DE102023203148A1 - Electric axle drive for a vehicle in a housing - Google Patents

Abstract

An electric axle drive is proposed for a vehicle (1) in a housing (2) with a first electric machine (EM1) with a first rotor shaft (3) as the drive, wherein the first rotor shaft (3) can be coupled via a first spur gear stage (5) to a first wheel output shaft (6) arranged axially parallel to the first rotor shaft (3) as the output, and with a second electric machine (EM2) with a second rotor shaft (4) is proposed as the drive, wherein the second rotor shaft (4) can be coupled via a second spur gear stage (7) to a second wheel output shaft (8) arranged axially parallel to the second rotor shaft (4) as the output, wherein the rotor shafts (3, 4) of the electric machines (EM1, EM2) are each assigned a pinion with a smaller number of teeth, which engages with a spur gear of the associated spur gear stage (5, 7) with a larger number of teeth. A vehicle (1) with the electric axle drive is also proposed.

Description

The present invention relates to an electric axle drive for a vehicle in a housing with a first electric machine with a first rotor shaft as a drive and a second electric machine with a second rotor shaft as a drive, wherein the rotor shafts can be coupled to wheel output shafts as an output. The invention further relates to a vehicle with the electric axle drive.

Electric axle drives with a first electric machine and a second electric machine for driving two wheel output shafts are generally known from vehicle technology. The two electric machines can be arranged coaxially to the wheel output shafts, which requires a considerable amount of axial space. Furthermore, the two electric machines can also be arranged axially parallel to the wheel output shafts, which requires a considerable amount of radial space, since the two electric machines are coupled to the wheel output shafts via several gear stages to achieve the necessary transmission ratios.

The present invention is based on the object of proposing an electric axle drive and a vehicle with the electric axle drive, in which a compact, simple structure with as few components as possible and high efficiency is realized.

This object is achieved according to the invention by the features of patent claim 1 or 8. Advantageous and claimed further developments emerge from the subclaims and the description as well as the drawings.

Thus, an electric axle drive for a vehicle in a housing is proposed with a first electric machine with a first rotor shaft as a drive, wherein the first rotor shaft can be coupled via a first spur gear stage as a spur gear to a first wheel output shaft arranged axially parallel to the first rotor shaft as an output, and with a second electric machine with a second rotor shaft as a drive, wherein the second rotor shaft can be coupled via a second spur gear stage as a spur gear to a second wheel output shaft arranged axially parallel to the second rotor shaft as an output, wherein the rotor shafts of the electric machines are each assigned a pinion with a smaller number of teeth in order to achieve a sufficient gear ratio, which pinion engages with a spur gear of the assigned spur gear stage with a correspondingly larger number of teeth.

With the proposed axle drive, a very effective drive can be implemented in a very compact manner due to the direct coupling via only one gear stage without an intermediate shaft and the corresponding bearings. The necessary transmission ratio with only one spur gear stage in the proposed axle drive is achieved by assigning a pinion with a smaller dimension in terms of the number of teeth and the diameter to each of the rotor shafts of the electric machine, with the smaller dimensioned pinion engaging with a spur gear of the assigned spur gear stage with a larger dimension in terms of the number of teeth and the diameter.

In a particularly advantageous embodiment variant, a common bearing point is provided in the efficient electric axle drive for an even more compact design with particularly few components in that the axially opposite rotor shafts and the axially opposite wheel output shafts are jointly mounted on a bearing bracket or the like in the housing.

For example, this common bearing can be realized by the bearing bracket in that the bearing bracket has a first bearing receiving area for the mutually facing ends of the first rotor shaft and the second rotor shaft and in that the bearing bracket has a second bearing receiving area for the mutually facing ends of the first wheel output shaft and the second wheel output shaft.

In order to enable a compact and simple design for the electric axle drive, including with regard to the oil supply, the bearing bracket can have oil channels or the like for oil distribution in the housing, which are connected to an oil supply. In this way, the oil can be supplied, for example to the receiving areas and other bearing areas to be supplied, in a space-saving manner and without additional components in the housing of the proposed electric axle drive through the bearing bracket.

Another design variant for the joint bearing of the proposed electric axle drive for the most compact design possible without additional components can be achieved by having the axially opposite rotor shafts and the axially opposite wheel output shafts each mounted inside the other. In this way, the rotor shafts and the wheel output shafts support each other without additional components.

In order to implement a so-called disconnect function in the proposed electric axle drive, it can be provided that at least one switching element is provided for decoupling the drive and output. The switching element can be assigned to the rotor shafts or the spur gear stages or also the wheel output shaft. A positive switching element such as a switching claw or a frictional switching element as a multi-disk clutch can preferably be provided as the switching element. It is also possible for a freewheel or the like to be provided as the switching element in order to decouple the shafts from one another depending on the direction without any actuation being necessary.

As part of a further development of the present invention, it can be provided that at least one of the electric machines can be coupled to the wheel output shafts via a switchable differential gear. This allows the operating mode of the proposed electric axle drive to be expanded, for example by temporarily using only one electric machine as a drive for both wheel output shafts.

The object underlying the invention is also achieved by a vehicle with at least one electric axle drive as described above, resulting in the advantages already described and further advantages.

The present invention is further explained below with reference to the drawings.

• 1 eine schematische Ansicht eines erfindungsgemäßen elektrischen Achsantriebes;
• 2 eine schematische Ansicht einer ersten Lagervariante des elektrischen Achsantriebes;
• 3 eine schematische Ansicht einer zweiten Lagervariante des elektrischen Achsantriebes;
• 4 eine schematische Ansicht möglicher Anordnungspositionen eines oder mehrerer Schaltelemente zum Entkoppeln von Antrieb und Abtrieb; und
• 5 eine schematische Ansicht des elektrischen Achsantriebes mit einem schaltbaren Differentialgetriebe.

They show:

• 1 a schematic view of an electric axle drive according to the invention;
• 2 a schematic view of a first bearing variant of the electric axle drive;
• 3 a schematic view of a second bearing variant of the electric axle drive;
• 4 a schematic view of possible arrangement positions of one or more switching elements for decoupling drive and output; and
• 5 a schematic view of the electric axle drive with a switchable differential gear.

In the 1 to 5 Various embodiments of an electric axle drive according to the invention are shown as examples in a vehicle 1.

The electric axle drive is arranged in a housing 2. The axle drive comprises a first electric machine EM1 with a first rotor shaft 3 as the first drive and a second electric machine EM2 with a second rotor shaft 4 as the second drive. The first rotor shaft 3 can be coupled via a first spur gear stage 5 to a first wheel output shaft 6 arranged axially parallel to the first rotor shaft 3 as the output. The second rotor shaft 4 can be coupled via a second spur gear stage 7 to a second wheel output shaft 8 arranged axially parallel to the second rotor shaft 4 as the output.

As can be seen from the schematically 1 to 5 As can be seen from the dimensions of the components shown, the rotor shafts 3, 4 of the electrical machines EM1, EM2 are each assigned a pinion with a smaller number of teeth, which engages with a spur gear of the associated spur gear stage 5, 7 with a correspondingly larger number of teeth, in order to realize the necessary transmission ratio without additional gear stages in the electric axle drive.

In 2 a first bearing design of the electric axle drive is shown. In this case, it is provided that the opposite ends of the rotor shafts 3, 4 and the axially opposite ends of the wheel output shafts 6, 8 are mounted together in a bearing housing 9 in the housing 2.

The bearing bracket 9 has a first bearing receiving area 10 for the mutually facing ends of the first rotor shaft 3 and the second rotor shaft 4, wherein the ends of the rotor shafts 3, 4 are supported via corresponding bearings in the first bearing receiving area 10. The bearing bracket 9 has a second bearing receiving area 11 for the mutually facing ends of the first wheel output shaft 6 and the second wheel output shaft 8, wherein the ends of the wheel output shafts 6, 8 are supported via corresponding bearings in the second bearing receiving area 11.

The term bearing bracket 9 results from the spectacle-like shape of the bearing bracket 9 when viewed axially. The bearing bracket 9 is supported on the housing 2 via a bearing web.

The housing 2 can preferably be designed in two parts or in several parts. 2 and 3 The housing comprises a first housing half 20 and a second housing half 21, which are divided in the area of the bearing bracket 9 and are fastened to one another.

By arrows in 2 Oil channels 19 integrated into the bearing frame 9 for oil distribution in the housing 2 are indicated, which are connected to an oil supply.

In 3 a second bearing design of the electric axle drive is shown, in which, within the framework of a so-called pilot bearing, it is provided that the axially opposite ends of the rotor shafts 3, 4 and the axially opposite ends of the wheel output shafts 6, 8 are each mounted in one another and thus support one another.

In 4 Possible arrangement positions for the proposed electric axle drive are shown using indicated switching elements 12, 13, 14, 15, 16, 17, wherein the switching elements 12, 13, 14, 15, 16, 17 can be designed as a switching claw, multi-plate clutch or freewheel in order to enable decoupling between the drive and the output.

5 shows a further embodiment of the proposed electric axle drive with a switchable differential gear 18 in order to enable both wheel output shafts 6, 8 to be driven via only one electric machine EM1, EM2.

reference sign

1

vehicle

2

Housing

3

first rotor shaft

4

second rotor shaft

5

first spur gear stage or first spur gear

6

first wheel output shaft

7

second spur gear stage or second spur gear

8

second wheel output shaft

9

storage glasses

10

first bearing receiving area of the bearing glasses

11

second bearing receiving area of the bearing glasses

12

switching element

13

switching element

14

switching element

15

switching element

16

switching element

17

switching element

18

switchable differential gear

19

oil channels

20

first half of the housing

21

second half of the housing

EM1

first electric machine

EM2

second electric machine

Claims (8)

Electric axle drive for a vehicle (1) in a housing (2) with a first electric machine (EM1) with a first rotor shaft (3) as the drive, wherein the first rotor shaft (3) can be coupled via a first spur gear stage (5) to a first wheel output shaft (6) arranged axially parallel to the first rotor shaft (3) as the output, and with a second electric machine (EM2) with a second rotor shaft (4) as the drive, wherein the second rotor shaft (4) can be coupled via a second spur gear stage (7) to a second wheel output shaft (8) arranged axially parallel to the second rotor shaft (4) as the output, wherein the rotor shafts (3, 4) of the electric machines (EM1, EM2) are each assigned a pinion which is smaller in terms of the number of teeth and which engages with a spur gear of the associated spur gear stage (5, 7) which is larger in terms of the number of teeth. Electric axle drive according to claim 1 , characterized in that the axially opposite rotor shafts (3, 4) and the axially opposite wheel output shafts (6, 8) are jointly mounted on a bearing bracket (9) in the housing (2). Electric axle drive according to claim 2 , characterized in that the bearing bracket (9) has a first bearing receiving area (10) for the mutually facing ends of the first rotor shaft (3) and the second rotor shaft (4), and that the bearing bracket (9) has a second bearing receiving area (11) for the mutually facing ends of the first wheel output shaft (6) and the second wheel output shaft (8). Electric axle drive according to one of the Claims 2 or 3 , characterized in that the bearing bracket (9) has oil channels (19) for oil distribution in the housing (2), wherein the oil channels (19) are connected to an oil supply. Electric axle drive according to claim 1 , characterized in that the axially opposite rotor shafts (3, 4) and the axially opposite wheel output shafts (6, 8) are each mounted one inside the other. Electric axle drive according to one of the preceding claims, characterized in that at least one switching element (12, 13, 14, 15, 16, 17) is provided for decoupling the drive and output. Electric axle drive according to one of the preceding claims, characterized in that at least one of the electric machines (EM1, EM2) can be coupled to the wheel output shafts (6, 8) via a switchable differential gear (18). Vehicle (1) with at least one electric axle drive according to one of the preceding claims.

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