Electric machine for a motor vehicle

Abstract

The invention relates to an electric machine (1) for a motor vehicle, comprising a temperature control device for controlling the temperature, in particular cooling, of at least one part of the electric machine (1), the electric machine (1) having a laminated core (2) with a plurality of laminations arranged one behind the other in the axial direction, which laminations form grooves and teeth alternating in the circumferential direction on the inner sides thereof, the temperature control device has at least one temperature control channel which extends in the teeth in the axial direction and through which a temperature control medium can be conveyed, and wherein at least one connection lamination (10) is arranged between an outer lamination (8) arranged on the axial feed side (4) of the lamination stack (2) and a channel lamination (15) facing the middle of the lamination stack (2), a connection opening (11) of the connection stack (10) connects a channel opening (14) of the channel stack (15) to a feed opening (7) of the outer stack (8), the channel opening (14) being arranged further inward in the radial direction than the feed opening (7), the connection opening (11) forming a defined channel overlap (17) with the channel opening (14) and a defined outlet overlap (16) with the outlet opening (9) of the outer stack (8).

Description

Technical Field

[0001] The present invention relates to an electric motor for a motor vehicle, comprising a temperature control device for temperature control, in particular cooling, of at least a portion of the electric motor. The electric motor comprises a laminated core having a plurality of laminated cores arranged one behind the other in the axial direction, the laminated cores forming grooves and teeth alternating in the circumferential direction on their inner sides. The temperature control device comprises at least one temperature control channel extending in the axial direction in the tooth, through which a temperature control medium can be conveyed. Background Art

[0002] Electric motors for motor vehicles, which serve, for example, as drive units for the motors, and temperature control devices for controlling the temperature of the motors, in particular for cooling the stators of the motors, are generally known from the prior art. Such temperature control devices can be implemented using a variety of temperature control configurations, arrangements, or principles. In this context, the location or path of the at least one temperature control channel can be determined in various ways. For example, known temperature control devices have temperature control channels arranged in the region of the stator housing, for example, in the form of "water jacket cooling." Alternatively, at least one temperature control channel can be positioned within a stator slot, allowing the temperature control medium to flow directly around the conductors accommodated therein. Another possibility is to arrange the temperature control channel within the teeth, more specifically, the stator teeth.

[0003] Regardless, it must be ensured that the temperature-control medium can be properly guided into the temperature-control channels and that sufficient heat conduction is achieved there between the individual stator laminations and the temperature-control medium. In particular, it must be ensured that the temperature-control channels are sufficiently filled to exclude air, so that no air locks that would reduce thermal conductivity are formed. Furthermore, it must be ensured that the pressure of the temperature-control medium in the temperature-control channels is sufficient, especially in the starting and ending areas, i.e., at the axial end faces of the stator, to allow the temperature-control medium to flow out through the openings provided there, thereby providing sufficient cooling for the winding heads.

[0004] This usually requires a complex design of the motor or temperature control device, which takes up a lot of installation space and is difficult to assemble, and requires a large number of different components. Summary of the Invention

[0005] The object of the present invention is to provide an electric machine for a motor vehicle which is improved compared to the above and which is less complex, in particular with regard to its temperature control.

[0006] This object is achieved by an electric machine having the features of claim 1. Preferred embodiments are the subject matter of the dependent claims.

[0007] As described above, the present invention relates to an electric motor for a motor vehicle, comprising a temperature control device for controlling the temperature of, and in particular, cooling, at least one portion of the electric motor. The electric motor comprises a laminated core, which is formed from a plurality of laminated cores arranged one behind the other or in a series in the axial direction. These laminated cores may also be referred to as a "plate core" or a plate core. These laminated cores have grooves and teeth formed on their inner sides that alternate in the circumferential direction. At least one temperature control channel of the temperature control device is formed in one of the teeth. In particular, each tooth contains a temperature control channel. A temperature control medium, such as water or oil, can be conveyed through the at least one temperature control channel, thereby enabling heat exchange between the temperature control medium and the laminated core. The laminated core may, in particular, be a component of a stator base. Typically, the temperature control medium is supplied to the laminated core from the axial end faces, in particular from the outermost laminated cores of the laminated core, also referred to as the "outer laminated cores."

[0008] The present invention is based on the knowledge that at least one connecting lamination is arranged between an outer lamination arranged on the axial supply side of the lamination stack and a channel lamination facing the center of the lamination stack, wherein a connecting opening of the connecting lamination connects a channel opening of the channel lamination with a supply opening of the outer lamination, wherein the channel opening is arranged radially further inward than the supply opening, wherein the connecting opening forms a defined channel overlap with the channel opening and a defined outlet overlap with the outlet opening of the outer lamination. Within the framework of the present application, an "overlap" is understood to be the overlap of the cross sections of the respective openings, viewed in the axial direction. The effective flow cross section in this region is determined based on the respective dimensions of the overlap. In other words, the larger the overlap, the larger the flow cross section and the lower the flow resistance.

[0009] Therefore, according to the present invention, a specific sequence of different laminations—namely, outer laminations, connecting laminations, and channel laminations—is used to guide the temperature control medium into the temperature control channels and through the outlet openings. On the supply side, the outer laminations are used to supply the temperature control medium into the lamination stack through their supply openings. These supply openings are connected to the connection openings of the connecting laminations, i.e., they overlap in the axial direction. This means that the temperature control medium enters the connection openings through the supply openings and is guided radially inward by the connecting laminations. There, the connection openings overlap axially with the channel openings of the channel laminations and, in the opposite direction, with the outlet openings of the outer laminations.

[0010] Thus, the temperature control medium flowing through the connecting laminations can enter the temperature control channel from the connecting openings in the axial direction, i.e., through the channel openings formed in the channel laminations. In the opposite direction, the temperature control medium flows from the connecting laminations through the connecting openings into the outlet openings of the outer laminations, and from there out of the laminated stack in the axial direction, in particular, counter to the supply direction. Here, the outlet openings can be in fluid communication with the winding heads of the electric machine and thus serve to cool the winding heads.

[0011] By defining the overlaps, namely the channel overlap and the outlet overlap, the pressure ratio or distribution of the temperature control medium is determined. This ensures that the temperature control channels are fully filled and sufficient temperature control medium can flow through the outlet opening to cool the winding head without requiring additional complex equipment or components. Thus, by arranging the temperature control channels in the stator teeth, the temperature control medium is directed close to the heat-generating areas, namely the conductors housed in the grooves. This eliminates the need for temperature control channels on the outer circumference of the laminations, significantly saving material and labor.

[0012] The described electric motor can be further developed so that the laminated core consists of exactly three types of laminates. As mentioned at the outset, guiding the temperature control channels within the laminated core and ensuring that the various areas receive sufficient filling, exhaust, and volume flow presents a challenge that is typically addressed through complex structural designs. According to the described design, the laminated core can be formed from exactly three types of laminates, which are arranged in a specific manner in the axial direction to meet the requirements for the distribution of the temperature control medium, in particular through the overlap described above. These three types of laminates can be understood in particular as outer laminates, at least one connecting laminate, and a channel laminate. In this case, all laminates of the same type are identical and can therefore be designed as identical components. This reduces the complexity of the assembly, manufacture, and design of the electric motor.

[0013] Furthermore, it can be provided for the electric machine that the laminated core is formed in a defined sequence in the axial direction, wherein at least one outer core is arranged on the supply side, followed by at least one connecting core, followed by a plurality of channel cores, wherein on the discharge side, at least one outer core follows the plurality of channel cores, and the laminated core ends with the at least one outer core. As described above, the laminated core of the electric machine advantageously consists of only three different laminate types. It is provided that an outer core is provided on the supply side, i.e., on the axial side of the laminated core to which the temperature control medium is supplied.

[0014] For example, depending on the axial dimensions, i.e., thickness, of the laminate, more than one outer laminate can be provided, wherein these outer laminates are identical to one another, as described. In the axial direction, one or more outer laminates are followed by one or more connecting laminates. Continuing axially toward the discharge side, opposite the supply side, at least one connecting laminate is followed by a plurality of channel laminates, which ultimately form temperature control channels through the laminate stack with their sequentially arranged channel openings. On the discharge side, the laminate stack concludes with at least one outer laminate, whose construction is identical to that of the outer laminate on the supply side. Thus, in the simplest case, the laminate stack is arranged in a defined sequence of one outer laminate, one connecting laminate, a plurality of channel laminates, and a further outer laminate.

[0015] As described, the temperature control medium is advantageously guided through the temperature control channel, and the defined overlap ensures a defined supply of temperature control medium to the winding heads, a defined filling of the temperature control channel, and the removal of air therefrom. Furthermore, the described motor concept can be readily adapted to stators of varying lengths or axial extensions of the laminated core, since the distribution of the temperature control medium is not determined by the size of the temperature control channel, for example, its diameter through the laminated core, but rather by the overlap between the individual components (i.e., the outlet opening, the connection opening, and the channel opening).

[0016] As already described, the outer laminations have outlet openings through which the temperature control medium can flow into the external area, in particular to the winding heads. Furthermore, the channel laminations have channel openings that ultimately define a temperature control channel within the laminated core. According to one embodiment of the electric machine, it can be provided that at least one outlet opening is smaller than at least one channel opening. As a result, the volume flow from the connection opening through the outlet opening is smaller than the volume flow from the connection opening into the temperature control channel, so that the amount flowing out through the outlet opening toward the winding heads is significantly smaller than the amount directed through the temperature control channel. This ensures that the temperature control channel is fully filled and the air therein is exhausted, thereby achieving good heat transfer between the laminated core and the temperature control medium. In the radial direction, the outlet opening can overlap with the channel opening.

[0017] The motor can also be further modified so that the outlet openings of the outer laminations facing away from the supply side form an output overlap with the axially adjacent channel laminations, where the output overlap is larger than the outlet overlap. As described, the outlet overlap on the supply side is formed by the overlap of the connection openings with the outlet openings of the outer laminations arranged on the supply side. This outlet overlap ensures that excessive temperature control medium from the supply side does not escape through the outlet openings, ensuring that the temperature control channels remain adequately filled. In contrast, the output overlap formed by the channel openings of the channel laminations and the outlet openings of the outer laminations arranged on the discharge side is larger because there is no overlap with the connection openings. Consequently, the temperature control medium can more easily exit the outlet opening on the discharge side, while still ensuring that the temperature control channels remain adequately filled and vented.

[0018] The shape of the individual openings in the laminations can be chosen essentially arbitrarily. For example, the outlet opening can be circular or annular. The supply opening can be rectangular or square. The passage opening can be elongated, in particular rectangular, oval, or slot-shaped, in order to occupy as much of the passage surface as possible in the stator teeth.

[0019] The connecting laminations can have a connecting opening with a radially oriented tip. For example, the connecting opening can be essentially pentagonal, wherein the connecting opening can be rectangular in the outer region, tapering radially to the tip. The pointed or triangular shape forms the outlet overlap and the channel overlap, since the temperature control medium is guided by the connecting laminations, as described, and discharged at the outer laminations, i.e., through the outlet openings, and at the channel laminations, i.e., through the channel openings. By designing the connecting openings in the overlap region as pointed, tolerance variations can be kept very low. Positional deviations of the tip do not significantly alter the overlap; positioning the tip to form the overlap only changes its position, not the size of the overlap. Consequently, the assembly of the individual laminations, and in particular their positioning, has little influence on the achieved overlap and, therefore, the volume flow.

[0020] As described, the temperature control medium is supplied from the supply side to the laminated core through supply openings in the first outer lamination. Therefore, a sealed supply cavity can be axially connected to the supply openings, from which the temperature control medium is introduced into the supply openings. The supply cavity, which can also be referred to as a "plenum," extends annularly in the circumferential direction through multiple supply openings and ensures uniform supply to the laminated core. The sealed supply cavity ensures that the temperature control medium is introduced only into the supply openings and passes through the supply openings, i.e., via the fluid path described above in the connection of the laminations, to the outlet openings to reach the winding head. This achieves a defined supply of the temperature control medium to the temperature control device.

[0021] In addition to an electric motor, the present invention also relates to an electric axle drive comprising the electric motor. Furthermore, the present invention relates to a drive train comprising the electric motor and / or the electric axle drive. Furthermore, the present invention relates to a motor vehicle having the electric motor and / or the electric axle drive and / or the drive train.

[0022] All advantages, details and features described with respect to the electric machine are fully transferable to the electric axle drive, the drive train and the motor vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be explained below by way of examples with reference to the accompanying drawings. These drawings are schematic diagrams, in which:

[0024] Figure 1 A portion of the motor is shown in longitudinal section;

[0025] Figure 2 Shown Figure 1 The outer laminations of the motor;

[0026] Figure 3 Shown Figure 1 The connection laminations of the motor;

[0027] Figure 4 Shown Figure 1 The channel laminations of the motor;

[0028] Figure 5 The cross-sectional view shows Figure 1 Details of a part of the motor;

[0029] Figure 6 The cross-sectional view shows Figure 1 Details of a part of the motor;

[0030] Figure 7 Shown Figure 1 A perspective view of a portion of a motor;

[0031] Figure 8 Shown Figure 1 A perspective cross-sectional view of a portion of a motor;

[0032] Figure 9 Shown Figure 1 a perspective cross-sectional view of a portion of the motor in; and

[0033] Figure 10 Shown Figure 1 Detail of a part of the motor. DETAILED DESCRIPTION

[0034] Figure 1 A portion of an electric motor 1 is shown in a longitudinal section, particularly along the axis of rotation of its rotor (not shown in detail). This longitudinal section is, for example, arranged along the longitudinal axis of the laminated core 2 of the stator 3 of the electric motor 1. The electric motor 1 essentially has a supply side 4 and a discharge side 5, wherein a temperature control medium is conveyed from the supply side 4 to the discharge side 5 by means of a temperature control device. The temperature control device can, for example, comprise a suitable conveying device, such as a pump or the like, which is not shown for the sake of clarity. A sealed supply chamber 6 is arranged axially adjacent to the supply side 4, in which the temperature control medium can be collected and thus introduced into the laminated core 2.

[0035] The supply chamber 6 is fluidically connected to a supply opening 7 formed in an outer core 8. The outer core 8 forms a first core of the core 2, viewed in the axial direction. Figure 2 The outer laminations 8 are shown separately. It can be seen that, in addition to the supply openings 7, the outer laminations 8 also have outlet openings 9. Each supply opening 7 has a defined radial position, and each outlet opening 9 also has a defined radial position that is radially further inward. The supply openings 7 are, for example, rectangular and larger than the outlet openings 9, which are, for example, circular.

[0036] Adjacent to the outer laminations 8 in the axial direction is a connection lamination 10 having a connection opening 11. For example, Figure 3 The connecting lamination 10 is shown separately in FIG. In this embodiment, the connecting opening 11 has a basic pentagonal shape and a radially pointing tip 12. The connecting opening 11 is in fluid communication with the aforementioned supply opening 7 and outlet opening 9. In other words, the temperature control medium flows through the supply opening 7 into the connecting opening 11 and is thereby directed radially inward. A portion of the temperature control medium flows through the outlet opening 9 to the winding heads 13 of the motor 1. The majority of the volume flow of the temperature control medium flows out of the connecting opening 11 into the channel opening 14 of the channel lamination 15 axially adjacent to the connecting lamination 10.

[0037] Figure 4 The channel lamination 15 is shown separately as an example. It can be seen that the channel lamination 15 also has channel openings 14 distributed along the circumference, and these channel openings are also arranged at specific radial positions. The channel openings 14 can be elongated, for example, rectangular, oval, or slotted. For example, the supply opening 7 can be arranged at a first radial position, the outlet opening 9 at a second radial position, the connection opening 11 at a third radial position, and the channel opening 14 at a fourth radial position.

[0038] The laminated core 2 shown in this exemplary embodiment is formed from a defined sequence of laminates, namely, precisely three laminate types. In other words, the electric machine 1 has precisely three different laminate types: outer laminates 8, connecting laminates 10, and channel laminates 15. These laminates are arranged one after the other in a defined sequence in the axial direction in order to selectively adjust the flow of the temperature control medium and thereby achieve the desired volume flow or pressure.

[0039] As can be seen, the lamination stack 2 begins in the axial direction with an outer lamination 8. Instead of using a single outer lamination 8, a plurality of outer laminations 8 can also be used, for example when the thickness of a single outer lamination 8 is insufficient. All outer laminations 8 of the lamination stack 2 are designed as identical components and therefore have the same structure. This also applies to all laminations of the same lamination type.

[0040] As described, adjacent to the outer laminations 8 in the axial direction is the connecting lamination 10. Similarly, before the first channel lamination 15 adjoins the connecting lamination 10, one connecting lamination 10 or multiple connecting laminations 10 can also be arranged one after another in the axial direction. This is followed by multiple channel laminations 15, which ultimately determine the axial size of the lamination stack 2, wherein the sum of the channel openings 14 arranged one after another in the axial direction forms a temperature control channel through the lamination stack 2. The lamination stack 2 ends again with the outer lamination 8 on the discharge side 5. Here, more than one outer lamination 8 can also be used to end the lamination stack 2. On the discharge side 5, the supply openings 7 of at least one outer lamination 8 are designed as "blind holes" or "dead holes" because they are not connected to the temperature control channel. Obviously, the arrangement of the laminations therefore follows the following order of lamination types: outer lamination 8, connecting lamination 10, channel lamination 15, outer lamination 8.

[0041] Since the individual openings are arranged in a defined manner, a defined overlap results between the individual openings, in particular between the connecting opening 11 and the outlet opening 9 and between the connecting opening 11 and the passage opening 14 . Figure 5 and Figure 6 These overlaps, namely the outlet overlap 16 and the channel overlap 17 are shown. Figure 5 A view in the axial direction is shown, wherein the openings are superimposed, so that a channel overlap 17 is shown, which is larger than Figure 6 The outlet overlap 16 shown is significantly larger. This means that the distribution of the temperature control medium at this point, namely at the tip 12, is determined by the corresponding flow cross section. This ensures that significantly more temperature control medium flows into the temperature control channel, namely into the channel opening 14, than is released through the outlet opening 9 in the direction of the winding end 13.

[0042] Figures 7 to 9 Shown is a perspective view, in particular Figure 8 and Figure 9 A perspective cross-sectional view in the area of ​​the temperature control channel is shown. In particular, Figure 9 It is shown that the temperature control medium flowing through the supply opening 7 into the area bounded by the connecting opening 11 is guided radially inward, i.e., into the tip 12 of the connecting opening 11. From there, the temperature control medium can flow axially into the successively arranged channel openings 14 of the channel stack 15 or, in the opposite flow path, via the significantly smaller outlet overlap 16 through the outlet opening 9 to the winding head 13. The design of the tip 12 in the overlap region ensures a high tolerance for positioning errors.

[0043] Figure 10Another part of the longitudinal section of the electric machine 1 in the area of ​​the discharge side 5 is shown. As described, the outer lamination 8 is also arranged in this area. The supply opening 7 of the outer lamination 8 is designed as a "blind hole" here, because it is covered by the continuous area of ​​the channel lamination 15 adjacent in the axial direction. The outlet opening 9 of the outer lamination 8 overlaps with the channel opening 14 of the channel lamination 15 located before the outer lamination 8 in the axial direction. This clearly defines the output overlap, which ultimately causes the temperature control medium to stagnate (Aufstauen) in the temperature control channel within the lamination stack 2. The temperature control medium can flow out of the outlet opening 9 of the outer lamination 8, which ends the lamination stack 2 in the axial direction, and reach the winding head 13 ( Figure 1 ). In particular, the temperature control medium can be guided in a circular manner and thus return after leaving the temperature control channel and be supplied to the supply chamber 6 again.

[0044] The advantages, details, and features described in the various exemplary embodiments or with reference to the accompanying drawings can be combined, interchanged, and repurposed as desired. The electric motor 1 can be part of an electric axle drive or a drive train of a motor vehicle. Thus, such a motor vehicle can include the electric motor 1 or a drive train or axle drive having the electric motor 1.

[0045] List of reference numerals:

[0046] 1 motor

[0047] 2 lamination packs

[0048] 3 Stator

[0049] 4 Supply Side

[0050] 5 Discharge side

[0051] 6 Supply chamber

[0052] 7 Supply opening

[0053] 8 outer laminations

[0054] 9 Exit opening

[0055] 10 Connecting the laminations

[0056] 11 Connection opening

[0057] 12 Tip

[0058] 13 Winding head

[0059] 14 channel opening

[0060] 15-channel stack

[0061] 16 Exit overlap

[0062] 17 channel overlap.

Claims

1. An electric motor (1) for a motor vehicle, comprising a temperature control device for temperature control, in particular cooling, of at least a portion of the electric motor (1), wherein: The motor (1) has a lamination stack (2), the lamination stack having a plurality of laminations arranged successively in an axial direction, the laminations forming grooves and teeth alternating in a circumferential direction on their inner sides, wherein the temperature control device has at least one temperature control channel extending in the axial direction in the teeth, through which a temperature control medium can be conveyed, and is characterized in that at least one connecting lamination (10) is arranged between an outer lamination (8) arranged at an axial supply side (4) of the lamination stack (2) and a channel lamination toward the center of the lamination stack (2). The invention relates to a method for manufacturing a plurality of transmission elements of the transmission element, wherein the connection opening (11) of the connection lamination (10) connects the channel opening (14) of the channel lamination (15) and the supply opening (7) of the outer lamination (8), wherein the channel opening (14) is arranged radially inwardly of the supply opening (7), wherein the connection opening (11) forms a defined channel overlap (17) with the channel opening (14) and a defined outlet overlap (16) with the outlet opening (9) of the outer lamination (8).

2. The electric motor (1) according to claim 1, characterized in that The laminated core (2) is formed from exactly three laminated core types.

3. The electric motor (1) according to claim 1 or 2, characterized in that The laminated core (2) is formed in a defined sequence in the axial direction, wherein at least one outer laminate (8) is arranged on the supply side (4), followed by at least one connecting laminate (10), followed by a plurality of channel laminates (15), wherein, on the discharge side (5), at least one outer laminate (8) follows the plurality of channel laminates (15), with the laminated core (2) ending with the at least one outer laminate (8).

4. An electric machine (1) according to any one of the preceding claims, characterized in that At least one of the outlet openings (9) is smaller than at least one of the passage openings (14).

5. An electric machine (1) according to any one of the preceding claims, characterized in that The outlet opening (9) of the outer lamination (8) facing away from the supply side (4) forms an output overlap with the axially adjacent channel lamination (15), which is larger than the outlet overlap (16).

6. An electric machine (1) according to any one of the preceding claims, characterized in that The connecting opening (11) of the at least one connecting lamination (10) has a tip (12) pointing in the radial direction.

7. An electric machine (1) according to any one of the preceding claims, characterized in that A sealed supply chamber (4) is provided at the supply opening (7) in the axial direction.

8. Electric axle drive comprising an electric machine (1) according to any one of the preceding claims.

9. Drive train comprising an electric machine (1) according to any one of claims 1 to 7 and / or an electric axle drive according to claim 8.

10. A motor vehicle comprising an electric machine (1) according to any one of claims 1 to 7 and / or an electric axle drive according to claim 8 and / or a drive train according to claim 9.

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