged, around which the cooling medium flows. This Y-shaped structure provides an enlarged surface area, which improves heat transfer and maximizes cooling performance. The Y-shaped insert 19 acts as a turbulator, disrupting the flow of the cooling medium and thereby generating turbulence, which significantly increases the heat transfer coefficient.

[0094] The housing 9 can be manufactured from a sheet of metal through a series of manufacturing steps, mainly based on stamping, bending and forming processes P241214

[0095] - 19 - are based on this process. First, a flat sheet of metal is selected that meets the desired material properties, such as strength, corrosion resistance, and thermal conductivity. In the first step, the sheet is stamped. This process shapes the sheet into a desired basic form, which defines the basic contours of the later housing 9. This is done through a stamping process in which the sheet is precisely cut with a tool. Openings, such as cooling channels or recesses for later connecting elements, are incorporated directly into the sheet.

[0096] After punching, the bending process takes place. Here, the flat sheet metal is formed into the three-dimensional Y-shape that is the characteristic feature of the housing 9. This process is carried out using special bending tools or presses that deform the sheet metal along predefined lines. Additional forming processes, such as embossing or drawing, can be applied to create specific geometric features of the housing 9, such as the flow elements 10 or reinforcing structures. These processes deform the sheet metal locally to create the necessary surface structures that optimize heat transfer or the flow characteristics of the cooling medium.

[0097] After bending and forming, the individual components of the housing can be joined together by welding. Finally, the formed housing can undergo surface treatment to increase corrosion resistance and improve mechanical properties. This could be, for example, electroplating or powder coating, depending on the requirements of the final application.

[0098] A cavity is formed in groove 3, which is bounded by one of the windings 4 and the separating body 7, and which contains a potting compound. In other words, the existing cavities between the separating body 7 and one of the windings 4 are filled with a potting compound, thus improving the thermal connection of the windings 4 to the separating body 7. This measure ensures optimized heat dissipation from the windings 4 to the cooling channel 8, thereby improving P241214

[0099] - 20 - overheating of the windings 4 is avoided. The cavity results from manufacturing tolerances of the windings 4 and the separating body 7, which is effectively compensated for by the potting material, thus ensuring homogeneous heat conduction.

[0100] The Y-shaped housing 9 has flow elements 10 projecting into the cooling channel 8. The Y-shaped insert 19 also has flow elements 11 projecting into the cooling channel 8. These flow elements 10, 11 increase the surface area in contact with the cooling medium, thereby enhancing heat transfer. They can have different shapes, such as knobby, cuboid, or ellipsoidal forms, to influence the flow dynamics of the cooling medium and thus control heat transfer. The variability of the shapes allows the cooling performance to be adapted to specific application requirements.

[0101] The flow elements 10 of the housing 9 rest against the insert 19, and the flow elements 11 of the insert 19 rest against the housing 9. This arrangement ensures a close coupling between the housing 9 and the insert 19, which increases the mechanical stability of the entire system and ensures that the flow of the cooling medium is uniform along the entire surface of the cooling channel 8. The flow elements 10 of the housing 9 are metallurgically bonded to the insert 19, and the flow elements 11 of the insert 19 are metallurgically bonded to the housing 9, in particular by resistance welding. This joining method guarantees a permanent and strong connection that remains stable even under thermal and mechanical stresses.

[0102] As shown, among other things, in Figure 2, the Y-shaped housing 9 is closed at a first end face 12 by a closure 13 and at a second end face 14 by a closure 15. These closures 13, 15 prevent the cooling medium from escaping the cooling channel 8 and ensure a closed cooling circuit. Figure 2 further shows that a fluid inlet 16 and a fluid outlet 17 are formed axially at closures 13, 15. These axial inlets and outlets are P241214

[0103] - 21 -

[0104] Outlets 16,17 enable efficient supply and discharge of the cooling medium along the rotor axis, which further optimizes the cooling process.

[0105] Figure 5 shows an embodiment in which a fluid inlet 16 and a fluid outlet 17 are formed radially on the Y-shaped housing 9. This configuration utilizes the centrifugal force generated by the rotation of the rotor to direct the cooling medium radially outwards. This enables particularly efficient cooling during rotor operation.

[0106] In the illustrated embodiments, the Y-shaped housing 9 and the Y-shaped insert 19 are formed from a stamped and bent sheet metal part. This manufacturing technique offers the advantage of cost-efficient production while simultaneously ensuring high precision and strength of the components. The use of stamped and bent sheet metal parts also allows for flexible adaptation of the geometry to different requirements.

[0107] The flow elements 10 of the housing 9 and / or the flow elements 11 of the insert 19 can be arranged equidistantly or unequally spaced from each other. This variable arrangement allows for targeted control of the flow characteristics of the cooling medium, so that the cooling capacity can be increased in areas with higher heat generation.

[0108] Figures 1-7 show Y-shaped housings 9 and inserts 19, which differ from one another particularly in the shape and arrangement of the flow elements 10, 11. The embodiment shown in Figures 2-3 has knob-like flow elements 11, which are arranged in a grid-like pattern in the area of ​​the splayed legs of the housing 9 and the insert 19. Similarly, the Y-shaped insert 19 also has knob-like and grid-like flow elements 11 in the area of ​​its splayed legs.

[0109] Figure 4 shows an embodiment in which knob-like flow elements 11 are arranged in two parallel but offset rows in the area of ​​the splayed legs of the housing 9. P241214

[0110] - 22 -

[0111] Figure 6 shows a Y-shaped housing 9 with cuboid flow elements 10, with a longitudinal extension in the axial direction. Figure 7 shows a Y-shaped housing 9 with ellipsoidal flow elements 9.

[0112] The invention is not limited to the embodiments illustrated in the figures. The foregoing description is therefore not to be considered limiting, but rather explanatory. 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. Insofar as the claims and the foregoing description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing any hierarchy.

[0113] P241214

[0114] - 23 -

[0115] List of reference signs

[0116] 1 Rotor arrangement

[0117] 2 rotor bodies

[0118] 3 grooves

[0119] 4 windings

[0120] 5 rotor poles

[0121] 6 slot closure elements

[0122] 7 separating bodies

[0123] 8 Cooling channel

[0124] 9 cases

[0125] 10 flow elements

[0126] 11 flow elements

[0127] 12 Front

[0128] 13 Closure

[0129] 14 Front

[0130] 15 Closure

[0131] 16 Fluid inlet

[0132] 17 Fluid outlet

[0133] 19 deployment

Claims

P241214 - 24 - Claims 1. Rotor arrangement (1) comprising a rotor body (2) which forms several slots (3) in the axial direction for receiving a winding (4), Rotor poles (5), which are formed in a radial direction between each of the slots (3), windings (4) which run in the slots (3) and enclose the rotor poles (5), Slot closure elements (6) which close the slots (3) in a radial direction, at least one separating body (7) which is arranged in one of the slots (3) in a circumferential direction between two of the windings (4), wherein the separating body (7) comprises at least one axially extending, continuous cooling channel (8) which can be permeated by a cooling medium, characterized in that the separating body (7) has a Y-shaped housing (9) with a Y-shaped cooling channel (8), wherein a Y-shaped insert (19) which can be permeated and / or permeated by the cooling medium is arranged in the cooling channel (8).

2. Rotor arrangement (1) according to claim 1, characterized in that P241214 - 25 - the Y-shaped housing (9) has flow elements (10) projecting into the cooling channel (8) and / or the Y-shaped insert (19) has flow elements (11) projecting into the cooling channel (8).

3. Rotor arrangement (1) according to claim 1 or 2, characterized in that the flow elements (10) of the housing (9) and / or the Flow elements (11) of the insert (19) have a knob-like shape and / or a cuboid-like shape and / or an ellipsoid-like shape.

4. Rotor arrangement (1 ) according to one of the preceding claims, characterized in that the Y-shaped housing (9) is closed at a first end face (12) by a closure (13) and / or the Y-shaped housing (9) is closed at a second end face (14) by a closure (15).

5. Rotor arrangement (1 ) according to one of the preceding claims, characterized in that a fluid inlet (16) is formed in the axial direction on a closure (13,15) and / or a fluid outlet (17) is formed in the axial direction on a closure (13,15).

6. Rotor arrangement (1 ) according to one of the preceding claims, characterized in that a fluid inlet (16) is formed in a radial direction on the Y-shaped housing (9) and / or a fluid outlet (17) is formed in a radial direction on the Y-shaped housing (9). P241214 - 26 - 7. Rotor arrangement (1 ) according to one of the preceding claims, characterized in that the Y-shaped housing (9) and / or the Y-shaped insert (19) are formed from a sheet metal stamping and bending part.

8. Rotor arrangement (1 ) according to one of the preceding claims, characterized in that the flow elements (10) of the housing (9) and / or the flow elements (11 ) of the insert (19) are arranged equidistantly or unequally apart from each other.

9. Rotor arrangement (1 ) according to one of the preceding claims, characterized in that the flow elements (10) of the housing (9) bear against the insert (19) and / or the flow elements (11 ) of the insert (19) bear against the housing (9).

10. Rotor arrangement (1 ) according to claim 9, characterized in that the flow elements (10) of the housing (9) are materially bonded to the insert (19) and / or the flow elements (11) of the insert (19) are materially bonded to the housing (9), in particular by means of resistance welding.

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