WO2020244703A1

WO2020244703A1 - Electric axle drive unit having a two-gear transmission device; and motor vehicle

Info

Publication number: WO2020244703A1
Application number: PCT/DE2020/100387
Authority: WO
Inventors: Laurent BAYOUX; Matthieu Rihn
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2019-06-07
Filing date: 2020-05-08
Publication date: 2020-12-10
Also published as: DE102019115557A1

Abstract

The invention relates to an electric axle drive unit (1) for a motor vehicle (2), having an electric machine (3), a two-gear transmission device (5) having a two-stage planetary gear system (4), wherein an input shaft (6) of the transmission device (5) is connected for conjoint rotation to a rotor (7) of the electric machine (3) and an output shaft (8) of the transmission device (5) can further be connected to an output (9) of a drive train (10), and with a plurality of switching devices (11, 12), each of which can be displaced between an activated position and a deactivated position, no more than two switching devices (11, 12) being used to implement two different transmission ratios between the input shaft (6) and the output shaft (8), the switching devices (11, 12) each being implemented as a brake acting on a sun gear (13, 14) of a gear stage of the planetary gear system (4), or the switching devices (11, 12) each being implemented as a clutch incorporated to act between the input shaft (6) and a component (13, 16) of the planetary gear system. The invention further relates to a motor vehicle (2) having said axle drive unit (1).

Description

Electric axle drive unit with a two-way gear unit;

as well as motor vehicle

The invention relates to an electric axle drive unit (also referred to as electric axle / E-axle for short) for a motor vehicle, such as a car, truck, bus or other commercial vehicle, with an electric machine, a two-speed transmission device having a two-stage Pla designated gear, wherein a The input shaft of the transmission device is non-rotatably connected to a rotor of the electrical machine and an output shaft of the transmission device can be further connected to an output of a drive train, as well as a plurality of switching devices that can be adjusted between an activated fourth position and a deactivated position. In addition, the invention relates to a motor vehicle that is equipped with this electrical Achsan drive unit.

Drive units of the type that can be used in drive trains of a motor vehicle are already sufficiently known from the prior art. In this regard, WO 2018/099542 A1, for example, discloses a switchable two-speed transmission, in particular for e-drive applications. Further prior art is known from DE 10 2018 005 372 A1 and WO 2018/153403 A1.

Thus, on the one hand, applications are already known in which an axle drive unit can be equipped either with a single fixed gear or with two gears. The designs implemented with a fixed gear mostly have the disadvantage that they do not meet the requirements with regard to torque for low speeds and the requirements for high maximum speeds of the vehicle. The disadvantage of the versions implemented with the two gears is that they are mostly designed for electric axles with a relatively low production volume. These axes are therefore relatively complex to manufacture. It is therefore the object of the present invention to remedy these disadvantages known from the prior art and to provide an electric axle drive unit which has an efficient mode of operation in as many required driving states of the motor vehicle as possible and can be produced with little manufacturing effort.

This is achieved according to the invention in that no more than two switching devices are used to convert two different gear ratios between the input shaft and the output shaft, the switching devices each being implemented as a brake acting on a sun gear of a gear stage of the planetary gear or as one between the input shaft and a component of the planetary gear acting clutch is implemented.

As a result, an electrical axle drive unit, which is further improved in terms of its efficiency, is made available, which is simply implemented in structure and can consequently be produced in series in a particularly efficient manner.

Further advantageous embodiments are claimed with the subclaims and explained in more detail below.

First, advantageous statements on the formation of the two Schaltein directions will be discussed as a brake.

Accordingly, it is also advantageous if a first switching device acts on a first sun gear (a first gear stage) of the planetary gear and several first planet gears in meshing engagement with the first sun gear are rotatably mounted on a first planet carrier, which first planet carrier is connected to the input shaft in a rotationally fixed manner is. As a result, the first switching device can be integrated in a space-saving manner. Consequently, it is useful if the first switching device is arranged and designed in such a way that it blocks rotation of the first sun wheel in its activated position and enables free rotation of the first sun wheel in its deactivated position.

If a second switching device acts on a second sun gear (a second gearbox stage) of the planetary gear and several second planet gears in meshing engagement with the second sun gear are rotatably mounted on a second planet carrier, which second planet carrier is non-rotatably connected to the output shaft is also the second switching device can be integrated to save space.

Accordingly, it is also expedient if the second switching device is arranged and designed in such a way that it blocks rotation of the second sun gear in its activated position and enables free rotation of the second sun gear in its deactivated position.

For the formation of the two switching devices as a clutch, the following are particularly advantageous guides.

Accordingly, it is also advantageous if a first shifting device is designed as a clutch that acts between the input shaft and a first sun gear (a first gear stage) of the planetary gear, so that in an activated position of the first shifting device, a drive power between the input shaft and can be transmitted to the first sun gear and, in the deactivated position of the first switching device, no drive power can be transmitted between the input shaft and the first sun gear.

Furthermore, it is useful if a second switching device is designed as a clutch acting between the input shaft and a planet carrier of a first planetary gear set (a first gear stage) of the planetary gear so that, in the activated position of the second switching device, a drive power between the input shaft and the planet carrier of the first planetary gear set can be transmitted and none in the deactivated position of the second switching device Drive power between the input shaft and the planetary carrier of the first Pla designated gear set can be transmitted.

For both designs of the switching device as a brake or clutch, it is also useful if a first ring gear that is in meshing engagement with the first planetary gear set of the planetary gear set is rotatably coupled to a planet carrier of a second planetary gear set of the planetary gear and / or the plane carrier of the first planetary gear set is non-rotatably coupled to a second ring gear in meshing engagement with the second planetary gear set. This results in a clever design of the planetary gear to implement the translations in the corresponding gears of the transmission device.

Furthermore, the invention relates to a motor vehicle that is equipped with at least one axle drive unit of the embodiments described above, the output shaft of the axle drive unit being coupled to output shafts for driving at least two wheels of the motor vehicle.

In other words, an electric axle with two gears is implemented according to the invention. In order to achieve two purely electrical gears, an electrical machine with two brakes is preferably used. No further switching devices are necessary.

The invention will now be explained in more detail with reference to figures.

Show it:

Fig. 1 is a schematic longitudinal sectional view of an inventive

Axle drive unit according to a first embodiment, wherein two shifting devices enabling the different gears of a transmission device are implemented as brakes,

2 shows a diagram to illustrate the various operating modes of the

Axle drive unit according to Fig. 1 with the exemplary selected translations, as they can be implemented through the gears, 3 shows a schematic longitudinal sectional illustration of an inventive

Axle drive unit according to a second embodiment, which differs from the first embodiment in particular by the design of the two switching devices as a clutch,

FIG. 4 shows a diagram to illustrate the operating modes that can be implemented by the axle drive unit according to FIG. 3, together with the gear ratios selected by way of example, and FIG

FIG. 5 is a plan view of a schematically illustrated motor vehicle, as it is with one of the axle drive units of FIGS. 1 and 3 can be equipped.

The figures are only of a schematic nature and are used exclusively for understanding the invention. The same elements are provided with the same reference numerals.

With the FIGS. 1 and 3, two differently designed axle drive units 1 according to the invention are illustrated. The illustrated with Fig. 1 electrical Achsan drive unit 1 according to a first embodiment is constructed and functions essentially in accordance with the axle drive unit 1 of the second embodiment according to FIG. 3. For the sake of brevity, only the differences between these two exemplary embodiments are described below.

As can initially be seen in FIG. 1 with regard to the first exemplary embodiment, the axle drive unit 1 is implemented as a purely electric axle drive unit 1. This electric axle drive unit 1 thus has an electric machine 3 which alone forms a drive motor of a drive train 10 of a motor vehicle 2 indicated in connection with FIG.

With FIG. 1 it is further clear that the electrical machine 3 typically has a stator 25 and a rotor 7 that is rotatably mounted relative to this stator 25. The rotor 7 is directly connected to an input shaft 6 of a gear unit 5 of the axle drive unit 1 in a rotationally fixed manner. The transmission device 5 has furthermore a two-stage planetary gear 4. In the first exemplary embodiment, the planetary gear 4 is connected non-rotatably to the input shaft 6 on the input side (on the part of a planetary carrier 16) and non-rotatably connected to an output shaft 8 on the output side.

Furthermore, it can be seen in principle in Fig. 1 that the output of the axle drive unit 1, i.e. the output shaft 8 can be connected to other devices provided in the drive train 10 of the motor vehicle 2. In this embodiment, the output shaft 8 merges into an element of an output 9, referred to as final drive 26, which final drive 26 / output is in turn coupled to a differential 27. Two output shafts 24a, 24b are typically coupled to the differential 27, which output shafts 24a, 24b are rotatably connected to wheels 23a and 23b of the motor vehicle 2 as shown in FIG.

With regard to the further structure of the planetary gear 4, it should be noted that a first gear stage of this planetary gear 4 / the gear device 5 is also formed by a first planetary gear set 19. The first planetary gear set 19 is rotatably mounted on a first planet carrier 16. Consequently, a plurality of first planet gears 15 of the first planetary gear set 19, which are arranged distributed in the circumferential direction, are each rotatably supported on the first planet carrier 16. In the embodiment according to FIG. 1, the first planetary carrier 16 is connected directly and permanently to the input shaft 6 and thus to the rotor 7 in a rotationally fixed manner. A first sun gear 13 is in meshing engagement with the first planetary gear set 19. The first planetary gear set 19 is also in tooth engagement with a first flea wheel 20. The first flea wheel 20, the first planetary gear set 19, with the first planet carrier 16, and the first sun gear 13 thus together form the first gear stage.

A second gear stage of the planetary gear 4 / the gear unit 5 is also formed by a second planetary gear set 21. The second planetary gear set 21 is rotatably mounted on a second planet carrier 18. In particular, a plurality of second planet gears 17 of the second planetary gear set 21, which are arranged distributed in the circumferential direction, are each rotatably received on the second planet carrier 18. The second planetary carrier 18 is directly rotated with the output shaft 8 verbun the. The second gear stage also has a second sun gear 14, which is in meshing engagement with the second planetary gear set 21. The second gear stage also has a second ring gear 22, which is also in meshing engagement with the second planetary gear set 21. It can also be seen that the first planetary carrier 16 is permanently connected to the second ring gear 22 in a rotationally fixed manner. The first ring gear 20 is permanently non-rotatably connected to the second plane carrier 18.

According to the invention, no more than two shifting devices 1 1, 12 are additionally available in order to shift exactly two gears of the transmission device 5 / of the planetary gear 4. The two switching devices 11 and 12 are thus used to convert two different gear ratios between the input shaft 6 and the output shaft 8.

In the first exemplary embodiment according to FIG. 1, a first switching device 11 and a second switching device 12 are each implemented as a brake. The first switching device 1 1 acts on the first sun gear 13. The second switching device 12 acts on the second sun gear 14. The first switching device 11 thus holds the first sun gear 13 in its activated position relative to an area 28 fixed to the vehicle frame. In a deactivated position of the first switching device 11, the first switching device 11 enables rotation of the first sun gear 13.

According to the design of the first switching device 1 1, the second Schaltein direction 12 is constructed. The second switching device 12 thus has a blocking effect on the second sun gear 14 in its activated position and holds it in place relative to the area 28 fixed to the vehicle frame. In a deactivated position of the second switching device 12, free rotation of the second sun gear 14 is made possible.

In conjunction with Fig. 2, the two different Getriebübersetzun conditions / gears, as they are made possible by the two switching devices 1 1, 12 according to FIG. 1, shown by way of example with regard to their translations. In a übli chen pure electric drive (pure electric operation) of the axle drive unit 1 1 (first Operating state) a first gear is switched between the input shaft 6 and the output shaft 8 by the first switching device 11 is brought into its deactivated position and the second switching device 12 is brought into its activated position. In this first gear there is, for example, a translation of the planetary gear 4 / between the input shaft 6 and the output shaft 8 of i1 = 1.5.

In a second gear of the axle drive unit 1, the first switching device 11 is in its activated position and the second switching device 12 is in its deactivated position. This results in a translation of the planetary gearbox 4 of i2 = 0.74.

Since the final drive 26 also has a gear ratio of 9, there is a total gear ratio of 13.5 in first gear and 6.66 in second gear. A gear jump between first gear and second gear is therefore 2.03.

In a further second operating state of the axle drive unit 1, it is possible to drive backwards, which is also purely electrically. Here, the first switching device 11 is preferably in its deactivated position and the second switching device 12 in its activated position. This in turn results in a ratio of 1.5.

The illustrated with Fig. 3 second embodiment differs from the first embodiment in particular by forming the two switching devices 1 1, 12. In this embodiment, too, only two switching devices 1 1, 12 are present. Each of the two switching devices 1 1, 12 is implemented as a clutch used between the input shaft 6 and an input-side component of the planetary gear 4, namely the first sun gear 13 and the first Planetenträ ger 16 acting.

The first switching device 1 1 is used between the input shaft 6 and the first Son nenrad 13 acting. The second switching device 12 is used between the A output shaft 6 and the first planetary carrier 16 acting. In an activated position of the first switching device 1 1, the input shaft 6 and the first are Sun gear 13 rotatably connected to one another. In a deactivated position of the first switching device 11, the input shaft 6 is decoupled from the first sun gear 13 for rotation and thus freely rotatable relative to this. In an activated position of the second switching device 12, the input shaft 6 is non-rotatably connected to the first plane carrier 16 and in a deactivated position of the second switching device 12 is decoupled from the latter in terms of rotation.

Furthermore, in the second exemplary embodiment, the second sun gear 14 is permanently connected to the area 28 fixed to the vehicle frame and is thus held in place relative to it.

As can again be seen in Fig. 4, a first gear in the first Antriebszu was between the input shaft 6 and the output shaft 8 by activating the first switching device 1 1 and deactivating the second switching device 12 it is enough. A gear ratio of i1 = 2.75 occurs in first gear. In the second gear, the first switching device 1 1 is deactivated and the second switching device 12 is activated. This results in a ratio of 1.5. In the second operating state according to reversing, the first switching device 11 is activated and the second switching device 12 is deactivated. This results in a ratio of 2.75. The Final Drive 26 has a gear ratio of 4.8. This results in a total gear ratio of 13.2 in first gear and 7.2 in second gear. A gear jump between first gear and second gear results in fleas of 1.83.

In other words, according to the invention, an electric axle 1 / e-drive with two gears is proposed. In addition to an electrical machine 3, two brakes 1 1, 12 are present in a preferred embodiment in order to obtain two pure electrical gears. In a further embodiment, the brakes 1 1, 12 are replaced by clutches 1 1, 12. List of reference symbols for axle drive unit

Motor vehicle

electric machine

Planetary gear

Transmission device

Input shaft

rotor

Output shaft

Downforce

Powertrain

first switching device

second switching device

first sun gear

second sun gear

first planet gear

first planet carrier

second planet gear

second planet carrier

first planetary gear set

first ring gear

second planetary gear set

second ring gear

a first wheel

b second wheel

a first output shaft

b second output shaft

stator

Final Drive

differential

area fixed to the vehicle frame

Claims

1. Electric axle drive unit (1) for a motor vehicle (2), with an electrical machine's (3), a two-stage planetary gear (4) having two-speed gear device (5), an input shaft (6) of the Ge gear device (5) with a rotor (7) of the electrical machine (3) is rotatably connected and an output shaft (8) of the transmission device (5) with an output (9) of a drive train (10) can be further connected, as well as several between an activated position and a deactivated position adjustable shifting devices (11, 12), characterized in that no more than two shifting devices (11, 12) are used for converting two different gear ratios between the input shaft (6) and the output shaft (8), the shifting devices (11, 12) are implemented as a brake acting on a sun gear (13, 14) of a gear stage of the planetary gear (4).

2. Axle drive unit (1) according to claim 1, characterized in that a first switching device (11) acts on a first sun gear (13) of the planetary gear (4) and a plurality of first planet gears (15) in meshing engagement with the first sun gear (13) ) are rotatably mounted on a first planet carrier (16), which first planet carrier (16) is non-rotatably connected to the input shaft (6).

3. Axle drive unit (1) according to claim 2, characterized in that the first switching device (11) is arranged and designed such that it blocks a rotation of the first sun gear (13) in its activated position and a free rotation of the in its deactivated position first sun gear

(13) allows.

4. axle drive unit (1) according to one of claims 1 to 3, characterized in that a second switching device (12) on a second sun gear

(14) of the planetary gear (4) acts and several with the second Son nenrad (14) located in meshing second planetary gears (17) on one second planet carrier (18) are rotatably mounted, which second planet carrier (18) rotates is connected to the output shaft (8).

5. Axle drive unit (1) according to claim 4, characterized in that the second switching device (12) is arranged and designed such that it blocks rotation of the second sun gear (14) in its activated position and free rotation in its deactivated position the second Son nenrades (14) allows.

6. Electric axle drive unit (1) for a motor vehicle (2), with an electrical machine's (3), a two-stage planetary gear (4) having two-speed gear device (5), an input shaft (6) of the Ge gear device (5) with a rotor (7) of the electrical machine (3) is rotatably connected and an output shaft (8) of the transmission device (5) with an output (9) of a drive train (10) can be further connected, as well as several between an activated position and a deactivated position adjustable shifting devices (11, 12), characterized in that no more than two shifting devices (11, 12) are used for converting two different gear ratios between the input shaft (6) and the output shaft (8), the shifting devices (11, 12) are each implemented as a coupling acting between the input shaft (6) and a component (13, 16) of the planetary gear (4).

7. Axle drive unit (1) according to claim 6, characterized in that a first switching device (11) is designed as a clutch used between the input shaft (6) and a first sun gear (13) of the planetary gear (4) acting so that in a In the activated position of the first switching device (11), a drive power can be transmitted between the input shaft (6) and the first sun gear (13) and in the deactivated position of the first switching device (11) no drive power between the input shaft (6) and the first sun gear ( 13) is transferable.

8. axle drive unit (1) according to claim 6 or 7, characterized in that a second switching device (12) as one between the input shaft (6) and a planet carrier (16) of a first planetary gear set (19) of the planetary gear (4) acting clutch is formed so that in the activated fourth position of the second switching device (12) a drive power between the input shaft (6) and the planet carrier ( 16) of the first planetary gear set (19) is transferable and in the deactivated position of the second switching device (12) no drive power can be transferred between the input shaft (6) and the planet carrier (16) of the first planetary gear set (19).

9. axle drive unit (1) according to any one of claims 1 to 8, characterized in that a with the first planetary gear set (19) of the planetary gear (4) located in meshing first ring gear (20) with a planet carrier

(18) of a second planetary gear set (21) of the planetary gear (4) is rotatably coupled and / or the planet carrier (16) of the first planetary gear set

(19) is rotatably coupled to a second ring gear (22) in tooth engagement with the second planetary gear set (21).

10. Motor vehicle (2) with an axle drive unit (1) according to one of claims 1 to 9, wherein the output shaft (8) of the axle drive unit (1) is coupled to drive at least two wheels (23a, 23b) with output shafts (24a, 24b) .