Cooling system for an electric machine

Abstract

Cooling system for an electric machine, including: a stator arrangement that includes: a stator core with several coolant channels running axially through it; and several stator windings extending through the stator core and forming end windings on opposite axial sides of the stator core; and a pair of sealing rings that are directly coupled to opposite axial sides of the stator core and arranged radially outside the stator windings; where each of the sealing rings in the pair of sealing rings comprises: an outer seal that is arranged radially outwards from an inner seal; a sealed coolant channel formed between the inner seal and the outer seal, which is in fluid communication with the multiple coolant channels; and a multitude of nozzles that spray coolant towards the end windings.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] The present application claims priority from U.S. Preliminary Application No. 63 / 704,692 entitled "Cooling System for an Electric Machine," which was filed on October 8, 2024. The entire contents of the aforementioned application are hereby incorporated by reference for all purposes. TECHNICAL AREA

[0002] The present disclosure relates to an electric machine with a cooling system for a stator arrangement. BACKGROUND AND DETOUR

[0003] In electric vehicle (EV) motors and other motors, spray cooling systems were used to direct the coolant onto the stator windings. In other motors, complex immersion cooling systems were employed to distribute the coolant more evenly to the stator windings in a closed circuit.

[0004] The inventors identified several challenges with both spray cooling and immersion cooling systems. For example, spray cooling systems cannot effectively cool the stator when continuous torque is required. Immersion cooling systems have traditionally been more complex than other types of cooling systems, requiring a large number of components to seal the immersion cooling chambers. Specifically, certain cooling systems have used plastic end sleeves to cool the wires in the stator windings by immersion.

[0005] To overcome at least some of the aforementioned problems, the inventors developed a cooling system for an electric machine. In one example, the cooling system comprises a stator assembly consisting of a stator core with multiple coolant channels extending axially through it, and multiple stator windings extending through the stator core and forming end windings on opposite axial sides of the core. The cooling system further includes a pair of sealing rings directly connected to opposite axial sides of the stator core.Furthermore, in the cooling system, each of the sealing rings of the sealing ring pair comprises an outer seal arranged radially outside an inner seal, a sealed coolant channel formed between the inner and outer seals and in fluid communication with the multiple coolant channels, and several nozzles that spray coolant towards the end windings. In this way, the end windings can be effectively cooled even when the electric machine is operated under continuous torque.

[0006] In another example, at least one of the sealing rings of the pair can have a coolant inlet that directs coolant into the sealed coolant channel. In this way, the coolant is directed to the sealing rings in a less complicated manner than in other cooling systems, such as immersion cooling. Consequently, the electric machine can achieve its cooling objectives with a less complex system than with immersion cooling systems.

[0007] It should be noted that the foregoing summary serves to present, in simplified form, a selection of concepts that are further explained in the detailed description. It does not serve to identify essential features of the claimed subject matter, the scope of which is defined exclusively by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that eliminate the disadvantages mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 shows an electric motor with a cooling system. Fig. Figure 2 shows a perspective view of an example of a stator arrangement with a cooling system. Fig. Figure 3 shows a cross-sectional view of the stator arrangement and the cooling system, which is shown in Fig. 2 are shown. Fig. Figures 4-5 show detailed views of the interfaces between the sealing ring and the stator core, which are located in Fig. 2 are shown. Fig. Figure 6 shows a detailed view of the in Fig. 3 sealing rings shown. DETAILED DESCRIPTION

[0008] Systems and methods for the effective cooling of electric machines allow for increased cooling capacity and, if desired, operation at continuous torque. To increase cooling capacity, one example of an electric machine cooling system includes a pair of sealing rings directly connected to a stator core. These rings incorporate inner and outer seals, creating a coolant channel within the rings. Coolant is sprayed from this channel onto the stator windings via nozzles integrated into the sealing rings. This results in a simpler and more robust cooling system suitable for electric axles and other similar applications.

[0009] Fig. Figure 1 shows a representation of an electric machine 100 (e.g., an electric motor). The electric machine 100 can be designed as an electric motor-generator and integrated into a system 102, which can take various forms. For example, the electric machine 100 can be installed in the electric drive system of an electric vehicle (EV). The electric motor is thus a traction motor, and the electric drive can also include a transmission (e.g., a gearbox). In the EV example, the EV can be a fully electric vehicle (e.g., a battery electric vehicle (BEV)) or, in another example, a hybrid electric vehicle (HEV) with an internal combustion engine. In the EV example, the system can be an electric axle in which the electric machine, a transmission, and a differential are integrated into an electric axle assembly. However, the motor can also be integrated into other suitable systems (e.g.,stationary systems) such as industrial machinery, agricultural systems, mining systems and the like.

[0010] The electric machine 100 comprises a rotor 104 that interacts electromagnetically with a stator assembly 106 to drive the rotation of a rotor shaft 108 integrated into the rotor. In the illustrated example, the electric machine 100 includes a housing 110 with an electrical interface 112 for the stator assembly 106. The electrical interface 112 can be a multi-phase electrical interface with multiple electrical terminals 114. In the illustrated example, the electrical interface 112 is a three-phase interface. However, it is understood that in other examples the electrical interface can be a six- or nine-phase interface. More generally, the electric machine 100 can be a multi-phase alternating current (AC) machine. In other examples, however, the electric machine 100 can also be a direct current (DC) machine.

[0011] As in Fig. As shown in Figure 1, the electric machine 100 can be electrically coupled to an inverter 116. The inverter 116 is designed to convert direct current (DC) to alternating current (AC) and vice versa. The electric machine 100 can be an AC motor, as described above. In other examples, however, the electric machine 100 can be a DC electric motor (as previously stated), and the inverter 116 can therefore be omitted from the system 102. The inverter 116 can receive electrical energy from one or more energy storage devices 118 (e.g., traction batteries, capacitors, combinations thereof, and the like). The arrows 120 indicate the electrical energy transfer between the electric machine 100, the inverter 116, and the energy storage device(s) 118, which can occur during the various operating modes of the system.The electric machine 100 can be a multi-phase (e.g., a three-phase, a six-phase, a nine-phase, etc.) electric machine.

[0012] The electric machine 100 has a cooling system 160. The working medium in the cooling system 160 can be oil in one example. The cooling system 160 can include a sump 162 formed in the housing 110. The sump 162 is configured to collect the coolant that is sprayed onto the stator windings. The cooling system 160 can also include a pump 164 and a filter 166. In the example shown, the pump 164 and the filter 166 are located outside the housing 110. Alternatively, in other examples, the pump 164 and the filter 166 can be installed in, enclosed within, or connected to the housing 110. The pump 164 is configured to deliver coolant to one or more coolant inlets in a sealing ring in the stator assembly 106. The sealing rings and other components of the cooling system are explained in more detail here. A detailed example of a cooling system for an electric machine is given in the Fig. 2-6 is shown and is explained in more detail here.

[0013] The in Fig. The system 102 shown in Figure 1 can additionally include a control subsystem 180 with a controller 182. The controller 182 comprises a processor 184 and a memory 186. Instructions can be stored in the memory 186 which, when executed by the processor 184, cause the control unit 182 to perform the various procedures, control techniques, and the like described herein. The processor 184 can contain a microprocessor unit and / or other types of circuitry. The memory 186 can comprise known data storage media, such as random access memory, read-only memory, keep-alive memory, combinations thereof, and the like.

[0014] The control unit 182 can receive various signals from sensors 188 located at different positions within the system 102. These sensors 188 may include a speed sensor for the electric machine, one or more temperature sensors for the energy storage device, one or more state-of-charge sensors for the energy storage device, a power sensor for the inverter, and similar sensors. The control unit 182 can also send control signals to various actuators 190 located at different points within the system 102. For example, the control unit 182 can send signals to the inverter 116 to adjust the speed of the electric machine 100. In another example, the control unit 182 can send a command signal to the electric machine 100 and / or the inverter 116, which then adjusts the motor speed.The other controllable components of System 102 can function in a similar manner with regard to the command signals and the setting of the actuators.

[0015] The system 102 may also include one or more input device(s) 192 (e.g., an accelerator pedal, a brake pedal, a console instrument panel, a touch interface, a touch panel, a keyboard, combinations thereof, and the like). The input device(s) 192 may, in response to user input, generate a request to adjust the engine speed.

[0016] A coordinate system is used as a reference. Fig. 1 as well as in Fig. Figures 2-6 illustrate this. In one example, the z-axis can be a vertical axis (e.g., parallel to a gravitational axis), the x-axis can be a lateral axis (e.g., a horizontal axis), and / or the y-axis can be a longitudinal axis. In other examples, however, the axes can have other orientations. The rotational axis 199 of the electric machine 100 is shown in Fig. 1 as well as in the Fig. 2-3 and 6 further shown.

[0017] Fig. Figure 2 shows an example of a stator arrangement 200 and a cooling system 202. The stator arrangement 200 and the cooling system 202 can be used in the electric machine 100 (in Fig. (1 shown) and the system 102 in general. Thus, the features of the stator arrangement 200 and the cooling system 202 can be integrated into the electric machine 100 and the system 102, or vice versa.

[0018] The stator assembly 200 comprises a stator core 201. The stator windings extend through the stator core 201 and form the end windings 204 and 205 on opposite axial sides of the stator assembly. The end windings 205 are weld-side end windings. These end windings are hairpin windings, as shown in the example. It is understood that the hairpin windings are formed from solid copper bars with flat surfaces, unlike end windings with a round cross-sectional profile. Hairpin windings increase the fill factor of the stator winding and thus the machine's power output. However, other suitable types of end windings can also be used in other examples.

[0019] A pair of sealing rings 206, comprising sealing rings 208 and 210, is included in the cooling system 202. The sealing rings 208 and 210 can be designed as continuous structures to enable more efficient manufacturing. For example, each sealing ring can be formed as a single-piece molded part. In this way, the sealing rings can form a continuous (e.g., monolithic) structure. In the illustrated example, the sealing rings 208 and 210 extend circumferentially around the surfaces 211 and 213 of the stator core 201. The sealing rings 208 and 210 are also located radially outside the end windings 204 and 205. Furthermore, in the illustrated example, the sealing rings 208 and 210 include stepped sections 215 and 217 in which the radial thickness of the sealing ring is reduced. However, other sealing ring profiles are also possible.

[0020] The sealing rings 208 and 210 are directly connected to the stator core 201. Specifically, inner and outer seals form sealed coolant channels (which are located in the Fig. 2-6 are explained in more detail), which serve as distributors for the nozzles 212 in the sealing rings 208 and 210.

[0021] In the example shown, a coolant inlet 214 is also provided in the sealing ring 208. A pump 216 (in Fig. (2 shown schematically) supplies coolant (e.g., oil) to the coolant inlet 214, as indicated by arrow 218. Arrows 220 indicate the flow of coolant to pump 216 from a sump (e.g., the one in Fig. 1 depicted sump 162), which is formed in the housing of the electric machine.

[0022] In the example shown, the stator core 201 includes mounting lugs 222 with openings 224. However, other stator core designs were also considered. In the example shown, the coolant inlet 214 is located radially inward from one of the mounting lugs 222. However, other positions for the coolant inlet were also considered.

[0023] A cutting plane AA' for the in Fig. The cross-sectional view shown in Figure 3 is in Fig. 2 shown. The section plane AA' passes through the axis of rotation 199 of the electric machine 100.

[0024] Fig. Figure 3 shows a cross-sectional view of the stator arrangement 200 and the cooling system 202. Fig. Figure 3 shows in particular the stator core 201, the stator windings 300 (e.g., copper and / or aluminum windings) extending through the stator core 201, the end windings 204 and 205, and the sealing rings 208 and 210. The end windings 204 and 205 can be configured as hairpin windings. The end windings 205 can also be referred to as weld-side windings.

[0025] The coolant inlet 214 supplies coolant to a sealed coolant channel 302 in the sealing ring 208. To seal the coolant channel 302, the sealing ring 208 comprises an inner seal 304 and an outer seal 306. In the example shown, the inner seal 304 and the outer seal 306 extend circumferentially around the sealing ring 208. Furthermore, the seals 304 and 306 are in sealing contact with a surface 308 of the stator core 201. Coolant is sprayed from the sealed coolant channel 302 onto the end windings 204 via nozzles 212.

[0026] In the illustrated example, the stator core 201 comprises coolant channels 310 that extend axially through it and are in fluid communication with the coolant channel 302 in the sealing ring 208. The coolant channels 310 are also in fluid communication with another coolant channel 312 in the sealing ring 210. Here, too, an inner seal 314 and an outer seal 316 are provided in the sealing ring 210 to seal the coolant channel 312. In particular, the inner seal 314 and the outer seal 316 are in sealing contact with a surface 318 of the stator core 201. The nozzles 212 spray coolant onto the end windings 205.

[0027] Fig. Figure 4 shows a detailed view of the sealing ring 208 and the end windings 204. Fig. Figure 4 shows the coolant inlet 214, the inner seal 304, the outer seal 306 and the sealed coolant channel 302 in the sealing ring 208.

[0028] The sealed coolant channel 302 comprises a section 420 that extends circumferentially around the stator and sections 422 that extend axially from section 420 to the nozzles 212. In the example shown, the sections 422 taper in the downstream direction. However, other sealed coolant channel contours are also possible.

[0029] As in Fig. As shown in Figure 4, the inner seal 304 and the outer seal 306 comprise axial extensions 410 and 412 that align with recesses 414 and 416 in the stator core 201. Specifically, the recesses 414 and 416 extend axially inward from a surface 418 of the stator core 201. In the Fig. In the example shown in Figure 4, the coolant inlet 214 also includes a section 424 that extends radially outwards from the end developments 204.

[0030] Fig. Figure 5 shows a further detailed view of the sealing ring 208 and the end windings 204. Fig. Figure 5 shows an outlet 501 of one of the coolant channels 310. As shown, the outlet 501 opens into the sealed coolant channel 302. The stator windings 300 and the end windings 206 are also in Fig. 5 shown.

[0031] An angle 505 of one of the nozzles 212 is in Fig. Figure 5 illustrates this. The angle 505° and the other nozzle angles can vary depending on the design of the final windings and the cooling requirements of the motor. To clarify: The nozzle angles can all be varied in the same way, so that in one example the nozzles may all have similar angles. In other examples, some nozzles may have a larger angle than others.

[0032] The inner seal 304, the outer seal 306 and the sealed coolant channel 302 in the sealing ring 208 are in Fig. 5 shown again. The nozzles 212 in the sealing ring 208, which spray coolant towards the end windings 204, are in Fig. 5 additionally shown. The width 500 of one of the nozzles 212 is in Fig. Figure 5 shows the following. The width 500 and the other nozzle angles can be varied depending on the design of the end windings and the cooling requirements of the motor. The nozzle width can be varied uniformly, so that all nozzles have a similar width. In other examples, some nozzles may have a wider width than others. Additionally, in some cases, the number and / or position of the nozzles can be adjusted. In this way, the geometry and / or size of the nozzles can be varied to meet the cooling requirements of a wide variety of electric motors. The sealing ring 208 includes a recessed section 503 that allows the nozzles 212 to spray coolant over a larger portion of the end windings 204.

[0033] Fig. Figure 6 shows a detailed view of the sealing rings 208 and 210. The coolant inlet 214 and the nozzles 212 in the sealing ring 208 are also shown. The nozzles 212 can be provided with customer-specific flow patterns to increase the cooling system's performance with regard to heat dissipation from the stator.

[0034] Fig. Figure 6 also shows the inner seal 314 and the outer seal 316 in the sealing ring 210. As shown, the seals 314 and 316 extend circumferentially around the sealing ring 210. However, other sealing profiles can be used in other examples. The extensions 610 and 612 (similar to the extensions 410 and 412 in Fig. 4) The sealing rings 314 and 316 are in Fig. Figure 6 is shown in more detail. As shown, the nozzles 212 are evenly distributed around the circumference of the sealing ring 208. However, other nozzle arrangements are also possible.

[0035] The Fig. Figures 1-6 show an operating method for a cooling system for an electric machine, in which coolant is sprayed onto the stator ends from a plurality of nozzles in a pair of sealing rings contained in a stator assembly. The method can further include, prior to spraying the coolant towards the stator windings, coolant flowing from a sump into a coolant inlet, the coolant inlet being integrated into one of the sealing rings contained in the pair of sealing rings. It is understood that these process steps can be implemented via a pump control system. For example, the pump output can be increased or decreased depending on the cooling requirements of the electric machine.

[0036] Features described as axial may be approximately parallel to a reference axis unless otherwise specified. Features described as antiaxial may be approximately perpendicular to the referenced axis unless otherwise specified. Features described as radial may circumferentially surround or extend outward from an axis, such as the reference axis, or a component or feature previously described as radial to a reference axis, unless otherwise specified. Unless otherwise specified, the referenced axis may be the axis of rotation.

[0037] The invention is described in more detail in the following paragraphs. In one aspect, a cooling system for an electric machine is provided, comprising a stator arrangement comprising: a stator core with multiple coolant channels extending axially through it; multiple stator windings extending through the stator core and forming end windings on opposite axial sides of the stator core; and a pair of sealing rings directly coupled to opposite axial sides of the stator core; each of the sealing rings in the pair of sealing rings comprising: an outer seal positioned radially outside an inner seal; a sealed coolant channel formed between the inner seal and the outer seal and in fluid communication with the multiple coolant channels; and a plurality of nozzles spraying coolant in the direction of the end windings.In one example, at least one of the sealing rings of the sealing ring pair can have a coolant inlet that directs coolant into the sealed coolant channel. In another example, the coolant inlet can extend axially outward from the stator core. In yet another example, the cooling system for an electric machine can operate with oil as the working fluid. In another example, each sealing ring of the sealing ring pair can form a continuous structure. In one example, the cooling system for an electric machine can also include a sump designed to collect the sprayed coolant. In another example, the cooling system for an electric machine can be incorporated into an electric drive.

[0038] In another aspect, a method for operating a cooling system for an electric machine is provided, comprising spraying coolant towards the stator ends from a plurality of nozzles in a pair of sealing rings contained in a stator assembly; wherein the stator assembly comprises: a stator core with multiple coolant channels extending axially through it; and multiple stator windings extending through the stator core and forming end windings on opposite axial sides of the stator core; and a pair of sealing rings directly coupled to opposite axial sides of the stator core; wherein each of the sealing rings in the pair of sealing rings comprises: an outer seal positioned radially outward from an inner seal;and a sealed coolant channel formed between the inner and outer seals and in fluid communication with the multiple coolant channels; and the plurality of nozzles. In one example, the method may further include, prior to spraying the coolant towards the stator windings, allowing coolant to flow into a coolant inlet integrated into one of the sealing rings of the sealing ring pair. In another example, the coolant may be oil.

[0039] In another aspect, a cooling system for a traction motor is provided, comprising a stator assembly that includes: a stator core with multiple coolant channels extending axially through it; multiple stator windings extending through the stator core and forming end windings on opposite axial sides of the stator core; and a pair of sealing rings directly coupled to opposite axial sides of the stator core; each of the sealing rings in the pair of sealing rings forming a continuous structure and comprising: an outer seal arranged radially outside an inner seal; a sealed coolant channel formed between the inner seal and the outer seal and in fluid communication with the multiple coolant channels; and a plurality of nozzles spraying coolant in the direction of the end windings.In one example, the stator arrangement can be a hairpin winding. In another example, the end windings can be hairpin windings. In yet another example, the traction motor's cooling system can be integrated into an electric axle. In another example, at least one of the sealing rings of the sealing ring pair can have a coolant inlet that directs coolant into the sealed coolant channel; and / or the coolant inlet can be aligned axially parallel to a rotational axis of the traction motor. In yet another example, the outer seal and the inner seal can have extensions that align with recesses in the stator core.

[0040] Apart from the schematically depicted components, Fig. Figures 1-6 are drawn approximately to scale. In other embodiments, however, the components may have different relative dimensions.

[0041] Fig.Figures 1-6 show example configurations with the relative arrangement of the various components. If these elements are in direct contact with each other or directly coupled, they can be described as being in direct contact or directly coupled, respectively, in at least one example. Similarly, elements shown side by side or adjacent to each other can be described as being adjacent to each other or adjacent to each other, respectively, in at least one example. For instance, components that are in planar contact with each other can be described as being in planar contact. As another example, elements that are separated from each other, with only a gap between them and that have no other components, can be described as such in at least one case.In yet another example, elements that are displayed above / below each other, on opposite sides, or to the left / right of each other can be described as such, relative to one another. Furthermore, in at least one example, as shown in the figures, a topmost element or the highest point of an element can be referred to as the "top" of the component, and a bottommost element or the lowest point of the element can be referred to as the "bottom" of the component. The terms top / bottom, upper / lower, and above / below used here can refer to a vertical axis of the figures and be used to describe the positioning of elements within the figures relative to each other. Thus, in one example, elements displayed above other elements are arranged vertically above the other elements.As a further example, the shapes of the elements depicted in the figures can be described as such (e.g., circular, straight, planar, curved, rounded, beveled, angled, and the like). Furthermore, in one example, elements that are coaxial with each other can be described as such. Additionally, the depicted elements that intersect each other can be described as intersecting elements or as mutually intersecting elements in at least one example. Moreover, an element that is depicted inside or outside another element can be described as such. In other examples, elements that are offset from each other can be described as such. Elements that are arranged coaxially or parallel to each other can also be described as such. Another example: features that are described as being "essentially" shaped, e.g.,Ring-shaped, flat, planar, prismatic, circular, etc., mean that the features are sufficiently shaped as such to be regarded as such by a person skilled in the art.

[0042] It should be noted that the example control and estimation routines contained herein can be used with various engine configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transient memory and can be executed by the control system, including the control device, in combination with the various sensors, actuators, and other electrical drive and / or vehicle hardware, in combination with the electronic control device. Thus, the described actions, operations, and / or functions can graphically represent code programmed into non-volatile memory of the computer-readable storage medium in the vehicle and / or the powertrain control system. One or more of the depicted actions, operations, and / or functions can be performed repeatedly, depending on the method used.One or more of the procedural steps described here can be omitted if desired.

[0043] Although various embodiments have been described above, it should be understood that these are to be considered examples and not limitations. Those skilled in the art will recognize that the disclosed subject matter can be implemented in other specific forms without deviating from the spirit of the subject matter. The embodiments described above are therefore to be regarded in every respect as illustrative and not as limiting. Thus, the configurations and routines disclosed here are exemplary in nature, and the specific examples are not to be considered limiting, since numerous variations are possible. The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions, and / or properties disclosed herein.

[0044] The following claims highlight in particular certain combinations and subcombinations that are to be considered novel and not obvious. These claims may refer to "one" element or "a first" element, or the equivalent thereof. Such claims are to be understood as including one or more such elements, with two or more such elements neither required nor excluded. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether they have a broader, narrower, the same, or different scope than the original claims, are also to be considered included in the subject matter of the present disclosure. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 704,692

[0001]

Claims

[1] Cooling system for an electric machine, comprising: a stator arrangement that includes: a stator core with several coolant channels running axially through it; and several stator windings extending through the stator core and forming end windings on opposite axial sides of the stator core; and a pair of sealing rings that are directly coupled to opposite axial sides of the stator core and arranged radially outside the stator windings; where each of the sealing rings in the pair of sealing rings comprises: an outer seal that is arranged radially outwards from an inner seal; a sealed coolant channel formed between the inner seal and the outer seal, which is in fluid communication with the multiple coolant channels; and a multitude of nozzles that spray coolant towards the end windings. [2] Cooling system for electric machines according to claim 1, wherein at least one of the sealing rings in the pair of sealing rings has a coolant inlet which is in direct fluid communication with the sealed coolant channel. [3] Cooling system for electric machines according to claim 2, wherein the coolant inlet extends axially from the stator core to the outside. [4] Cooling system for electric machines according to one of the preceding claims, wherein the multiple coolant channels are arranged radially outside the multiple stator windings. [5] Cooling system for electric machines according to one of the preceding claims, wherein a working fluid in the cooling system for electric machines is oil. [6] Cooling system for electric machines according to one of the preceding claims, wherein each sealing ring in the pair of sealing rings forms a continuous structure extending circumferentially around a surface of the stator core. [7] Cooling system for electric machines according to one of the preceding claims, further comprising a sump designed to receive the sprayed coolant. [8] Cooling system for an electric machine according to one of the preceding claims, wherein the cooling system for an electric machine is included in an electric drive. [9] Cooling system for an electric machine according to any one of the preceding claims, wherein: the stator arrangement is a multiphase stator arrangement; and / or The ends are hairpin turns. [10] Cooling system for an electric machine according to any of the preceding claims, wherein: at least one of the sealing rings in the pair of sealing rings has a coolant inlet that is in direct fluid contact with one of the sealed coolant channels; the coolant inlet is aligned axially parallel to a rotational axis of the traction motor; and / or the multiple coolant channels are arranged radially outside the multiple stator windings.

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