Rotor assembly with motor

Abstract

The invention relates to a rotor assembly (1) comprising a rotor body (2) which forms a plurality of slots (3) in axial direction for accommodating windings (4), rotor poles (5) which are formed in radial direction between each two slots (3), windings (4) which are arranged in the slots (3) and which surround the rotor poles (5), slot closure elements (6) which close the slots (3) in radial direction, at least one spacer (7) which is arranged in circumferential direction between two windings (4) in one slot (3), wherein the spacer (7) comprises at least one continuous cooling channel (8) which extends in axial direction and which can be flowed through by a cooling medium, wherein a fluid inlet element (41) is connected to a first axial end (40) of the cooling channel (8) and a fluid outlet element (43) is connected to a second axial end (42) of the cooling channel (8) such that the cooling medium can flow into the cooling channel (8) through the fluid inlet element (41) and out of the cooling channel (8) through the fluid outlet element (43).

Description

[0001] This invention relates to a rotor assembly comprising a rotor body having a plurality of slots formed axially to accommodate windings, rotor poles formed radially between every two slots, windings arranged within the slots and surrounding the rotor poles, slot closure elements closing the slots radially, and at least one isolator arranged circumferentially between two windings within a slot, wherein the isolator includes at least one axially extending continuous cooling channel through which a cooling medium may flow. The invention also relates to an electric motor.

[0002] In motor vehicles, electric motors are increasingly being used to replace internal combustion engines that require fossil fuels. Significant efforts have been made to improve the everyday usability of electric drives and provide users with familiar driving comfort.

[0003] In the development of motors specifically designed for electric drive axles or hybrid power modules, there is a persistent need to improve power density and efficiency while reducing manufacturing costs. Against this backdrop, it is also known to design motors as externally excited synchronous motors (FSMs). An externally excited synchronous motor is a special type of synchronous motor in which the magnetic field in the rotor is not generated by permanent magnets, but by energized coils. These coils are often referred to as field coils or excitation coils. To power the coils in the rotating rotor, a suitable transmission device must be used to supply current.

[0004] Due to manufacturing processes, gaps may occur between every two excitation windings of the rotor. In particular, supports or isolators are inserted into these gaps, completely or largely filling them. Especially for high-speed applications, the isolators can prevent accidental movement of the excitation coil windings in a centrifugal force field. EP 1 494 335 B1 discloses a corresponding isolator disposed between adjacent excitation coils.

[0005] Especially in improving power density and efficiency, it is particularly necessary to cool the rotor and dissipate heat during operation, especially in externally excited synchronous motors. For example, air-cooled rotors or fluid-cooled hollow shafts are known in the prior art. DE102018220810A1 discloses a fluid-cooled rotor for an electric motor, and an externally excited synchronous motor with directly or near-loss-cooled rotor windings. EP3618241A1 discloses a fluid-cooled hollow shaft with tapered walls.

[0006] The objective of this invention is to provide a device suitable for discharging heat energy from the rotor of an externally excited synchronous motor, which has a compact structure and high operational safety.

[0007] This task is achieved by a rotor assembly comprising a rotor body having a plurality of slots formed axially to accommodate windings, rotor poles formed radially between every two slots, windings arranged in the slots and surrounding the rotor poles, slot closure elements closing the slots radially, and at least one isolator arranged circumferentially between two windings in a slot, wherein the isolator includes at least one axially extending continuous cooling channel through which a cooling medium can flow, wherein a fluid inlet element is connected to a first axial end of the cooling channel and a fluid outlet element is connected to a second axial end of the cooling channel, such that the cooling medium can flow into the cooling channel through the fluid inlet element and out of the cooling channel through the fluid outlet element.

[0008] This allows for a particularly advantageous connection between the isolator and the cooling circuit. Preferably, the fluid inlet element and the fluid outlet element are designed to be substantially identical.

[0009] The isolator is designed with an inner wall region at at least one axial end to form a smooth inner profile along its axial length (preferably up to 15 mm). This region can also be post-processed, particularly by machining. An inlet or outlet element for the cooling medium is then inserted into this region. The inlet and / or outlet elements can be connected to the isolator by bonding, welding, interference fit, and / or form fit. In a preferred embodiment, the inlet or outlet element is sealed to the isolator by a seal (e.g., an O-ring seal). This produces a sealed, cooling medium-sealed assembly, each inserted between two rotor coils but substantially not exceeding the axial length of the rotor coils, thus the assembly does not significantly increase the axial length of the rotor.

[0010] Preferably, the interior of the inlet element and / or outlet element includes openings and / or channels for guiding the cooling medium to flow axially and / or radially, thereby transforming the shape of the openings inside the isolator into a shape suitable for guiding the cooling medium to adjacent components.

[0011] Preferred embodiments of the present invention According to a preferred embodiment of the invention, a filler made of a non-ferromagnetic material may be placed within the cooling channel, and cooling fins protrude from the surface of the filler towards the inner wall of the insulator. The insulator and the filler with cooling fins provide a particularly large surface area for the cooling medium within the cooling channel, thereby achieving good heat transfer to the cooling medium. Furthermore, the cooling medium is preferably guided near the outer contour of the insulator, which also helps to improve the effectiveness of heat transfer to the cooling medium.

[0012] According to a preferred embodiment of the invention, the cooling fins and the filler can be integrally formed, preferably as a single piece. This embodiment has the advantage of achieving particularly good heat transfer and allowing the cooling fins to be formed in a particularly advantageous manufacturing method.

[0013] Cooling fins can optimize heat transfer from the filler and insulator to the cooling medium by increasing the surface area. Cooling fins can be embedded in the filler, for example, through extrusion or pressing processes.

[0014] Preferably, the cooling fins have a constant cross-section in the axial direction. Furthermore, the cooling fins preferably maintain a substantially constant radial distance from the axis of rotation in the axial direction.

[0015] The advantage of this embodiment is that, through the design of the cooling fins, the pumping effect related to the rotational speed and direction of rotation that occurs when the cooling fins extend into the cooling channels can be avoided. Furthermore, this embodiment allows the filler to be manufactured via extrusion and / or injection molding processes.

[0016] It is also preferable that the cooling fins have essentially the same geometry, which is particularly advantageous in manufacturing and simplifies the modeling of heat transfer.

[0017] In principle, it can also be envisioned that the insulator also has cooling fins that extend from the inner wall of the insulator toward the filler.

[0018] According to one embodiment, a cavity is formed within the slot, defined by the winding and the isolator, and the cavity is filled with a potting material. An advantage of this embodiment is that the potting material within the cavity improves the thermal connection between the winding and the isolator. The cavity is formed due to component tolerances of the winding and the isolator.

[0019] According to one embodiment, the cooling medium is a coolant. The advantage of this embodiment is that, compared to gas, the coolant has a higher heat capacity and higher thermal conductivity, thus enabling better cooling or removal of lost power. In particular, the coolant includes oil and / or water.

[0020] According to one embodiment, the rotor body is designed as a laminated package. The advantage of this embodiment is that it minimizes eddy current losses within the rotor body.

[0021] The isolator is preferably made of a non-ferromagnetic material to avoid affecting the electromagnetic function of the rotor or motor. The isolator is preferably at least partially made of a material with good thermal conductivity to achieve a good thermal connection between the rotor windings and the cooling medium. Here, the isolator can be manufactured using aluminum extrusion, plastic extrusion, or plastic injection molding processes. This allows for a hollow internal but sealed external structure, enabling the flow of the cooling medium and maintaining a seal even under high pressure.

[0022] Therefore, the isolator essentially provides two functions. On the one hand, the isolator helps to hold the windings in place within the slots under centrifugal force; on the other hand, it enables fluid-based cooling within the slots through cooling channels. Thus, the rotor windings achieve speed-resistant support and are simultaneously cooled through this isolator.

[0023] According to a further preferred improvement of the invention, the filler may be provided with a fastener on at least one front end face, by which the filler is connected to an axially adjacent component. The advantage of this embodiment is that the filler can be securely fixed relative to the isolator at a predetermined position. The fastener also enables a modular and compact axial structure for the rotor assembly. Furthermore, the fastener helps the filler, and indirectly the isolator, to withstand the high centrifugal forces applied by the windings at rotational speeds and maintain shape stability under these external forces.

[0024] Fasteners can be selected from form-fit fasteners, force-fit fasteners, and / or material-fit fasteners.

[0025] In one possible implementation, the fastener is designed as a thread, preferably a monolithic structure, integrally formed with the filler. Preferably, the thread protrudes from one front end face of the filler. Even more preferably, a first thread protrudes from a first front end face of the filler, and a second thread protrudes from a second front end face of the filler.

[0026] Preferably, the fastener is designed as a threaded profile. In this context, it is particularly preferred that the profile at least partially passes through the filler and protrudes from one front end face of the filler. It is also particularly preferred that the profile completely passes through the filler and protrudes from both front end faces of the filler. The profile can be rotatably or fixedly disposed within the filler. Furthermore, it is also preferred that the profile protruding from only one front end face of the filler is threaded. It is also preferable that the profile has a generally circular cross-sectional profile.

[0027] The fastener can also be designed as an internal thread formed within the filler body, preferably a monolithic structure integrally molded with the filler body. Preferably, the internal thread extends into one front end face of the filler body. Alternatively, a first internal thread extends to a first front end face of the filler body, and a second internal thread extends to a second front end face of the filler body.

[0028] According to a further preferred embodiment of the present invention, the fastener may also be designed as a bushing with internal threads, which is fixedly inserted into the filler body. Preferably, the first bushing is inserted into the first front end face of the filler body, and the second bushing is inserted into the second front end face of the filler body.

[0029] In principle, fasteners can also be designed to connect to axially adjacent components through forming. For example, riveting bosses can be used.

[0030] Furthermore, according to another preferred embodiment of the invention, adjacent components can be configured as fluid inlet elements or fluid outlet elements, thereby enabling a particularly compact rotor assembly structure in the axial direction.

[0031] According to a further particularly preferred embodiment of the invention, the inner wall of the isolator can be configured as a planar structure in the region where the cooling fins protrude from the filler, which offers advantages in manufacturing processes. In this context, it is conceivable that the isolator be manufactured by forming (e.g., from a sheet metal). For example, when the isolator is manufactured using an extrusion process, the simplified geometry also provides a particularly advantageous reduction in manufacturing costs.

[0032] Furthermore, the invention can be further improved such that the fluid inlet element and / or fluid outlet element are at least partially inserted into the isolator and conform to the inner wall of the isolator. This achieves a high degree of sealing between the fluid inlet element and / or fluid outlet element and the isolator. This embodiment has also proven particularly advantageous in terms of bearing and supporting centrifugal forces during rotor assembly operation.

[0033] In another preferred embodiment of the invention, the fluid inlet element and / or fluid outlet element may each have a hydraulic passage for guiding the cooling medium radially. It can also be advantageously further modified so that the fluid inlet element and / or fluid outlet element each have a hydraulic passage for guiding the cooling medium axially. This forms a channel system through which the cooling medium can be selectively introduced into and / or drawn out of the isolator. The hydraulic passage may include open or closed channels, inlet surfaces, centrifugal sections, and / or free-fall sections.

[0034] In a further preferred embodiment, the inlet element and / or outlet element each have an axial opening. This allows the cooling medium to be guided through its respective axial opening into components axially adjacent to the inlet element and / or outlet element.

[0035] In a further preferred embodiment, the outlet element may have an axial opening through which the cooling medium is thrown out of the rotor and sprayed radially outwards onto the stator components during operation, thereby achieving additional cooling of the stator components.

[0036] According to one embodiment, the rotor assembly includes a rotor shaft designed as a hollow shaft and having radial openings for guiding cooling medium.

[0037] According to a further preferred embodiment of the present invention, a fluid inlet element and / or a fluid outlet element may be respectively connected to a rotor shaft configured as a hollow shaft, such that the cooling medium can flow from the rotor shaft into the fluid inlet element and / or from the fluid outlet element into the rotor shaft.

[0038] Preferably, the fluid inlet element and / or fluid outlet element each have a radial opening that connects to a corresponding radial opening in the rotor shaft. Most preferably, the radial openings of the fluid inlet element and / or fluid outlet element are sealed to the radial openings of the rotor shaft by seals. This allows cooling medium to be introduced from the rotor shaft into the isolator or from the isolator into the rotor shaft without integrating the guidance of the cooling medium into the axial rotor housing components, allowing these components to be designed with particularly economical axial space.

[0039] Therefore, the radial opening of the rotor shaft is connected to the cooling channel of the isolator via a fluid inlet element and / or a fluid outlet element to guide the cooling medium, thereby forming a channel system. As described in the preferred embodiment of the invention, the cooling channel can be connected to the cooling system through this channel system. Particularly advantageously, the cooling channel is connected to the cooling system at its two front ends via corresponding components, preferably fluid inlet elements and / or fluid outlet elements, thereby forming a closed cooling loop.

[0040] Finally, the invention can also be advantageously implemented such that the filler has a fastener on its first front end face to connect the filler to an axially adjacent component, and the filler has a fastener on its second front end face to connect the filler to an axially adjacent component.

[0041] In a further preferred embodiment of the invention, the isolator may be provided with an electrically insulating layer at least partially on its outer wall. The insulating layer may be designed, for example, as an electrically insulating coating. Alternatively, the insulating layer may be designed as a separate component, detachably or fixedly connected to the isolator. This allows the isolator to achieve electrical insulation from live parts, particularly preventing electrical contact between excitation coils or between the excitation coils and the vehicle, thereby meeting high-voltage safety requirements. The coating can be achieved by painting, covering, or adhesive application. For less stringent electrical insulation requirements, the aluminum isolator can be anodized. For higher requirements, it can be covered with plastic, coated with an alternative material, or a thin film can be applied to the contact surface with the rotor coils. This ensures that no electrical short circuits are formed between the excitation coils or between the excitation coils and the vehicle.

[0042] According to a further preferred embodiment of the invention, the spacer may be provided with a length greater than that of the filler. Particularly preferred is that the filler is completely contained within the spacer and does not protrude axially from the spacer. Most preferred is that the filler is retracted at one front end face of the spacer. Most preferably, the filler is retracted relative to the spacer at both front end faces.

[0043] The isolator is preferably connected to a slot closure element, which radially closes the slot and provides anti-speed support to the support body. The slot closure element is preferably made of a non-ferromagnetic and non-conductive material (such as plastic) so as not to affect the electromagnetic performance of the motor and to prevent additional eddy current losses. The slot closure element can be manufactured by plastic injection molding or extrusion processes and can be shaped to fit or bonded to the isolator. Alternatively, the slot closure element can be directly overlaid on the isolator. In this case, it can be integrally molded with the plastic overlay of the isolator.

[0044] The invention can also be advantageously implemented in which the slot closure element is integrally connected with the isolator.

[0045] The advantage of this embodiment is that, through integral connection, the slot closure element and the isolator can be manufactured as a single component. Therefore, the complexity of the rotor assembly is reduced. Another advantage is that integral connection provides more stable components. Particularly preferred is that the slot closure element and the isolator are monolithic structures, for example, made of aluminum or plastic.

[0046] In another preferred embodiment of the invention, the isolator may also be made of aluminum. The isolator is preferably manufactured using an aluminum extrusion process. The material properties of aluminum allow for good mechanical properties and good thermal conductivity within the isolator. Since aluminum is non-ferromagnetic, it does not affect the electromagnetic function of the motor. Alternatively, the isolator can be manufactured using a plastic extrusion process, but this typically requires a lower thermal conductivity.

[0047] Furthermore, the invention can be further improved such that at least two cooling channels are separated from each other by ribs extending tangentially along the cross-section of the isolator. These ribs inside the isolator help maintain shape stability under high external centrifugal forces. Therefore, the isolator is particularly able to withstand the centrifugal forces of surrounding components without undergoing critical deformation.

[0048] The external cross-sectional profile of the isolator can also be non-rectangular. Preferably, the cross-sectional profile of the isolator is designed to minimize the distance between the winding and the isolator. For example, it can be envisioned that the isolator has a trapezoidal segment at its radially outer end, with its short side connected to a radially inward rectangular segment. This further optimizes heat transfer from the winding to the isolator, since the thermal conductivity of the potting material that typically fills the cavity between the winding and the isolator is lower than that of the isolator.

[0049] According to a further preferred improvement of the invention, the isolator may also include a plurality of cooling channels spaced apart from each other in the radial and / or circumferential directions. An advantage of this embodiment is that it allows for better cooling or removal of power losses. Another advantage is that the multiple spaced-apart cooling channels enable more uniform cooling or removal of power losses.

[0050] The object of the invention is also achieved by an electric motor, particularly an electric motor for a motor vehicle powertrain, comprising a rotor assembly according to any one of claims 1-12.

[0051] The invention will be further described below with reference to the accompanying drawings, but this does not limit the general concept of the invention. Attached Figure Description Attached image description: Figure 1 : Segmented cross-sectional view of the rotor assembly Figure 2 : Detailed cross-sectional view of the rotor assembly implementation. Figure 3 Exploded view of the rotor assembly's isolator and its adjacent components. Figure 4 : Axial cross-sectional view of the rotor assembly Figure 5 : A schematic diagram of a motor vehicle equipped with an electric drive system.

[0053] Figure 1 A rotor assembly 1 is shown, including a rotor body 2 having a plurality of slots 3 formed axially to receive windings 4, and rotor poles 5 formed radially between every two slots 3. The rotor assembly 1 also includes windings 4 arranged within the slots 3 and surrounding the rotor poles 5. The slots 3 are closed radially by slot closure elements 6. The slot closure elements 6 may be integrally formed with an isolator 7.

[0054] The rotor assembly 1 also includes an isolator 7, each isolator 7 being arranged in a slot 3 between two windings 4 in a circumferential direction, wherein the isolator 7 includes at least one axially extending continuous cooling channel 8 through which a cooling medium can flow.

[0055] A filler 11 made of a non-ferromagnetic material is placed inside the cooling channel 8. Cooling fins 12 protrude from the surface of the filler 11 toward the inner wall 19 of the insulator 7; these cooling fins 12 are integrally formed with the filler 11. The inner wall 19 of the insulator 7 has a planar structure in the area where the cooling fins 12 protrude from the filler 11, such as... Figure 2 As shown in the embodiment, the isolator 7 and the filler 11 with cooling fins 12 can thus provide a larger surface area for the cooling medium within the cooling channel 8 to achieve efficient heat transfer. Furthermore, the cooling medium is optimally guided along the outer contour of the isolator 7, which helps to improve heat transfer efficiency. In the illustrated embodiment, the filler 11 has a two-part structure, including a filler portion with a rectangular cross-section and a body portion with a trapezoidal cross-section.

[0056] The isolator 7 essentially serves two functions. On one hand, it helps maintain the stability of the winding 4 within the slot 3 under centrifugal force; on the other hand, it cools the liquid within the slot through the cooling channel 8. Therefore, the rotor winding 4 is safely and firmly supported by the isolator 7, while simultaneously achieving efficient cooling.

[0057] exist Figure 2 In this embodiment, a connecting member 38 extends radially outward into the isolator 7 at the bottom of the groove 3 and forms a shape-fitting connection with it, thereby better supporting centrifugal force during the operation of the rotor assembly.

[0058] Both the isolator 7 and the filler 11 have a trapezoidal cross-section on the radially outer side, and a rectangular cross-section extending radially inward from their shorter radially inner side, pointing radially inward toward the rotor shaft 46. In this embodiment, the cross-sectional profile of the isolator 7 or the filler 11 resembles a key. The filler 11 is therefore a two-part structure, with the trapezoidal portion as the first part and the rectangular portion as the second part. Figure 1 and Figure 3 A comprehensive comparison clearly shows that the isolator 7 forms a radially outer and a radially inner cooling channel 8 through ribs extending along the circumference.

[0059] At least a portion of the outer wall 36 of the isolator 7 is provided with an electrical insulating layer 37, such as Figure 2 As shown. Insulating layer 37 can be as follows: Figure 2 The part shown is a single component, but it can also be a coating on the outer wall 36.

[0060] from Figure 3 It can be seen that the filler 11 has a fastener 31 on at least one front end face 30, through which the filler 11 is connected to the axially adjacent component 32.

[0061] exist Figure 3 In this embodiment, the fastener 31 is designed as a thread, preferably a single-piece structure, integrally formed with the filler 11. The thread protrudes from one front end face 30 of the filler 11. Figure 3 In the embodiment shown, the second thread, which serves as a fastener 34, protrudes from the opposite front end face 33 of the filler 11.

[0062] Fastener 31 is designed as a threaded profile that completely passes through the filler 11 and protrudes from its front end face. The profile is fixed within the filler and cannot rotate. Figure 3 As shown, the profile protruding only from the front faces 30 and 33 of the filler 11 is threaded. The profile has a generally circular cross-section. In the assembled state of the rotor assembly 1, the fastener 34 passes through the socket 48 of the fluid outlet element 43 and is locked by a nut. Similarly, the fastener 31 passes through the socket 47 of the fluid inlet element 41 and is also locked by a nut.

[0063] The adjacent component 32 serves as a fluid inlet element 41 on one side and a fluid outlet element 43 on the other. A fluid inlet element 41 is connected to the first axial end 40 of the cooling channel 8, and a fluid outlet element 43 is connected to the second axial end 42 of the cooling channel 8, so that the cooling medium can flow into the cooling channel 8 through the fluid inlet element 41 and flow out of the cooling channel 8 through the fluid outlet element 43.

[0064] The spacer 7 has a longer length than the filler 11, which is completely contained within the spacer 7 and does not protrude axially from the spacer 7, but rather retracts relative to the spacer 7 at both front end faces. Figure 3-4 The comprehensive comparison also shows that the fluid inlet element 41 and the fluid outlet element 43 are at least partially inserted into the isolator 7 and conform to the inner wall 19 of the isolator 7. The fluid inlet element 41 and the fluid outlet element 43 have a profile corresponding to the profile 49 of the inner wall 19 of the isolator 7.

[0065] The inner wall 19 region of the isolator 7 at its axial ends 40, 42 is designed to form a uniform inner contour along its axial length (preferably up to 15 mm). These regions can be formed by machining processes. In these regions, during the assembly of the rotor assembly 1, fluid inlet and outlet elements 41, 43 for the cooling medium are inserted and fixed within the isolator 7 by bonding, welding, interference fit, or form fit. The fluid inlet and outlet elements 41, 43 can be sealed to the isolator 7 by seals (such as O-rings). This allows for the manufacture of sealed, cooling medium-sealed assemblies inserted between the two windings 4 without significantly exceeding the axial length of the windings 4 of the rotor assembly 1, thus preventing a significant increase in the axial length of the rotor assembly 1.

[0066] The fluid inlet and outlet elements 41 and 43 are internally provided with openings and / or channels for guiding the cooling medium axially and / or radially, thereby adjusting the shape of the openings inside the isolator 7 to suit the guidance of the cooling medium to adjacent components. For this purpose, the fluid inlet element 41 and the fluid outlet element 43 respectively have a hydraulic channel 44 for guiding the cooling medium radially and a hydraulic channel 45 for guiding the cooling medium axially. This can also be achieved through… Figure 4 The arrows in the text are used for illustration.

[0067] Fluid inlet element 41 and fluid outlet element 43 are respectively connected to the rotor shaft 46, which is configured as a hollow shaft, allowing cooling medium to flow from the rotor shaft 46 into the fluid inlet element 41 and from the fluid outlet element 43 into the rotor shaft 46. Fluid inlet element 41 and fluid outlet element 43 each have a radial opening that connects to a corresponding radial opening in the rotor shaft 46. This allows cooling medium to be introduced from the rotor shaft 46 into the isolator 7, or from the isolator 7 into the rotor shaft 46, without integrating the guidance of the cooling medium into the axial rotor housing components, thus allowing these components to be designed with particularly economical axial space. The radial opening of the rotor shaft 46 is connected to the cooling channel 8 of the isolator 7 via the fluid inlet element 41 and fluid outlet element 43 for guiding the cooling medium, thereby forming a channel system, which in Figure 4 This can be clearly seen in the diagram.

[0068] The filler 11 has a fastener 31 on its first front end face 30, through which the filler 11 is connected to the axially adjacent component 32, and the filler 11 has a fastener 34 on its second front end face 33, through which the filler 11 is connected to the axially adjacent component 35.

[0069] from Figure 1-4 The rotor assembly 1 shown can be specifically used in motor 50, which is used in the powertrain 51 of motor vehicle 52, such as... Figure 5 As shown.

[0070] This invention is not limited to the embodiments shown in the figures. The above description should not be considered restrictive but rather illustrative. The following patent claims should be understood as meaning that the described features are present in at least one embodiment of the invention. This does not exclude the presence of other features. If the patent claims and the above description define "first" and "second" features, such designations are used only to distinguish two features of the same type and do not indicate any order of priority.

[0071] Explanation of reference numerals in the attached figures 1 Rotor assembly 2 Rotor body 3 slots 4 windings 5 rotor poles 6-slot closure element 7. Insulator 8 Cooling Channels 11. Filler 12 Cooling fins 19 Inner Wall 30 Front end 31 Fasteners 32 parts 33 Front end 34 Fasteners 35 parts 36 outer wall 37 Insulation layer 38 Connecting parts 40 end 41 Fluid inlet element 42 end 43 Fluid outlet element 44 Hydraulic Channel 45 Hydraulic Channel 46 Rotor shaft 47 sockets 48 sockets 49. Outline 50 motors 51 Powertrain System 52 Motor vehicles

Claims

1. A rotor assembly (1), comprising: • A rotor body (2) having multiple slots (3) formed in the axial direction to accommodate windings (4). • Rotor poles (5), which are formed radially between every two slots (3), • Winding (4), which is arranged in slot (3) and surrounds rotor pole (5). • A slot closing element (6) that closes the slot (3) in the radial direction. • At least one isolator (7) is arranged circumferentially between two windings (4) in a slot (3). The isolation body (7) includes at least one axially extending continuous cooling channel (8) through which a cooling medium can flow. The feature is that the first axial end (40) of the cooling channel (8) is connected to a fluid inlet element (41), and the second axial end (42) is connected to a fluid outlet element (43), so that the cooling medium can flow into the cooling channel (8) through the fluid inlet element (41) and flow out of the cooling channel (8) through the fluid outlet element (43).

2. The rotor assembly (1) according to claim 1, characterized in that, The cooling channel (8) is provided with a filler (11) made of non-ferromagnetic material, and cooling fins (12) protrude from the surface of the filler (11) toward the inner wall (19) of the isolator (7).

3. The rotor assembly (1) according to claim 1 or 2, characterized in that, The filler (11) has a fastener (31) on at least one front end face (30) to connect the filler (11) to an axially adjacent component (32).

4. The rotor assembly (1) according to claim 3, characterized in that, The adjacent component (32) is either a fluid inlet element (41) or a fluid outlet element (43).

5. The rotor assembly (1) according to any one of claims 2-4, characterized in that, The inner wall (19) of the isolator (7) is planar in the area where the cooling fins (12) protrude from the filler (11).

6. The rotor assembly (1) according to any one of the preceding claims, characterized in that, The fluid inlet element (41) and / or the fluid outlet element (43) are at least partially inserted into the isolator (7) and attached to the inner wall (19) of the isolator (7).

7. The rotor assembly (1) according to any one of the preceding claims, characterized in that, The fluid inlet element (41) and / or the fluid outlet element (43) each have a hydraulic passage (44) for guiding the cooling medium to flow radially.

8. The rotor assembly (1) according to any one of the preceding claims, characterized in that, The fluid inlet element (41) and / or the fluid outlet element (43) each have a hydraulic passage (45) for guiding the cooling medium to flow axially.

9. The rotor assembly (1) according to any one of the preceding claims, characterized in that, The fluid inlet element (41) and / or the fluid outlet element (43) are respectively connected to the rotor shaft (46) which is configured as a hollow shaft, so that the cooling medium can flow from the rotor shaft (46) into the fluid inlet element (41) and / or from the fluid outlet element (43) into the rotor shaft (46).

10. The rotor assembly (1) according to any one of claims 3-9, characterized in that, The filler (11) has a fastener (31) on its first front end face (30) to connect the filler (11) to an axially adjacent component (32), and the filler (11) has a fastener (34) on its second front end face (33) to connect the filler (11) to an axially adjacent component (35).

11. The rotor assembly (1) according to any one of the preceding claims, characterized in that, The insulator (7) has at least a partial electrical insulating layer (37) on its outer wall (36).

12. An electric motor (50), particularly a power transmission system (51) for a motor vehicle (52), comprising a rotor assembly (1) according to any of the preceding claims.

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