DE102021212032A1 - E-axle module of an electrically powered vehicle - Google Patents

Abstract

The invention relates to an e-axle module (10) of an electrically driven vehicle. The e-axis module (10) comprises at least one electrical machine (14), power electronics (12) and a transmission (16). An electrical interface (30) between the power electronics (12) and the electrical machine (14) is essentially assigned to a transmission side (20) of the E-axis module (10). The invention also relates to the use of the e-axle module (10) in an electrically powered vehicle.

Description

technical field

The invention relates to an e-axle module of an electrically driven vehicle, the e-axle module comprising at least one electrical machine, power electronics and a transmission. Furthermore, the invention relates to the use of the e-axle module in an electrically driven vehicle, in particular in a passenger car or a light commercial vehicle.

State of the art

In the case of electric drives in vehicles, subsystems, in particular power electronics, an electric machine and a transmission, are used within an electric axle module. These can have other optional components, such as a parking lock. In the case of electric drive units that are generally used, the electrical connection between the power electronics and the electric machine takes place via busbars and cables, which are arranged on a side facing away from the transmission, which is referred to as the B-bearing side. The side of the e-axle module where the gearbox is located is called the A-bearing side. The conductor rails or power cables of the electrical interface require additional axial installation space on the electric machine side of the electric axis module, particularly when the electrical connection is made in a horizontal position. With a vertical design of the electrical connection, a minimum width is required at the end winding of the stator of the electrical machine, which also leads to a higher installation space requirement on the electrical machine side of the electrical axis module. If the electrical interface is implemented on the e-machine side of the e-axis module, a relatively large amount of installation space is required and the freely accessible area on the power electronics and on the e-machine side is therefore limited. This means that the area available for positioning additional plugs and connections, for example a cooling water connection, is restricted. The same applies to the mechanical connection of the e-axle module to the vehicle. In general, the electrical interface between the power electronics and the electrical machine is not cooled. If, on the other hand, cooling is required, separate cooling components must be installed, since it is not possible to use existing components and principles of cooling, for example in the electrical machine.

Presentation of the invention

According to the invention, an e-axle module of an electrically driven vehicle is proposed, the e-axle module comprising at least one electrical machine, power electronics and a transmission. An electrical interface between the power electronics and the electric machine is essentially assigned to a transmission side of the e-axis module. The design of the electrical interface essentially on the transmission side of the e-axis module saves installation space on the e-machine side of the e-axis module. In addition, the electrical interface can be moved inside the housing of the e-axis module and the space available there can be used sensibly. This results in improved accessibility on the e-machine side of the e-axis module, which enables additional variance in the arrangement of further connections.

In an advantageous development of the E-axis module proposed according to the invention, the electrical interface is formed by current conductors, which are designed either as busbars or as cables.

In an advantageous development of the e-axis module proposed according to the invention, the electrical interface is accommodated inside a modular housing or an integrated housing of the e-axis module. By integrating the electrical interface into the interior of the housing, the space available there can be used more effectively. There is therefore more space available on the outside of the modular housing or the integrated housing of the e-axis module, which can be used to attach customer-specific interfaces.

In a further advantageous embodiment variant of the E-axis module proposed according to the invention, the electrical interface has a vertical outlet from the power electronics. As a result, the electrical interface can be kept relatively short, which optimally reduces the amount of material used for the conductors, whether busbars or cables.

Furthermore, the E-axis module according to the present invention is designed in such a way that the electrical interface has a horizontal entry into the electrical machine, in particular in the area of the end winding. According to this embodiment variant, too, the electrical interface is designed in such a way that an electrical interface that is as short as possible is realized which is also relocated to the interior of the e-axis module.

In a further advantageous embodiment of the E-axis module proposed according to the invention, the electrical interface includes a vertical exit from the power electronics and also a vertical entry into the electrical machine in the area of the end winding. This embodiment variant allows an electrical interface to be represented in an optimal manner as an extremely short arrangement of the current conductors, i. H. the busbars or cables.

The E-axis module proposed according to the invention can be designed in such a way that the electrical interface in a dry-running E-machine, which is separated from the transmission by a radial shaft sealing ring, for example, is cooled by the lubricating medium. In this embodiment variant of the electrical interface, cooling by the lubricating medium is inherent in the system, without the need for additional cooling components to be provided separately for the electrical interface.

Alternatively, there is the possibility of configuring the E-axis module proposed according to the invention in such a way that the electrical interface is cooled by the lubricating medium in a wet-running electrical machine. In this embodiment variant, no separation between the electric machine and the transmission is to be provided in the wet-running electric machine, so that the centrifuged lubricating medium can be used directly to cool the electric interface in the form of the current conductor. With the E-axle module proposed according to the invention, there is the possibility of accommodating its components, in particular the power electronics, the actual electrical machine and the transmission, in a modular housing comprising a plurality of housings and covers.

Alternatively, it is also possible to design the e-axis module in such a way that its components, in particular the power electronics, the electric machine and the transmission, are accommodated in a common, integrated housing.

In addition, the invention relates to the use of the e-axle module in an electrically driven vehicle, in particular in a passenger car or in a light commercial vehicle.

Advantages of the Invention

The placement of the electrical interface between the power electronics and the machine installed in the e-axis module, as proposed according to the invention, is characterized by a smaller installation space requirement. By positioning the electrical interface on the transmission side, the e-machine side of the e-axle module can be made flatter and more compact, which reduces the overall installation space requirement of the e-axle module in the vehicle. The interface located inside the modular housing or the integrated housing of the e-axis module can increase flexibility when positioning plugs, connections and mechanical vehicle connections. In the solution proposed according to the invention, the entire surface of the electric machine side is now available for positioning further plug connections, for example cooling water connections and the like. Furthermore, there is a significant improvement in the accessibility of the e-machine side of the e-axis module.

In addition, cooling of the electrical interface can be achieved by the solution proposed according to the invention. For this purpose, existing components, for example the lubricating medium of the transmission, can be used as a cooling medium without the need for additional cooling components. In particular, the cooling components of the electrical machine and the transmission can be used to cool the electrical interface.

Integrating the electrical interface into the interior of the modular housing or the integrated housing also allows the current conductors, whether busbars or cables, to be routed briefly between the power electronics and the end winding of the stator of the electrical machine. This in turn allows a relatively low cost of materials.

The solution proposed according to the invention makes it possible to scale an electrical machine, i. H. to make them cost-effective in terms of lengthening or shortening the active parts, such as the rotor shaft, the rotor and the stator, in the direction of the B bearing. Advantageously, the fact that the electrical interface to the power electronics or to the inverter remains constant can be used. Furthermore, the application of the solution proposed according to the invention results in the possibility of using the installation space between the housing and the end winding, which is created by the intermediate bearing in the transmission.

character list

Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

• 1 eine perspektivische Darstellung der Komponenten eines E-Achsen-Moduls für elektrisch angetriebene Fahrzeuge,
• 2 eine schematische Darstellung einer horizontalen Ausführung einer elektrischen Schnittstelle zwischen Leistungselektronik und elektrischer Maschine,
• 3 eine Darstellung einer vertikalen Ausführung der elektrischen Schnittstelle zwischen der Leistungselektronik und der elektrischen Maschine,
• 4 eine gekühlte elektrische Schnittstelle in einer trockenlaufenden elektrischen Maschine und
• 5 eine gekühlte elektrische Schnittstelle in einer nasslaufenden elektrischen Maschine.

Show it:

• 1 a perspective view of the components of an e-axle module for electrically powered vehicles,
• 2 a schematic representation of a horizontal design of an electrical interface between power electronics and electrical machine,
• 3 a representation of a vertical design of the electrical interface between the power electronics and the electrical machine,
• 4 a cooled electrical interface in a dry electrical machine and
• 5 a cooled electrical interface in a wet electrical machine.

Embodiments of the invention

In the following description of the embodiments of the invention, the same or similar elements are denoted by the same reference symbols, with a repeated description of these elements being dispensed with in individual cases. The figures represent the subject matter of the invention only schematically.

According to the perspective view 1 an E-axis module 10 can be seen, which has several components. The e-axis module 10 includes power electronics 12 which are arranged above an electric machine 14 . A gear 16 is located on the side of the e-axis module 10. An electrical connection 18 is provided on the power electronics 12 for connecting a device according to the perspective view 1 not shown traction battery of an electric vehicle formed.

According to the illustration 2 A horizontal embodiment of an electrical interface 30 can be seen from FIG. 2 shows the individual components of the E-axis module 10 only in a schematic manner. The e-axis module 10 includes a transmission side 20, which is also referred to as the A side, and an opposite e-machine side 22, which is also referred to as the B side.

In the E-axis module 10 as shown in FIG 2 the electrical machine 14 includes a stator 24 on which a winding overhang 28 is formed on one side. The stationary mounted stator 24 of the electrical machine 14 encloses a rotor 26 which is arranged on a rotor shaft 32 in a rotationally fixed manner. The E-axis module 10 is divided by a radial shaft sealing ring 34 . The radial shaft sealing ring 34 separates a transmission 16 and the lubricating medium circulating therein from the electric machine 14.

According to the illustration 2 it follows that the rotor shaft 32 is connected via a plug connection 36 to a gear shaft on which a gear wheel 38 is accommodated. Other components of the transmission 16 are shown in FIG 2 not shown.

According to the illustration 2 It can also be seen that the electrical interface 30 between the power electronics 12 and the end winding 28 of the stator 24 of the electrical machine 14 is formed by current conductors 40 . Either curved busbars 42 or busbars that are otherwise adapted in terms of their geometry can be used as the current conductor 40, or cables 44 can also be used. According to the illustration 2 it follows that the electrical interface 30 has a vertical outlet 46 from the power electronics 12 in relation to the latter. In the embodiment variant of the electrical interface 30 according to 2 , which is essentially assigned to the transmission side 20 of the E-axis module 10 , the electrical interface 30 also has a horizontal entrance 48 into the end winding 28 of the stator 24 of the electrical machine 14 . In the variant according to 2 the electrical interface 30 is arranged in the interior of the E-axis module 10 between the end winding 28 of the stator 24 on the one hand and the radial shaft sealing ring 34 separating the transmission 16 from the electric machine 14 . through the in 2 In the solution shown, the E-machine side 22 or its end face remains freely accessible and free of components that require space in the horizontal direction.

According to the illustration 3 shows a vertical embodiment of the electrical interface 30 between the power electronics 12 and the end winding 28 of the stator 24 of the electrical machine 14 .

In 3 the electrical interface 30 is designed in such a way that it includes both a vertical exit 46 on the underside of the power electronics 12 and a vertical entry 50 into the end winding 28 of the stator 24 of the electrical machine 14 . The current conductors 40 of the electrical interface 30 as shown in FIG 3 can likewise be designed both as busbars 42 and as cables 44 . At the in 3 The vertical embodiment of the electrical interface 30 shown in the vertical embodiment allows for an extremely low amount of material to be used to form the electrical interface 30, since the components to be connected to one another, namely the power electronics 12 and the end winding 28 of the stator 24 of the electrical machine 14, are only slightly apart, so that a very small distance has to be bridged in the radial direction. According to the illustration 3 it follows that in the vertical embodiment of the electrical interface 30 the transmission 16 is separated from the electrical machine 14 by the arrangement of the radial shaft sealing ring 34 in a dry and a wet area. The radial shaft sealing ring 34 runs on a seat 54 of the jacket 52 of the rotor shaft 32 of the electrical machine 14. The electrical interface 30 in the vertical embodiment as shown in FIG 3 is also assigned to the transmission side 20 of the e-axis module 10 . As a result, it can also be achieved according to this embodiment variant that the end face of the e-axis module 10 lying on the e-machine side 22 is freely accessible and can be used for other connections.

4 shows a cooled electrical interface 30 of an electrical machine, which is designed as a dry-running electric machine 56 .

in the in 4 The embodiment variant shown is the electrical connection 18 (?) analogous to the electrical interface 30 according to the embodiment variant in FIG 2 built up. The electrical interface 30 namely includes a vertical outlet 46 on the underside of the power electronics 12 and a horizontal inlet 48 in the end winding 28 of the stator 24 of the dry-running electric machine 56. Also in FIG 4 In the illustrated embodiment, the electrical interface 30 is formed by the current conductors 40, which can be designed as current rails 42 bent by 90° here, for example, or correspondingly bent cables 44. In contrast to the variant according to 2 is in the dry-running E-machine 56 according to 4 illustrated electrical interface 30 cooled. For this purpose, the electrical interface 30 passes through the radial shaft sealing ring 34, which separates the transmission 16 from the dry-running electric machine 56. The lubricating medium thrown up in the area of the transmission 16 serves as a cooling medium for the electrical interface 30, which runs essentially through the transmission 16 and is formed from correspondingly bent busbars or correspondingly deflected cables 44. Through the radial shaft sealing ring 34, which is stationary in a modular housing 60 or an integrated Housing 62 is arranged is received on the jacket 52 of the rotor shaft 32 in the seat 54 and biased by a spring ring. This radial shaft sealing ring 34 separates the dry-running electric machine 56 from the lubricating medium circulating in the transmission 16 , which in this case can be used as a cooling medium for the electrical interface 30 . The radial shaft sealing ring 34 prevents the lubricating medium from transferring from the transmission 16 into the space of the modular housing 60 or the integrated housing 62 in which the dry-running electric machine 56 is accommodated. In the present context, a modular housing 60 is to be understood as a housing made up of several housing and cover parts. In contrast, an integrated housing 62 is to be understood as meaning one which serves as a common housing for the power electronics 12 , the electric machine 14 and the transmission 16 .

In the representation according to 4 the electrical interface 30 is analogous to the embodiment variant of the electrical interface 30 according to FIG 2 configured and includes the vertical exit 46 on the underside of the power electronics 12 on the one hand and the horizontal entry 48 into the end winding 28 of the stator 24 of the dry-running electric machine 56 on the other hand. Also in the variant according to 4 For example, the rotor shaft 32, which accommodates the rotor 26 of the dry-running electric machine 56, can be firmly connected to the transmission shaft by means of a plug connection 36, on which the transmission gear wheel 38 is accommodated, which is representative of other components of the transmission 16.

5 also shows a cooled electrical interface, but formed in a wet-running e-machine 58.

In contrast to the in 4 illustrated dry-running E-machine 56 is missing in the embodiment according to 5 , ie in the case of the wet-running electric machine 58 on a radial shaft sealing ring 34 which separates the wet-running electric machine 58 from the transmission 16. Analogously to the embodiment variant according to FIG 4 with a dry-running E-machine 56, the electrical interface 30 of the wet-running E-machine 58 is designed in such a way that it has the vertical exit 46 from the power electronics 12 on the one hand and the horizontal entry 48 into the end winding 28 of the stator 24 of the wet-running E- Machine 58 has. Also in the 5 The embodiment variant shown can be designed either as busbars 42 bent by 90° or as cables 44, the individual, preferably three, current conductors. According to both embodiment variants, namely the dry-running electric machine 56 4 as well as the wet-running E-machine 58 according to 5 What they have in common is that the electrical interface 30 is essentially on the transmission side 20 of the e-axis module 10 . As a result, the end face essentially remains on the electric machine side 22 chen free of connection components, so that on the one hand their accessibility is improved and on the other hand, for example, coolant connections and the like could be accommodated there. Both variants according to the 4 and 5 is that the electrical interface 30 is cooled without additional components. This is accomplished in that both in the variant with a dry-running E-machine 56 according to 4 as well as in the embodiment variant with wet-running electric machine 58 according to 5 the lubricating medium thrown up in the transmission 16 serves as a cooling medium for the electrical interface 30 . This can thus be accommodated both inside the modular housing 60 and inside the integrated housing 62 without the need for additional separate cooling components for the electrical interface 30 . Rather, it is cooled by the lubricating oil in the transmission 16, which serves as a cooling medium and which dissipates waste heat from the busbars 42 or the cables 44, which represent the electrical interface 30, when these heat up during operation.

Through all variants of the proposed solution according to the invention 2 until 5 , i.e. through the in 2 shown horizontal version of the electrical interface 30, which is shown in 3 illustrated vertical embodiment of the electrical interface 30 and by the cooled electrical interfaces 30 in the dry-running E-machine 56 according to 4 as well as in the wet-running e-machine 58, the electrical interface 30 is relocated to the interior of the e-axis module 10. As a result, the e-machine side 22 remains free of components that require installation space in the horizontal direction, such as connections; Furthermore, optimal accessibility of the e-axis module 10 on the e-machine side 22 can be achieved by the solution proposed according to the invention. Cooling components for the electrical interface 30 are obsolete. Rather, they can be effectively cooled by existing components, such as the lubricant circuit within the transmission 16 .

The design of the electrical interface 30 in the interior of the modular housing 60 or the integrated housing 62 makes much better use of the space available there in the interior of the corresponding housing 60, 62 for accommodating the electrical interface 30. It is irrelevant whether the electrical interface 30 is formed with a vertical outlet 46 and a horizontal inlet 48 or by the vertical outlet 46 from the power electronics 12 and the vertical inlet 50 in the end winding 28 of the stator 24 .

The invention is not limited to the exemplary embodiments described here and the aspects highlighted therein. Rather, within the range specified by the claims, a large number of modifications are possible, which are within the scope of expert action.

Claims (11)

E-axis module (10) of an electrically powered vehicle, wherein the E-axis module (10) comprises at least one electric machine (14), power electronics (12) and a transmission (16), characterized in that an electric Interface (30) between the power electronics (12) and the electric machine (14) is assigned essentially to a transmission side (20) of the E-axis module (10). E-axis module (10) according to claim 1 , characterized in that the electrical interface (30) is formed by current conductors (40), which are designed as busbars (42) or cables (44). E-axis module (10) according to the claims 1 and 2 , characterized in that the electrical interface (30) is housed inside a modular housing (60) or an integrated housing (62). E-axis module (10) according to the claims 1 until 3 , characterized in that the electrical interface (30) comprises a vertical outlet (46) from the power electronics (12). E-axis module (10) according to the claims 1 until 4 , characterized in that the electrical interface (30) has a horizontal entry (48) into the electrical machine (14), in particular in the region of the end winding (28). E-axis module (10) according to the claims 1 until 3 , characterized in that the electrical interface (30) comprises a vertical outlet (46) from the power electronics (12) and a vertical inlet (50) into the electrical machine (14) in the region of the end winding (28). E-axis module (10) according to the claims 1 until 6 , characterized in that the electrical interface (30) in a dry-running E-machine (56), which is separated from the transmission (16) by a radial shaft sealing ring (34), is cooled by a lubricating medium. E-axis module (10) according to the claims 1 until 6 , characterized in that the electrical interface (30) in a wet-running elec technical machine (58) is cooled by a lubricating medium. E-axis module (10) according to the claims 1 until 8th , characterized in that its components, in particular the power electronics (12), the electrical machine (14, 56, 58) and the transmission (16) are accommodated in a modular housing (60) comprising a plurality of housings and covers. E-axis module (10) according to the claims 1 until 8th , characterized in that its components, in particular the power electronics (12), the electric machine (14, 56, 58) and the transmission (16) are accommodated in a common integrated housing (62). Use of the E-axis module (10) according to one of Claims 1 until 10 in an electrically driven vehicle, in particular in a passenger car or a light commercial vehicle.

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