DE102020211067A1 - Electric propulsion, powertrain and method - Google Patents

Abstract

The invention relates to an electric drive for a vehicle, comprising: an electric machine (2), the rotor (2.1) of which is connected to an input shaft (11) of a first planetary gear set (7), an output shaft (12) arranged coaxially with the input shaft (11), and three shifting elements (3, 4, 5) for engaging gears, the first planetary gear set being designed as a stepped planetary gear whose planetary gears (7.3, 7.4) mounted on a planetary carrier (7.5) have two different effective diameters, with a first sun gear (7.1) of the planetary gearset (7) with the larger effective diameter (7.3) of the planetary gears is in meshing engagement, with a second sun gear (7.2) of the planetary gearset (7) with the smaller effective diameter (7.4) of the planetary gears being in meshed engagement, with a ring gear ( 7.6) of the planetary gear set (7) with the larger effective diameter (7.3) is in tooth engagement. The first sun gear (7.1) of the planetary gear set (7) is non-rotatably connected to the first input shaft (11). The second sun gear (7.2) of the planetary gear set (7) is non-rotatably connected to the output shaft (12). A first switching element (3) is designed to fix the planet carrier (7.5) of the planetary gear set (7) to a non-rotatable component (0). A second switching element (4) is designed to lock the planetary gear set (7). A third switching element (5) is designed to fix the ring gear (7.6) on the non-rotatable component (0).

Description

The invention relates to an electric drive transmission for an electric drive of a vehicle, a drive train with such a transmission and a method for shifting the same.

the WO 2014/029650 relates to a drive unit for an electrically driven vehicle, with an electric machine and a transmission with a first planetary gear set having a first sun gear, at least one first planetary gear and a first ring gear, and a second planetary gear set having a second sun gear, at least one second planetary gear and a second ring gear Planetary gear set, wherein the first and the second sun gear are arranged coaxially and the first and second planetary gear are rotatably mounted on a common planetary carrier, and wherein the drive shaft of the electric machine is drive-connected to the first sun gear, and at least one ring gear can be held in place via a braking device. The second sun gear of the second planetary gear set is connected to an output shaft and at least a first planet gear of the first planetary gear set is rotatably connected to a second planet gear of the second planetary gear set.

The object of the present invention is to provide an alternative electric drive for a motor vehicle and an alternative drive train. In particular, an electric drive or a drive train is to be provided that is axially short. In addition, a method for switching the electric drive is to be provided. The object is solved by the features of the independent claims. Preferred embodiments emerge from the dependent claims

According to a first aspect of the invention, an electric drive for a vehicle is provided. The electric drive comprises an electric machine, the rotor of which is connected to an input shaft of a first planetary gear set, an output shaft arranged coaxially to the input shaft, and three, preferably exactly three, shifting elements for engaging gears. The first planetary gear set is designed as a stepped planetary gear, whose planetary gears mounted on a planetary gear carrier have two different effective diameters. A first sun gear of the planetary gear set meshes with the larger effective diameter of the planetary gears. A second sun gear of the planetary gear set meshes with the smaller effective diameter of the planetary gears. A ring gear of the planetary gear set meshes with the larger effective diameter. The first sun gear of the planetary gear set is non-rotatably connected to the first input shaft. The second sun gear of the planetary gear set is non-rotatably connected to the output shaft. A first switching element is designed to fix the planet carrier of the planetary gear set to a non-rotatable component. A second shifting element is designed to block the planetary gear set. A third switching element is designed to fix the ring gear on the non-rotatable component.

A respective non-rotatable connection of the rotatable components of the electric drive is preferably implemented according to the invention via one or more intermediate shafts, which can also be present as short intermediate pieces when the components are spatially close together. In concrete terms, the components that are permanently connected to one another in a rotationally fixed manner can each be present either as individual components that are connected to one another in a rotationally fixed manner or also in one piece. In the second-mentioned case, the respective components and the shaft that may be present are then formed by a common component, this being realized in particular when the respective components in the transmission are spatially close to one another.

In the case of components of the electric drive which are connected to one another in a rotationally fixed manner only by actuation of a respective switching element, a connection is also preferably implemented via one or more intermediate shafts. Fixing takes place in particular by non-rotatable connection with a non-rotatable component of the transmission, which is preferably a permanently stationary component, preferably a housing of a transmission, a part of such a housing or a non-rotatably connected component. The "connection" of the rotor of the electric machine to the input shaft is to be understood as such a connection that there is a constant speed dependency between the rotor of the electric machine and the input shaft.

If a planetary gear set is blocked, the translation is always one, regardless of the number of teeth. In other words, the planetary gear set rotates as a block. The blocking can be brought about in particular by the second switching element connecting the first sun gear and the second sun gear to one another or connecting the second sun gear and the planet carrier sun gear to one another.

The electric drive enables up to three gears to be shifted, preferably exactly three gears. It is preferred if, by closing the first shifting element, a first gear; and/or a second gear by closing the third shifting element; and/or by closing the second Switching element results in a third gear. In first gear there is a ratio of i>1. The ratio of the third gear is 1.0. This gear is a direct gear that occurs when the planetary gear set is blocked. The translation of the second gear is between the first and the third gear. The efficiencies of this preferred connection are very high. In 1st gear, an efficiency of 97.5% can be achieved. In second gear, an efficiency of 98.5% can be achieved. In third gear, 100% efficiency can be achieved.

The electric drive enables an output that is axis-parallel to the input shafts or also coaxial. The transmission can therefore be used in particular for a front-transverse drive train of a motor vehicle. The electric drive according to the invention manages without a second ring gear, so that a three-speed electric drive can be provided that has few components. It is preferred if the planetary gear set is arranged radially inside the rotor, which means that this electric drive is particularly short axially. It is also preferred if the output shaft is arranged within the hollow input shaft.

The individual switching elements can be present both as a non-positive and as a form-fitting switching element. Force-locking or friction-locking shifting elements are, for example, multi-plate shifting elements, in particular in the form of multi-plate clutches. Positive shifting elements are, for example, claw shifting elements and cone shifting elements in the form of claw or cone clutches. If the shifting elements are in the form of non-positive shifting elements, the three gears can be fully shifted under power. The switching elements can be arranged axially next to one another. However, it is also possible for two of the shifting elements to be axially separated by the planetary gear set.

According to a second aspect of the invention, a powertrain for a vehicle is provided. The powertrain includes an electric drive according to the first aspect of the invention and a differential device connected to the output shaft of the first planetary gear set. The differential device can be formed in many ways. The individual advantages of the electric drive apply mutatis mutandis to the drive train.

A drive train is preferred if the differential device comprises a bevel gear differential and a transmission gear in the form of a second planetary gear set, the sun gear of the second planetary gear set being connected to the second sun gear of the first planetary gear set, the planet carrier being connected to an input element of the bevel gear differential, the ring gear on the non-rotatable component is fixed.

A drive train is preferred if the differential device comprises a bevel gear differential and a transmission gear in the form of a single-stage spur gear stage with a first spur gear and a second spur gear, the first spur gear being non-rotatably connected to the second sun gear of the stepped planetary gear set and meshing with the second spur gear second Stirnra is rotatably connected to an input element of the bevel gear differential. Such an arrangement is an example of an axis-parallel output and is axially particularly compact.

A drive train is preferred if the differential device comprises a bevel gear differential and a transmission gear in the form of a two-stage spur gear stage with a first spur gear, a second spur gear and a third spur gear, with the first spur gear being non-rotatably connected to the second sun gear of the stepped planetary gear set and to the third spur gear in Gear meshing is, the third spur gear is non-rotatably connected to the second spur gear, and the second spur gear is non-rotatably connected to an input element of the bevel gear differential. Such an arrangement is an example of an axis-parallel output and is axially particularly compact.

A drive train is preferred if the differential device comprises a second planetary gear set and a third planetary gear set, the sun gear of the second planetary gear set being connected to the second sun gear of the first planetary gear set, the planet carrier being connected to a first output shaft, the ring gear of the second planetary gear set being connected to the sun gear of the third planetary gear set is connected, the planet carrier is fixed to the non-rotatable component, the ring gear is connected to a second output shaft.

The drive train is particularly short axially if the first planetary gear set is arranged radially inside the rotor. It is also short if the differential device is arranged radially inside the rotor.

According to a third aspect of the invention, a method for shifting the electric drive and/or the drive train is provided. In a first gear, the first shifting element is closed and the second shifting element and the third shifting element are opened. In a second gear, the third shift element is closed and the first shift element and the second shift items are opened. In a third gear, the second shifting element will be closed and the first shifting element and the third shifting element will be opened.

• 1-3 jeweils eine schematische Ansicht eines Kraftfahrzeugantriebsstrangs eines Fahrzeugs bei welchem das erfindungsgemäße Getriebe zur Anwendung kommt;
• 4 eine schematische Ansicht eines Elektroantriebs in einer bevorzugten Ausführungsform;
• 5 eine Schaltmatrix des Elektroantriebs aus 4;
• 6-11 jeweils eine schematische Ansicht eines Getriebes in einer bevorzugten Ausführungsform; und
• 12-16 jeweils eine schematische Ansicht eines Antriebsstrangs in einer bevorzugten Ausführungsform.

Advantageous embodiments of the invention, which are explained below, are shown in the drawings. It shows:

• 1-3 in each case a schematic view of a motor vehicle drive train of a vehicle in which the transmission according to the invention is used;
• 4 a schematic view of an electric drive in a preferred embodiment;
• 5 a switching matrix of the electric drive 4 ;
• 6-11 each a schematic view of a transmission in a preferred embodiment; and
• 12-16 each a schematic view of a drive train in a preferred embodiment.

1 until 3 each show a schematic view of a motor vehicle drive train 100 of a vehicle 1000. The vehicle is a passenger car.

The powertrain 100 according to FIG 1 shows an electric drive that drives the front axle B of the vehicle 1000 . The drive train 100 includes a transmission 1 with a planetary gear set, not shown, which divides the drive torque of the electric machine 2 over two output shafts 9.11 and 9.12. The drive train 100 also includes a differential device, which has a bevel gear differential 9 and a transmission 14 in the form of a spur gear. The transmission 1 and electric machine 2 are arranged coaxially to an axis A. Axis A and axis B are arranged paraxially, so that there is an paraxial output. The forward direction of travel is represented by the arrow 99 . As also in 1 can be seen, the transmission 1 and the electric machine 2 are aligned transversely to the direction of travel 99 of the vehicle 1000 .

The powertrain 100 according to FIG 2 shows an electric drive that drives the front axle B of the vehicle 1000 . The drive train includes a transmission 1 with a planetary gear set, not shown, which divides the drive torque of the electric machine 2 over two output shafts 9.11 and 9.12. The drive train 100 also includes a differential device, which includes a planetary gear 8 and a bevel gear differential 9 . Transmission 1 and electric machine 2 are arranged coaxially to an axis A, which coincides with the drive axis B, so that there is a coaxial output. The forward direction of travel is represented by the arrow 99 . As also in 2 can be seen, the transmission 1 and the electric machine 2 are aligned transversely to the direction of travel 99 of the vehicle 1000 .

The powertrain 100 according to FIG 3 shows an electric drive that drives the front axle B of the vehicle 1000 . The drive train includes a transmission 1 with a planetary gear set, not shown, which divides the drive torque of the electric machine 2 over two output shafts 13.11 and 8.12. The drive train 100 also includes a differential device which includes two planetary gears 8 , 13 . Transmission 1 and electric machine 2 are arranged coaxially to an axis A, which coincides with the drive axis B, so that there is a coaxial output. The forward direction of travel is represented by the arrow 99 . As also in 3 can be seen, the transmission 1 and the electric machine 2 are aligned transversely to the direction of travel 99 of the vehicle 1000 .

4 shows a transmission 1 and an electric machine 2 as part of an electric drive in a first embodiment of the invention, as can be used, for example, in the drive train 100 of the vehicle 1000 . The electric drive comprises an electric machine 2, the rotor 2.1 of which is connected to an input shaft 11 of a first planetary gear set 7, an output shaft 12 arranged coaxially with the input shaft 11, and three shifting elements 3, 4, 5 for engaging gears.

The first planetary gear set 7 is designed as a stepped planetary gear. The stepped planetary gear has two planetary gears 7.3, 7.4 mounted on a planetary gear carrier 7.5 and having two different effective diameters. A first sun gear 7.1 of the planetary gear set 7 meshes with the larger effective diameter 7.3 of the planetary gears. A second sun gear 7.2 of the planetary gear set 7 meshes with the smaller effective diameter 7.4 of the planetary gears. A ring gear 7.6 of the planetary gear set 7 meshes with the larger effective diameter 7.3.

The first sun gear 7.1 is connected to the first input shaft 11 in a torque-proof manner. The second sun gear 7.2 of the planetary gear set 7 is connected to the output shaft 12 in a rotationally fixed manner. A first switching element 3 is designed to fix the planetary gear carrier 7.5 of the planetary gearset 7 to a non-rotatable component 0. The non-rotatable component 0 is in this case a housing of the transmission 1. If the first shifting element 3 is actuated, the planetary gear wheel is accordingly eng 7.5 rotatably connected to the housing. A second shifting element 4 is designed to block the planetary gear set 7 . This is done according to the embodiment according to 4 characterized in that in the actuated state of the second switching element 4, the planetary gear carrier 7.5 is non-rotatably connected to the second sun gear 7.2. A third switching element 5 is designed to fix the ring gear 7.6 of the planetary gear set 7 on the non-rotatable component 0. So if the third switching element is actuated, the ring gear 7.6 is fixed to the transmission housing and is thus prevented from rotating. The three switching elements 3, 4, 5 are each designed as a multi-plate clutch.

The input shaft 11 and the output shaft 12 are arranged axially offset from one another, that is, the drive axis A and the output axis B coincide. The ring gear 7.6 is at least partially hollow. The planet carrier 7.5 is also partially hollow. The output shaft 12 designed as a solid shaft is guided through the hollow shaft 7.5. The hollow shaft 7.5 in turn is guided through the hollow shaft 7.6.

The planetary gear set 7 is arranged radially inside the rotor 2.1 of the electric machine 2. The three switching elements 3, 4, 5 are arranged axially side by side. The result is the axial sequence of first planetary gearset 7, third shifting element 5, first shifting element 3 and second shifting element 4. If first shifting element 3 is engaged, a first electric gear is displayed. By actuating the third switching element 5, a second electrical gear is displayed. By actuating the second switching element 5, a third electrical gear is displayed. In first gear, the efficiency is approximately 97.5%. In second gear, the efficiency is about 98.5%. In third gear, i.e. in direct gear, an efficiency of approx. 100% is achieved. Since the shifting elements are multi-plate clutches, all gears can be shifted under full power.

5 shows a shift matrix of the transmission 4 . Three forward gears E1, E2 and E3 are listed in the rows of the matrix. An “X” in the columns of the switching matrix shows which of the switching elements 3, 4 and 5 are closed in which gear. Closing the first shifting element 3 creates a first gear E1, closing the third shifting element 5 creates a second gear E2 and closing the second shifting element 4 creates a third gear E3. During the first gear E1, the second and third shifting element 4, 5 are open. During the second gear E2, the first and second shifting element 3, 4 are open. During the third gear E3, the first and third shifting element 3, 5 are open. In first gear E1, the translation is greater than 1. In third gear, the translation is exactly 1. In second gear, the translation is between first and third gear.

6 shows an electric drive in a second embodiment of the invention for a drive train 100 of a vehicle. In contrast to the embodiment according to 4 the planetary gear set 7 is arranged axially between the second shifting element 4 and the third shifting element 5 . For this purpose, the input shaft 11 is designed as a hollow shaft. A part of the output shaft 12 is guided through the hollow shaft 11 . In this embodiment, the blocking takes place in that the second switching element 4 in the actuated state connects the two sun gears 7.1, 7.2 to one another in a rotationally fixed manner. In addition, this embodiment corresponds to the embodiment according to FIG 4 , so that reference is also made to these statements.

7 shows an electric drive in a third embodiment of the invention for a drive train 100 of a vehicle. In contrast to the embodiment according to 4 the first switching element 3 is designed as a claw switching element. The planetary gear set is arranged axially between the first shifting element 3 and the second shifting element 4 . The traction-power shift from first gear to second gear and from second gear to third gear and vice versa are still possible with multi-plate clutches 4, 5. Overrun/power shifting from third gear to second gear is also possible. An even cheaper electric drive can be provided by a first shifting element 3 designed as a claw clutch. In addition, this embodiment corresponds to the embodiment according to FIG 4 , so that reference is also made to these statements.

8th shows an electric drive in a fourth embodiment of the invention for a drive train 100 of a vehicle. In contrast to the embodiment according to 4 the first shifting element 3 is designed as a claw shifting element, which is arranged axially between the planetary gear set 7 and the second shifting element 4 . The traction-power shift from first gear to second gear and from second gear to third gear and vice versa are still possible with multi-plate clutches 4, 5. Overrun/power shifting from third gear to second gear is also possible. An even cheaper electric drive can be provided by a first shifting element 3 designed as a claw clutch. In addition, this embodiment corresponds to the embodiment according to FIG 6 , so that reference is also made to these statements.

9 shows an electric drive in a fifth embodiment of the invention for a drive train 100 of a vehicle. In contrast to the embodiment according to 4 all three shifting elements are designed as claw shifting elements, with the first shifting element 3 being arranged axially between the third shifting element 5 and the second shifting element 4 . Shifting elements 3 and 5 are designed as a double shifting element, to which an actuating element is assigned, whereby the first shifting element 3 and the third shifting element 5 can be actuated from a neutral position via the actuating element. The double switching element thus has three switching positions. By simultaneously closing two of the three switching elements, the planetary gear set and thus the output are blocked against the housing. In other words, the electric machine 2 and thus also the output (output shaft 12) are braked or blocked by the locked wheel set 5 against the housing 0. A parking lock function can be displayed in this way. In addition, this embodiment corresponds to the embodiment according to FIG 4 , so that reference is also made to these statements.

10 shows an electric drive in a sixth embodiment of the invention for a drive train 100 of a vehicle. In contrast to the embodiment according to 9 the three claw shifting elements 3 , 4 , 5 are axially separated by the planetary gear set 7 , with the planetary gear set 7 now being arranged axially between the second shifting element 4 and the third shifting element 5 . The claw 4 is arranged radially outside of the rotor 2.1. The input shaft 11 is at least partially designed as a hollow shaft. The output shaft 12 is partially guided through this hollow shaft. In addition, this embodiment corresponds to the embodiment according to FIG 9 , so that reference is also made to these statements.

11 shows an electric drive in a seventh embodiment of the invention for a drive train 100 of a vehicle. In contrast to the embodiment according to 4 the first and second shifting element 3, 4 are designed as claw shifting elements, with these shifting elements also being designed as a double shifting element, to which an actuating element is assigned, with the first shifting element 3 on the one hand and the second shifting element 4 on the other hand being able to be actuated via the actuating element from a neutral position is. The double switching element thus has three switching positions. The third shifting element 5 is designed as a multi-disk clutch in order to enable a traction power shift from first gear E1 to second gear E2 and vice versa. This makes sense because the drop in traction at low speeds would otherwise be felt by the vehicle occupants. When shifting from first gear E1 to third gear E3 at higher speeds, on the other hand, this is hardly noticeable. In addition, this embodiment corresponds to the embodiment according to FIG 4 , so that reference is also made to these statements.

The following 12 until 16 show a drive train comprising a transmission 1, an electric machine 2 and a differential device which is connected to the output shaft 12 of the first planetary gear set 7.

12 therefore shows a preferred first drive train comprising the electric drive according to FIG 4 and a differential device, the differential device being formed by a second planetary gear set 8 and a bevel gear differential 9 . Drive axis A and output axis B coincide. Accordingly, there is a coaxial output.

The bevel gear differential 9 has two wheel-side driven elements, which are designed as a first driven wheel 9.1 and a second driven wheel 9.2. The driven gears 9.1, 9.2 each mesh with a compensating element 9.3 designed as a spur gear. The compensating elements 9.3 are rotatably mounted about their own axis in a differential cage 9.4. The first output gear 9.1 is non-rotatably connected to a first output shaft 9.11 and the second output gear 9.2 to a second output shaft 9.12. The differential gears 9.3, which act between the cage 9.4 and the two driven gears 9.1, 9.2, can transmit a rotational movement from the cage 9.4 to the two driven gears 9.1, 9.2 and provide a compensating rotational movement between the two driven gears 9.1, 9.2.

The negative planetary gear set 8 comprises a ring gear 8.3 fixed to the transmission housing 0, a planet carrier 8.2 and a sun gear 8.1. The planet carrier 8.2 is rotatably connected to the cage 9.4. In the present case, the cage 9.4 also serves as an input element of the differential. The sun gear 8.1 is connected to the output shaft 12 in a torque-proof manner. The planetary gear sets 7 and 8 and the bevel gear differential 9 are arranged axially next to one another, with the second planetary gear set 8 being arranged axially between the first planetary gear set 7 and the bevel gear differential 9 . The shafts 11, 12 are each designed as a hollow shaft. The second output shaft 9.12 is guided through the respective hollow shaft 11, 12. A combination of the transmission 1 with a minus planetary gear set is advantageous because it allows a high overall transmission ratio 6<i<18.5 to be generated. by means of the cone wheel differentials, the torque is passed to the two output shafts 9.11, 9.12.

This embodiment enables an axially compact drive train with a high overall transmission ratio. For the rest, the transmission corresponds to 1 acc. 12 according to the gearbox 4 , so that reference is made to these statements.

13 shows a preferred second drive train. Unlike in 12 the bevel gear differential 9 is arranged radially inside the rotor 2.1. The first planetary gear set 7 is arranged axially between the differential 9 and the second planetary gear set 8 . In this embodiment, the first output shaft 9.11 is guided through the respective hollow shaft 11, 12. This embodiment also enables an axially compact drive train. For the rest, the drive train 100 acc. 13 according to the drive train 12 , so that reference is made to these statements.

14 shows a preferred third drive train comprising the electric drive according to FIG 9 and a differential device, the differential device being formed by a second planetary gear set 8 and a third planetary gear set 13 . Drive axis A and output axis B coincide. Accordingly, there is a coaxial output. The planetary gear set 8 includes a sun gear 8.1, a planet carrier 8.2 and a ring gear 8.3. The planetary gear set 13 includes a sun gear 13.1, a planet carrier 13.2 and a ring gear 13.3. Planetary gearset 8 and 13 are arranged radially one above the other, with the planetary gearset 8 being arranged radially inward. Ring gear 8.3 is non-rotatably connected to sun gear 13.1. Ring gear 8.3 and sun gear 13.1 are designed in one piece according to this embodiment. The planet carrier 13.2 is fixed. The sun gear 8.1 is connected to the output shaft 12. The ring gear 13.1 is connected to a first output shaft 13.11. The planet carrier 8.2 is connected to a second output shaft 8.12.

The shafts 11, 12 are each designed as a hollow shaft. The second output shaft 8.12 is guided through the respective hollow shaft 11, 12 and is connected at one axial end to the planet carrier 8.2. In other words, a so-called integrated differential is used in this embodiment. The function of generating the overall gear ratio and the differential function are simultaneously represented via this differential gear set. For the rest, the transmission 1 corresponds to the embodiment according to FIG. 9 , so that reference is made to these statements.

15 shows a preferred fourth drive train comprising the electric drive according to FIG 10 as well as a differential device, the differential device comprising a bevel gear differential 9 and a transmission gear, the transmission gear being formed by a single-stage spur gear stage 14 . Unlike the electric drive according to 9 the first and third switching elements 3, 5 are each designed as a single switching element. Accordingly, both switching elements 3, 5 can be inserted at the same time. As a result, the electric machine 2 and thus also the output (output shaft 12) are braked or blocked by the blocked planetary gear set 7 against the housing 0. A parking lock function can be displayed in this way. However, the switching elements could also be designed as lamellar switching elements. In addition, the electric drive corresponds to that of 10 . The output axis B is arranged axis-parallel to the input axis A. There is therefore an axis-parallel output. The single-stage transmission of the spur gear stage causes the overall transmission from axis A of the input to axis B of the output. The spur gear includes two spur gears 14.1 and 14.2. The spur gear 14.1 is non-rotatably connected to the output shaft 12 and meshes with the spur gear 14.2. The spur gear 14.2 is non-rotatably connected to the cage 9.4 and can drive it.

16 shows a preferred fifth powertrain. This embodiment differs from the embodiment according to FIG 15 characterized in that the transmission gear is formed by a two-stage spur gear 14. The output axis B is arranged axis-parallel to the input axis A. There is therefore an axis-parallel output. The two-stage translation of the spur gear causes the overall translation from axis A of the input to axis B of the output. The spur gear includes four spur gears 14.1, 14.2, 14.3 and 14.4. The spur gear 14.1 is connected to the output shaft 12 in a torque-proof manner. The spur gear 14.2 is non-rotatably connected to the cage 9.4 of the differential 9 and can drive it. Between the spur gears 14.1 and 14.2, two spur gears 14.3 and 14.4 which are non-rotatably connected to one another are arranged as a further stage. The spur gear 14.3 meshes with the spur gear 14.1. Spur gear 14.4 meshes with spur gear 14.2. Otherwise, reference is made to the remarks 15 referred.

Reference List

1

transmission

2

electric machine

2.1

rotor

2.2

stator

3

switching element

4

switching element

5

switching element

7

Planetary gear set, first

7.1

sun gear

7.2

sun gear

7.3

planet wheel

7.4

planet wheel

7.5

ring gear

7.6

planet carrier

8th

Planetary gear set, second

8.1

sun gear

8.2

planet carrier

8.3

ring gear

9

bevel gear differential

9.1

output gear

9.2

output gear

9.3

compensating element(s)

9.4

Differential cage, cage

9.11

first output shaft

9.12

second output shaft

11

input shaft

12

output shaft, output

13

Planetary gear set, third

13.1

sun gear

13.2

planet carrier

13.3

ring gear

14

Spur gear stage, one-stage, two-stage

14.1

spur gear

14.2

spur gear

14.3

spur gear

14.4

spur gear

99

driving direction

100

powertrain

1000

vehicle, car

A

drive axle

B

output axis

E1

first course

E2

second gear

E3

third gear

i

translation

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2014/029650 [0002]

Claims (14)

Electric drive for a vehicle, comprising: - An electric machine (2) whose rotor (2.1) is connected to an input shaft (11) of a first planetary gear set (7), an output shaft (12) arranged coaxially with the input shaft (11), and - three, preferably exactly three shifting elements (3, 4, 5) for engaging gears, - where the first planetary gear set, o is designed as a stepped planetary gear, the planet wheels (7.3, 7.4) mounted on a planet carrier (7.5) having two different effective diameters, o wherein a first sun gear (7.1) of the planetary gear set (7) meshes with the larger effective diameter (7.3) of the planetary gears, o wherein a second sun gear (7.2) of the planetary gear set (7) meshes with the smaller effective diameter (7.4) of the planetary gears, o wherein a ring gear (7.6) of the planetary gear set (7) with the larger effective diameter (7.3) is in tooth mesh, - the first sun gear (7.1) of the planetary gear set (7) being non-rotatably connected to the first input shaft (11), - the second sun gear (7.2) of the planetary gear set (7) being non-rotatably connected to the output shaft (12), - wherein a first switching element (3) is designed to fix the planet carrier (7.5) of the planetary gear set (7) on a non-rotatable component (0), - wherein a second switching element (4) is designed to block the planetary gear set (7), and - Wherein a third switching element (5) is designed to fix the ring gear (7.6) on the non-rotatable component (0). electric drive after claim 1 , wherein by closing the first switching element, a first gear (E1); and/or a second gear (E2) by closing the third shifting element (5); and/or a third gear (E3) results by closing the second shifting element (4). electric drive after claim 1 or 2 , wherein the second switching element (4) causes the locking by - non-rotatably connecting the first sun gear (7.1) and the second sun gear (7.2), or - non-rotatably connecting the second sun gear (7.2) and the planet carrier (7.5), or - causes. Electric drive according to one of the preceding claims, wherein the output shaft (12) is arranged inside the hollow input shaft (11). Electric drive according to one of the preceding claims, wherein at least one of the shifting elements (3, 4, 5) is designed as a positive shifting element, in particular as a claw clutch. Electric drive according to one of the preceding claims, wherein at least one of the two shifting elements (3, 4, 5) is designed as a frictional shifting element, in particular as a multi-plate clutch or a cone clutch. Drive train (100) for a vehicle with an electric drive according to one of Claims 1 until 6 and a differential device connected to the output shaft (12) of the first planetary gear set (7). drive train after claim 7 , wherein the differential device comprises a bevel gear differential (9) and a transmission gear in the form of a second planetary gear set (8), wherein - the sun gear (8.1) of the second planetary gear set (8) is connected to the second sun gear (7.2) of the first planetary gear set (7). - the planet carrier (8.2) is connected to an input element (9.3) of the bevel gear differential (9), - the ring gear (8.3) is fixed to the non-rotating component (0). drive train after claim 7 , wherein the differential device comprises a bevel gear differential (9) and a transmission gear in the form of a single-stage spur gear (14) with a first spur gear (14.1) and a second spur gear (14.2), wherein - the first spur gear (14.1) with the second sun gear (7.2 ) of the stepped planetary gear set (5) is non-rotatably connected and meshes with the second spur gear (14.2), - the second spur gear (14.2) is non-rotatably connected with an input element (9.3) of the bevel gear differential (9). drive train after claim 7 , wherein the differential device comprises a bevel gear differential (9) and a transmission gear in the form of a two-stage spur gear (14) with a first spur gear (14.1), a second spur gear (14.2) and a third spur gear (14.3), wherein - the first spur gear (14.1 ) is non-rotatably connected to the second sun gear (7.2) of the stepped planetary gear set (7) and meshes with the third spur gear (14.3), - the third spur gear (14.3) is non-rotatably connected to the second spur gear (14.2), and - the second Spur gear (14.2) is non-rotatably connected to an input element (9.3) of the bevel gear differential (9). drive train after claim 7 , wherein the differential device comprises a second planetary gear set (8) and a third planetary gear set (13), wherein - the sun gear (8.1) of the second planetary gear set (8) is connected to the second sun gear (7.2) of the first planetary gear set (7), - the planet carrier (8.2) is connected to a first output shaft (8.4), - the ring gear (8.3) of the second planetary gear set (8) is connected to the sun gear (13.1) of the third planetary gear set (13), - the planet carrier (13.2) to the non-rotatable Component (0) is fixed, - the ring gear (13.3) is connected to a second output shaft (13.4). Powertrain according to one of Claims 7 until 11 , wherein the first planetary gear set (7) is arranged radially inside the rotor (2.1). drive train after claim 7 or 8th , wherein the differential device is arranged radially inside the rotor (2.1). Method for switching the electric drive and / or the drive train according to any one of the preceding claims, wherein - In a first gear (E1), the first switching element (3) is closed and the second switching element (4) and the third switching element (5) are opened, wherein - In a second gear (E2), the third switching element (5) is closed and the first switching element (3) and the second switching element (4) are opened, and wherein - In a third gear (E3), the second switching element (4) is closed and the first switching element (3) and the third switching element (5) are opened.

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