WO2023072658A1

WO2023072658A1 - Electric drive axle module of an electrically driven vehicle

Info

Publication number: WO2023072658A1
Application number: PCT/EP2022/078834
Authority: WO
Inventors: Andreas Wuensch; Philipp Breinlinger
Original assignee: Robert Bosch Gmbh
Priority date: 2021-10-26
Filing date: 2022-10-17
Publication date: 2023-05-04
Also published as: DE102021212032A1; CN118176127A

Abstract

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

Description

E-axle module of an electrically powered vehicle

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. Will the If the electrical interface is designed on the e-machine side of the e-axis module, a relatively large amount of 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. By designing the electrical interface essentially on the transmission side of the e-axis module, space is saved 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 that 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 inside a modular housing or an integrated housing of the E-axis module accommodated. By integrating the electrical interface into the interior of the housing, the space available there can be used more effectively. More space is therefore 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 implemented, which is also shifted into 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. Of 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.

Brief description of the drawings

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

Show it: Figure 1 is a perspective view of the components of an e-axle module for electrically powered vehicles,

Figure 2 shows a schematic representation of a horizontal embodiment of an electrical interface between power electronics and electrical machine,

FIG. 3 shows a representation of a vertical design of the electrical interface between the power electronics and the electrical machine,

FIG. 4 shows a cooled electrical interface in a dry-running electrical machine and

FIG. 5 shows a cooled electrical interface in a wet-running 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.

The perspective representation according to FIG. 1 shows an e-axis module 10 which has a number of 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-axle module 10. An electrical connection 18 for connecting a traction battery of an electric vehicle, not shown in detail in the perspective view according to FIG. 1, is formed on the power electronics 12.

A horizontal embodiment of an electrical interface 30 can be seen from the illustration according to FIG. Figure 2 shows the individual components of the E-axes module 10 only in a schematic way. 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.

The illustration according to FIG. 2 shows that the rotor shaft 32 is connected via a plug-in connection 36 to a gear shaft on which a gear wheel 38 is accommodated. Further components of the transmission 16 are not shown in the illustration according to FIG.

The illustration according to FIG. 2 also shows 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. The illustration according to FIG. 2 shows that the electrical interface 30 has a vertical outlet 46 from the power electronics 12 . In the embodiment variant of the electrical interface 30 according to FIG. In the embodiment variant according to FIG. Due to the solution shown in FIG. 2, the E machine side 22 or its end face remains freely accessible and free from components that require space in the horizontal direction. 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 can be seen from the illustration according to FIG.

In FIG. 3, the electrical interface 30 is designed in such a way that it includes both a vertical outlet 46 on the underside of the power electronics 12 and a vertical inlet 50 into the end winding 28 of the stator 24 of the electrical machine 14 . The current conductors 40 of the electrical interface 30 according to the illustration in FIG. In the vertical embodiment of the electrical interface 30 shown in Figure 3, an extremely low amount of material can be achieved for representing 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 minimally separated are removed, so that a very small distance seen in the radial direction can be bridged. The representation according to FIG. 3 shows that in the vertical embodiment of the electrical interface 30 the transmission 16 is also 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 casing 52 of the rotor shaft 32 of the electric machine 14. The electrical interface 30 in the vertical embodiment according to the illustration in FIG. 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.

FIG. 4 shows a cooled electrical interface 30 of an electrical machine that is designed as a dry-running electrical machine 56 .

In the embodiment variant shown in FIG. 4, the electrical connection 18 (?) is constructed analogously to the electrical interface 30 according to the embodiment variant in FIG. The electrical interface 30 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. In the embodiment variant shown in Figure 4, the electrical interface 30 is Current conductor 40 formed, as here around For example, 90 ° curved busbars 42 or correspondingly curved cables 44 can be formed. In contrast to the embodiment variant according to FIG. 2, the electrical interface 30 shown in the dry-running electric machine 56 according to FIG. 4 is 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 Figure 4, the electrical interface 30 is configured analogously to the embodiment variant of the electrical interface 30 according to Figure 2 and includes the vertical outlet 46 on the underside of the power electronics 12 on the one hand and the horizontal inlet 48 in the end winding 28 of the stator 24 of the dry-running E -Machine 56 on the other hand. In the embodiment variant according to FIG. 4, too, 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, which is representative of other components of the transmission 16, is accommodated.

Figure 5 also shows a cooled electrical interface, but formed in a wet-running electric machine 58. In contrast to the dry-running electric machine 56 shown in FIG. 4, the embodiment variant according to FIG. 5, i.e. the wet-running electric machine 58, lacks a radial shaft sealing ring 34 separating the wet-running electric machine 58 from the transmission 16. Analogous to the embodiment variant according to FIG of 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 allows 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 on the other 58 has. In the embodiment variant shown in FIG. 5, the individual, preferably three, current conductors can also be designed either as current rails 42 bent by 90° or as cables 44. Both design variants, namely the dry-running electric machine 56 according to FIG. 4 as well as the wet-running electric machine 58 according to FIG. As a result, the end face on the electric machine side 22 remains essentially free of connection components, so that on the one hand their accessibility is improved and on the other hand coolant connections and the like, for example, could be accommodated there. What both embodiment variants according to FIGS. 4 and 5 have in common is that the electrical interface 30 is cooled without additional components. This is accomplished by the fact that the lubricating medium thrown up in the transmission 16 serves as a cooling medium for the electrical interface 30 both in the embodiment variant with a dry-running electric machine 56 according to FIG. 4 and in the embodiment variant with a wet-running electric machine 58 according to FIG. 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.

2 to 5, i.e. the horizontal design of the electrical interface 30 shown in FIG. 2, the vertical design of the electrical interface 30 shown in FIG electric machine 56 according to FIG. 4 as well as in the case of 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

Expectations

1. E-axle module (10) of an electrically powered vehicle, wherein the E-axle module (10) comprises at least one electrical machine (14), power electronics (12) and a transmission (16), characterized in that an electrical interface (30) between the power electronics (12) and the electric machine (14) is essentially assigned to a transmission side (20) of the E-axis module (10).

2. 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).

3. E-axis module (10) according to claims 1 and 2, characterized in that the electrical interface (30) is housed inside a modular housing (60) or an integrated housing (62).

4. E-axis module (10) according to claims 1 to 3, characterized in that the electrical interface (30) comprises a vertical exit (46) from the power electronics (12).

5. E-axis module (10) according to claims 1 to 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). .

6. E-axis module (10) according to claims 1 to 3, characterized in that the electrical interface (30) has a vertical exit (46) from the power electronics (12) and a vertical entry (50) into the electrical machine (14) in the area of the end winding (28). E-axis module (10) according to Claims 1 to 6, characterized in that the electrical interface (30) in a dry-running electric machine (56), which is separated from the transmission (16) by a radial shaft sealing ring (34), is cooled by lubricating medium. E-axis module (10) according to Claims 1 to 6, characterized in that the electrical interface (30) in a wet-running electrical machine (58) is cooled by a lubricating medium. E-axis module (10) according to claims 1 to 8, characterized in that its components, in particular the power electronics (12), the electric machine (14, 56, 58) and the transmission (16) in one, several housing and a cover comprising a modular housing (60). E-axis module (10) according to claims 1 to 8, characterized in that its components, in particular the power electronics (12), the electric machine (14, 56, 58) and the transmission (16) in a common integrated housing (62) are included. Use of the E-axle module (10) according to one of Claims 1 to 10 in an electrically driven vehicle, in particular in a passenger car or a light commercial vehicle.