Electric machine with stator cooling

Abstract

The present invention relates to an electric machine (1) for powering a motor vehicle (2), comprising a stator (4) with a stator winding having winding heads (6), a rotor (7) rotatably arranged on the stator (4), and a machine housing (8), wherein a cooling jacket (9) is arranged between the stator (4) and the machine housing (8), the cooling jacket having an outlet nozzle (11) at each end region (10) for releasing coolant onto the winding heads (6). On an outer surface (12) of the cooling jacket (9), a sealing device (13) is arranged such that the outlet nozzles (11) of both end regions (10) are arranged axially between the sealing devices (13). A fluid channel (15) is formed between the sealing devices (13), the cooling jacket (9) and the housing wall (14), wherein a fluid inlet (16) is formed in the housing wall (14) for introducing the coolant into the fluid channel (15).Furthermore, the invention relates to a motor vehicle (2) and a method for manufacturing an electric machine (1) with stator cooling.

Description

The present invention relates to an electric machine for powering a motor vehicle. The invention further relates to a motor vehicle with an electric drive system or a hybrid drive system, and to a method for manufacturing an electric machine with stator cooling. During operation, electric motors experience particularly high thermal stress in the stator windings. In particular, the end sections of the stator windings, or the so-called winding ends, can overheat and impair the motor's lifespan. To dissipate the excess heat from the stator windings, coolant channels integrated into the stator are known, but these increase the space required and the complexity of the stator's design. Document DE 10 2017 222 227 A1 discloses an electric machine with stator cooling. The stator cooling system comprises a cooling channel formed between an outer surface of a stator body and a tubular element sealed circumferentially against the stator body. Thus, a central area of ​​the stator can be cooled by the stator cooling system. Cooling of the stator winding ends is not implemented. Documents DE 10 2021 121 035 A1, DE 10 2021 121 031 A1 and DE 10 2021 121 032 A1 disclose various electric machines in which a machine housing has several cooling channels open radially inwards, which are closed radially by a stator core. Coolant can be introduced into the machine housing via an inlet and conveyed to several outlets via the cooling channels. Coolant can then be conveyed to the winding heads of the stator via these outlets. Document DE 10 2012 003 101 A1 describes an electric machine with a cooling jacket formed by a stator support and a machine housing. Cooling of the winding heads is not provided by the cooling jacket due to a sealing arrangement and an attached vibration decoupling structure. Other electric machines with cooling jackets are known, for example, from documents CN 1 06 787 452 A, US 2021 / 0 257 878 ​​A1, US 2022 / 0 006 349 A1, and US 7 834 492 B2. Common electric motors have the disadvantage that they often lack adequate or no cooling of the winding heads. Furthermore, due to the stator cooling requirements, common electric motors sometimes have a very complex design and are therefore particularly expensive and costly to manufacture. It is therefore an object of the present invention to eliminate, or at least partially eliminate, the disadvantages described above in an electric motor for powering a motor vehicle. In particular, it is an object of the present invention to provide an electric motor for powering a motor vehicle and a motor vehicle with an electric drive system or hybrid drive system that have a simplified design and / or ensure improved stator cooling in a simple and cost-effective manner. The aforementioned problem is solved by the patent claims. Accordingly, the problem is solved by an electric machine for driving a motor vehicle with the features of independent claim 1 and by a motor vehicle with an electric drive system or hybrid drive system with the features of dependent claim 8. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the electric machine according to the invention naturally also apply in connection with the motor vehicle according to the invention, and vice versa, so that the disclosure regarding the individual aspects of the invention always refers, or can refer, to each other. According to a first aspect of the invention, the problem is solved by an electric motor for powering a motor vehicle. The electric motor has a stator extending along a longitudinal axis, the stator comprising a stator body with a stator winding arranged thereon, the stator winding having a winding head at each end face of the stator body. The stator winding can, for example, be designed as a hairpin winding made of hairpins or as a wound stator winding made of a continuous winding wire per stator phase. The hairpins or the winding wire preferably comprise copper, which is completely coated with an electrically insulating layer, such as a lacquer. Furthermore, the electric machine comprises a rotor rotatably mounted on the stator and extending coaxially to the stator's longitudinal axis, and a machine housing that accommodates the stator. A cooling jacket enclosing the stator is arranged between the stator and the machine housing. The rotor preferably has a rotor body in which magnetic pockets with permanent magnets and a rotor backplate are formed. Alternatively, the rotor can also be designed as a squirrel-cage rotor. According to the invention, the cooling jacket has at least one outlet nozzle at each of its opposite end regions for discharging coolant onto the winding heads of the stator. A sealing device is arranged on the outer surface of the cooling jacket, pointing away from the longitudinal axis of the stator, such that the outlet nozzles of both end regions are arranged axially between the sealing devices. The sealing devices seal a gap between the outer surface of the jacket and a housing wall of the machine housing, forming a fluid channel between the sealing devices, the cooling jacket, and the housing wall. A fluid inlet is formed in the housing wall for introducing the coolant into the fluid channel.Furthermore, one of the outlet nozzles is sealed in the axial direction to the fluid channel by a sealing device, wherein a further fluid inlet is formed in the housing wall for introducing coolant into this outlet nozzle, or that the outlet nozzles are each sealed in the axial direction to the fluid channel by a sealing device, wherein two further fluid inlets are formed in the housing wall, wherein the fluid inlets are each designed for introducing coolant into one of the outlet nozzles. The electric machine comprises a stator and a rotor rotatably mounted on the stator. The rotor can, for example, be rotatably mounted on the machine housing via a bearing device. The stator is designed as a cooled stator, with the stator cooling system serving to cool the winding heads of the stator winding, the stator winding formed between the winding heads, and the stator body. To cool the winding heads, the cooling jacket has outlet nozzles. An outlet nozzle is understood to be an opening through which a coolant, such as oil or the like, can flow and be directed towards the winding head. According to the invention, an outlet nozzle can also be understood to be an arrangement of several outlet nozzles, which are, for example, distributed in the circumferential direction of the cooling jacket, preferably on the same longitudinal axis segment, i.e., on a circular or ring path extending around the stator's longitudinal axis. For the sake of clarity, the invention refers to one outlet nozzle per winding head, which can therefore also mean at least one outlet nozzle or several outlet nozzles per winding head. The outlet nozzle is preferably arranged above the winding head so that the coolant can be directed from above onto the winding head through the outlet nozzle under the influence of gravity.Preferably, between 1 and 150 outlet nozzles are provided per winding head. More preferably, between 5 and 120 outlet nozzles are provided per winding head. Particularly preferably, between 10 and 90 outlet nozzles are provided per winding head. More preferably, between 15 and 60 outlet nozzles are provided per winding head. According to a particularly preferred embodiment of the invention, between 20 and 30 outlet nozzles are provided per winding head. The arrangement of the cooling jacket with the sealing devices on the machine housing forms the fluid channel, which completely surrounds a central region of the stator winding, i.e., a region of the stator winding located between the winding heads. The sealing device is preferably annular and preferably made of an elastomer. Coolant can be introduced into the fluid channel via the fluid inlet. According to a preferred embodiment of the invention, the outlet nozzles are fluidly coupled to the fluid channel and thus also to the fluid inlet, so that the coolant introduced into the fluid channel via the fluid inlet can be directed to the winding heads via the outlet nozzles. The sealing devices prevent lateral escape of the coolant in the axial direction. An electric motor according to the invention for powering a motor vehicle has the advantage over conventional electric motors that particularly efficient stator cooling is provided using simple and cost-effective means. Targeted cooling of a central section of the stator winding and the stator body can be achieved via the fluid channel. Targeted direct cooling of the stator winding heads can be achieved via the outlet nozzles. The cooling jacket, which is sealed axially against the motor housing, allows the cooling device to be manufactured simply and is easy to assemble and disassemble. Furthermore, the cooling jacket can be easily attached to the stator in a pre-assembly step, thus ensuring particularly simple final assembly of the electric motor. The one-piece design of the cooling jacket further reduces the number and variety of parts. According to a preferred embodiment of the invention, an electric motor for powering a motor vehicle may be provided with a fluid guide element arranged between the cooling jacket and the housing wall. A fluid guide element is understood to be a device designed to direct the flow of coolant. Coolant flowing through the fluid inlet can be directed by the fluid guide element, for example, along the longitudinal axis of the stator and / or in the circumferential direction of the stator, so that, for example, the most uniform possible distribution of the coolant over the circumferential surface of the stator can be achieved. Accordingly, the fluid guide element has a component extending in the circumferential direction and / or in the longitudinal direction of the stator. Furthermore, the fluid guide element has a component extending in the radial direction. The fluid guide element is preferably designed to direct the coolant from the fluid inlet to the outlet nozzles.The fluid guide element is preferably designed as a plastic part. More preferably, the fluid guide element is designed as a circumferential component that surrounds the stator completely. For guiding the fluid, the fluid guide element preferably has one or more ribs. Preferably, the fluid guide element is designed as a separate component. More preferably, the fluid guide element is positively secured in the axial direction, for example, by engaging in a groove formed in the housing wall. Alternatively, the fluid guide element can also be designed as part of the housing wall or the cooling jacket. According to the invention, it can also be provided that part of the fluid guide element is designed as part of the housing wall and another part of the fluid guide element as part of the cooling jacket. This has the advantage that targeted cooling of the stator can be further improved in a simple and cost-effective manner. According to the invention, it is preferred that the fluid guide element is designed as a connection between the cooling jacket and the housing wall. In other words, the fluid guide element preferably extends from the outer surface of the jacket to the housing wall and contacts both the outer surface of the jacket and the housing wall. Preferably, the fluid guide element is pressed against the housing wall under residual stress, thus providing a sealing effect and / or vibration damping. This has the advantage that targeted cooling of the stator can be further improved in a simple and cost-effective manner. Preferably, the stator base body contacts the cooling jacket. The cooling jacket thus preferably forms a enveloping surface around the stator base body. Preferably, the cooling jacket is arranged on the stator base body without stress at room temperature, preferably without clearance. The direct contact of the stator base body provides improved heat dissipation from the stator winding via the wall of the cooling jacket to the coolant. According to the invention, a thermal conductor, such as a thermally conductive gel or the like, can be arranged between the cooling jacket and the stator base body to improve heat transfer from the stator winding to the cooling jacket. This has the advantage that targeted cooling of the stator is further improved in a simple and cost-effective manner. In a particularly preferred embodiment of the invention, the sealing device of an electric machine can be held on the outer surface of the casing. For this purpose, the outer surface of the casing can, for example, have a circumferential groove, a circumferential shoulder, or a circumferential sealing surface. The sealing device can be designed, for example, as an O-ring or an injection-molded sealing device. The sealing device can be held on the outer surface of the casing by positive locking, frictional locking, and / or adhesive locking. This has the advantage that targeted cooling of the stator can be further improved in a simple and cost-effective manner. According to the invention, one of the outlet nozzles is sealed axially to the fluid channel by a sealing device, wherein a further fluid inlet is formed in the housing wall for introducing coolant into this outlet nozzle, or that the outlet nozzles are each sealed axially to the fluid channel by a sealing device, wherein two further fluid inlets are formed in the housing wall, each of which is designed for introducing coolant into one of the outlet nozzles. Thus, according to a preferred first alternative, a first outlet nozzle is fluidly coupled to the fluid channel, while the second outlet nozzle is sealed against the fluid channel by the sealing device. The first outlet nozzle can therefore be supplied with coolant via the fluid channel, while the further fluid inlet is provided for supplying fluid to the second outlet nozzle.The machine housing therefore has at least two fluid inlets. According to the second preferred alternative, both fluid outlets are sealed against the fluid channel by means of a sealing device. To supply the fluid outlets with coolant, a further fluid inlet is provided for each of the fluid outlets, so that the machine housing has a total of at least three fluid inlets. Due to the fluid-tight seals, the fluid outlets and the fluid channel can be supplied with different coolant flows, which can differ, for example, in fluid temperature, flow velocity, volume flow rate, and / or coolant composition. In other words, the fluid flows can be supplied independently of one another. Thus, inhomogeneous cooling of the stator can be achieved.This has the advantage that targeted cooling of the stator can be further improved using simple means and in a cost-effective manner. According to a preferred embodiment of the invention, the cooling jacket is designed as a steel sheet or as an aluminum casting. A cooling jacket designed as a steel sheet preferably has a wall thickness that is significantly less than the wall thickness of the machine housing. In this case, the sealing device is preferably injection-molded onto the steel sheet. A cooling jacket designed as an aluminum casting preferably has a wall thickness that corresponds to or is slightly greater than the wall thickness of the machine housing. In this case, the sealing device is preferably designed as an O-ring and arranged in a groove of the aluminum casting. This has the advantage that targeted cooling of the stator can be further improved in a simple and cost-effective manner. The outlet nozzles preferably have a hole diameter of between 0.1 mm and 2 mm. More preferably, the outlet nozzles have a hole diameter of between 0.3 mm and 1.6 mm. Particularly preferably, the outlet nozzles have a hole diameter of between 0.5 mm and 1.2 mm. According to a particularly preferred embodiment, the outlet nozzles have a hole diameter of between 0.7 mm and 0.8 mm. Sufficient coolant supply to the winding heads can be ensured via such outlet nozzles. This has the advantage that targeted cooling of the stator can be further improved in a simple and cost-effective manner. According to a second aspect of the invention, the problem is solved by a motor vehicle. The motor vehicle has an electric drive system or a hybrid drive system for propelling the motor vehicle. According to the invention, the electric drive system or the hybrid drive system has an electric machine according to one of the preceding claims for propelling the motor vehicle. Accordingly, the motor vehicle according to the invention comprises an electric motor according to the invention for driving the motor vehicle. The electric motor has stator cooling, which is essentially formed by a cooling jacket with outlet openings, a housing wall of the motor housing, and sealing devices arranged between the cooling jacket and the housing wall. The motor vehicle according to the invention offers all the advantages already described for an electric motor for propelling a motor vehicle according to the first aspect of the invention. Accordingly, the motor vehicle according to the invention has the advantage over conventional motor vehicles that particularly efficient stator cooling is provided using simple and cost-effective means. Targeted cooling of a central section of the stator winding can be achieved via the fluid channel. Targeted direct cooling of the winding heads of the stator winding can be achieved via the outlet nozzles. Due to the cooling jacket being sealed axially against the machine housing, the cooling device can be manufactured using simple means and is easy to assemble and disassemble.Furthermore, the cooling jacket can be easily attached to the stator in a pre-assembly step, ensuring particularly simple final assembly of the electric motor. The one-piece design of the cooling jacket further reduces the number and variety of parts. Furthermore, a method for manufacturing an electric machine with stator cooling is described. The method comprises: - providing a stator of the electric machine extending along a longitudinal axis, wherein the stator has a stator body with a stator winding arranged thereon, the stator winding having a winding head at each end face of the stator body; - providing a cooling jacket, wherein the cooling jacket has an outlet nozzle for releasing coolant at opposite end regions; - arranging sealing devices at opposite end regions of the cooling jacket on an outer surface of the cooling jacket pointing away from the longitudinal axis of the stator, such that the outlet nozzles are arranged axially between two sealing devices; - arranging the stator in the cooling jacket such that the outlet nozzles are directed towards the winding heads; - arranging the cooling jacket in a machine housing such that...that the sealing devices abut a housing wall of the machine housing, wherein a fluid channel is formed between the sealing devices, the cooling jacket and the housing wall, wherein a fluid inlet is formed in the housing wall for introducing the coolant into the fluid channel, and - insertion of a rotor into the stator. An electric machine according to the first aspect of the invention can be manufactured using such a method. The method is preferably carried out by first inserting the stator into the cooling jacket and then arranging the stator with the cooling jacket attached to it in the machine housing. According to the invention, the sealing device can be attached to the cooling jacket either before or after the stator is placed in the cooling jacket, or after and before the cooling jacket is placed in the machine housing. Thus, the sealing devices contact one of the inner surfaces of the machine housing. Preferably, the cooling jacket is screwed to the machine housing by a fastening means, such as a screw. The rotor is preferably inserted after the stator with the cooling jacket attached to it has been placed in the machine housing, and particularly preferably after the cooling jacket has been fixed to the machine housing. This method for manufacturing an electric machine with stator cooling offers all the advantages already described for an electric machine for powering a motor vehicle according to the first aspect of the invention, as well as for a motor vehicle according to the second aspect of the invention. Accordingly, the method described above for manufacturing an electric machine with stator cooling has the advantage over various conventional methods that particularly efficient stator cooling is provided using simple and cost-effective means. Targeted cooling of a central section of the stator winding can be achieved via the fluid channel. Targeted direct cooling of the winding heads of the stator winding can be achieved via the outlet nozzles.The cooling jacket, sealed axially against the machine housing, allows the cooling device to be manufactured using simple means and is easy to assemble and disassemble. Furthermore, the cooling jacket can be easily positioned on the stator in a pre-assembly step, ensuring particularly simple final assembly of the electric machine. The one-piece design of the cooling jacket further reduces the number and variety of parts. An electric motor according to the invention for driving a motor vehicle, a motor vehicle according to the invention, and a preferred method for manufacturing an electric motor with stator cooling are explained in more detail below with reference to the drawings. The drawings schematically show: Fig. 1 in a perspective view of an electric motor according to a preferred embodiment of the invention, Fig. 2 in a sectional view of a section of an electric motor according to a preferred first embodiment of the invention, Fig. 3 in a sectional view of a section of an electric motor according to a preferred second embodiment of the invention, Fig. 4 in a sectional view of a section of an electric motor according to an exemplary embodiment, Fig. 5 in a side view of a preferred embodiment of a motor vehicle according to the invention, Fig.Figure 6 shows an exemplary embodiment of a method for manufacturing an electric machine with stator cooling in a flowchart, and Figure 7 shows several different variants of the outlet nozzles in a sectional view. Elements with the same function and mode of operation are each provided with the same reference numerals in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7. Figure 1 shows a schematic perspective view of an electric machine 1 according to a preferred embodiment of the invention. The electric machine 1 has a stator 4 extending along a longitudinal axis 3. The stator 4 has a base body 5 on which a stator winding is arranged. At each end face of the base body 5, the stator winding has a winding head 6 that projects from the base body. The electric machine 1 also has a rotor 7 that can be rotatably arranged coaxially with the longitudinal axis 3 within the stator 4. Furthermore, the electric machine 1 has a cooling jacket 9 extending coaxially to the stator longitudinal axis 3, with an outer jacket surface 12 pointing away from the stator longitudinal axis 3, into which the stator 4 can be received. The cooling jacket 9 has two opposite end regions 10 in the axial direction, with a circumferential sealing device 13 arranged on the outer jacket surface 12 in each end region 10. Outlet nozzles 11 (see Fig. 2) are also formed in the cooling jacket 9, which are not visible in this view. To receive the cooling jacket 9 with the stator 4 and rotor 7 arranged therein, the electric machine 1 has a multi-part machine housing 8 with a housing wall 14. For energizing the stator winding of the stator 4, the electric machine 1 has power electronics 19 integrated into the machine housing 8, which are fluidly insulated from the stator 4. Furthermore, a single-stage gearbox 20 is integrated into the machine housing 8. Fig. 2 schematically shows a section of an electric machine 1 according to a preferred first embodiment of the invention in a sectional view. In this view, a portion of the stator 4 with the axially projecting winding heads 6 is visible. The cooling jacket 9 rests against the stator 4 and, at its end regions 10, against the housing wall 14 of the machine housing 8. In this embodiment, the cooling jacket 9 is designed as a sheet metal component. In a central section, a circumferential fluid channel 15 is formed between the cooling jacket 9 and the machine housing 8, which is bounded axially by circumferential sealing devices 13. The sealing devices 13 can, for example, be designed as injection-molded sealing devices 13. To supply the fluid channel 15 with a coolant, a fluid inlet 16 is formed in the machine housing 8, which opens into the fluid channel 15.To guide the coolant, a separately designed fluid guiding element 17 is arranged in the fluid channel 15, which contacts the machine housing 8 and the cooling jacket 9 and is positively locked to the housing wall 14 in the axial direction. Viewed axially from the fluid channel 15, downstream of the sealing device 13, an outlet nozzle 11 is formed at both end regions 10 of the cooling jacket 9, through which the coolant can be sprayed onto the winding head 6. To supply the outlet nozzles 11 with the coolant, a further fluid inlet 16 is arranged in the machine housing 8 for each outlet nozzle 11, each of which is fluidly coupled to one of the outlet nozzles 11. To prevent lateral outflow of the coolant in the axial direction, a further circumferential sealing device 13 is arranged on each outlet nozzle 11 in the axial direction. The sealing devices 13 can also be designed as injection-molded sealing devices 13. Thus, each outlet nozzle 11 is surrounded on both sides by directly adjacent sealing devices 13.In this embodiment, it can be provided according to the invention that the three fluid inlets 16 can be selectively supplied with different fluids, fluid volume flows or fluid pressures in order to achieve demand-based cooling of the stator 4. Figure 3 schematically depicts a section of an electric machine 1 according to a preferred second embodiment of the invention in a sectional view. The second embodiment of the invention differs from the first embodiment in the design of the cooling jacket 9. In this embodiment, the cooling jacket 9 is designed as a cast aluminum component and has a greater wall thickness than the sheet metal cooling jacket 9 according to the first embodiment of the invention. Furthermore, the sealing devices 13 are designed as O-rings arranged in grooves on the outer surface 12 of the cooling jacket. The fluid guide element 17 is formed by ribs of the cooling jacket 9, which contact the housing wall 14 of the machine housing 8. Fig. 4 schematically shows a section of an electric machine 1 according to an exemplary embodiment in a sectional view. This exemplary embodiment differs from the first embodiment of the invention in the arrangement of the sealing devices 13 and the fluid inlets 16. In this embodiment, the axially inner sealing devices 13 are omitted, so that the two outlet nozzles 11 are fluidly coupled to the fluid channel 15. Thus, the two fluid inlets 16, which in the first embodiment of the invention are associated with the outlet nozzles 11, are no longer required. Therefore, in this embodiment, the machine housing 8 has only one fluid inlet 16, which opens into the fluid channel 15. Coolant introduced via the fluid inlet 16 can thus be distributed via the fluid channel 15 and supplied to the outlet nozzles 11 for spraying onto the winding heads 6.To prevent lateral outflow of the coolant in an axial direction, a circumferential sealing device 13 is arranged at each outlet nozzle 11, extending axially outwards. The sealing devices 13 can, for example, be designed as injection-molded sealing devices 13. It is also possible within the scope of the invention that the sealing devices 13 shown in Fig. 4 are not present. In this case, it is preferred that the cooling jacket 9 abuts the housing wall 14 of the machine housing 8 at its end regions 10 in a sealing manner, for example by means of a fit or, in the case of an elastic design of the cooling jacket 9, by means of compressive stress. Figure 5 shows a schematic side view of a preferred embodiment of a motor vehicle 2 according to the invention. The motor vehicle 2 has an electric drive system 18 with an electric machine 1 according to the invention and a traction battery 21 for providing electrical energy to operate the electric machine 1 for driving the motor vehicle 2. Fig. 6 schematically shows an exemplary embodiment of a method for manufacturing an electric machine 1 with stator cooling in a flowchart. In a first process step 100, a stator 4 of the electric machine 1 is provided. The stator 4 has a stator body 5 extending along a longitudinal axis 3, with a stator winding arranged thereon. At the end faces of the stator body 5, the stator winding extends axially out of the stator body 5, forming a winding head 6 at each end. In a second process step 200, a cooling jacket 9 is provided. The cooling jacket 9 has two opposing end regions 10 in the axial direction. In each of the end regions 10, an outlet nozzle 11 is arranged for conveying coolant through the cooling jacket 9. In a third process step 300, sealing devices 13 are arranged at the end regions 10 on an outer surface 12 of the cooling jacket 9 pointing away from the longitudinal axis 3 of the stator, such that the outlet nozzles 11 are arranged axially between the sealing devices 13. In a fourth process step 400, the stator is arranged in the cooling jacket 9 such that the outlet nozzles 11 are directed towards the winding heads 6 of the stator 4. In a fifth process step 500, the cooling jacket 9 with the stator 4 arranged therein is positioned in a machine housing 8, such that the sealing devices 13 bear against a housing wall 14 of the machine housing 8 that points towards the longitudinal axis 3 of the stator. In this way, a fluid channel 15 is formed between the sealing devices 13, the cooling jacket 9, and the housing wall 14, which is fluidly coupled to a fluid inlet 16 formed in the housing wall 14. If no further sealing devices 13 are provided, the fluid channel 15 is also fluidly coupled to the outlet nozzles 11. Alternatively, an additional sealing device 13 can be arranged on each of the outlet nozzles 11 located on the opposite side in the axial direction, so that the outlet nozzles 11 are sealed to the fluid channel 15 via the additional sealing devices 13.To supply the outlet nozzles 11 with the coolant, the machine housing 8 provided in this case has two further fluid inlets 16, each assigned to an outlet nozzle 11 and coupled to the respective outlet nozzle 11 in a fluid-communicating manner. In a sixth process action 600, a rotor 7 is inserted into the stator 4 and the machine housing 8 is closed. Fig. 7 schematically shows several different variants of the exhaust nozzles 11 in a sectional view. The exhaust nozzles 11 can, for example, have a cylindrical or a truncated conical cross-section, which preferably widens in the flow direction. Alternatively, the cross-section can also taper in the flow direction. According to a further alternative, the exhaust nozzles 11 can, for example, initially have a cylindrical cross-section that transitions into a truncated conical cross-section, which preferably widens in the flow direction. The outlet nozzles 11 can, for example, also have two successive obtuse conical cross-sections, wherein the cross-section of the outlet nozzles 11 initially narrows and then widens in the flow direction. According to the invention, it can also be provided that the change in the cross-section of the outlet nozzles 11 is progressive. The illustrated outlet nozzles 11 represent only a preferred selection, whereby outlet nozzles 11 with other geometries can also be provided according to the invention. Reference symbol list 1 Electric machine 2 Motor vehicle 3 Stator longitudinal axis 4 Stator 5 Stator base 6 Winding head 7 Rotor 8 Machine housing 9 Cooling jacket 10 End area 11 Outlet nozzle 12 Jacket outer surface 13 Sealing device 14 Housing wall 15 Fluid channel 16 Fluid inlet 17 Fluid guide element 18 Electric drive system 19 Power electronics 20 Gearbox 21 Traction battery 100 First process action 200 Second process action 300 Third process action 400 Fourth process action 500 Fifth process action 600 Sixth process action

Claims

An electric machine (1) for powering a motor vehicle (2), comprising a stator (4) extending along a stator longitudinal axis (3), wherein the stator (4) has a stator body (5) with a stator winding arranged thereon, wherein the stator winding has a winding head (6) at each end face of the stator body (5), a rotor (7) rotatably arranged on the stator (4) and extending coaxially to the stator longitudinal axis (3), and a machine housing (8) accommodating the stator (4), wherein a cooling jacket (9) enclosing the stator (4) is arranged between the stator (4) and the machine housing (8), wherein the cooling jacket (9) has an outlet nozzle (11) at each of opposite end regions (10) for discharging coolant onto the winding heads (6), wherein on an outer surface (12) of the cooling jacket (9) pointing away from the stator longitudinal axis (3) a sealing device (13) is arranged such thatthat the outlet nozzles (11) of both end regions (10) are arranged axially between the sealing devices (13), and wherein the sealing devices (13) seal a gap between the outer surface (12) of the jacket and a housing wall (14) of the machine housing (8) such that a fluid channel (15) is formed between the sealing devices (13), the cooling jacket (9) and the housing wall (14), wherein a fluid inlet (16) for introducing the coolant into the fluid channel (15) is formed in the housing wall (14), wherein one of the outlet nozzles (11) is sealed axially to the fluid channel (15) by a sealing device (13), wherein a further fluid inlet (16) for introducing coolant into this outlet nozzle (11) is formed in the housing wall (14), or wherein the outlet nozzles (11) are each sealed axially by a sealing device (13) are sealed to the fluid channel (15),wherein two further fluid inlets (16) are formed in the housing wall (14), wherein the further fluid inlets (16) are each designed to introduce coolant into one of the outlet nozzles (11). Electric machine (1) according to claim 1, characterized in that a fluid guide element (17) is arranged between the cooling jacket (9) and the housing wall (14). Electric machine (1) according to claim 2, characterized in that the fluid guiding element (17) is designed as a connection between the cooling jacket (9) and the housing wall (14). Electric machine (1) according to one of the preceding claims, characterized in that the stator base body contacts the cooling jacket (9). Electric machine (1) according to one of the preceding claims, characterized in that the sealing device (13) is held on the outer surface (12) of the casing. Electric machine (1) according to one of the preceding claims, characterized in that the cooling jacket (9) is designed as a sheet steel or as an aluminum casting. Electric machine (1) according to one of the preceding claims, characterized in that the outlet nozzles (11) have a hole diameter of between 0.1 mm and 2 mm. motor vehicle (2) comprising an electric drive system (18) or a hybrid drive system for driving the motor vehicle (2), characterized in that the electric drive system (18) or the hybrid drive system for driving the motor vehicle (2) comprises an electric machine (1) according to one of the preceding claims.

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