Rotor for an electric machine

Abstract

The present invention relates to a rotor (1) for an electrical machine (2), in particular for a separately excited synchronous machine. The rotor (1) comprises a rotor shaft (3) designed as a hollow shaft with a bearing seat (11) on its outer surface, as well as a slip ring module (4) inserted into the rotor shaft (3). The slip ring module (4) consists of a first and a second hollow-cylindrical slip ring carrier (5, 7), each carrying a slip ring (6, 8) on its outer surface. The slip ring carriers (5, 7) are arranged coaxially to the rotational axis (12) of the rotor (1), with the second slip ring carrier (7) partially engaging in a receiving opening (13) of the first slip ring carrier (5). An insulating wall (16) extends radially outward from the first slip ring carrier (5). The outer diameter (17) of the insulating wall (16) is equal to or smaller than the outer diameter (10) of the bearing seat (11).The outer diameters of the slip rings (6, 8) are adjusted so that no outer diameter is larger than that of the first slip ring (6).

Description

[0001] The present invention relates to a rotor for an electrical machine, in particular for a separately excited synchronous machine, comprising a rotor shaft designed as a hollow shaft with an inner diameter, which in the region of one of its distal ends has a bearing seat formed on its outer surface and lying on a first outer diameter, and a slip ring module inserted into the rotor shaft, wherein the slip ring module has a first electrically non-conductive, hollow cylindrical slip ring carrier with a first slip ring fixed to its outer surface and a second electrically non-conductive, hollow cylindrical slip ring carrier with a second slip ring fixed to its outer surface,and a first busbar is connected to the first slip ring and extends at least partially in the axial direction through the first slip ring carrier and into the rotor shaft, and a second busbar is connected to the second slip ring and extends at least partially in the axial direction through the second slip ring carrier and into the rotor shaft, and the first slip ring carrier has a receiving opening running coaxially to the rotational axis of the rotor, into which the second slip ring carrier engages axially at least partially, wherein a first annular disk-like insulating wall, axially spaced from the first slip ring, extends radially outward from the first slip ring carrier with a second outer diameter.

[0002] The state of the art in connection with a rotor for an electrical machine, particularly for a separately excited synchronous machine, shows that previous designs typically utilize a solid shaft into which various components such as slip rings and busbars are integrated. A well-known example corresponding to this technical area is US patent US1870236.

[0003] A disadvantage of these conventional rotors is that the integration of the slip rings and busbars often requires complicated and time-consuming assembly. The electrical connections between the busbars and the slip rings often have to be made after the bearing has been installed, complicating the electrical contacting process. In addition, existing rotors usually require larger installation volumes because the components are mounted on the side of the rotor shaft, which often leads to inefficient use of installation space.

[0004] Another problem is the limited availability of prefabrication. The rotors must be assembled in multiple steps, which increases production time and increases the risk of assembly errors. Furthermore, efficient thermal control is often lacking, as existing rotors lack optimized cooling devices to ensure even heat dissipation.

[0005] In summary, existing rotor manufacturing solutions suffer from problems related to complex assembly, inefficient space utilization, and inadequate cooling. This leads to limitations in the performance and reliability of electrical machines, especially in separately excited synchronous machines, which place high demands on operational reliability and efficiency.

[0006] It is therefore the object of the invention to provide a rotor for an electrical machine, in particular for a separately excited synchronous machine, which avoids or at least reduces the disadvantages known from the prior art.

[0007] This object is achieved by a rotor for an electrical machine, in particular for a separately excited synchronous machine, comprising a rotor shaft designed as a hollow shaft with an inner diameter, which in the region of one of its distal ends has a bearing seat formed on its outer surface and lying on a first outer diameter, and a slip ring module inserted into the rotor shaft, wherein the slip ring module has a first electrically non-conductive, hollow cylindrical slip ring carrier with a first slip ring fixed to its outer surface and a second electrically non-conductive, hollow cylindrical slip ring carrier with a second slip ring fixed to its outer surface,and a first busbar is connected to the first slip ring and extends at least partially in the axial direction through the first slip ring carrier and into the rotor shaft, and a second busbar is connected to the second slip ring and extends at least partially in the axial direction through the second slip ring carrier and into the rotor shaft, and the first slip ring carrier has a receiving opening running coaxially to the rotational axis of the rotor, into which the second slip ring carrier engages axially at least partially, wherein a first annular disk-like insulating wall, axially spaced from the first slip ring, extends radially outward from the first slip ring carrier with a second outer diameter, wherein the second outer diameter of the first insulating wall of the first slip ring carrier is less than or equal to the first outer diameter of the bearing seat of the rotor shaft,and the outer diameter of the first slip ring is less than or equal to the second outer diameter of the first insulation wall, and the outer diameter of the second slip ring is less than or equal to the outer diameter of the first slip ring, and there is no outer diameter between the first slip ring and the second slip ring on the slip ring module that is greater than the outer diameter of the first slip ring.

[0008] The rotor according to the invention offers the advantage that the slip ring module can be inserted into the rotor shaft before the rolling bearing is mounted on the bearing seat. This makes it possible to position the slip ring module in the rotor shaft and then establish electrical contact, for example, by welding to the rotor winding, without compromising the rolling bearing or other mechanical components. A further advantage of this arrangement is that, after the electrical contact has been established, the rolling bearing can be easily mounted on the bearing seat, and finally, the brush module for contacting the slip rings can be attached. This allows the rotor to be fully prefabricated before being integrated into the electrical machine.This approach not only reduces assembly effort but also enables precise and safe installation of the slip ring module, as well as greater ease of production and service.

[0009] First, the individual elements of the claimed subject matter of the invention are explained in the order in which they appear in the set of claims, and subsequently particularly preferred embodiments of the subject matter of the invention are described. Slip ring module

[0010] For the purposes of this patent application, a slip ring module is an assembly that establishes an electrical connection between rotating and stationary components of an electrical machine, in particular a rotor. The slip ring module consists of at least one electrically non-conductive slip ring carrier, on whose outer surface one or more slip rings are located. These slip rings are connected via busbars to the corresponding electrical connections, which extend through the slip ring carrier and into the rotor shaft. The slip ring module is designed to be inserted into the rotor shaft and firmly integrated there, ensuring the safe and reliable transmission of electrical currents.

[0011] According to the invention, the slip ring module is constructed such that it consists of a first and a second hollow-cylindrical slip ring carrier, which are arranged coaxially to one another and mesh with one another in the axial direction. This arrangement enables a compact and space-saving design in which the slip ring carriers are securely and stably aligned with one another. The first slip ring carrier carries a first slip ring on its outer surface, while the second slip ring carrier similarly carries a second slip ring on its outer surface. The axial meshing of the two slip ring carriers ensures precise positioning of the slip rings, thereby optimizing the electrical contact between the rotating and stationary components.

[0012] The coaxial alignment of the slip ring carriers ensures even distribution of forces and facilitates the installation of the slip ring module into the rotor shaft. This design also allows the busbars connected to the slip rings to pass through the slip ring carriers and the rotor shaft without requiring additional installation space. This allows the slip ring module to be integrated into the rotor shaft in one piece and securely fixed, improving assembly efficiency and increasing operational reliability.

[0013] Conceivable embodiments of the slip ring module include variants in which a different number of slip rings is provided to implement different circuits. Furthermore, different materials can be used for the slip ring carriers and the slip rings to meet the requirements of specific applications. Slip ring carrier

[0014] For the purposes of this patent application, a slip-ring carrier is a component that is at least partially hollow cylindrical and serves to accommodate and secure one or more slip rings. The slip-ring carrier is made of an electrically non-conductive material that ensures reliable electrical insulation between the slip rings and other components of the rotor. The slip-ring carrier forms the mechanical foundation on which the slip rings are attached and precisely positioned to enable reliable electrical contact by the brushes of the brush module.

[0015] The slip-ring carrier is designed to support the slip ring(s) on its outer surface. It can also be equipped with additional elements such as insulating walls or grooves that provide additional electrical isolation or mechanical stabilization. The slip-ring carrier preferably runs coaxially to the rotor's rotational axis, enabling symmetrical load distribution. In a preferred embodiment, a receiving opening in the first slip-ring carrier allows a second slip-ring carrier to engage axially, at least in sections, thereby achieving a compact and space-saving arrangement of the slip rings.

[0016] Functionally, the slip ring carrier essentially serves to mechanically secure and electrically insulate the slip ring(s), while simultaneously ensuring reliable contact between the slip ring(s) through the brushes. This contact occurs during operation of the electrical machine, with the slip rings rotating and a continuous electrical connection maintained. Furthermore, the slip ring carrier ensures that the busbars can be safely routed through it without causing unwanted short circuits or malfunctions.

[0017] Conceivable embodiments of the slip ring carrier include various geometric adaptations to meet specific requirements for insulation, mechanical stability, or integration into the rotor. For example, the slip ring carrier can be provided with additional insulation walls that extend radially outward or inward to ensure optimal electrical separation of the slip rings. The slip ring carrier is preferably made of high-strength, non-conductive materials, preferably plastic, particularly preferably fiber-reinforced plastic, which not only ensure electrical insulation but also increase the thermal and mechanical load capacity of the entire rotor. slip ring

[0018] For the purposes of this patent application, a slip ring is a rotationally symmetrical component that is attached to the outer surface of a slip ring carrier and serves to transmit electrical energy or signals between rotating and stationary components of an electrical machine. The slip ring consists of an electrically conductive material that is in contact with a brush system on its outer surface. This ensures a continuous electrical connection while the rotor rotates. Functionally, the slip ring enables the transmission of electrical currents or signals from the stationary parts of the machine, such as the brushes, to the rotating parts without the need for a rigid electrical connection. This is particularly advantageous in applications where the rotor shaft rotates continuously and a reliable electrical connection must be maintained.The slip rings are arranged on the slip ring carrier coaxially to the rotation axis of the rotor so that they are optimally integrated into the system.

[0019] The design of a slip ring can vary, with a cylindrical or slightly conical shape being preferred to ensure optimal contact surface with the brushes. The slip ring is advantageously made of materials such as copper or a copper alloy, as these materials exhibit high electrical conductivity while also being wear-resistant. To minimize abrasion caused by the brushes, the slip rings can be additionally surface-treated or coated, for example, using electroplating or hard metal coatings.

[0020] Conceivable designs of the slip ring include different sizes and shapes, adapted to the specific requirements of the electrical machine. For example, the outer diameter of the slip ring can be varied to optimize the electrical load capacity, or the slip ring material can be adapted to special operating conditions, such as high temperatures or aggressive environments. It is also possible to arrange multiple slip rings on a carrier to enable the parallel transmission of multiple electrical phases or signals. warehouse location

[0021] For the purposes of this patent application, a bearing seat is an element or area of ​​a rotor shaft that serves to accommodate and position a bearing. The bearing seat is preferably an integral part of the rotor shaft and designed for the precise and stable mounting of the shaft or rotor within the electrical machine. The function of the bearing seat is essentially to position a bearing securely and precisely, thereby ensuring the correct alignment of the rotor shaft. The design of the bearing seat includes a defined geometric shape that is tailored to the specific type of bearing. This can include a cylindrical, conical, or other shaped surface, depending on the bearing used. The bearing seat is advantageously designed to have a high dimensional accuracy in order to provide an optimal fit for the bearing. It is fundamentally conceivable for a plain or rolling bearing to sit on the bearing seat.Bearing seats designed to accommodate rolling bearings, such as ball or roller bearings, are preferred. It is also possible for the rolling elements of a rolling bearing to roll directly on the bearing seat. In this case, the bearing seat also forms the raceway for the rolling elements of the rolling bearing. Bearing seats can also incorporate additional features such as grooved grooves or stop surfaces for retaining rings, which enable precise axial positioning of the bearing. In highly loaded applications, bearing seats can also be provided with additional reinforcements or special coatings to reduce wear and increase durability. Insulation wall

[0022] For the purposes of this patent application, an insulation wall is a component that serves to electrically insulate electrical components, particularly slip rings, from one another in order to prevent unwanted current flows or short circuits. The insulation wall is preferably designed as a circular disk-like structure made of an electrically non-conductive material, extending radially outward from a slip ring carrier. It spatially separates the various electrical components and ensures that there is no electrical connection between them, except at the designated contact points.

[0023] The insulation wall is advantageously dimensioned such that its outer diameter is smaller than or equal to the outer diameter of the adjacent bearing seat on the rotor shaft, so that a bearing can be pushed axially over the insulation wall onto the bearing seat.

[0024] The insulation wall is preferably made of a thermally stable and electrically insulating material that can withstand the mechanical and thermal stresses encountered during operation of the electrical machine. One conceivable embodiment of the insulation wall could be a rigid, dimensionally stable disc made of a ceramic or polymer material. Alternatively, the insulation wall can also be constructed in multiple layers, combining several layers of different insulating materials to ensure particularly high dielectric strength.

[0025] Particularly preferably, an insulation wall is formed in one piece, in particular monolithically, with a slip ring carrier.

[0026] In a further preferred embodiment, the insulation wall can be provided with additional structures such as grooves or ribs to increase mechanical stability or improve heat dissipation. A flexible insulation wall is also conceivable, which can compensate for minor movements or vibrations during operation without losing its insulating function. Busbar

[0027] For the purposes of this patent application, a busbar is an electrically conductive component used to transmit electrical energy between different components of the rotor. The busbar extends axially through a slip-ring carrier and is electrically connected to a slip ring, thus conducting current from the slip ring to the rotor winding or vice versa.

[0028] The busbar can be designed to be made of an electrically conductive material such as copper or aluminum, which has high conductivity. The busbar can be guided axially through the slip-ring carrier and extended radially outward in certain areas to enable contact with the rotor winding or other components. Advantageously, the busbar is guided in retaining sleeves or slots at certain sections to ensure precise alignment and fixation in the slip-ring module. This not only ensures precise electrical contact but also protects the busbar from mechanical damage.

[0029] Conceivable embodiments of the busbar can vary. A preferred embodiment comprises a radial extension of the busbar through openings in the rotor shaft to enable simple and direct electrical contact from the outside. Another embodiment could include additional mechanical support of the busbar through positive connections within the rotor to further increase its stability under dynamic operating conditions. Alternatively, the busbar could be guided in a hollow cylindrical retaining sleeve to provide an even more robust structure and improved thermal insulation. Insulation groove

[0030] For the purposes of this patent application, an insulation groove is a radially inwardly extending recess in a component, particularly a slip-ring carrier, that serves to improve electrical insulation between adjacent components. The insulation groove creates additional physical distance between the conductive parts, thereby reducing the risk of electrical flashovers or short circuits. It ensures that voltage differences between electrical contacts, such as between slip rings, are safely managed by providing increased dielectric strength.

[0031] The insulation groove is preferably designed to run coaxially with the rotor's rotational axis and extend radially inward into the slip ring carrier. Advantageously, the insulation groove is dimensioned to have sufficient depth and width to ensure reliable insulation at high voltages. One possible embodiment consists of a circumferential, circular groove that runs around the entire circumference of the slip ring carrier and provides a uniform insulation effect. Alternatively, the insulation groove can also be designed in sub-segments to separate specific areas of the electrical components from one another. In a further embodiment, the insulation groove can be designed in combination with additional insulation materials to achieve even greater insulation efficiency. retaining sleeve

[0032] For the purposes of this patent application, a retaining sleeve is a hollow cylindrical component used to arrange the busbars in the rotor shaft and ensure their stable positioning. The retaining sleeve forms a mechanical mount for the busbars, reliably guiding them and protecting them against external mechanical influences, such as vibrations and thermal expansion. At the same time, the retaining sleeve ensures that the busbars remain in their intended position during operation and guarantees a consistently reliable electrical connection to the slip rings.

[0033] Preferably, cooling fluid channels are integrated into the outer surface of the retaining sleeve, which contribute to effective heat dissipation during operation. These channels can extend in the axial direction and have radial connecting channels that ensure optimal distribution of the cooling fluid. The retaining sleeve can also have one or more openings aligned with corresponding openings in the rotor shaft to accommodate a fixing means, such as a pin or a screw. This ensures that the retaining sleeve is secured both axially and circumferentially relative to the rotor shaft, guaranteeing a secure and stable connection.

[0034] Advantageously, the retaining sleeve can have an anti-twist feature formed by a form-locking element on the end face of the retaining sleeve and the slip ring carrier. This prevents the slip ring carrier from twisting relative to the retaining sleeve and ensures stable and precise alignment of the electrical contacts. The retaining sleeve is preferably molded from a plastic. Advantageous embodiments of the invention

[0035] According to an advantageous embodiment of the invention, it can be provided that the first busbar has a first busbar section extending radially outwards through a first opening in the rotor shaft and / or the second busbar has a second busbar section extending radially outwards through a second opening in the rotor shaft. The key advantage of the radial extension of the busbar sections through openings in the rotor shaft is that electrical contact can be made from the outside without intensive disassembly of the rotor structure. This simplifies production and enables efficient, clean, and precise connection of the electrical busbars to the slip ring module. After contact has been made, the rolling bearings and other components can be easily installed, thereby optimizing production and the maintenance process.This arrangement also improves accessibility to the busbars for possible repairs or maintenance.

[0036] According to a further preferred development of the invention, it can also be provided that a first positive locking means is formed on the first busbar section, which interacts with a corresponding positive locking means of the rotor such that the first busbar section is supported radially outwards and / or a third positive locking means is formed on the second busbar section, which interacts with a corresponding positive locking means of the rotor such that the second busbar section is supported radially outwards. The decisive advantage of radially supporting the busbar sections by means of positive locking connections lies in the additional stability and securing of the busbars. This prevents movement or twisting of the busbars during operation, which increases the mechanical load-bearing capacity and ensures a permanently reliable electrical connection.The positive connection also compensates for vibrations and other mechanical stresses that occur during operation, ensuring a long service life for the entire assembly.

[0037] Furthermore, according to a likewise advantageous embodiment of the invention, a first circumferential insulation groove can be provided on the side of the first insulation wall facing away from the first slip ring, extending radially inward into the first slip ring carrier. This minimizes the risk of unwanted electrical arcing, leading to increased operational reliability. Furthermore, the insulation groove can be integrated during the prefabrication of the rotor, simplifying the assembly process and increasing the quality of the insulation during operation.

[0038] According to another particularly preferred embodiment of the invention, a second circumferential insulating groove can be provided, extending radially inward into the second slip ring carrier on the side facing away from the second slip ring. Similar to the first insulating groove, the second circumferential insulating groove also offers an additional safety measure against electrical short circuits or flashovers. This design ensures reliable electrical isolation of the components, which is particularly important at high operating voltages. The insulating groove can be fully integrated into the slip ring carrier during prefabrication of the rotor, thereby shortening assembly time and improving the overall safety of the machine.

[0039] Furthermore, the invention can also be further developed such that the first busbar is received in a first receiving slot of a hollow cylindrical holding sleeve in its region extending axially through the first slip ring carrier and / or the second busbar is received in a second receiving slot of a hollow cylindrical holding sleeve in its region extending axially through the second slip ring carrier. The advantage of receiving the busbars in hollow cylindrical holding sleeves is that the busbars are stably and securely fixed in the axial direction. This improves the mechanical integrity of the rotor and protects the busbars from mechanical damage during operation. Furthermore, this design enables easy assembly of the busbars, as they can be correctly positioned before final assembly of the rotor.This reduces assembly time and improves the quality and reliability of the electrical contacts.

[0040] In a likewise preferred embodiment of the invention, it can also be provided that the holding sleeve has at least one opening running perpendicular to the axis of rotation of the rotor and passing through the holding sleeve, which opening is arranged in alignment with corresponding openings in the rotor shaft, and a fixing means passes through the opening in the holding sleeve and the openings in the rotor shaft, so that the holding sleeve is fixed at least axially and circumferentially relative to the rotor shaft. By using a positive fixing of the holding sleeve in the rotor shaft, a particularly stable and permanent fastening is achieved, which prevents twisting or displacement of the holding sleeve. This ensures precise alignment of the busbars and slip rings, guaranteeing a permanently reliable electrical connection.In addition, this design allows for easy assembly and disassembly of the retaining sleeve, which reduces maintenance effort and increases the serviceability of the rotor.

[0041] It may also be advantageous to further develop the invention such that cooling fluid channels extending in the axial direction and distributed around the circumference are formed on the outer surface of the retaining sleeve, each of which has a radially extending connecting channel to the inner surface of the retaining sleeve. The cooling fluid channels integrated into the retaining sleeve offer the advantage of efficient heat dissipation during operation. This improves the thermal stability of the rotor and protects the electrical and mechanical components from overheating. Targeted cooling enables higher operating performance without compromising the service life of the rotor. Furthermore, the design of the cooling fluid channels contributes to the even distribution of the cooling fluid, which ensures optimized cooling of the entire assembly.

[0042] According to a further preferred embodiment of the subject matter of the invention, it can be provided that a hollow cylindrical cooling fluid line extends axially, at least in sections, through the rotor shaft and coaxially to the rotational axis, wherein the inner circumferential surface of the retaining sleeve preferably rests against the outer circumferential surface of the cooling fluid line and / or preferably the inner circumferential surface of the second slip ring carrier rests against the outer circumferential surface of the cooling fluid line. The advantage of the axially extending cooling fluid line is that the rotor is evenly cooled from the inside out. This ensures effective heat dissipation and prevents hot spots that could lead to thermal overloads. Especially with higher power requirements, this cooling design contributes to maximizing the service life and reliability of the rotor.The close connection of the cooling fluid line to the inner surfaces of the retaining sleeve and the slip ring carrier further optimizes heat transfer and ensures uniform cooling of the entire assembly.

[0043] Finally, the invention can also be advantageously implemented such that the holding sleeve has at least one positive locking means on its end face facing the first slip ring, which, together with a corresponding positive locking means on the first slip ring carrier, forms a rotation lock of the first slip ring carrier relative to the holding sleeve. The advantage of the rotation lock between the holding sleeve and the slip ring carrier is that it achieves a stable mechanical fixation that prevents the components from rotating relative to one another. This ensures permanent alignment of the electrical and mechanical components, which increases the operational reliability and longevity of the assembly. Furthermore, this lock ensures consistently precise electrical contact, thereby preventing malfunctions and improving the overall efficiency of the rotor.

[0044] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

[0045] It shows: Fig. 1 a first embodiment of a rotor with a slip ring module in a perspective axial sectional view, Fig. 2 a perspective view of the isolated slip ring module, Fig. 3 an axial sectional view of a first slip ring carrier, Fig. 4 an axial sectional view of a second slip ring carrier, Fig. 5 is an axial sectional view of the first and second slip ring carriers in an assembled state, Fig. 6 a perspective axial sectional view of the first slip ring carrier and the holding sleeve in a perspective view.

[0046] The Fig. 1-6 show an embodiment of a slip ring module 4 for a rotor 1 of an electrical machine 2 in different views.

[0047] Fig. 1 shows a rotor 1 for an electrical machine 2, in particular for a separately excited synchronous machine, comprising a rotor shaft 3 designed as a hollow shaft with an inner diameter 18, which has, in the region of one of its distal ends, a bearing seat 11 formed on its outer surface and lying on a first outer diameter 50, as well as a slip ring module 4 inserted into the rotor shaft 3.

[0048] The slip ring module 4 has a first electrically non-conductive, hollow-cylindrical slip ring carrier 5 with a first slip ring 6 fixed to its outer surface 14, and a second electrically non-conductive, hollow-cylindrical slip ring carrier 7 with a second slip ring 8 fixed to its outer surface 15. A first busbar 9 is connected to the first slip ring 6 and extends at least partially in the axial direction through the first slip ring carrier 5 and into the rotor shaft 3. Analogously, a second busbar 10 is connected to the second slip ring 8 and extends at least partially in the axial direction through the second slip ring carrier 7 and into the rotor shaft 3.

[0049] The first slip ring carrier 5 has a receiving opening 13 which runs coaxially to the rotational axis 12 of the rotor 1 and into which the second slip ring carrier 7 engages axially at least in sections, which can also be clearly seen from the synopsis of the Fig. 3 with the Fig. 5 can be understood.

[0050] A first annular disk-like insulation wall 16, which is axially spaced from the first slip ring 6, extends radially outwards from the first slip ring carrier 5 with a second outer diameter 17, wherein the second outer diameter 17 of the first insulation wall 16 of the first slip ring carrier 5 is less than or equal to the first outer diameter 50 of the bearing seat 11 of the rotor shaft 3, and the outer diameter 19 of the first slip ring 6 is less than or equal to the second outer diameter 17 of the first insulation wall 16, and the outer diameter 20 of the second slip ring 8 is less than or equal to the outer diameter 19 of the first slip ring 6, and there is no outer diameter greater than the outer diameter 19 of the first slip ring 6 on the slip ring module 4 between the first slip ring 6 and the second slip ring 8.

[0051] The first busbar 9 further has a first busbar section 22 extending radially outwards through a first opening 35 of the rotor shaft 3, and the second busbar 10 similarly has a second busbar section 24 extending radially outwards through a second opening 36 of the rotor shaft 3.

[0052] It is clear from the Fig. 1 further that a hollow cylindrical cooling fluid line 42 extends axially at least in sections and coaxially to the rotation axis 12 through the rotor shaft 3, wherein preferably the inner circumferential surface 41 of the holding sleeve 32 rests on the outer circumferential surface 43 of the cooling fluid line 42 and the inner circumferential surface 44 of the second slip ring carrier 7 rests on the outer circumferential surface 43 of the cooling fluid line 42.

[0053] The Fig. 3-4 also clearly shows that a first positive locking means 27 is formed on the first busbar section 22, which cooperates with a corresponding positive locking means 28 of the rotor cover 49 of the rotor 1 such that the first busbar section 22 is supported radially outward. A third positive locking means 29 is also formed on the second busbar section 24, which cooperates with a corresponding positive locking means 30 of the rotor cover 49 of the rotor 1 such that the second busbar section 24 is supported radially outward.

[0054] As in the Fig. 3, a first circumferential insulation groove 25 extends radially inward into the first slip ring carrier 5 on the side of the first insulation wall 16 facing away from the first slip ring 6. The Fig. 4 shows, among other things, that in an analogous manner, on the side facing away from the second slip ring 8, a second circumferential insulation groove 26 extends radially inwards into the second slip ring carrier 7.

[0055] In the Fig. 6 shows that the first busbar 9 is received in a first receiving slot 31 of a hollow cylindrical holding sleeve 32 in its region extending axially through the first slip-ring carrier 5, and the second busbar 10 is received in a second receiving slot 33 of a hollow cylindrical holding sleeve 32 in its region extending axially through the second slip-ring carrier 7. In the embodiment shown, the receiving slots 31, 33 are formed as a common slot.

[0056] What the Fig. 6 is that the holding sleeve 32 has at least one opening 34 running perpendicular to the axis of rotation 12 of the rotor 1 and passing through the holding sleeve 32, which is arranged in alignment with corresponding openings 35, 36 of the rotor shaft 3, and a fixing means 37 passes through the opening 34 of the holding sleeve 32 and the openings 35, 36 of the rotor shaft 3, so that the holding sleeve 32 is fixed at least axially and circumferentially relative to the rotor shaft 3.

[0057] Also in the Fig. 6 shows that on the outer surface 38 of the retaining sleeve 32, cooling fluid channels 39 are formed which extend in the axial direction and are distributed around the circumference and each have a radially extending connecting channel 40 to the inner surface 41 of the retaining sleeve 32. Fig. 6 also shows that the holding sleeve 32 has at least one form-locking means 46 on its end face 45 facing the first slip ring 6, which, together with a corresponding form-locking means 47 on the first slip ring carrier 5, forms a rotation lock of the first slip ring carrier 5 relative to the holding sleeve 32.

[0058] In summary, the embodiment shown relates to a rotor 1 for an electrical machine 2, in particular for a separately excited synchronous machine, comprising a slip ring module 4 that can be pre-assembled and inserted into the rotor shaft 3 before the rolling bearing is mounted on the bearing seat 11. This solution allows the electrical contacting of the busbars 9, 10, for example by welding, to be carried out before the bearing and the brush module are mounted. The pre-assembled configuration significantly simplifies production and assembly and provides efficient integration of the slip ring modules into the rotor 1.

[0059] An essential feature of the invention in this regard is the use of a slip ring carrier 5 with a circumferential, plate-ring-shaped insulating wall 16, which has been reduced to a small diameter 17 so that the bearing can be pushed onto the bearing seat 11. In order to nevertheless maintain the required creepage distance, an insulating groove 25 was machined into the slip ring carrier 5 and an insulating groove 26 into the slip ring carrier 7. These insulating grooves 25, 26 can advantageously also be designed in an L-shape (which is not shown in the figures) in order to further extend the creepage distance. In the exemplary embodiment shown, the insulating wall 48 of the second slip ring carrier 7 is mounted subsequently, which offers flexibility during assembly and simplifies the production process.

[0060] Another important aspect of the invention is the optimization of the welding process through the introduction of one-piece busbars 9, 10 that protrude radially outward from the rotor shaft 3. This simplifies the contacting of the busbars and enables the welding process outside the rotor shaft 3, making the busbars 9, 10 easily accessible. The busbars 9, 10 and the slip ring carriers 5, 7 also have centrifugal force supports in the form of the form-locking means 27, 28, 29, 30, which prevent deformation under high speeds and thus ensure the mechanical stability of the slip ring module 4.

[0061] The slip ring module 4 can be cooled during operation of the rotor 1 using a cooling fluid, such as cooling oil, and heat can be dissipated from the electrically or thermally stressed areas of the slip ring module 4. For this purpose, the slip ring module 4 can be mounted on a cooling fluid line 42 coaxial with it and rotating during operation, so that the cooling fluid is propelled radially outward by centrifugal force and can enter the radially extending connecting channels 40 of the retaining sleeve 32. The cooling fluid can then be further conducted and distributed axially via the cooling fluid channels 39.

[0062] The slip ring module 4 is axially secured in the rotor shaft 3 by preloading it with a disc spring 51, which is supported on a circumferential shoulder of the cooling fluid line 42. This design ensures that the slip ring module 4 can be secured with a defined force without excessive stress on the plastic parts. The slip ring module is secured against rotation by positive connections such as lugs and recesses, which ensure precise alignment of the modules and prevent rotation during operation, as is also exemplified in the Fig. 6 is shown.

[0063] The invention is not limited to the embodiments illustrated in the figures. The above description is therefore not to be considered restrictive, but rather explanatory. The following claims are to be understood in such a way that a stated feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. Where the claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a priority. List of reference symbols 1 rotor 2 electric machine 3 Rotor shaft 4 slip ring module 5 slip ring carriers 6 slip ring 7 slip ring carriers 8 Slip ring 9 Busbar 10 Busbar 11 Bearing seat 12 Rotation axis 13 Receiving opening 14 Shell surface 15 Shell surface 16 Insulation wall 17 outer diameter 18 inner diameter 19 outer diameter 20 outer diameter 22 conductor rail section 24 conductor rail section 25 Insulation groove 26 Insulation groove 27 Form-locking devices 28 Form-locking devices 29 Form-locking devices 30 form-locking agents 31 Recording slot 32 retaining sleeve 33 Recording slot 34 Opening 35 Opening 36 Opening 37 Fixatives 38 lateral surface 39 cooling fluid channels 40 connecting channel 41 lateral surface 42 Cooling fluid line 43 lateral surface 44 lateral surface 45 front side 46 form-locking devices 47 Form-locking devices 48 Insulation wall 49 Rotor cover 50 outer diameter 51 disc spring

Claims

[1] Rotor (1) for an electrical machine (2), in particular for a separately excited synchronous machine, comprising • a rotor shaft (3) designed as a hollow shaft with an inner diameter (18), which has, in the region of one of its distal ends, a bearing seat (11) formed on its outer surface and lying on a first outer diameter (50), and • a slip ring module (4) inserted into the rotor shaft (3), wherein • the slip ring module (4) has a first electrically non-conductive, hollow-cylindrical slip ring carrier (5) with a first slip ring (6) fixed to its outer surface (14) and a second electrically non-conductive, hollow-cylindrical slip ring carrier (7) with a second slip ring (8) fixed to its outer surface (15), and • a first busbar (9) is connected to the first slip ring (6) and extends at least partially in the axial direction through the first slip ring carrier (5) and into the rotor shaft (3), and • a second busbar (10) is connected to the second slip ring (8) and extends at least partially in the axial direction through the second slip ring carrier (7) and into the rotor shaft (3), and • the first slip ring carrier (5) has a receiving opening (13) running coaxially to the rotational axis (12) of the rotor (1), into which the second slip ring carrier (7) engages axially at least in sections, • wherein a first circular disk-like insulation wall (16) axially spaced from the first slip ring (6) extends radially outwardly from the first slip ring carrier (5) with a second outer diameter (17), characterized by , that • the second outer diameter (17) of the first insulation wall (16) of the first slip ring carrier (5) is less than or equal to the first outer diameter (50) of the bearing seat (11) of the rotor shaft (3), and • the outer diameter (19) of the first slip ring (6) is less than or equal to the second outer diameter (17) of the first insulation wall (16), and • the outer diameter (20) of the second slip ring (8) is smaller than or equal to the outer diameter (19) of the first slip ring (6) and • between the first slip ring (6) and the second slip ring (8) there is no outer diameter larger than the outer diameter (19) of the first slip ring (6) on the slip ring module (4). [2] Rotor (1) according to claim 1, characterized by , that the first busbar (9) has a first busbar section (22) extending radially outward through a first opening (35) of the rotor shaft (3) and / or the second busbar (10) has a second busbar section (24) extending radially outward through a second opening (36) of the rotor shaft (3). [3] Rotor (1) according to claim 2, characterized by , that a first form-locking means (27) is formed on the first busbar section (22) which cooperates with a corresponding form-locking means (28) of the rotor (1) in such a way that the first busbar section (22) is supported radially outwards and / or a third form-locking means (29) is formed on the second busbar section (24) which cooperates with a corresponding form-locking means (30) of the rotor (1) in such a way that the second busbar section (24) is supported radially outwards. [4] Rotor (1) according to one of the preceding claims, characterized bythat on the side of the first insulation wall (16) facing away from the first slip ring (6), a first circumferential insulation groove (25) extends radially inwards into the first slip ring carrier (5). [5] Rotor (1) according to one of the preceding claims, characterized by that on the side facing away from the second slip ring (8) a second circumferential insulation groove (26) extends radially inwards into the second slip ring carrier (7). [6] Rotor (1) according to one of the preceding claims, characterized by that the first busbar (9) is received in its region extending axially through the first slip ring carrier (5) in a first receiving slot (31) of a hollow cylindrical holding sleeve (32) and / or the second busbar (10) is received in its region extending axially through the second slip ring carrier (7) in a second receiving slot (33) of a hollow cylindrical holding sleeve (32). [7] Rotor (1) according to one of the preceding claims, characterized by that the holding sleeve (32) has at least one opening (34) which runs perpendicular to the axis of rotation (12) of the rotor (1) and passes through the holding sleeve (32), which opening is arranged in alignment with corresponding openings (35, 36) of the rotor shaft (3), and a fixing means (37) passes through the opening (34) of the holding sleeve (32) and the openings (35, 36) of the rotor shaft (3), so that the holding sleeve (32) is fixed at least axially and circumferentially relative to the rotor shaft (3). [8] Rotor (1) according to one of the preceding claims, characterized by that on the outer circumferential surface (38) of the holding sleeve (32) there are formed cooling fluid channels (39) which extend in the axial direction and are arranged in a circumferentially distributed manner and which each have a radially extending connecting channel (40) to the inner circumferential surface (41) of the holding sleeve (32). [9] Rotor (1) according to one of the preceding claims, characterized bythat a hollow cylindrical cooling fluid line (42) extends axially at least in sections and coaxially to the rotation axis (12) through the rotor shaft (3), wherein preferably the inner circumferential surface (41) of the holding sleeve (32) bears against the outer circumferential surface (43) of the cooling fluid line (42) and / or preferably the inner circumferential surface (44) of the second slip ring carrier (7) bears against the outer circumferential surface (43) of the cooling fluid line (42). [10] Rotor (1) according to one of the preceding claims 6-9, characterized by that the holding sleeve (32) has at least one form-locking means (46) on its end face (45) facing the first slip ring (6), which, together with a corresponding form-locking means (47) on the first slip ring carrier (5), forms a rotation lock of the first slip ring carrier (5) relative to the holding sleeve (32).

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