Cooling system, electric vehicle, electric drive unit and method for cooling thereof

Abstract

The invention relates to a cooling system (1), in particular for a drive motor (M) in an electric vehicle (F), having a cooling sleeve (2) with a longitudinal axis (3) and a thermally conductive structure (4), the cooling sleeve (2) enclosing the thermally conductive structure (4) in a region along the longitudinal axis (3), whereby a cooling channel (5) is formed between the cooling sleeve (2) and the thermally conductive structure (4) in order to guide a cooling fluid (6) in the cooling channel, the thermally conductive structure (4) being configured and defined for accommodating a first heat source (7) in the region, the first heat source being in particular a stator of the drive motor (M) for the electric vehicle (F). The thermally conductive structure (4) is configured for thermally conductively contacting a second heat source (8), the second heat source (8) being in particular a power electronics for the drive motor (M) in the electric vehicle (F), the second heat source being arranged axially opposite the first heat source (7) along the longitudinal axis (3).

Description

Technical Field

[0001] The invention relates to a cooling system, in particular a cooling system for a drive motor of an electric vehicle, comprising a cooling sleeve with a longitudinal axis and a heat-conducting structure, wherein the cooling sleeve surrounds the heat-conducting structure in a region along the longitudinal axis, thereby forming a cooling channel between the cooling sleeve and the heat-conducting structure for conducting a cooling fluid therein, the heat-conducting structure being designed and dimensioned for accommodating a first heat source in said region, in particular a stator of the drive motor in an electric vehicle.

[0002] The invention further relates to an electric drive unit, an electric vehicle and a method for cooling an electric drive unit. Background Art

[0003] Cooling systems of this type are known in the prior art and serve to dissipate heat generated during operation of certain devices, in particular in electric machines or their surrounding flow-conducting components, and to prevent damage to the device to be cooled.

[0004] In particular, electric motors that can be used as drive motors for electric vehicles may have multiple heat sources. A first heat source of this type may be the stator of the motor, which is essentially hollow-cylindrical and arranged along the longitudinal axis of the motor. The stator generally comprises a stator lamination stack and an electrical conductor, which is configured to generate a moving magnetic field when an electric current is generated. The moving magnetic field in turn causes the rotor, which is arranged in an inner region of the stator, to move. Due to the flow of the current, the electrical conductor and the stator themselves heat up, which can lead to a reduction in efficiency. In addition, overheating of the stator can lead to irreversible damage or even complete failure of the motor.

[0005] If the first heat source is surrounded by a heat-conducting structure, in particular a sleeve-shaped stator support as is commonly used in known electric machines, the heat released by the first heat source can be dissipated via the aforementioned heat-conducting structure. By additionally providing a cooling sleeve around the periphery of the heat-conducting structure, cooling channels can be formed that are suitable for guiding a cooling fluid through the heat-conducting structure and thereby intensifying the cooling effect. Such a cooling sleeve is known from DE 10 2018 109 420 A1.

[0006] If the device to be cooled has additional heat sources, in particular inverters or other power electronics, the heat released by these additional heat sources must also be dissipated. If a first cooling system with a heat-conducting structure and a cooling jacket is already provided in the region of the first heat source, in known devices this involves arranging the second heat source outside the cooling jacket, thereby transferring two heat flows to the cooling fluid. This arrangement is also known from DE 10 2018 109 420 A1.

[0007] However, arranging the second heat source on the outer circumference of the cooling jacket results in a radial increase in the required installation space, which is often limited, particularly in vehicles. Consequently, with this arrangement, the cooling jacket must not exceed its maximum permitted outer diameter. This also limits the amount of available cooling fluid that can be guided through the cooling channels. Since the transferable heat flux is directly related to the amount of cooling fluid, the available radial installation space is a decisive factor influencing the achievable cooling effect of the cooling system. Summary of the Invention

[0008] The object of the present invention is therefore to improve the cooling effect of a cooling system, in particular for cooling an electric motor. Furthermore, the object of the present invention is to provide an electric drive unit and an electric vehicle having a cooling system with an improved cooling effect. Finally, the object of the present invention is to provide a method for cooling an electric drive unit, with which an improved cooling effect can be achieved.

[0009] According to the invention, this object is achieved by a cooling system, by an electric drive unit, by an electric vehicle, and by a method. Advantageous embodiments are the subject matter.

[0010] The present invention provides a cooling system, particularly for a drive motor in an electric vehicle. The cooling system comprises a cooling sleeve having a longitudinal axis and a heat-conducting structure. The cooling sleeve surrounds the heat-conducting structure in a region along the longitudinal axis, thereby forming a cooling channel between the cooling sleeve and the heat-conducting structure for conducting a cooling fluid in the cooling channel. The heat-conducting structure is configured and defined to accommodate a first heat source in the region, particularly a stator of the drive motor in the electric vehicle. The heat-conducting structure is configured to thermally contact a second heat source, particularly power electronics for the drive motor in the electric vehicle, the second heat source being arranged axially opposite the first heat source along the longitudinal axis.

[0011] The present invention further provides an electric drive unit, in particular an electric drive unit for an electric vehicle, wherein the vehicle has an electric machine comprising a rotor, a stator, a stator support, power electronics, and a cooling system according to the present invention, wherein the stator support is designed as the heat-conducting structure.

[0012] Furthermore, the present invention provides an electric vehicle having an electric drive unit, which includes the cooling system according to the present invention.

[0013] The present invention also provides a method for cooling an electric drive unit, comprising a cooling system according to the present invention. In the method, a cooling fluid is temperature-controlled to an inlet temperature and then delivered to a cooling channel. A first heat source and a second heat source each transfer heat to a heat-conducting structure, which in turn transfers heat to the cooling fluid. The cooling fluid is then delivered from the cooling channel.

[0014] The cooling system according to the present invention achieves an improved cooling effect compared to known cooling systems. This is achieved by allowing the structural space previously occupied by a second heat source arranged radially relative to the cooling jacket in known cooling systems to be used to construct the cooling jacket itself. The second heat source, in particular a power electronic component, is arranged axially along the longitudinal axis of the cooling jacket relative to the first heat source, in particular a stator. The heat-conducting structure is designed to thermally contact the first and second heat sources and thereby dissipate heat.

[0015] The cooling channel is preferably formed by a cavity provided between the cooling jacket and the heat-conducting structure. The geometry of the cooling channel is determined at least in part by the inner contour of the cooling jacket, thereby enabling the cooling jacket to be designed to guide the cooling fluid along a defined path. In particular, the inner contour of the cooling jacket can include depressions (troughs or peaks), grooves, or troughs that are formed along and / or transversely to the longitudinal axis of the cooling jacket, thereby forming, in cooperation with the surface of the heat-conducting structure, cooling channels that also extend along and / or transversely to the longitudinal axis, preferably in a helical manner.

[0016] Within the scope of the present invention, the cooling channel has a different, in particular shorter, overall length along its longitudinal axis than the heat-conducting structure. In particular, the first heat source can be arranged only in the region along the longitudinal axis of the cooling jacket, while the second heat source is not directly surrounded by the cooling jacket. In this case, the heat flow from the second heat source first flows along the heat-conducting structure into the region where the cooling jacket is located, where it is absorbed and carried away by the cooling fluid.

[0017] By arranging the first and second heat sources axially, the cooling channel itself can be enlarged, particularly in the radial direction (i.e., transverse to the longitudinal axis), thereby achieving a greater volumetric flow rate of the cooling fluid. Alternatively or additionally, given the same cooling sleeve size or cooling channel size, the required radial installation space can be reduced, which is particularly advantageous in vehicle construction. Because the heat-conducting structure also at least partially serves to establish thermal contact with the first heat source, a high degree of functional integration is achieved. This, in particular, reduces the manufacturing costs of the cooling system according to the present invention.

[0018] In a preferred embodiment, the cooling system includes a heat conducting structure configured and defined to at least partially accommodate the second heat source.

[0019] The provision of a heat-conducting structure capable of accommodating both the first and second heat sources achieves the advantage of a particularly high level of functional integration. The heat-conducting structure can be designed as a stator support for the motor. Preferably, a single component is required to accommodate and dissipate heat from both the first and second heat sources. This eliminates the need for an additional housing to enclose the second heat source. Consequently, several time-consuming and costly manufacturing and assembly steps are eliminated in the production of the cooling system.

[0020] In another preferred design, the heat-conducting structure includes a stator support for the drive motor, and the stator support is particularly a sleeve-shaped stator support.

[0021] This type of stator support is a well-known component of electric motors and commonly used in the art. It serves to both enclose and support the stator. The stator support is typically sleeve-shaped and made of a metal material, with a (cylindrical) outer and inner surfaces. The outer surface is particularly suitable for connection to a cooling sleeve, thereby forming a cooling channel. As a result, the stator meets all basic requirements for a heat-conducting structure, enabling thermal contact with both a first heat source and a second heat source. This completely eliminates the need for a separate component to form the heat-conducting structure, which reduces manufacturing costs.

[0022] In another preferred embodiment, the cooling jacket is at least partially corrugated and preferably made of a metallic material, and the cooling channels at least partially have a cooling channel geometry corresponding to the corrugated geometry of the cooling jacket.

[0023] Compared to a cylindrical cooling jacket, the corrugated design of the cooling jacket allows for a larger surface area on the outer surface of the cooling jacket. This intensifies the potential cooling effect, which can be associated with lower ambient temperatures in the area outside the cooling jacket. The corrugation can be implemented in particular by designing the cooling jacket as a corrugated tube or (annular) bellows. This allows for a defined deformability of the cooling jacket, in particular transversely to its longitudinal axis.

[0024] Furthermore, the cooling sleeve designed as a corrugated tube or (annular) bellows tube can be realized in a variable length, whereby different lengths of the heat-conducting structure can be enclosed with the only construction form of the corrugated tube cooling sleeve. For the production of such a cooling sleeve from sheet metal, a relatively economical and well-controllable forming process can be used. Here, the resulting cooling sleeve is relatively light in weight, which is advantageous in particular in vehicle construction. In particular in electric vehicles, a low weight has a positive effect on the required cooling power of the cooling system, since only a smaller mass has to be accelerated by the electric drive and thus only a smaller torque has to be provided by the electric machine. These in turn are associated with a lower current, which is why at least the first heat source in the form of the stator transfers less heat to the cooling system.

[0025] In another preferred design, the cooling channel is at least partially configured in a helical or thread-like manner along and / or around the longitudinal axis.

[0026] This helical design of the cooling channel has the advantage that the cooling fluid can be guided both on the periphery of the heat-conducting structure and over the length of the cooling sleeve. This helical course of the cooling channel can have a pitch which is determined in terms of construction. Together with the nominal flow speed of the cooling fluid, the time over which a certain amount of heat is input into the cooling fluid can be determined at least partially by the pitch. Furthermore, the pitch of the helical cooling channel can interact with the diameter of the cooling channel. The helical configuration of the cooling channel thus generally enables a good adjustability of the cooling effect.

[0027] In a preferred design, the cooling sleeve is connected to the heat-conducting structure in at least one joining region in a material-locking manner, in particular sealing the cooling channel in the joining region.

[0028] The material-locking connection of the cooling sleeve to the heat-conducting structure can be realized in one or more joining regions, which can be distributed uniformly or non-uniformly on the longitudinal axis. In the case of a wave-like cooling sleeve, in particular regions with a smaller cross-section (valleys) are suitable for contact with the outer side of the heat-conducting structure and are brazed, bonded or welded to the heat-conducting structure in these regions. Thereby, a defined individualization of the cooling channel can be achieved by the gas- or fluid-tight connection of the cooling sleeve to the heat-conducting structure, so that a mixing of the cooling fluid of adjacent regions and a correspondingly reduced cooling effect can be avoided.

[0029] In another preferred design, the heat-conducting structure comprises a bearing shield, in particular a bearing shield for a drive motor in an electric vehicle, which is arranged on the longitudinal axis between the first heat source and the second heat source.

[0030] The bearing shield is a known component, in particular in electric machines. It serves to hold bearings, in particular rolling bearings, on which movable parts of the electric machine, in particular the rotor or the output shaft, can be positioned and supported. The applicant has achieved in a particularly advantageous manner that, in addition to its function as a bearing seat, it can also be used as part of a cooling system by utilizing its thermal conductivity. This can be achieved in the form of a thermally conductive connection between the bearing shield and the stator support, or in such a way that the bearing shield has a structurally formed, thermally conductive element, via which the bearing shield can be connected to a heat-conducting structure. The arrangement of the bearing shield between a first heat source, which can be configured as a stator, and a second heat source, which can be configured as a power electronic device, offers the advantage that both the first heat source and the second heat source can transfer heat to the cooling fluid via the bearing shield, which forms part of the heat-conducting structure. In other words, the bearing shield can form an integral part of the heat-conducting structure.

[0031] In another preferred design scheme, the bearing shield has at least one axial through hole, which is arranged and constructed for contacting the first heat source and / or the second heat source, in particular for electrically contacting the first heat source and / or the second heat source, for example by contacting with a cable guided through the axial through hole.

[0032] The advantage achieved by the axial through-hole for contacting the first heat source and the second heat source is that a high degree of functional integration is achieved in the bearing shield. In addition to its function as a force transmission and heat transmission element, the bearing shield can also clearly and reliably position conductors, in particular electrical conductors. This is particularly advantageous when the first heat source and / or the second heat source vibrate or undergo unforeseen relative movements with respect to each other, as the contact between the heat sources may be damaged or the connection to the heat source may become loose due to the vibrations or relative movements. The axial through-hole can preferably contain a seal or a tension release element in order to achieve the advantages to a particularly great extent. In addition, the axial through-hole also provides the possibility of forming the contact only within the sealed inner cavity of the heat-conducting structure. In this way, in particular, the electrical contact can be protected from the effects of external environmental influences, so that such a contact can achieve a longer service life during operation.

[0033] In another preferred embodiment, the bearing shield is at least partially formed by forming, in particular by deep drawing and / or by preform forming, in particular by casting or by generative production.

[0034] The bearing shield is configured to be produced by means of forming, in particular deep-drawn components bring advantages in terms of component weight, in particular when the bearing shield is configured as a plate component or plate member. As explained above, a low component weight has a favorable influence on the necessary cooling power in an electric vehicle.

[0035] By producing the bearing shield by means of primary forming, in particular by means of casting forming, a high component stiffness can be achieved, whereby the cooling system as a whole is designed to be only slightly deformable and whereby in particular existing joint locations, such as weld seams or screw connections, are only subjected to a small load. Furthermore, in particular by using casting cores or using generative methods it is possible to configure cavities which have a favorable influence on the achievable cooling effect and the weight of the bearing shield.

[0036] It is also within the scope of the present application that the bearing shield is configured from a combination of a transformed and a primary formed component. Thereby it is possible to simultaneously utilize the characteristic advantages of both manufacturing method types.

[0042] In another preferred design variant, the bearing shield is configured for thermally conducting contact with the second heat source in such a way that the bearing shield is configured at least partially corresponding to the geometry of the second heat source, that is to say, in particular, partially complementary to the shaping of the second heat source.

[0038] By configuring the bearing shield with a geometry which is adapted to the geometry of the second heat source, it is possible to enlarge the surface which is available for the thermal conduction from the second heat source via the bearing shield or the thermally conducting structure to the cooling fluid. Thereby it is possible to correspondingly introduce more heat into the cooling system, so that the cooling effect of the cooling system as a whole can be improved.

[0039] In another preferred design variant, the second heat source is connected to the bearing shield by means of a thermally conducting intermediate layer, in particular the second heat source is connected to the bearing shield by means of a thermally conducting paste.

[0040] By introducing a thermally conducting intermediate layer, in particular in the form of a thermally conducting paste, it is possible to enlarge the contact surface between the second heat source and the bearing shield without having to specially adapt the geometry of the two components to one another. This is in particular advantageous when the second heat source is an electric power electronics which comprises electronic components which, for reasons of construction, have a geometry which cannot easily be adapted to external conditions. Thereby it is possible to improve the cooling effect without structural adaptation.

[0041] In a preferred design, the second heat source is disposed on a support plate that is mechanically connected to the bearing shield, in particular detachably connected thereto, preferably connected thereto by bolts. Most preferably, the second heat source is disposed on a side of the bearing shield facing away from the first heat source. The support plate may be a circuit board or the like.

[0042] Arranging the second heat source on the support plate offers the advantage of functionally separating the thermal connection from the mechanical connection. The support plate can be fixed to the bearing shield via a threaded connection, i.e., at a location of the bearing shield with a greater wall thickness, while the second heat source can be arranged at a location of the bearing shield with a relatively smaller wall thickness. This provides advantages for both the mechanical connection and the thermal connection of the heat source to the bearing shield. Furthermore, arranging the second heat source on the support plate facilitates installation on the cooling system, as the second heat source can be arranged on the support plate in a pre-assembled step so that it can subsequently be directly mounted on the bearing shield with minimal operational effort.

[0043] In another preferred embodiment, the heat conducting structure has radial through-holes, and the cooling channels are connected to the radial channels in a flow-conducting manner.

[0044] By forming radial through-holes, cooling fluid can be conducted from the outer region of the heat-conducting structure into its inner region, whereby the heat flow to be dissipated can be branched off, in particular from the interior of the electric machine, in order to cool different spatially separated regions in this way.

[0045] In another preferred embodiment, the bearing shield comprises a flow-conducting cooling channel continuation, which is directly or indirectly connected to the cooling channel in a flow-conducting manner.

[0046] The cooling channel continuation provides an additional flow path for the cooling fluid. This flow path can be formed entirely or partially in or on the bearing shield. This flow path can physically or geometrically expand the flow-conducting area of ​​the cooling system, thereby directing a larger amount of cooling fluid to the first heat source and the second heat source. This can improve the overall cooling efficiency of the cooling system.

[0047] The invention is not limited to a specific design in terms of shape and position of the cooling channel continuation. Instead, the cooling channel continuation can be a set of separate flow-guiding channels that are fluidically connected to the cooling channel, or it can be a closed cavity into which the cooling fluid flows from the cooling channel, circulates within the cavity, and then exits again.

[0048] In any case, the bearing shield and possibly other components arranged in or on the bearing shield, such as bearings, shafts or the like, can therefore be cooled in a targeted manner, which can be advantageous during operation.

[0049] In another preferred design, the cooling channel continuation is integrally formed inside the bearing shield.

[0050] The integral design of the cooling channel continuation within the bearing shield offers the advantage of a high degree of functional integration. The cooling channel continuation can be formed during manufacture by means of a core when the bearing shield is constructed as a cast component, or it can be produced by a subsequent machining step in which the cooling channel continuation is drilled or milled into the bearing shield. It is also possible to form one or more complex spatial profiles of the cooling channel continuation by means of a generative manufacturing process. The integral design of the cooling channel continuation makes it possible to dispense with sealing surfaces that could become damaged during assembly or operation of the cooling system. This reduces the risk of leakage of the cooling fluid and increases the achievable service life of the cooling system.

[0051] In another preferred design, the cooling channel continuation includes at least one first partial continuation and at least one second partial continuation, so as to guide a first partial flow or a second partial flow of the cooling fluid, respectively, and the first partial flow and the second partial flow preferably have a first fluid temperature or a second fluid temperature, respectively.

[0052] By providing at least two partial continuations, the temperature distribution within the cooling system can be favorably influenced, thereby facilitating the achievable cooling effect. The partial continuations can be designed in terms of their profile and diameter so that the cooling fluid is divided into a first partial flow and a second partial flow as desired and directed so as to achieve targeted thermal contact with areas generating high heat. The partial continuations can extend partially either parallel to or transversely to the longitudinal axis of the cooling jacket.

[0053] In another preferred design, the bearing shield is constructed as an assembly, which includes a first bearing shield component and a second bearing shield component, and the first bearing shield component and the second bearing shield component are configured to cooperate with each other to form the cooling channel continuation portion.

[0054] In contrast to a one-piece design, designing the bearing shield as an assembly of at least two bearing shield parts allows for complex spatial arrangements of the cooling channel continuation without requiring the use of complex manufacturing methods. The cooling channel continuation can be formed by machining the first bearing shield part and the second bearing shield part. This is achieved by milling out sections of the cooling channel continuation contour in each of the first and second bearing shield parts, and then forming the cooling channel continuation by assembling the two bearing shield parts. This split design offers the advantage of a high degree of interchangeability of the individual components during maintenance, without having to replace the entire bearing shield.

[0055] In another preferred design, the first bearing shield component or the second bearing shield component has a higher mechanical rigidity than the corresponding other bearing shield component. For example, one bearing shield component can be constructed as a casting, while the other bearing shield component can be constructed as a metal sheet or stamping.

[0056] By configuring the first bearing shield component to have a higher mechanical strength than the second bearing shield component, a high degree of functional separation can be achieved. This is particularly advantageous when the first bearing shield component is primarily designed to support the rotor and accordingly requires high rigidity, while the second bearing shield component comprises a large portion of the flow-guiding structure of the cooling channel continuation or defines the cooling channel continuation. Consequently, the majority of the resulting supporting forces can be absorbed directly by the first bearing shield component, while the second bearing shield component is protected from unacceptable deformations due to structural damage to the flow-guiding structure.

[0057] In a further preferred embodiment, the higher mechanical rigidity is achieved by increased material rigidity and / or by increased geometrical moment of inertia, preferably by providing ribs and / or beads which form corresponding bearing shield components.

[0058] The higher rigidity is influenced by both the properties of the material from which the corresponding bearing shield is made and its shape. When selecting the material, the elastic modulus of the material to be used can be taken into account, in particular, even during the structural design phase, in order to determine whether additional structural rigidity must be achieved or whether a smaller wall thickness can even be achieved to reduce component weight. To adjust the rigidity structurally, in particular, the moment of inertia of the relevant cross-section of the bearing shield can be adjusted using standardized structural elements such as ribs, beads, folds, etc. Standardized structural elements also have the advantage that they provide a known reinforcement effect, eliminating the need for individually designed structural reinforcement elements during construction. This reduces the construction effort and the associated costs.

[0059] In another preferred design, the cooling channel continuation is provided between the bearing shield and a housing, and the housing is axially provided on the heat conducting structure for axially enclosing the second heat source along the longitudinal axis.

[0060] An advantage of this embodiment is that the housing of the second heat source can be designed independently of the outer shape of the heat-conducting structure. This may be necessary in particular when the second heat source may have different shapes or output different amounts of heat depending on the structural shape. In order to eliminate this situation, the bearing shield may include a first part of the fluid channel continuation, which is uniformly constructed, while another part of the same fluid channel continuation can be separately constructed in a housing to be provided for enclosing the second heat source. Thus, a unique variant of the cooling channel continuation can be formed by the uniform design of the bearing shield and the unique design of the housing. This can further improve the cooling effect.

[0061] In another preferred design, the heat conducting structure has a flange surface or other types of connecting surfaces, which are configured for detachably arranging the housing on the heat conducting structure, in particular, the housing is arranged on the heat conducting structure via a threaded connection structure.

[0062] The advantage achieved by using such a connection surface or flange surface is that the housing can be easily positioned on the heat-conducting structure, thereby avoiding errors during the assembly of the two components and reducing the costs of errors.

[0063] In another preferred design, the cooling channel continuation is formed by the outer side of the housing and the outer side of the bearing shield.

[0064] In this embodiment, the cooling channel continuation extends only between the mutually facing surfaces of the bearing shield and the housing for surrounding the second heat source. Thus, the cooling channel continuation can be easily approached for maintenance purposes and can be maintained and / or cleaned with low effort when necessary.

[0065] In another preferred embodiment, the housing has a connection opening in order to connect an inner area of ​​the housing to the cooling channel continuation in a fluid-conducting manner.

[0066] Unlike the cooling channel continuation provided on the surface of the housing that surrounds the second heat source, the design with the connection port allows for directing cooling fluid from the cooling channel continuation into the interior of the housing. This allows the second heat source disposed within the housing to come into direct heat-conducting contact with the cooling fluid, thereby optimizing the cooling effect. In one possible design of this embodiment, the second heat source is surrounded by flexible or rigid tubing or other forms of conduit, through which the cooling fluid flows.

[0067] In another preferred embodiment, the second heat source has a flow-conducting region which is connected to the cooling channel in a flow-conducting manner.

[0068] By forming the flow-guiding area in or on the second heat source, the cooling fluid can be directed directly through the second heat source. In one possible design of this embodiment, the second heat source has integrated fluid channels to guide the cooling fluid within the second heat source to the areas generating the greater heat as needed. This provides the advantage of a more efficient and direct cooling effect.

[0069] In another preferred design, a holding component is provided on the outer side of the cooling jacket facing away from the heat conducting structure. The holding component is in particular a torque support.

[0070] The retaining element can be designed to position the cooling jacket in a specific position. If the cooling system is designed to cool the electric drive unit, the retaining element can also support the forces and moments generated by the drive unit, particularly for driving the vehicle. If the heat-conducting structure is a stator support surrounded by the cooling jacket, a mechanical interface for the retaining element may not be necessary in the structural design of the stator support, as the retaining element can be directly attached to the cooling jacket. The retaining element can, in particular, be a torque support that, when used with the electric drive unit, can have high torsional stiffness to allow the drive torque of the electric drive unit to be transmitted directly and vibration-free to the drive train of the electric vehicle.

[0071] In another preferred embodiment, the heat-conducting structure includes a first cross-sectional area having a first diameter and a second cross-sectional area having a second diameter along the longitudinal axis, wherein the first diameter is configured to surround the first heat source and the second diameter is configured to surround the second heat source. The two diameters may have different forms and / or sizes.

[0072] The advantage of forming two different cross-sectional areas within the heat-conducting structure is that only one component is required to enclose both the first and second heat sources, even though the first and second heat sources typically have different dimensions. The cross-sectional transition required for this purpose can be subsequently formed on the cylindrical heat-conducting structure by appropriate deformation forming, in particular by hydroforming. This allows different geometries for the heat-conducting structure to be economically produced starting from a heat-conducting structure with uniform characteristics.

[0073] In another preferred embodiment, the retaining component is arranged along the longitudinal axis in the region of the bearing shield.

[0074] Arranging the holding component in the region of the bearing shield has the advantage that the bearing forces generated can be transferred via the bearing shield along a direct force transmission path to the holding component. As a result, the deformability of the cooling system can be limited in a targeted manner.

[0075] In another preferred embodiment, the cooling jacket has at least one inlet region and at least one outlet region, wherein the inlet region is configured to introduce the cooling fluid into the cooling channel and the outlet region is configured to discharge the cooling fluid from the cooling channel.

[0076] The spatial separation of the inlet and outlet regions has the advantage that the temperature of the incoming cooling fluid is lower than that of the outgoing cooling fluid and the incoming cooling fluid is not heated by the outgoing cooling fluid, thereby increasing the achievable efficiency of the cooling system.

[0077] In another preferred embodiment, the cooling system has a heat exchanger, which is configured to control the temperature of the cooling fluid from a first temperature to a second temperature, wherein the first temperature substantially corresponds to the discharge temperature of the cooling fluid in the outlet region and the second temperature substantially corresponds to the inlet temperature of the cooling fluid in the inlet region.

[0078] By configuring the heat exchanger as a component of the cooling system, the heat exchanger can be operated in a power-regulated manner, in which the cooling power provided by the heat exchanger is regulated according to the outlet temperature of the cooling fluid in the outlet area. To this end, the heat exchanger has a regulation system that is connected to a temperature sensor. The temperature sensor can be configured to detect the outlet temperature and transmit it to the regulation system. If the outlet temperature exceeds a predetermined limit value, the regulation system can conclude that the cooling power provided by the heat exchanger is insufficient to discharge the heat flow from the first heat source and the second heat source. Based on this, the cooling power is regulated using PID control or a similar method. If, on the other hand, the outlet temperature falls below the same or another limit value, the efficiency of the system can be increased by adjusting the heat exchanger to a lower cooling power.

[0079] In another preferred design, the inlet region is arranged axially along the longitudinal axis so that its distance from the second heat source is smaller than its distance from the outlet region.

[0080] If the cooling fluid passes along the longitudinal axis through an area in which a first heat source and a second heat source are provided, the cooling fluid is first heated by one of the two heat sources and then by the corresponding other heat source. In the electric motor, the stator is preferably the first heat source and the power electronics are the second heat source, the heat transferred not necessarily having to have the same values. In particular, due to the structural form of the stator and the contact area with the stator support, a greater amount of heat can be output by the stator than by the power electronics. If the cooling fluid is thus overheated by the stator, this reduces the cooling effect of the cooling fluid in the area of ​​the power electronics. In order to eliminate this problem, the inlet area can be arranged in the area of ​​the second heat source, in particular in the area of ​​the power electronics, so that the cooling fluid first flows through the area of ​​the second heat source and only then reaches the first heat source and from there reaches the outlet area.

[0081] In another preferred embodiment, the cooling system has a cooling circuit comprising a cooling fluid for absorbing and dissipating the total heat input, a fluid storage container for storing the cooling fluid, and a pipe system configured to guide the cooling fluid into the cooling channel in an inlet region and to discharge the cooling fluid from the cooling channel in an outlet region.

[0082] The cooling circuit, in which the cooling fluid circulates between the fluid storage container and the cooling channel, has the advantage that the cooling fluid in the cooling system can be used throughout the entire service life of the cooling system. Therefore, the cooling circuit only needs to be filled with cooling fluid once, thereby eliminating the additional cost of refilling the cooling fluid. Preferably, the cooling system is designed to have a sealing element that ensures that there is only a negligible small leakage of cooling fluid, so that there is no need to refill the cooling fluid. As a result, the maintenance cost of the cooling system is low. In particular, when the cooling system is used in an electric vehicle, its components can be designed so that there is no need to consider special requirements for its accessibility.

[0083] In another preferred embodiment, the cooling system has a pump unit, which is configured to convey cooling fluid from a fluid storage container to the cooling channel and / or to convey cooling fluid from the cooling channel into a fluid storage container.

[0084] In accordance with the advantages of the heat exchanger as a component of the cooling system, the provision of a pump unit allows the volume flow and / or mass flow of the cooling fluid entering the cooling channel to be adjusted as needed. This can be particularly advantageous in conjunction with a control system, since the pump unit can also be regulated, at least partially, depending on the output temperature. This allows for efficient cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Further advantages and configurations of the present invention will be apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

[0086] Figures 1 to 15 An embodiment of a cooling system is shown respectively;

[0087] as well as

[0088] Figure 16 An electric vehicle with an electric drive unit and a cooling system is shown. DETAILED DESCRIPTION

[0089] Figure 1 A cooling system 1 is shown, which comprises a cooling jacket 2 which extends along a longitudinal axis 3 and surrounds a sleeve-shaped stator support 4 of an electric machine M.

[0090] The cooling jacket 2 has a substantially cylindrical basic shape and a wall that is undulating along its longitudinal axis. In the schematic embodiment shown, the undulations are configured such that they have an inclination (not indicated) along the longitudinal axis 3, thereby forming a thread-like space bounded on one side by the cooling jacket 2. Alternatively to the helical configuration of the space, other distributions are also possible, in which the space extends at least partially along or parallel to the longitudinal axis of the cooling jacket. The cooling jacket is also connected to the stator support 4 and mechanically secured thereto, preferably by shrink fit. This connection is achieved, in particular, via various contact areas that correspond to the undulations of the cooling jacket's wall. In these areas of smaller diameter, the cooling jacket 2 is plastically and elastically formed onto the outer side of the stator support 4, thereby forming a circumferential cooling channel 5. Additionally or alternatively, the connection can be materially bonded, in particular by brazing.

[0091] The cooling channel 5 has an inlet E through which a cooling fluid 6 enters the cooling channel and exits the cooling channel again through an outlet (not visible). It is within the scope of the invention that the inlet E can also be used as an outlet and vice versa.

[0092] The stator 7 is arranged on the inner side 4i of the stator support 4 and is connected to the stator support 4 in a heat-conducting manner. Thus, the stator support 4 forms a heat-conducting structure. The stator 7 generates heat during the operation of the motor M due to known effects, and the stator transfers the heat as a heat flow via the heat-conducting connection. is transferred to the stator support 4 in the form of.

[0093] The power electronics 8 is arranged axially offset from the stator 7 along the longitudinal axis 3. Like the stator 7, the power electronics 8 is also in thermal connection with the stator support 4. When the motor is running, the power electronics also generates heat, which is transferred to the stator 7 via the thermal connection as a heat flux. is transferred to the stator support 4 in the form of.

[0094] Thus, the stator 7 constitutes the first heat source, and the power electronics 8 constitutes the second heat source. By heat flow and The first heat flow and the second heat flow can have different proportional relationships with each other. The cooling system of the motor is designed to be used with the heat flow and The total heat flow is derived independently of the ratio , in that the cooling fluid 6 flows around the stator support 4 in the region along the longitudinal axis 3 , in which region the stator 7 and the power electronics 8 are arranged in order to absorb and dissipate heat.

[0095] The cooling channels 5 have a cooling channel geometry 9 that essentially corresponds to the geometry of the cooling sleeve 2 . In the region of smaller cross-section, that is, in the region of its wave troughs, the cooling sleeve 2 contacts the stator support 4 and has a joint region 10 at the contact point, in which the cooling sleeve is materially connected to the stator support 4 . This connection is designed as a materially bonded soldered connection, but within the scope of the present invention, it can also be achieved by a non-positive connection using a press-fit connection, or by a combination of material-locking and non-positive connection methods. This connection separates adjacent passages of the cooling channels 5 from one another in a sealed or fluid-tight manner, thereby preventing mixing of the cooling fluid 6 between the passages (so-called "crosstalk") and achieving optimal temperature distribution in the cooling system.

[0096] The stator 7 is essentially sleeve-shaped and surrounds a rotor 13 rotatably supported within its interior. The rotor 13 is supported on a bearing shield 11 disposed on the A side of the motor via a first roller bearing L1 and on a bearing shield 12 disposed on the B side of the motor via a second roller bearing L2. In addition to its supporting function, the first bearing shield 11 also serves to form part of a housing that encloses transmission components (not shown) mechanically connected to the rotor 13.

[0097] The second bearing shield 12 is arranged axially along the longitudinal axis 3 between the stator 7 and the power electronics 8 and is pressed into the stator support 4, thereby connecting the second bearing shield to the stator support in a mechanical and thermally conductive manner. A cover D closes the inner area of ​​the stator support 4 at the end.

[0098] Figure 2 A second embodiment of the cooling system 1 is shown, which has Figure 1 In addition to the components shown in FIG, the bearing shield 12 has a first axial through-hole 14 and a second axial through-hole 15 .

[0099] The first axial through-hole 14 is configured to electrically connect the stator 7 and the power electronics 8. In the case of a cooled electric machine, the through-hole 14 can be used to apply the AC voltage converted by the power electronics 8 to the electrical conductors of the stator 7. The axial through-hole 14 can be designed to be sealed in order to separate the power electronics 7 from the lubricant used in the process of supporting the stator 7.

[0100] The second axial through-hole 15 is designed to connect the power electronics 8 to the rotor 13 via a converter (not shown here), in order to implement speed control for the electric machine in particular. The second axial through-hole 15 can also be designed to be sealed.

[0101] Figure 3 A third embodiment of the cooling system 1 is shown, in which the stator carrier 4 has different cross-sections in some areas. The stator 7 and the power electronics 8 have different dimensions in the radial direction relative to the longitudinal axis 3. Accordingly, the stator carrier 4 has a first cross-sectional area 35 in which the stator 7 is arranged and a second cross-sectional area 36 in which the power electronics 8 are arranged.

[0102] Between the cross-sectional area 35 and the cross-sectional area 36, ​​the stator support 4 has a cross-sectional transition K, in which the stator support 4 is conical. This conical transition area serves on the inner side 4i of the stator support 4 to support the bearing shield 12 axially along the longitudinal axis 3 relative to the longitudinal axis 3. This is advantageous because the bearing shield 12 can transmit axial forces to the stator support 4 in a form-fitting manner, thereby allowing, in particular, the press-fit connection between the bearing shield 12 and the stator support 4 to be designed to be compact. Furthermore, the installation of the bearing shield 12 in the stator support 4 is simplified, as it can be positioned against a mechanical stop in the form of the conical inner side 4i of the stator support 4.

[0103] The cooling jacket 2 is formed or arranged only in the first cross-sectional area 35 along the longitudinal axis 3. In accordance with the advantages obtained by installing the bearing shield 12 in the cross-sectional transition K, the expansion in the cross-sectional profile of the stator support 4 can also be used as a support surface for installing the cooling jacket 2. The transfer of heat occurs via the stator support 4 , which serves as a heat-conducting structure.

[0104] Furthermore, the stator support 4 has a flange surface 28 , on which the stator support 4 is sealed or fluid-tightly closed by a cover D. This reduces the assembly effort.

[0105] Figure 4 A fourth embodiment of the cooling system 1 is shown. Figure 4 The cooling jacket 2 extends both in the first cross-sectional area 35 and in the second cross-sectional area 36. Figure 3 Compared with the third embodiment, the cooling effect is improved, especially in the second cross-sectional area 36 where the power electronic device 8 is arranged.

[0106] Furthermore, a retaining element 34 is provided on the outer side 37 of the cooling jacket, at the level of the bearing shield 12. This retaining element is designed as a torque support. This directly supports the forces acting between the rotor 13 and the bearing shield 12, thereby preventing force deflection and reducing overall deformation of the cooling system. Retaining element 34 has a through-hole 34d, which allows the electric machine to be removably fastened to the vehicle, in particular via a screw connection.

[0107] Figure 5 A fifth exemplary embodiment of a cooling system 1 is shown, which comprises a bearing shield 12 which is designed as a bent, deep-drawn sheet metal part. Figure 2 and Figure 3 The bearing shield 13 shown comprises a first axial through-hole 14 and a second axial through-hole 15. Configuring the bearing shield 12 as a deformed sheet metal part achieves a lower component weight while having a higher achievable dimensional stability.

[0108] Figure 6 A sixth exemplary embodiment of the cooling system 1 is shown, in which the stator support 4 has radial through-holes 18. In the exemplary embodiment shown, the radial through-holes 18 are formed only through the wall of the stator support 3; however, it is also within the scope of the invention to provide the radial through-holes in the edge region of the end face of the stator support 4 so that they are not closed circumferentially until they interact with a further housing element (not shown).

[0109] Furthermore, the bearing shield 12 is designed as an assembly having a first bearing shield part 23 and a second bearing shield part 24. These first bearing shield part 23 and second bearing shield part 24 are sealingly joined in the region of the bearing seat of the bearing L2 and are partially spaced apart from one another, so that a cooling channel continuation 19 is formed between the two bearing shield parts, which is connected in a fluid-conducting manner to the radial through-opening 18.

[0110] The first bearing shield part 23 and the second bearing shield part 24 can be designed as deep-drawn sheet metal parts and / or as solid cast parts, which can be joined to one another detachably, integrally or by deformation forming.

[0111] Figure 7 A seventh embodiment of the cooling system 1 is shown, in which the bearing shield 12 has a first bearing shield part 23 and a second bearing shield part 24, which are similar to the bearing shield parts according to Figure 6 The embodiment is designed to cooperate to form a cooling channel continuation. Unlike the sixth embodiment, the second bearing shield component 24 has a higher mechanical rigidity than the first bearing shield component 23. This is preferably achieved by configuring the second bearing shield component 24 as a cast part with a greater wall thickness in certain areas than the first bearing shield component 23, which is configured as a sheet metal part. As a result, the second bearing shield component 24 can be dimensioned so that it absorbs a greater portion of the forces supporting the rotor 13 than the first bearing shield component 23.

[0112] In addition, according to Figure 7 As shown, the cover D has an opening in the form of a neck opening 25 , through which the power electronics 8 can be connected via electrical conductors 26 to a not shown energy supply system, in particular a battery.

[0113] Figure 8 An eighth exemplary embodiment of a cooling system 1 is shown, in which the stator support 4 has radial through-openings 18 to which cooling channel continuations 19 are connected in a fluid-conducting manner. Figures 1 to 7 In contrast, the stator support 4 extends along the longitudinal axis 3 essentially only in the region in which the stator 7 is also arranged. A housing 27 , which is designed separately from the stator support 4 , is arranged at the front end of the stator support 4 and serves to enclose the power electronics 8 .

[0114] The cooling channel continuation 19 is formed by the outer side 29 of the housing 27 and the outer side 30 of the bearing shield. The power electronics 8 are cooled by the direct, heat-conducting connection between the power electronics and the inner side of the housing 27. The housing thus forms part of the heat-conducting structure. To maximize the cooling effect, the inner side of the housing 27 is partially designed to correspond to the geometry of the power electronics 8. In this area, the inner side of the housing 27 is in direct, heat-conducting contact with the power electronics 8. This identical geometry increases the contact area between the housing 27 and the power electronics 8.

[0115] Figure 9A ninth embodiment of the cooling system 1 is shown, in which a housing 27 surrounds the power electronics 8, so that an intermediate space 32 is formed between the wall of the housing 27 and the power electronics 8. In order to achieve heat transfer via the intermediate space 32 without having to establish direct contact between the power electronics 8 and the housing 27, the housing 27 has a connection opening 31, via which the power electronics 8 or the interior of the housing 27 is connected in a fluid-conducting manner to the cooling channel continuation 19.

[0116] Figure 10 A tenth embodiment of a cooling system 1 is shown, which has an inlet E and an outlet A for a cooling medium or cooling fluid, and in this embodiment the inlet E is arranged along the longitudinal axis 3 directly in the region of the power electronics 8. This makes it possible to ensure that the cooling fluid 6 is not affected by the heat flow of the stator 7 when it flows to the power electronics 8 to be cooled. Preheat.

[0117] Figure 11 An eleventh embodiment of the cooling system 1 is shown, in which the power electronics 8 has a flow-conducting region 33 which is connected in a flow-conducting manner to the inlet E arranged at the end and to the cooling channel 5. Figure 10 In the design of the tenth embodiment, since the cooling fluid 6 is not preheated by other heat sources, an improved cooling effect can be achieved on the power electronic device 8 by directly flowing the (fresh) cooling fluid 6 to the power electronic device 8.

[0118] Figure 12 A twelfth exemplary embodiment of a cooling system is shown, in which the bearing shield 12 has a cooling channel continuation 19 which is integrally formed in the bearing shield or integrally with the bearing shield 12. The bearing shield 12 can be produced in one piece using a preformed production method, thereby reducing the assembly effort and the resulting costs. Furthermore, complex channel geometries can be produced in this manner.

[0119] The bearing shield 12 also has a mechanical interface S1, through which the housing 27 surrounding the power electronics 8 can be fastened to the bearing shield 12 via a threaded connection. Furthermore, the power electronics 8 can be mounted on a support plate 17, which can also be bolted to the bearing shield 12 via a second mechanical interface S2. Thermal paste 16 is used to establish a thermally conductive contact between the power electronics 8 or support plate 17 and the bearing shield 12. This allows for a functional separation between the mechanical and thermal connections of the heat source and any heat-conducting medium.

[0120] Figure 13A thirteenth embodiment of the cooling system 1 is shown, in which the cooling channel continuation 19 comprises a first sub-extension 20 and a second sub-extension 21. The connection of the power electronic device 8 is similar to that according to Figure 11 In the embodiment, the connection is made by a threaded connection structure and thermal paste 16. Figure 13 In the embodiment of the present invention, the first sub-extension portion 20 and the second extension portion 21 are connected to each other in a fluid-conducting manner. Figure 14 The longitudinal axis 3 is designed asymmetrically.

[0121] Figure 15 An exemplary embodiment of a cooling system 1 is shown, in which radial through-openings 18 of the stator support 4 form a flow-conducting connection between the cooling duct 5 and the power electronics 8 .

[0122] Figure 16 An electric vehicle F is shown, which has an electric machine M (particularly for driving purposes) with a cooling system 1. The cooling system 1 includes a cooling jacket 2 oriented along a longitudinal axis 3. The electric machine M includes a stator 7 and power electronics 8 arranged along the longitudinal axis 3. A stator support 4 is arranged between the components of the electric machine M and the cooling jacket 2 and cooperates with the latter to form cooling channels 5. A cooling medium (cooling fluid) 6 is conveyed from a tank T via an electric pump P to a heat exchanger WT, where the cooling fluid 6 is brought to a suitable setpoint temperature in order to dissipate the heat generated by the stator 7 and the power electronics 8.

Claims

1. A cooling system (1), comprising a cooling sleeve (2) with a longitudinal axis (3) and a heat-conducting structure (4), wherein the cooling sleeve (2) surrounds the heat-conducting structure (4) in a region along the longitudinal axis (3), thereby forming a cooling channel (5) between the cooling sleeve (2) and the heat-conducting structure (4) for guiding a cooling fluid (6) in the cooling channel (5), the heat-conducting structure (4) being designed and defined for accommodating a first heat source (7) in the region, It is characterized in that The heat-conducting structure (4) is configured to contact a second heat source (8) in a heat-conducting manner, wherein the second heat source (8) is axially arranged opposite to the first heat source (7) along the longitudinal axis (3), and the heat-conducting structure (4) includes a bearing shield (12), wherein the bearing shield (12) includes a flow-guiding cooling channel extension (19), and the cooling channel extension (19) includes a first partial extension (20) and a second partial extension (21) so as to guide a first branch flow or a second branch flow of the cooling fluid, respectively.

2. The cooling system (1) according to claim 1, characterized in that The thermally conductive structure (4) is at least partially configured and defined to accommodate a second heat source (8).

3. The cooling system (1) according to claim 1, characterized in that The heat-conducting structure (4) comprises a stator support for driving a motor (M).

4. The cooling system (1) according to claim 1, characterized in that The cooling jacket (2) is at least partially embodied in a corrugated manner, and the cooling channels (5) at least partially have a cooling channel geometry (9) corresponding to the corrugated geometry of the cooling jacket (2).

5. The cooling system (1) according to claim 1, characterized in that The cooling channel (5) is at least partially designed in a spiral or thread-like manner along the longitudinal axis (3) and / or around the longitudinal axis (3).

6. The cooling system (1) according to claim 1, characterized in that The cooling sleeve (2) is connected to the heat-conducting structure (4) in a material-locking manner.

7. The cooling system (1) according to claim 1, characterized in that The bearing shield (12) is arranged between the first heat source (7) and the second heat source (8) on the longitudinal axis (3).

8. The cooling system (1) according to claim 7, characterized in that The bearing shield has at least one axial through hole (14, 15), which is arranged and configured to contact the first heat source and / or the second heat source.

9. The cooling system (1) according to claim 7 or 8, characterized in that The bearing shield (12) is at least partially constructed by molding.

10. The cooling system (1) according to claim 7, characterized in that The bearing shield (12) is designed for thermally conductive contact with the second heat source (8) by virtue of the bearing shield (12) being designed to correspond at least partially to the geometry of the second heat source (8).

11. The cooling system (1) according to claim 7, characterized in that The second heat source (8) is connected to the bearing shield via a heat-conducting intermediate layer (16).

12. The cooling system (1) according to claim 7, characterized in that The second heat source is arranged on a support plate (17), and the support plate (17) is mechanically connected to the bearing shield (12).

13. The cooling system (1) according to claim 1, characterized in that The heat-conducting structure (4) has a radial through-hole (18), and the cooling channel (5) is connected to the radial through-hole (18) in a fluid-conducting manner.

14. The cooling system (1) according to claim 7, characterized in that The cooling channel continuation (19) is directly or indirectly connected to the cooling channel (5) in a fluid-conducting manner.

15. The cooling system (1) according to claim 14, characterized in that The cooling channel continuation (19) is integrally formed inside the bearing shield.

16. The cooling system (1) according to claim 14, characterized in that The bearing shield (12) is designed as an assembly, which includes a first bearing shield component (23) and a second bearing shield component (24), wherein the first bearing shield component (23) and the second bearing shield component (24) are arranged to cooperate with each other to form the cooling channel extension (19).

17. The cooling system (1) according to claim 16, characterized in that The first bearing shield component (23) or the second bearing shield component (24) has a higher mechanical stiffness than the corresponding other bearing shield component.

18. The cooling system (1) according to claim 17, characterized in that The higher mechanical rigidity is achieved by an increased material rigidity of the respective bearing shield components (23, 24) and / or by an increased geometrical moment of inertia.

19. The cooling system (1) according to claim 14, characterized in that The cooling channel extension (19) is arranged between the bearing shield (12) and a housing (27), and the housing is axially arranged on the heat-conducting structure (4) for axially enclosing the second heat source (8) along the longitudinal axis (3).

20. The cooling system (1) according to claim 19, characterized in that The heat conducting structure (4) has a flange surface, and the flange surface is configured to be used for the housing (27) to be detachably arranged on the heat conducting structure (4).

21. The cooling system (1) according to claim 19 or 20, characterized in that The cooling channel continuation (19) is formed by the outer side (29) of the housing and the outer side (30) of the bearing shield.

22. The cooling system (1) according to claim 21, characterized in that The housing (27) has a connecting opening (31) for connecting an inner region of the housing (27) to the cooling channel continuation (19) in a fluid-conducting manner.

23. The cooling system (1) according to claim 1, characterized in that The second heat source (8) has a flow-conducting region (33), which is connected to the cooling channel (5) in a flow-conducting manner.

24. The cooling system (1) according to claim 7, characterized in that A retaining component (34) is provided on an outer side (37) of the cooling jacket facing away from the heat-conducting structure (4).

25. The cooling system (1) according to claim 1, characterized in that The heat conducting structure (4) comprises, along the longitudinal axis (3), a first cross-sectional area (35) having a first diameter and a second cross-sectional area (36) having a second diameter, wherein the first diameter is configured to surround the first heat source (7) and the second diameter is configured to surround the second heat source (8).

26. The cooling system (1) according to claim 24, characterized in that The retaining element is arranged along the longitudinal axis (3) in the region of the bearing shield (12).

27. The cooling system (1) according to claim 1, characterized in that The cooling jacket has at least one inlet region (E) and at least one outlet region (A), wherein the inlet region (E) is configured to introduce the cooling fluid (6) into the cooling channel (5) and the outlet region (A) is configured to discharge the cooling fluid (6) from the cooling channel (5).

28. The cooling system (1) according to claim 27, characterized in that The cooling system comprises a heat exchanger (WT) which is designed to adjust the temperature of the cooling fluid (6) from a first temperature substantially corresponding to the outlet temperature of the cooling fluid in an outlet region (A) to a second temperature substantially corresponding to the inlet temperature in an inlet region (E).

29. The cooling system (1) according to claim 27, characterized in that The inlet region is arranged axially along the longitudinal axis (3) at a distance from the second heat source (8) that is smaller than the distance from the outlet region (A).

30. The cooling system (1) according to claim 27, characterized in that The cooling system has a cooling circuit (K), which includes a cooling fluid (6) for absorbing and dissipating the total heat input, a fluid storage container (T) for storing the cooling fluid (6), and a pipe system, which is configured to guide the cooling fluid into the cooling channel in an inlet area (E) and to discharge the cooling fluid from the cooling channel (5) in an outlet area (A).

31. The cooling system (1) according to claim 30, characterized in that The cooling system comprises a pump unit (P) which is designed to convey the cooling fluid (6) from the fluid storage container (T) to the cooling channel and / or to convey the cooling fluid from the cooling channel into the fluid storage container.

32. Electric drive unit having an electric motor (M), the electric motor (M) comprising a rotor (13), a stator, a stator support and a cooling system (1) according to any one of the preceding claims, wherein The stator support is configured as the heat conducting structure.

33. An electric vehicle having an electric drive unit according to claim 32.

34. A method for cooling an electric drive unit, comprising the steps of: a) providing a cooling system (1) according to any one of claims 1 to 31; b) adjusting the temperature of the cooling fluid (6) to the inlet temperature; c) delivering cooling fluid (6) into the cooling channel (5); d) transferring heat from the first heat source (7) and the second heat source (8) to the heat-conducting structure (4); e) transferring heat from the heat-conducting structure (4) to the cooling fluid (6); f) conveying the cooling fluid (6) out of the cooling channel (5).

Images