DE102022107098B3 - Electrically operable final drive train and method for manufacturing an electrically operable final drive train - Google Patents

Abstract

The invention relates to an electrically operable axle drive train (1), wherein in the axle drive train (1) the electric machine (4) housed in a motor housing (9) is directly adjacent in the axial direction to the power electronics (3) housed in an inverter housing (8), and an electrical interface (7) is formed between the power electronics (3) and the electrical machine (4), by means of which electrical contact is made between a first electrical contact means (16), which is electrically conductively coupled to the electrical machine (4). , and a second electrical contact means (17), which is electrically conductively connected to a low-voltage connection, wherein the motor housing (9) has a first window section (11) on its lateral surface (10) and the inverter housing (8) has a second window section (13) on its lateral surface (12), with the first window section (11) and the second window section (13) defining a common assembly window (14) in the assembled state of the axle drive train (1), with a holding element (15) for releasably fixing the first electrical contacting means (16) on the motor housing (9), so that the first electrical contacting means (16) is held in the holding element (15) during assembly of the motor housing (9) on the inverter housing (8) and after the assembly of the motor housing (9) can be removed from the holding element (15) from the outside through the assembly window (14) and can be coupled to the second electrical contacting means (17).

Description

The present invention relates to an electrically operable final drive train for a motor vehicle, comprising an electric machine that can be energized by power electronics, wherein in the final drive train the electric machine accommodated in a motor housing is directly adjacent to the power electronics accommodated in an inverter housing in the axial direction, the motor housing and the inverter housing form a detachable structural unit, and an electrical interface is formed between the power electronics and the electrical machine, by means of which electrical contacting between a first electrical contacting means, which is electrically conductively coupled to the electrical machine, and a second electrical contacting means, which is connected to a Low-voltage connection is electrically connected, can be produced. The invention also relates to a method for producing the electrically operable axle drive train according to the invention.

Electric motors are increasingly being used to drive motor vehicles in order to create alternatives to internal combustion engines that require fossil fuels. Significant efforts have already been made to improve the suitability for everyday use of electric drives and also to be able to offer users the driving comfort they are accustomed to.

A detailed description of an electric drive can be found in an article in the ATZ magazine, volume 113, 05/2011, pages 360-365 by Erik Schneider, Frank Fickl, Bernd Cebulski and Jens Liebold with the title: Highly integrative and flexible electric drive unit for electric Vehicles, which is probably the closest state of the art. This article describes a drive unit for an axle of a vehicle, which includes an electric motor that is arranged concentrically and coaxially with a bevel gear differential, with a switchable 2-speed planetary gear set being arranged in the power train between the electric motor and the bevel gear differential, which is also is positioned coaxially to the electric motor or the bevel gear differential or spur gear differential. The drive unit is very compact and allows a good compromise between climbing ability, acceleration and energy consumption due to the switchable 2-speed planetary gear set. Such drive units are also referred to as e-axles or electrically operable drive trains.

Increasingly, axial flow machines are also used in such e-axes. An axial flux machine is a dynamo-electric machine in which the magnetic flux between the rotor and stator runs parallel to the axis of rotation of the rotor. Often, both the stator and the rotor are largely disc-shaped. Axial flow machines are particularly advantageous when the space available axially is limited in a given application. This is often the case, for example, with the electric drive systems for electric vehicles described at the outset. In addition to the shortened axial length, another advantage of the axial flow machine is its comparatively high torque density. The reason for this is the larger air gap area compared to radial flux machines, which is available for a given installation space. Furthermore, a lower iron volume is required compared to conventional machines, which has a positive effect on the efficiency of the machine.

Such electrical axial flux machines, as well as radial flux machines, are usually supplied with power using a power electronics module, which is also referred to as an inverter.

The generic DE 10 2019 129 738 A1 shows an electric motor assembly, comprising at least one electric machine with a stator fixed at least indirectly to a housing and a rotor that can be driven in rotation relative thereto, with the respective electric machine being connected to power electronics for control purposes, which are connected to a busbar arranged on the housing via a busbar integrated in the housing Socket is connected, wherein the socket is designed to receive a plug of a supply line of a battery module for the electrical supply of the power electronics.

The DE 10 2017 205 970 A1 shows a connection device for the detachable electrically conductive connection of power electronics for operating an electric machine with an electric winding of an electric machine. It also relates to a method for manufacturing such a connection device. It also relates to a drive unit with an electric machine, with power electronics and with such a connecting device. It also relates to a vehicle drive system with such a drive unit.

The U.S. 2016/0 218 602 A1 shows a motor housing which is connected to the inverter via a plug-type housing connector.

The DE 10 2019 217 872 A1 shows a modular axle drive, in particular a modular electric axle drive, for vehicles, a manufacturing method for a modular axle drive drive and assembly method of a modular final drive in a vehicle.

The DE 10 2020 202 745 A1 shows an electric drive unit, which comprises an electric machine for generating a drive torque, a transmission coupled to the electric machine for transmitting the drive torque, power electronics for controlling the electric machine and at least one further electric component.

The object of the invention is to provide an electric axle drive train for a motor vehicle whose electrical interface is easy to assemble and inexpensive to manufacture. Furthermore, the electric axle drive train should be compact. Finally, it is also the object of the invention to provide an assembly-friendly method for producing the axle drive train of a motor vehicle according to the invention.

The object is achieved by an electrically operable final drive train for a motor vehicle comprising an electric machine that can be energized by power electronics, wherein in the final drive train the electric machine accommodated in a motor housing is directly adjacent to the power electronics accommodated in an inverter housing in the axial direction, the motor housing and the inverter housing form a detachable structural unit, and an electrical interface is formed between the power electronics and the electrical machine, by means of which electrical contacting between a first electrical contacting means, which is electrically conductively coupled to the electrical machine, and a second electrical contacting means, which is connected to a low-voltage connection is electrically conductively connected, can be produced, with the motor housing having a first window section on its lateral surface and the inverter housing having a second window section on its lateral surface, with the first window section and the second window section defining a common assembly window in the assembled state of the axle drive train, with a retaining element is arranged for releasably fixing the first electrical contacting means on the motor housing, so that the first electrical contacting means is held in the holding element during assembly of the motor housing on the inverter housing and can be removed from the holding element from the outside through the assembly window after assembly of the motor housing and connected to the second electrical contacting means can be coupled, or a holding element for releasably fixing the second electrical contacting means is arranged on the inverter housing, so that the second electrical contacting means is held in the holding element during assembly of the motor housing on the inverter housing and from the outside after assembly of the motor housing can be removed through the assembly window and coupled to the first electrical contacting means.

This achieves the advantage that a particularly assembly-friendly axle drive train can be provided. Furthermore, the contact point is easily accessible for assembly and/or disassembly.

In order to ensure the electrical contacting, a form fit can particularly preferably be provided between the contacting means, for example a form fit can take place directly on the contacting partners/connector sets by means of mechanical snap-in lugs/snap-in hooks. Due to the mechanical locking option directly on the connector sets, contacting is more reliable and less susceptible to vibrations and tolerances. Furthermore, there is an easier way of checking that the assembly has been carried out correctly, since the contacting point and the mechanical locking are visible, but the locking process can also be heard by the fitter in the case of manual assembly.

An axle drive train that can be operated electrically according to the invention comprises an electric machine and preferably a transmission arrangement coupled to the electric machine. The gear arrangement and the electric machine form a structural unit. This can be formed, for example, by means of a drive train housing, in which the transmission arrangement and the electric machine are accommodated together.

Alternatively, it is possible for the electric machine to have a motor housing and/or the gearbox to have a gearbox housing, in which case the structural unit can then be effected by fixing the gearbox in relation to the electric machine.

In particular, the transmission arrangement can be coupled to the electric machine, which is designed to generate a drive torque for the motor vehicle. The drive torque is particularly preferably a main drive torque, so that the motor vehicle is driven exclusively by the drive torque. The gear arrangement is preferably designed as a planetary gear, very particularly preferably as a switchable, in particular two-speed planetary gear.

The motor housing encloses the electric machine. A motor housing can also also accommodate the control and power electronics. The motor housing can also be part of a cooling system for the electric machine and can be designed in such a way that cooling fluid can be supplied to the electric machine via the motor housing and/or the heat can be dissipated to the outside via the housing surfaces. In addition, the motor housing protects the electrical machine and any electronics that may be present from external influences.

A motor housing can be formed in particular from a metallic material. Advantageously, the motor housing can be formed from a metallic cast material, such as die-cast aluminum, die-cast magnesium, cast iron or cast steel.

In principle, it is conceivable that the transmission housing and the motor housing are designed in one piece, in particular monolithically, in sections or completely. It is also possible, for example to achieve particularly high system integration, for part of the transmission housing to be formed as part of a motor housing and/or part of the motor housing to be formed as part of the transmission housing.

The electrical machine is used to convert electrical energy into mechanical energy and/or vice versa, and it generally comprises a stationary part, referred to as a stator, stand or armature, and a stationary part, referred to as a rotor or runner, that is arranged such that it can move, in particular rotate, relative to the stationary part Part.

The electric machine of the axle drive train according to the invention is preferably designed as an axial flow machine. The magnetic flux in an electric axial flux machine (AFM) is directed in the air gap between the stator and rotor axially to a direction of rotation of the rotor of the axial flux machine. There are different types of axial flow machines. A known type is a so-called I-arrangement, in which the rotor is arranged axially next to a stator or between two stators. Another known type is a so-called H-arrangement, in which two rotors are arranged on opposite axial sides of a stator. The electric axial flux machine is preferably configured as an I type.

In principle, it is also possible for a plurality of rotor-stator configurations to be arranged axially next to one another as an I-type and/or H-type. It would also be possible in this context to arrange both one or more I-type rotor-stator configurations and one or more H-type rotor-stator configurations next to one another in the axial direction. In particular, it is also preferable that the rotor-stator configuration of the H-type and/or the I-type are each configured essentially identically, so that they can be assembled in a modular manner to form an overall configuration. Such rotor-stator configurations can in particular be arranged coaxially to one another and can be connected to a common rotor shaft or to a plurality of rotor shafts.

In particular, the electric machine is dimensioned in such a way that vehicle speeds of more than 50 km/h, preferably more than 80 km/h and in particular more than 100 km/h can be achieved. The electric motor particularly preferably has an output of more than 30 kW, preferably more than 50 kW and in particular more than 70 kW. Furthermore, it is preferred that the electrical machine provides speeds greater than 5,000 rpm, particularly preferably greater than 10,000 rpm, very particularly preferably greater than 12,500 rpm.

For the purposes of this application, motor vehicles are land vehicles that are moved by machine power without being tied to railroad tracks. A motor vehicle can be selected, for example, from the group of passenger cars (cars), trucks (lorries), mopeds, light motor vehicles, motorcycles, buses (COM) or tractors.

The power electronics are housed in an inverter housing. The inverter housing can preferably be formed from a metallic material, particularly preferably from aluminum, gray cast iron or cast steel, in particular by means of a primary shaping process such as casting or die-casting. The inverter housing particularly preferably has a pot-like three-dimensional shape. In this connection, it is particularly preferable that the inverter bottom is insertable into the pot-like inverter case. Alternatively, it would also be conceivable for the inverter base to rest on the cup-shaped inverter housing and cover its opening.

The inverter housing can also be part of the motor housing or vice versa. This means that the inverter housing is formed entirely or partially in one piece, in particular monolithically, with the motor housing.

According to an advantageous embodiment of the invention, it can be provided that the first window section and the second window section have an overlapping area in the axial direction. The advantage of this configuration lies in the fact that the window sections are stacked one on top of the other can run nested, which can bring advantages in terms of assembly technology.

According to a further preferred further development of the invention, it can also be provided that the retaining element is designed in one piece with the motor housing, which can be advantageous in terms of production technology and does not require any additional assembly of the retaining element.

Furthermore, it can be provided according to a likewise advantageous embodiment of the invention that the holding element is designed as a separate component, in particular molded from plastic, that is positively and/or materially and/or non-positively connected to the motor housing or inverter housing. The advantageous effect of this configuration is based on the fact that the holding element can be produced particularly inexpensively, for example in a plastic injection molding process.

According to a further particularly preferred embodiment of the invention, it can be provided that the holding element is designed for the detachable fixing of a plurality of electrical contacting means. In this way, the effect can be achieved in particular that different contacting means for different functions can be arranged on a holding element, which allows easy access to these contacting means that is easy to assemble.

Furthermore, the invention can also be further developed in such a way that the assembly window is closed by a cover element, in particular in a detachable manner. The advantage of this design is that the assembly window is thereby protected from unwanted mechanical or chemical influences from the outside.

In a likewise preferred embodiment variant of the invention, it can also be provided that the first electrical contacting means is in particular a multi-pole plug which is connected to a cable leading into the electrical machine. As a result, particularly simple wiring and contacting can be effected. It can also be advantageous to further develop the invention such that the cable makes electrically conductive contact with a sensor arranged in the electrical machine on the end remote from the first electrical contacting means.

According to a further preferred embodiment of the subject matter of the invention, it can be provided that the axle drive train includes a second electrical machine that can be energized by the power electronics, with the power electronics being positioned axially between the first electrical machine and the second electrical machine. In this way it can be achieved that the two drive wheels of a vehicle axle can each be driven with a separate electric machine.

• (a1) Bereitstellung einer durch eine Leistungselektronik bestrombaren und in einem Motorgehäuse aufgenommenen elektrischen Maschine, wobei das Motorgehäuse an seiner Mantelfläche einen ersten Fensterabschnitt aufweist,
• (a2) Bereitstellung einer in einem Invertergehäuse aufgenommenen Leistungselektronik, wobei das Invertergehäuse an seiner Mantelfläche einen zweiten Fensterabschnitt aufweist,
• (a3) Bereitstellung einer elektrische Schnittstelle zwischen der Leistungselektronik und der elektrischen Maschine, mittels derer eine elektrische Kontaktierung zwischen einem ersten elektrischen Kontaktierungsmittel, welches elektrisch leitend mit der elektrischen Maschine gekoppelt ist, und einem zweiten elektrischen Kontaktierungsmittel, welches mit der Leistungselektronik elektrisch leitend verbunden ist, herstellbar ist, wobei ein Halteelement zur lösbaren Fixierung des ersten elektrischen Kontaktierungsmittels an dem Motorgehäuse angeordnet ist, so dass das erste elektrische Kontaktierungsmittel während der Montage des Motorgehäuses an dem Invertergehäuse in dem Halteelement gehalten ist,
• (b) Verbinden des Motorgehäuse und des Invertergehäuses zu einer lösbaren baulichen Einheit, so dass die in einem Motorgehäuse aufgenommene elektrische Maschine in axialer Richtung unmittelbar an die in einem Invertergehäuse aufgenommene Leistungselektronik angrenzt und der erste Fensterabschnitt und der zweite Fensterabschnitt ein gemeinsames Montagefenster definieren,
• (c) Entnahme des ersten elektrischen Kontaktierungsmittels aus dem Halteelement von außen durch das Montagefenster und Koppeln des ersten elektrischen Kontaktierungsmittels mit dem zweiten elektrischen Kontaktierungsmittel.

Finally, the object of the invention can also be achieved by a method for producing an electrically operable axle drive train for a motor vehicle, comprising the following steps:

• (a1) Provision of an electrical machine that can be energized by power electronics and accommodated in a motor housing, the motor housing having a first window section on its lateral surface,
• (a2) Provision of power electronics accommodated in an inverter housing, the inverter housing having a second window section on its lateral surface,
• (a3) Provision of an electrical interface between the power electronics and the electrical machine, by means of which electrical contact is made between a first electrical contact means, which is electrically conductively coupled to the electrical machine, and a second electrical contact means, which is electrically conductively connected to the power electronics , can be produced, wherein a holding element for releasably fixing the first electrical contacting means is arranged on the motor housing, so that the first electrical contacting means is held in the holding element during assembly of the motor housing on the inverter housing,
• (b) connecting the motor housing and the inverter housing to form a detachable structural unit, so that the electric machine accommodated in a motor housing is directly adjacent to the power electronics accommodated in an inverter housing in the axial direction and the first window section and the second window section define a common assembly window,
• (c) Removal of the first electrical contacting means from the holding element from the outside through the assembly window and coupling of the first electrical contacting means to the second electrical contacting means.

The invention will be explained in more detail below with reference to figures without restricting the general inventive idea.

• 1 einen Achsantriebsstrang in drei Montagezuständen in jeweils einer schematischen Blockschaltdarstellung,
• 2 eine Aufsicht auf ein Montagefenster des Achsantriebsstrangs in zwei verschiedenen Montagezuständen,
• 3 eine Aufsicht auf ein von einem Deckelelement verschlossenes Montagefenster des Achsantriebsstrangs,
• 4 ein Halteelement in einer freigestellten perspektivischen Ansicht,
• 5 Querschnittsansicht auf die elektrische Maschine des Achsantriebsstrangs,
• 6 einen Achsantriebsstrang mit zwei elektrischen Maschinen in einer schematischen Blockschaltdarstellung,
• 7 ein Kraftfahrzeug mit einem elektrisch betreibbaren Achsantriebsstrang in einer schematischen Blockschaltdarstellung.

It shows:

• 1 an axle drive train in three assembly states, each in a schematic block diagram,
• 2 a top view of an assembly window of the final drive train in two different assembly states,
• 3 a top view of an assembly window of the final drive train that is closed by a cover element,
• 4 a holding element in a cut-out perspective view,
• 5 Cross-sectional view of the electric machine of the final drive train,
• 6 an axle drive train with two electrical machines in a schematic block diagram,
• 7 a motor vehicle with an electrically operable axle drive train in a schematic block diagram.

The 1 shows an electrically operable final drive train 1 for a motor vehicle 2, as an example in the 7 is shown. Such an axle drive train 1 generally also has a transmission arrangement 19 which is coupled to the electric machine 4 .

The final drive train 1 has an electric machine 4 that can be energized by power electronics 3. In the final drive train 1, the electric machine 4 accommodated in a motor housing 9 adjoins in the axial direction directly the power electronics 3 accommodated in an inverter housing 8, with the motor housing 9 and the inverter housing 8 form a detachable structural unit.

An electrical interface 7 is formed between the power electronics 3 and the electrical machine 4, by means of which electrical contact is established between a first electrical contact means 16, which is electrically conductively coupled to the electrical machine 4, and a second electrical contact means 17, which is connected to a low-voltage connection is electrically conductively connected, can be produced. The low-voltage connection is provided in or on the power electronics and/or arranged in the inverter housing 8 .

The motor housing 9 has a first window section 11 on its lateral surface 10 and the inverter housing 8 has a second window section 13 on its lateral surface 12, with the first window section 11 and the second window section 13 defining a common assembly window 14 in the assembled state of the final drive train 1, which is good from the 1 lets see.

The second window section 13 protrudes axially out of the inverter housing 8 and, when the power electronics 3 and motor housing 9 are joined together, engages in the motor housing 9 below or above the first window section 11, which can be clearly seen from the synopsis of the and the 1 reveals.

Furthermore, a holding element 15 for releasably fixing the first electrical contacting means 16 on the motor housing 9 is arranged, so that the first electrical contacting means 16 is held in the holding element 15 during the assembly of the motor housing 9 on the inverter housing 8 and after the assembly of the motor housing 9 from the Retaining element 15 can be removed from the outside through the mounting window 14 and can be coupled to the second electrical contacting means 17, which can be seen clearly from the and the 1 or that 2 can be understood.

Although in the embodiment of 1 not shown, it would of course also be possible to arrange a holding element 15 for releasably fixing the second electrical contacting means 17 on the inverter housing 8, so that the second electrical contacting means 17 is held in the holding element 15 during the assembly of the motor housing 9 on the inverter housing 8 and afterwards the assembly of the motor housing 9 can be removed from the holding element 15 from the outside through the assembly window 14 and coupled to the first electrical contact means 16 . The first electrical contact means 16 and the second electrical contact means 18 are each designed as a multi-pole plug which is connected to a cable 24 leading into the electrical machine 4 . After the assembly of the contacting means 17, the assembly window 14 can be closed by a cover element 23, in particular detachably, as is shown in FIG 3 is sketched.

From the 2 It can be seen that the first window section 11 and the second window section 13 have an overlapping area 22 in the axial direction, which comes about because the window sections 11 run one above the other on different levels, which can also be seen from FIG 1 lets see.

The holding element 15 can be formed in one piece with the motor housing 9 or, as in FIG 4 is shown as a separate component, in particular molded from plastic, that is positively and/or materially and/or non-positively connected to the motor housing 9 or the inverter housing 8 . The holding element 15 is here for detachable Fixation of two electrical contact means 16,18 formed.

From the synopsis of 1 and the 5 It is clearly evident that the cable 24 makes electrically conductive contact with a sensor 25 arranged in the electrical machine 4 on the end facing away from the first electrical contacting means 16 .

6 shows an embodiment of the axle drive train 1 in which there is a second electric machine 26 that can be energized by the power electronics 3 , the power electronics 3 being positioned axially between the first electric machine 4 and the second electric machine 26 . Such an axle drive train 1 is occasionally also referred to as a twin drive.

• Zunächst erfolgt die Bereitstellung einer durch eine Leistungselektronik 3 bestrombaren und in einem Motorgehäuse 9 aufgenommenen elektrischen Maschine 4, wobei das Motorgehäuse 9 an seiner Mantelfläche 10 einen ersten Fensterabschnitt 11 aufweist, sowie die Bereitstellung einer in einem Invertergehäuse 8 aufgenommenen Leistungselektronik 3, wobei das Invertergehäuse 8 an seiner Mantelfläche 12 einen zweiten Fensterabschnitt 13 aufweist, und die Bereitstellung einer elektrische Schnittstelle 7 zwischen der Leistungselektronik 3 und der elektrischen Maschine 4, mittels derer eine elektrische Kontaktierung zwischen einem ersten elektrischen Kontaktierungsmittel 16, welches elektrisch leitend mit der elektrischen Maschine 4 gekoppelt ist, und einem zweiten elektrischen Kontaktierungsmittel 17, welches mit der Leistungselektronik 3 elektrisch leitend verbunden ist, herstellbar ist, wobei ein Halteelement 15 zur lösbaren Fixierung des ersten elektrischen Kontaktierungsmittels 16 an dem Motorgehäuse 9 angeordnet ist, so dass das erste elektrische Kontaktierungsmittel 16 während der Montage des Motorgehäuses 9 an dem Invertergehäuse 8 in dem Halteelement 15 gehalten ist.

Based on 1-2 In particular, the method for producing an electrically operable axle drive train 1 for a motor vehicle 2 can also be explained once again. It includes the following steps:

• Firstly, an electrical machine 4 that can be powered by power electronics 3 and is housed in a motor housing 9 is provided, with the motor housing 9 having a first window section 11 on its lateral surface 10, and power electronics 3 housed in an inverter housing 8 are provided, with the inverter housing 8 has a second window section 13 on its lateral surface 12, and the provision of an electrical interface 7 between the power electronics 3 and the electrical machine 4, by means of which electrical contact is made between a first electrical contact means 16, which is electrically conductively coupled to the electrical machine 4. and a second electrical contacting means 17, which is electrically conductively connected to the power electronics 3, wherein a holding element 15 for the detachable fixing of the first electrical contacting means 16 is arranged on the motor housing 9, so that the first electrical contacting means 16 during assembly of the Motor housing 9 is held on the inverter housing 8 in the holding member 15.

The motor housing 9 and the inverter housing 8 are then connected to form a detachable structural unit, so that the electric machine 4 accommodated in a motor housing 9 is directly adjacent in the axial direction to the power electronics 3 accommodated in an inverter housing 8 and the first window section 11 and the second Window section 13 define a common assembly window 14 . This assembly state is in the the 1 shown.

Thereafter, the removal of the first electrical contacting means 16 from the holding element 15 from the outside through the assembly window 14 and the coupling of the first electrical contacting means 16 with the second electrical contacting means 17, which is well from the synopsis of and the 1 can be understood.

Reference List

1

final drive train

2

motor vehicle

3

power electronics

4

electric machine

7

interface

8th

inverter housing

9

motor housing

10

lateral surface

11

window section

12

lateral surface

13

window section

14

assembly window

15

holding element

16

contacting means

17

contacting means

18

contacting means

19

gear arrangement

22

overlap area

23

cover element

24

Cable

25

sensor

26

electric machine

Claims (10)

Electrically operable final drive train (1) for a motor vehicle (2), comprising an electric machine (4) that can be energized by power electronics (3), the electric machine (4) accommodated in a motor housing (9) in the final drive train (1) in an axial Directly adjacent to the power electronics (3) accommodated in an inverter housing (8), the motor housing (9) and the inverter housing (8) forming a detachable structural unit, and an electrical interface (7) between the power electronics ronik (3) and the electrical machine (4) is formed, by means of which an electrical contact between a first electrical contact means (16), which is electrically conductively coupled to the electrical machine (4), and a second electrical contact means (17), which is electrically conductively connected to a low-voltage connection, characterized in that the motor housing (9) has a first window section (11) on its lateral surface (10) and the inverter housing (8) has a second window section (13 ), wherein in the assembled state of the axle drive train (1), the first window section (11) and the second window section (13) define a common assembly window (14), with a holding element (15) for the detachable fixing of the first electrical contacting means (16). is arranged in the motor housing (9), so that the first electrical contacting means (16) is held in the holding element (15) during the assembly of the motor housing (9) on the inverter housing (8) and after the assembly of the motor housing (9) from the holding element (15) can be removed from the outside through the assembly window (14) and can be coupled to the second electrical contacting means (17), or a holding element (15) for releasably fixing the second electrical contacting means (17) is arranged on the inverter housing (8), see above that the second electrical contact means (17) is held in the holding element (15) during the assembly of the motor housing (9) on the inverter housing (8) and after the assembly of the motor housing (9) from the holding element (15) from the outside through the assembly window ( 14) can be removed and coupled to the first electrical contacting means (16). Final drive train (1) according to claim 1 , characterized in that the first window section (11) and the second window section (13) have an overlapping area (22) in the axial direction Axle drive train (1) according to one of the preceding claims, characterized in that the retaining element (15) is constructed in one piece with the motor housing (9). Axle drive train (1) according to one of the preceding claims, characterized in that the retaining element (15) is designed as a separate component, in particular molded from plastic, which is positively and/or materially and/or non-positively connected to the motor housing (9) or Inverter housing (8) is connected. Axle drive train (1) according to one of the preceding claims, characterized in that the holding element (15) is designed for the detachable fixing of a plurality of electrical contacting means (16, 18). Axle drive train (1) according to one of the preceding claims, characterized in that the assembly window (14) is closed by a cover element (23), in particular detachably. Axle drive train (1) according to one of the preceding claims, characterized in that the first electrical contacting means (16) is in particular a multi-pole plug which is connected to a cable (24) leading into the electrical machine (4). Axle drive train (1) according to one of the preceding claims, characterized in that the cable (24) at the end remote from the first electrical contacting means (16) makes electrically conductive contact with a sensor (25) arranged in the electrical machine (4). Axle drive train (1) according to one of the preceding claims, characterized in that the axle drive train (1) comprises a second electrical machine (26) which can be energized by the power electronics (3), the power electronics (3) being located axially between the first electrical machine (4) and the second electrical machine (26) is positioned. A method for producing an electrically operable axle drive train (1) for a motor vehicle (2), comprising the following steps: • (a1) providing a by a power electronics (3) energized and in a motor housing (9) accommodated electrical machine (4), wherein the motor housing (9) has a first window section (11) on its lateral surface (10), • (a2) providing power electronics (3) accommodated in an inverter housing (8), the inverter housing (8) on its lateral surface (12) having a second window section (13), • (a3) providing an electrical interface (7) between the power electronics (3) and the electrical machine (4), by means of which an electrical contact between a first electrical contact means (16), which is electrically conductive with is coupled to the electrical machine (4), and a second electrical contacting means (17) which is electrically conductively connected to the power electronics (3), wherein a retaining element (15) for releasably fixing the first electrical contacting means (16) on is arranged in the motor housing (9), so that the first electrical contact means (16) is held in the holding element (15) during assembly of the motor housing (9) on the inverter housing (8), • (b) connecting the motor housing (9) and the inverter housing (8) to form a detachable structural unit, so that the electric machine (4) accommodated in a motor housing (9) can be connected in the axial direction directly to the electric machine (4) accommodated in an inverter housing (8). Power electronics (3) adjoins and the first window section (11) and the second window section (13) define a common assembly window (14), • (c) removal of the first electrical contacting means (16) from the holding element (15) from the outside through the assembly window (14) • Coupling of the first electrical contacting means (16) with the second electrical contacting means (17).

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