Rotor with slip ring assembly for an externally excited electric machine, electric machine, motor vehicle, and method for producing a rotor
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- SCHAEFFLER TECHNOLOGIES AG & CO KG
- Filing Date
- 2024-07-08
- Publication Date
- 2026-05-13
AI Technical Summary
Rotors for separately excited electrical machines require significant axial installation space due to the need for a distance between the slip ring and the rotor winding, which complicates manufacturing and increases space requirements.
A rotor design where the connecting wire of the slip ring arrangement is guided through a ring carrier that extends between the shaft end section and the winding head, allowing the connecting wire to be embedded within the ring carrier, enabling the slip ring assembly to be easily attached without the need for a hollow shaft, and facilitating a reduced axial installation space by guiding the connecting end section under the winding head for a cohesive electrical connection.
This design reduces the axial installation space of the rotor, simplifies the manufacturing process, and allows for a space-reduced, permanent, and highly conductive electrical connection between the connecting end section and the rotor winding, while preventing cooling medium leakage and protecting the winding from damage.
Smart Images
Figure EP2024069191_16012025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Rotor with slip ring arrangement for a separately excited electrical machine, electrical machine, motor vehicle and method for producing a rotor
[0003] The invention relates to a rotor for a separately excited electrical machine, wherein the rotor has a rotor shaft on which a slip ring arrangement is arranged, and a connecting wire of the slip ring arrangement is electrically conductively connected to a rotor winding wound on the rotor or on a laminated core of the rotor. The invention also relates to an electrical machine having the rotor according to the invention. A further subject of the invention is a motor vehicle having the electrical machine according to the invention. Furthermore, the invention relates to a method for producing the rotor.
[0004] Rotors for separately excited electrical machines are well known. The rotors typically have a rotor shaft with a laminated core arranged on the rotor shaft. A rotor winding is wound on one pole of the laminated core. A slip ring arrangement is attached to the end of the rotor shaft, the slip ring of which is connected to the rotor winding via a connecting wire. The connecting wire is generally deflected from the slip ring arrangement in the radial direction of the rotor shaft in order to be connected to the rotor winding. Due to the fact that a distance from the winding head is required for a welding electrode to connect the connecting wire to the rotor winding, the installation space of the rotor is increased in the axial direction.
[0005] An object of the invention is to provide and / or produce a rotor for a separately excited electrical machine which can have a reduced axial installation space and is easy to produce.
[0006] The object of the invention is achieved by the subject matter of the independent patent claims. Preferred developments of the invention are the subject matter of the dependent patent claims, the following description, and the drawings. Each described and / or shown feature can represent an aspect of the invention, both individually and in combination, unless explicitly stated otherwise in the description. In a first aspect, the invention relates to a rotor for a separately excited electrical machine, comprising a rotor shaft with a laminated core arranged on the rotor shaft, wherein the laminated core has at least one salient pole with a rotor winding wound on the pole and an end side aligned in an axial direction of the rotor, wherein the rotor winding extending beyond the end side forms a winding head, a slip ring arrangement arranged on a shaft end section of the rotor shaft,which comprises a ring carrier, a slip ring, and a connecting wire connected to the slip ring, wherein the connecting wire is guided from the slip ring through the ring carrier, the ring carrier extends between a distal end of the shaft end portion and a region below the winding head, and a connecting end portion of the connecting wire, relative to a longitudinal direction of the rotor, is guided into the region below the winding head, and a conductor end of the rotor winding is electrically connected to the connecting end portion.
[0007] In other words, according to the first aspect of the invention, a rotor for a separately excited electrical machine is provided. The rotor has a rotor shaft. A laminated core is arranged in a rotationally fixed manner on the rotor shaft, in particular on an outer circumferential surface of the rotor shaft. The laminated core has at least one salient pole. The salient pole is usually aligned in a radial direction of the rotor. It is conceivable for the salient pole to have a pole shaft and a pole shoe adjacent to the pole shaft. As a rule, the rotor has a plurality of poles that are arranged and / or formed at regular or irregular intervals from one another in the circumferential direction of the laminated core. The laminated core also has an end side aligned in an axial direction of the rotor. A rotor winding is wound on the salient pole.The rotor winding is typically formed by an electrically conductive wire, preferably with an electrically insulating coating. The rotor winding extending beyond the end face forms a winding head.
[0008] A slip ring arrangement is arranged on a shaft end section of the rotor shaft. The slip ring arrangement comprises a ring carrier, at least one slip ring, and a connecting wire that is electrically connected to the slip ring. The connecting wire runs from the slip ring through the ring carrier. The ring carrier extends between a distal end of the shaft end section and an area below the winding overhang. Because the connecting wire is arranged and embedded in the ring carrier, the slip ring arrangement can be easily pushed onto the shaft end section from the outside. This eliminates the need for the shaft end section to be designed as a hollow shaft, and the complex task of routing the connecting wire through a hollow space is also eliminated. Consequently, the slip ring arrangement can be easily arranged on the shaft end section.
[0009] A free connecting end section of the connecting wire is guided into the area below the winding head, relative to a longitudinal direction of the rotor. A conductor end of the rotor winding is electrically conductively connected to the connecting end section. Due to the fact that the connecting end section is guided below the winding head, relative to the longitudinal direction of the rotor, the electrically conductive connection between the conductor end and the connecting end section can be formed close to the laminated core. The axial installation space of the rotor can thus be reduced. In addition, a connecting device, in particular a welding electrode, can be guided and / or displaced, preferably in the longitudinal direction of the rotor, in order to electrically conductively connect the connecting end section to the conductor end of the rotor winding.
[0010] The conductor end is guided from the winding head toward the rotor shaft or the rotor's longitudinal axis. In other words, the conductor end of the rotor winding runs in a predominantly radial direction from the winding head. "Predominantly radial" means that the conductor does not necessarily have to be straight and radial, but can be curved. However, the main direction of the conductor end is directed from the winding head toward the rotor shaft.
[0011] An advantageous development of the invention is that the electrically conductive connection is a material connection. A material connection allows for a space-saving, permanent, and highly conductive electrical connection between the connecting end section and the conductor end.
[0012] In this context, an advantageous embodiment of the invention is that the material-to-material connection is a welded connection, an electrically conductive adhesive connection, or a soldered connection. The welded connection is preferably carried out using a welding device with a welding electrode, wherein the welding electrode is preferably guided parallel to the longitudinal direction of the rotor in order to place it on the connecting end section and / or the conductor end at least in sections, and to connect the connecting end section and the conductor end to one another in a material-to-material manner. In the case of an adhesive connection, it can be provided that an adhesive and / or pressing device is displaced parallel to an axial direction of the rotor in order to place the adhesive and / or pressing device on the connecting end section and / or the conductor end at least in sections, and to connect the connecting end section and the conductor end to one another in a material-to-material manner.It is also conceivable that a soldering device is displaced parallel to the axial direction of the rotor in order to place the soldering device on the connecting end section and / or the conductor end at least in sections, and to connect the connecting end section and the conductor end to one another in a materially bonded manner.
[0013] According to an advantageous embodiment of the invention, it is provided that the connecting end section is deflected, relative to a longitudinal direction of the rotor, at an angle a between 0° < a < 80°, preferably between 15° < a < 75°, and particularly preferably between 30° < a < 60°, the limits being included. In other words, it is provided that the connecting end section is not oriented at an angle perpendicular to the longitudinal axis of the rotor in order to be connected to the conductor end of the rotor winding. Rather, it is provided that the connecting end section is deflected, relative to the longitudinal direction of the rotor, at an angle between 0° and 80°, in particular between 15° < a < 75° and very particularly preferably between 30° < a < 60°, in order to be connected to the conductor end.It is therefore conceivable that the conductor end of the rotor winding is placed directly or indirectly on the connecting end section and then an electrically conductive connection is made between the conductor end and the connecting end section.
[0014] A preferred development of the invention is that a sealing element is arranged between the rotor shaft and an inner circumferential surface of the ring carrier and / or between the shaft end section and the inner circumferential surface of the ring carrier. The sealing element can be used to easily prevent, for example, a cooling medium, in particular a fluid, for cooling the rotor winding from passing through an annular gap between the ring carrier and the rotor shaft or between the ring carrier and the shaft end section toward the slip ring.
[0015] A preferred embodiment of the invention is that a deflection cap for guiding the rotor winding in the region of the end side is arranged on the end side of the laminated core. The deflection cap is arranged and / or formed at least as an extension of the pole on the end side of the laminated core. The deflection cap can be used to specify a bending radius of the wire in the region of the winding head in order to wind the winding onto the salient pole in the region of the winding head without damage. Furthermore, the wire can be guided in a space-saving manner in the region of the deflection to form the winding head, preferably by means of an orthocyclic winding. In this way, the rotor winding can be deflected in the region of the winding head in a material-saving and space-saving manner.
[0016] It is conceivable that the deflection cap is formed separately from the ring carrier. It can be provided that the rotor shaft with the laminated core arranged on it is first prepared. The deflection cap is placed on the end of the laminated core, and the rotor winding is then wound on it. After the rotor winding has been wound, the slip ring assembly is placed on the shaft end section and moved to its end position, i.e., to the end side. The conductor end of the rotor winding and the connecting end section are then electrically connected to each other.
[0017] It is also conceivable that before arranging the deflection cap on the end side, the slip ring arrangement is first slipped onto the shaft end section and then the deflection cap is fastened to the end side. An advantageous development of the invention provides that the deflection cap overlaps the slip ring arrangement and / or the ring carrier at least in sections, so that the slip ring arrangement and / or the ring carrier is positively fixed to the shaft end section in the axial direction of the rotor by the slipped deflection cap. The rotor winding is then wound up and the conductor end of the rotor winding is electrically connected to the connecting section. This has the advantage that the conductor end of the rotor winding can preferably be placed directly onto the connecting end section and connected to it.An advantageous development of the invention is that the deflection cap and the ring carrier are formed integrally with one another. This allows the number of parts and, consequently, the number of manufacturing steps to be reduced, which can have a beneficial effect on manufacturing costs. Furthermore, this design allows the rotor winding to be wound onto the salient pole of the laminated core, with the conductor end of the rotor winding subsequently being guided directly to the connecting end section for electrically conductive connection.
[0018] The ring carrier is preferably made of an electrically insulating material. Particularly preferably, the ring carrier is made of a plastic and / or comprises a plastic at least in sections. The plastic is preferably a thermoplastic or a thermosetting plastic. It is conceivable that the plastic comprises a filler. The filler can preferably be glass-based, in particular a silicate glass, or carbon-based, preferably in the form of carbon fibers.
[0019] In an advantageous development of the invention, it is provided that the shaft end section has a bearing seat, wherein in the region of the bearing seat, on an outer side of the shaft end section oriented in the radial direction of the rotor, a groove running in the longitudinal direction of the rotor is formed, and a section of the ring carrier containing the connecting wire runs in this groove. In other words, it is provided that a bearing seat is formed on the shaft end section between the slip ring and the winding head. In the region of the bearing seat, a groove or channel running in the longitudinal direction of the rotor is formed on an outer side of the shaft end section. Thus, the bearing seat, with regard to the shaft end section, is not completely circular, but has at least one interruption in the form of a groove running in the longitudinal direction of the rotor.A section of the ring carrier, into which the connecting wire is embedded, engages in the groove. Consequently, the bearing seat is formed by both the shaft section and the ring carrier formed in the groove of the shaft section. The connecting wire thus runs not through the hollow shaft, but in an external groove of the shaft end section.
[0020] In this context, an advantageous development of the invention is that an outer diameter of the ring carrier in the region of the bearing seat is equal to or smaller than an outer diameter of the bearing seat of the shaft end section. Consequently, the bearing seat can be formed on the shaft end section in a simple manner.
[0021] According to a preferred embodiment of the invention, a sealing section for sealing with a shaft sealing ring is formed on an outer circumferential surface of the ring carrier. The sealing section is preferably formed between the bearing seat and the winding head. The sealing section is particularly preferably annular and is designed and / or formed without interruption in the circumferential direction of the rotor, i.e. continuously. The sealing section can be formed integrally with the ring carrier. The sealing section can thus be manufactured particularly inexpensively. Alternatively, it is conceivable for the sealing section to be made of metal. It is conceivable for the sealing section to be designed as a sleeve and to be arranged captively and / or rotationally fixed on the ring carrier.
[0022] The bearing seat and the sealing section preferably have different inner and / or outer diameters and are arranged or configured spaced apart from one another in the longitudinal direction of the rotor. Preferably, an outer diameter of the sealing section is larger than an outer diameter of the bearing seat.
[0023] In a preferred embodiment of the invention, an outer diameter of the bearing seat is larger than an outer diameter of the slip ring. In this way, a bearing device can be easily pushed over the distal end of the shaft end section, over the slip ring, and up to the bearing seat, and can preferably be positively secured in the final position.
[0024] An advantageous development of the invention is that the ring carrier is designed to be flush or recessed relative to a distal end of the shaft end section, relative to a longitudinal direction of the rotor. In other words, the ring carrier does not protrude beyond the distal end of the shaft end section, thereby reducing the installation space of the rotor in the axial direction.
[0025] In a second aspect, the invention relates to an electric machine with the rotor according to the invention. The electric machine is preferably a component of a traction drive, in particular an integrated traction drive, consisting of the electric machine, a transmission gear, which can also be referred to as a reducer, and an inverter.
[0026] In a third aspect, the invention relates to a motor vehicle with the electric machine according to the invention, wherein the electric machine is a component of a traction drive of the motor vehicle.
[0027] According to the third aspect, it is provided that a motor vehicle is provided which has the electric machine, wherein the electric machine comprises the separately excited rotor according to the invention. The electric machine is a component of a traction drive, wherein the traction drive is configured and / or designed to drive the motor vehicle, i.e., to set it in motion. In addition to the electric machine, the traction drive preferably comprises a transmission and / or an inverter. The traction drive can preferably be designed as an integrated traction drive. In other words, the electric machine, the inverter, and the transmission can be designed as a single unit and / or arranged in a housing.
[0028] In a fourth aspect, the invention relates to a method for producing a rotor, in particular the rotor according to the invention according to claim 1, comprising the steps:
[0029] - Providing a rotor shaft with a laminated core arranged on the rotor shaft, which core has at least one salient pole and has an end side aligned in an axial direction of the rotor;
[0030] - Winding a rotor winding onto the salient pole, whereby the rotor winding extending beyond the end face forms a winding head;
[0031] - Arranging a slip ring arrangement on a shaft end section of the rotor shaft, wherein the slip ring arrangement has a ring carrier, a slip ring and a connecting wire connected to the slip ring, and a connecting end section of the connecting wire, with respect to a longitudinal direction of the rotor, is guided, arranged and / or positioned below the winding head, i.e. between the rotor shaft and the winding head;
[0032] - Establishing an electrically conductive connection between a conductor end of the rotor winding and the connecting end portion of the connecting wire. In other words, according to the fourth aspect of the invention, a method for manufacturing a rotor is provided.
[0033] In a first step, a rotor shaft is provided with a laminated core arranged on the rotor shaft, wherein the laminated core has at least one salient pole. In an axial direction of the rotor, the laminated core has an end face.
[0034] In a second step, a slip ring assembly is arranged on a shaft end section of the rotor shaft. The slip ring assembly comprises a ring carrier, a slip ring, and a connecting wire connected to the slip ring. A connecting end section of the connecting wire is routed, relative to a longitudinal direction of the rotor, to below a winding head of a rotor winding, i.e., between the rotor shaft and the winding head of the rotor winding.
[0035] In a third step, the rotor winding is wound onto the salient pole, with the rotor winding extending beyond the end side forming the winding head of the rotor.
[0036] In a fourth step, an electrically conductive connection is established between a conductor end of the rotor winding and the connecting end portion of the connecting wire.
[0037] Because the connecting end section for connecting to the conductor end of the rotor winding is routed to a region below the winding head, the axial installation space of the rotor can be reduced. Furthermore, a connecting device can be routed, preferably in the axial direction of the rotor, to connect the connecting end section to the conductor end of the rotor winding.
[0038] A preferred embodiment of the invention provides that the slip ring arrangement comprising the connecting wire, wherein the connecting wire extends from the slip ring to the connecting end section in the ring carrier, is pushed onto the shaft end section in the axial direction of the rotor. In other words, a section of the ring carrier comprising the connecting wire preferably engages at least partially or partially into a groove on the outside of the shaft end section. Thus, the ring carrier can be easily pushed onto the shaft end section by a translational movement, thereby reducing manufacturing costs. A complex routing of the connecting wire through a shaft cavity can thus be avoided.
[0039] In an advantageous development of the invention, it is provided that a welding electrode of a welding device is guided in a direction parallel to the longitudinal axis of the rotor in order to establish the electrically conductive connection between the conductor end and the connecting end section. This has the advantage that, in order to relocate the welding electrode, only a minimum distance to the rotor shaft and not to the end of the laminated core or the winding head in the axial direction of the rotor needs to be maintained. Consequently, this creates a possibility in which the electrically conductive connection is made as close as possible to the laminated core, thereby reducing the installation space of the rotor in its axial direction.
[0040] According to a preferred development of the invention, the rotor winding is wound onto the salient pole after the slip ring arrangement has been arranged on the shaft end section. In other words, the rotor shaft comprising the laminated core is provided. The slip ring arrangement is arranged on the shaft end section of the rotor shaft. However, it is also conceivable for the slip ring arrangement to be formed separately from the deflection cap. Preferably, but not limited to, the slip ring arrangement is first slipped onto the shaft end section and subsequently the deflection cap is arranged on the end side of the laminated core. Preferably, the deflection cap overlaps the slip ring arrangement at least in sections and / or regions. The deflection cap can thus fix the slip ring arrangement or the ring carrier on the shaft end section in the axial direction of the rotor.It is also conceivable for the slip ring arrangement to be formed integrally with the deflection cap. Subsequently, after the slip ring arrangement has been slipped onto the shaft end section, the rotor winding is wound onto the salient pole and a conductor end of the rotor winding is guided to the connecting end section. With this method, the electrically conductive connection between the conductor end and the connecting end section can be easily established immediately after the rotor winding has been wound onto the pole. Alternatively, a preferred development of the invention resides in the rotor winding being wound onto the salient pole before the slip ring arrangement is arranged on the shaft end section. Thus, it is provided that the rotor shaft with the laminated core arranged thereon is first prepared.Subsequently, a deflection cap, preferably formed separately from the shaft end section, is placed on the end of the laminated core, and the rotor winding is wound onto the salient pole of the laminated core. After the rotor winding is formed, the slip ring assembly is placed onto the shaft end section until it reaches its final position, and the conductor end of the rotor winding is electrically connected to the connecting end section of the connecting wire.
[0041] It should be noted that all features described above and below with respect to one aspect of the present invention equally apply to any other aspect of the present invention. In particular, all features of the rotor can equally apply to the electric machine, the motor vehicle, and the method. This also applies vice versa.
[0042] Further features and advantages of the present invention emerge from the dependent claims and the following exemplary embodiments. The exemplary embodiments are not limiting, but rather are to be understood as examples. They are intended to enable the skilled person to implement the invention. The applicant reserves the right to make individual and / or several of the features disclosed in the exemplary embodiments the subject of patent claims or to incorporate such features into existing patent claims. The exemplary embodiments are explained in more detail with reference to drawings.
[0043] In these show:
[0044] Fig. 1 is a longitudinal section through a rotor according to a first embodiment of the invention;
[0045] Fig. 2 is a longitudinal section through the rotor in a second embodiment of the invention;
[0046] Fig. 3 is an isometric view of the rotor; Fig. 4 shows a motor vehicle with an electric machine;
[0047] Fig. 5 shows a method for manufacturing the rotor.
[0048] Fig. 1 shows a longitudinal section through a rotor 10 for a separately excited electrical machine 12 in a first embodiment. The rotor 10 has a rotor shaft 14. A laminated core 18 is arranged in a rotationally fixed manner on the rotor shaft 14, in particular on an outer circumferential surface 16 of the rotor shaft 14. The laminated core 18 has at least one salient pole 20. The salient pole 20 is aligned in a radial direction of the rotor 10. The laminated core 18 also has an end face 22 aligned in an axial direction of the rotor 10. A rotor winding 24 is wound on the salient pole 20. The rotor winding 24, which extends beyond the end face 22, forms a winding head 26.
[0049] The rotor shaft 14 has a shaft end section 28 at one axial end of the rotor shaft 14. A slip ring arrangement 30 is arranged on the shaft end section 28. The slip ring arrangement 30 comprises a ring carrier 32, at least one slip ring 34, and a connecting wire 36 electrically connected to the slip ring 34. A free connecting end section 38 of the connecting wire 36 is guided from the slip ring 34 formed at the end in the direction of the laminated core 18 into an area between the rotor shaft 14 and the winding head 26. A conductor end 42 of the rotor winding 24 is guided in the direction of the rotor shaft 14 and overlaps at least partially and / or regionally with the connecting end section 38. The connecting end section 38 is preferably forked so that the conductor end 42 can be inserted into the connecting end section 38. The conductor end 42 is electrically connected to the connecting end section 38.
[0050] Because the connecting end section 38 is guided, arranged, and / or positioned below the winding head 26 of the rotor winding 24, i.e., between the winding head 26 and the rotor shaft 14, the connection point between the connecting end section 38 and the conductor end 42 can be formed near the end face 22 of the laminated core 18. Thus, the axial installation space of the rotor 10 can be reduced. Furthermore, a connecting device for connecting the connecting end section 38 to the conductor end 42 of the rotor winding 24 can be guided in the axial direction of the rotor 10.
[0051] An advantageous development of the invention is that the electrically conductive connection is a material-to-material connection. A material-to-material connection can be used to create a space-saving, permanent, and highly conductive electrical connection between the connecting end section and the conductor end.
[0052] In the present embodiment, the electrically conductive connection is a material-to-material connection, with the material-to-material connection being a welded connection. The welded connection is preferably implemented using a welding device with a welding electrode, wherein the welding electrode is preferably guided parallel to the longitudinal direction of the rotor 10 in order to place it at least partially onto the connecting end section 38 and / or the conductor end 42 in order to firmly connect the connecting end section 38 and the conductor end 42 to one another.
[0053] Furthermore, it can be seen that the connecting wire 36 is initially guided toward the laminated core 18, and the connecting end section 38 is deflected below the winding head 26 and faces away from the end side 22 of the laminated core. In the present case, it is provided that the connecting end section 38 is deflected and / or aligned at an angle a of 45° relative to a longitudinal direction and / or longitudinal axis 46 of the rotor 10. Thus, the conductor end 42 can be placed directly or indirectly onto the connecting end section in order to subsequently be electrically connected.
[0054] A distal end of the connecting end section 38 can be V-shaped or U-shaped. Thus, the conductor end 42 can preferably be inserted into the V-shaped or U-shaped distal end of the connecting end section 38 and integrally connected to the connecting end section 38.
[0055] On the end side 22 of the laminated core 18, a deflection cap 50 is arranged for guiding the rotor winding 24 in the region of the end side 22. The deflection cap 50 is formed as an extension of the salient pole 20 on the end side 22 of the laminated core 18. The deflection cap 50 can be used to specify a bending radius of a wire of the rotor winding 24 in the region of the winding head 26 in order to prevent a coating of the wire from tearing due to the deflection of the wire in the region of the winding head 26. In addition, the wire can be guided in a space-saving manner in the region of the deflection to form the winding head 26, preferably using an orthocyclic winding. In this way, the rotor winding 24 can be deflected in the region of the winding head 26 in a material-saving and space-saving manner.
[0056] It is conceivable that the deflection cap 50 and the ring carrier 32 are formed as a single piece. In the present exemplary embodiment, the deflection cap 50 and the ring carrier 32 are formed separately from one another. It is provided that the ring carrier 32 is first slipped onto the shaft end section 28 and then the deflection cap 50 is arranged on the end side 22. The deflection cap 50 overlaps the ring carrier at least in sections, so that the latter can be fixed between the deflection cap 50 and the laminated core 18 in the axial direction of the rotor 10. After the deflection cap 50 has been arranged on the end side 22, the rotor winding 24 is wound onto the salient pole 20 and the conductor end 42 of the rotor winding 24 is guided to the connecting end section 38.
[0057] Fig. 2 shows a longitudinal section through the rotor 10 in a second embodiment. To avoid repetition, the description of the figures for the second embodiment will only address additional features and / or differences from the rotor 10 shown in Fig. 1.
[0058] A sealing element 48 is arranged between the outer circumferential surface 16 of the rotor shaft 14 and the ring carrier 32. The sealing element 48 can be used to easily prevent, for example, a cooling medium, in particular a fluid, for cooling the rotor winding 24 from passing through an annular gap between the ring carrier 32 and the rotor shaft 14 or between the ring carrier 32 and the shaft end section 28 in the direction of the slip ring 34.
[0059] The rotor 10 is rotatably mounted about a rotational axis or longitudinal axis 46 of the rotor 10 via a bearing device 44 in a housing 52 of the separately excited electrical machine 12. A first shaft sealing ring 54 is arranged between the bearing device 44 and the connecting end section 38. The first shaft sealing ring 54 seals, on the one hand, against the housing 52 and, on the other hand, directly or indirectly against the ring carrier 32. The first shaft sealing ring 54 can prevent a cooling medium for cooling the rotor winding 24 and / or the laminated core 18 from reaching the slip ring 34 via the bearing device 44. It can also be seen that a second shaft sealing ring 56 is arranged between the slip ring 34 and the bearing device 44. The second shaft sealing ring 56 seals, on the one hand, against the housing 52 and, on the other hand, directly or indirectly against the ring carrier 32.The second shaft seal 56 can prevent debris from the brush 58 resting on the slip ring 34 from reaching the bearing assembly 44. Particularly preferably, the second shaft seal 56 can be considered and / or designed as a dust seal. Thus, contamination of the bearing assembly can be reduced, ultimately minimizing friction losses and maintaining the long-term performance of the separately excited electrical machine 12.
[0060] In the present embodiment, the ring carrier 32 is configured to be recessed toward a distal end 60 of the shaft end portion 28 relative to a longitudinal direction of the rotor 10. In other words, the ring carrier 32 does not protrude beyond the distal end 60 of the shaft end portion 28, thereby reducing the installation space of the rotor 10 in the axial direction.
[0061] Fig. 3 shows a three-dimensional view of the rotor 10 as known from Fig. 1 and Fig. 2.
[0062] A distal end of the connecting end section 38 is U-shaped. The conductor end 42 extends from the winding head 26 of the rotor winding 24 toward the shaft end section 28 and is then inserted into the distal end of the connecting section 38 in a direction transverse to the longitudinal axis 46 to be firmly connected thereto.
[0063] On an outer surface 62 of the ring carrier 32, a bearing seat 64 for receiving the bearing device 44 and / or a sealing section 66 for sealing with the shaft seal 54, 56 is formed. The bearing seat 64 and / or the sealing section 66 can preferably be made of metal. It is conceivable that the bearing seat 64 and / or the sealing section 66 is formed as a sleeve and is arranged captively and / or rotationally fixedly on the outer surface 62 of the ring carrier 32.
[0064] Fig. 4 shows a motor vehicle 68 with the separately excited electric machine 12 according to the invention. The electric machine 12 comprises the rotor 10 according to the invention. Furthermore, the electric machine 12 is a component of a traction drive of the motor vehicle 68. In other words, the electric machine 12 is configured and / or designed to drive the motor vehicle 68, i.e., to set it in motion.
[0065] Fig. 5 shows a method for producing a rotor 10 of a separately excited electrical machine 12.
[0066] In a first step 100, a rotor shaft 14 is provided with a laminated core 18 arranged on the rotor shaft 14, wherein the laminated core 18 has at least one salient pole 20. In an axial direction of the rotor 10, the laminated core 18 has an end face 22.
[0067] In a second step 110, a slip ring assembly 30 is arranged on a shaft end portion 28 of the rotor shaft 14, wherein the slip ring assembly 30 comprises a ring carrier 32, a slip ring 34, and a connecting wire 36 connected to the slip ring 34. A connecting end portion 38 of the connecting wire 36 is guided, formed, and / or positioned from the slip ring 34 in the direction of the laminated core 18 into a region between the rotor shaft 14 and a winding head 26 of a rotor winding 24.
[0068] In a third step 120, the rotor winding 24 is wound onto the salient pole, wherein the rotor winding 24 extending beyond the end face 22 forms the winding head 26 of the rotor 10.
[0069] In a fourth step 130, an electrically conductive connection is established between a conductor end 42 of the rotor winding 24 and the connecting end portion 38 of the connecting wire 38.
[0070] Because the connecting end section 38 for connecting to the conductor end 42 of the rotor winding 24 is guided into a region below the winding head 26, the axial installation space of the rotor 10 can be reduced. Furthermore, a connecting device can be guided, preferably in the axial direction of the rotor 10, to connect the connecting end section 38 to the conductor end 42 of the rotor winding 24.
Claims
Patent claims 1 . Rotor (10) for a separately excited electrical machine (12), comprising a rotor shaft (14) with a laminated core (18) arranged on the rotor shaft (14), wherein the laminated core (18) has at least one salient pole (20) with a rotor winding (24) wound on the salient pole (20) and an end face (22) aligned in an axial direction of the rotor (10), wherein the rotor winding (24) extending beyond the end face (22) forms a winding head (26), a slip ring arrangement (30) arranged on a shaft end section (28) of the rotor shaft (14), which slip ring arrangement has a ring carrier (32), a slip ring (34), and a connecting wire (36) connected to the slip ring (34), wherein the connecting wire (36) is guided from the slip ring (34) through the ring carrier (32), the ring carrier (32) extending between a distal end (60) the shaft end section (28) and an area below the winding head (26),and a connecting end section (38) of the connecting wire (36), relative to a longitudinal direction of the rotor (10), is guided into the area below the winding head (26), and a conductor end (42) of the rotor winding (24) is electrically conductively connected to the connecting end section (38).
2. Rotor according to claim 1, characterized in that the electrically conductive connection is a material connection.
3. Rotor according to one of the preceding claims, characterized in that the connecting end portion (38) is arranged at an angle a between 30 < a < 85° relative to a longitudinal direction of the rotor, the limits being included.
4. Rotor according to one of the preceding claims, characterized in that a sealing element (48) is arranged between the rotor shaft (14) and an inner circumferential surface of the ring carrier (32) and / or between the shaft end section (28) and the inner circumferential surface of the ring carrier (32).
5. Rotor according to one of the preceding claims, characterized in that a deflection cap (50) for guiding the rotor winding (24) in the region of the end side (22) is arranged on the end side (22) of the laminated core (18).
6. Rotor according to one of the preceding claims, characterized in that the shaft end section (28) has a bearing seat (64), in the region of the bearing seat (64) on an outer side of the shaft end section (28) aligned in the radial direction of the rotor (10) a groove extending in the longitudinal direction of the rotor (10) is formed, and a section of the ring carrier (32) having the connecting section (36) runs in this groove.
7. Rotor according to claim 6, characterized in that an outer diameter of the ring carrier (32) in the region of the bearing seat (64) is equal to or smaller than an outer diameter of the bearing seat (64) of the shaft end section (28).
8. Rotor according to one of the preceding claims, characterized in that a sealing section (66) for sealing with a first shaft sealing ring (54) and / or a second shaft sealing ring (56) is formed on an outer circumferential surface (66) of the ring carrier (32).
9. Rotor according to claim 7 or 8, characterized in that an outer diameter of the bearing seat (64) and / or the sealing section (66) is larger than an outer diameter of the slip ring (34).
10. Electrical machine (12) with a rotor (10) according to one of the preceding claims.
11. Motor vehicle (68) with an electric machine (12) according to claim 10, wherein the electric machine (12) is a component of a traction drive of the motor vehicle (68).
12. A method for producing a rotor (10) comprising the steps: - Providing a rotor shaft (14) with a laminated core (18) arranged on the rotor shaft (14), which core has at least one salient pole (20) and has an end face (22) aligned in an axial direction of the rotor (10); - winding a rotor winding (24) onto the salient pole (20), wherein the rotor winding (24) extending beyond the end face (22) forms a winding head (26); - Arranging a slip ring arrangement (30) on a shaft end section (28) of the rotor shaft (14), wherein the slip ring arrangement (30) comprises a ring carrier (32), a slip ring (34) and a connecting wire (36) connected to the slip ring (34), and a connecting end section (38) of the connecting wire (36), relative to a longitudinal direction of the rotor, into a region below the winding head (26), i.e. between the rotor shaft (14) and the winding head (26); - Producing an electrically conductive connection between a conductor end (42) of the rotor winding (24) and the connecting end section (38) of the connecting wire (36).
13. The method according to claim 12, characterized in that the slip ring arrangement (30) having the connecting wire (36), wherein the connecting wire (36) extends from the slip ring (34) to the connecting end section (38) in the ring carrier (32), is pushed onto the shaft end section (28) in the axial direction of the rotor (10).
14. Method according to claim 12 or 13, characterized in that an electrode of a welding device is guided in a direction parallel to the longitudinal axis (46) of the rotor (10) in order to carry out the electrically conductive connection between the conductor end (42) and the connecting end portion (38).
15. Method according to one of claims 12 to 14, characterized in that the rotor winding (24) is wound onto the salient pole (20) after the arrangement of the slip ring arrangement (30) on the shaft end section (28) or is wound onto the salient pole (20) before the arrangement of the slip ring arrangement (30) on the shaft end section (28).