DE102021004159B3 - Electric drive device for a motor vehicle, in particular for a motor vehicle - Google Patents

Abstract

The invention relates to an electric drive device (10a) for a motor vehicle, with at least two shifting elements (B03, B04) for shifting three gears (G1, G2, G3) of the drive device (10a), with an electric machine (12), with a first planetary gear set (22), which has a first sun gear (26), a first planet carrier (28) and a first ring gear (30), with a second planetary gear set (24), which has a second sun gear (34), a second planet carrier (36 ) and a second ring gear (38), and with a differential gear (42) which has a differential input shaft (46) and two output shafts (52), the first sun gear (26) being non-rotatably connected to a rotor (16) of the electrical machine ( 12) is connected, and wherein the first planetary carrier (28), the second planetary carrier (36) and the differential input shaft (46) are non-rotatably connected to one another, the second sun gear (34) being non-rotatably connected to the first sun gear (26) v is bound.

Description

The invention relates to an electric drive device for a motor vehicle, in particular for a motor vehicle, according to the preamble of patent claim 1.

Such an electric drive device for a motor vehicle, in particular for a motor vehicle, is, for example, already DE 10 2013 225 519 A1 to be taken as known. The electric drive device has at least two shifting elements for shifting at least two transmission gears of the drive device. In addition, the electric drive device has an electric machine and a first planetary gear set, which has a first sun gear, a first planet carrier and a first ring gear. Furthermore, the electric drive device includes a second planetary gear set, which has a second sun gear, a second planet carrier and a second ring gear. In addition, a differential gear is provided which has a differential input shaft and two output shafts. The first sun gear is connected to a rotor of the electric machine in a rotationally fixed manner, and the first planet carrier, the second planet carrier and the differential input shaft are connected to one another in a rotationally fixed manner.

The generic DE 10 2015 106 503 A1 shows, in addition to the features mentioned above, that the first sun gear is non-rotatably connected to the second sun gear.

The object of the present invention is to improve an electric drive device of the type mentioned at the outset.

This problem is solved by an electric drive device with the features of patent claim 1 . Advantageous configurations with expedient developments of the invention are specified in the remaining claims.

As is known in the prior art, it is assumed that a second sun gear is connected to a first sun gear in a rotationally fixed manner. Furthermore, it is assumed that a first switching element is provided to connect a first ring gear to a housing in a rotationally fixed manner, and that a second switching element is provided to connect a second ring gear to the housing in a rotationally fixed manner. According to the invention, a third shifting element is provided to lock the first planetary gear set, the first shifting element having a claw shifting element and a freewheel shifting element, and the second shifting element being designed as a friction clutch.
In the context of the present disclosure, the feature that two components which are in particular rotatably mounted, i.e. rotatable about an axis of rotation relative to a housing of the electric drive device, are connected to one another in a rotationally fixed manner means that the two components are arranged coaxially with one another and connected to one another in this way are that they rotate at the same angular velocity, in particular about the axis of rotation common to the components and relative to the housing, in particular when the components are driven. Furthermore, it is preferably provided that the rotor of the electrical machine is arranged coaxially to the planetary gear sets. Furthermore, it is preferably provided that the planetary gear sets, also referred to as planetary gear sets, are arranged coaxially to one another.

The invention enables the realization of a three-gear structure capable of power shifting for shifting three transmission gears for, in particular, purely electric driving of the motor vehicle, in particular in a coaxial design with low power loss. The transmission gears are driving gears which can be used for forward travel and reverse travel, that is to say can cause the motor vehicle to travel forward and backward. The shifting of the transmission gears means that the respective transmission gear can be shifted, that is to say it can be engaged and disengaged. In particular, the transmission gears are gears of a transmission of the drive device, via the transmission of which the motor vehicle can be driven by the electric machine, in particular purely electrically. The transmission includes the planetary gear sets, with the transmission gears being realized by the planetary gear sets.

A first of the transmission gears can enable trailer operation, for example. In addition, for example, the first transmission gear can be used or provided for creeping operations, for example to protect the electric machine and power electronics associated with the electric machine from overheating.

• - verlustoptimierte und kompakte Bauweise;
• - mindestens eines der Schaltelemente kann zur weiteren Verlustreduzierung als Klauenschaltelement, insbesondere als eine Klauenbremse, das heißt als formschlüssiges Schaltelement oder aber auch als Freilaufschaltelement ausgeführt sein;
• - geringe Relativdrehzahlen in den offen laufenden Schaltelementen;
• - die Schaltelemente können sehr gut zugänglich sein, insbesondere dann, wenn die Schaltelemente als reibschlüssige Schaltelemente und somit beispielsweise als Bremsen, insbesondere als Reibbremsen ausgebildet sind;
• - Belastungen der Schaltelemente niedrig;
• - gute Verzahnungswirkungsgrade;
• - Drehzahlen der elektrischen Maschine können bei hoher Geschwindigkeit gering gehalten werden, insbesondere durch die Mehrgängigkeit;
• - Stufensprung sehr frei einstellbar.

In particular when power shifting is not possible, the shifting elements or all shifting elements can be designed as positive-locking shifting elements. In particular, the invention enables a clever coupling and nesting of the planetary gear sets and the differential gear, which is also simply referred to as a differential. At least the following advantages can be validated by the invention:

• - loss-optimized and compact design;
• - at least one of the shifting elements can be used as a claw shifting element, in particular as a claw brake, to further reduce losses, that is, be designed as a form-fit shifting element or as a freewheeling shifting element;
• - Low relative speeds in the open-running switching elements;
• - The switching elements can be very easily accessible, especially when the switching elements are designed as frictional switching elements and thus, for example, as brakes, in particular as friction brakes;
• - low loads on switching elements;
• - good gearing efficiencies;
• - Speeds of the electrical machine can be kept low at high speeds, in particular due to the multi-speed;
• - Increment very freely adjustable.

Further advantages, features and details of the invention result from the following description of a preferred exemplary embodiment and from the drawing. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention.

• 1 eine schematische Darstellung eines nicht unter den Anspruch 1 fallenden Ausführungsbeispiels einer elektrischen Antriebsvorrichtung für ein Kraftfahrzeug, insbesondere für einen Kraftwagen;
• 2 eine Schalttabelle des nicht unter den Anspruch 1 fallenden Ausführungsbeispiels der elektrischen Antriebsvorrichtung gemäß 1;
• 3 eine schematische Darstellung eines erfindungsgemäßen Ausführungsbeispiels der elektrischen Antriebsvorrichtung; und
• 4 eine weitere Schalttabelle für das erfindungsgemäße Ausführungsbeispiel.

The drawing shows in:

• 1 a schematic representation of an embodiment of an electric drive device for a motor vehicle, in particular for a motor vehicle, which does not fall under claim 1;
• 2 a shift table of the not falling under claim 1 embodiment of the electric drive device according to 1 ;
• 3 a schematic representation of an inventive embodiment of the electric drive device; and
• 4 another switching table for the inventive embodiment.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 shows a schematic representation of an exemplary embodiment of an electric drive device for a motor vehicle, in particular for a motor vehicle such as a passenger car. This means that the motor vehicle has the electric drive device 10 in its completely manufactured state and can be driven electrically, in particular purely electrically, by means of the electric drive device. The motor vehicle is therefore an electric vehicle, in particular a battery electric vehicle (BEV). The electric drive device 10 comprises at least or exactly two shifting elements B03 and B04, namely a first shifting element B03 and a second shifting element B04, for shifting at least or exactly two gears of the drive device 10. The gears are also referred to as driving gears or gears and can be shifted, that is, insertable and interpretable.

2 shows a shift table for the exemplary embodiment of the electric drive device 10 that does not fall under claim 1. In the shift table, a first gear of the gears is denoted by G1 and a second gear of the gears is denoted by G22. If or during, for example, the first gear G1 is engaged, the second gear G2 is designed and vice versa. Since the drive device 10 has the plurality of gears G1 and G2, the drive device 10 is a multi-gear structure, in the present case an at least two-gear structure.

The electric drive device 10 includes an electric machine 12 which has a stator 14 and a rotor 16 . For example, in its fully manufactured state, the motor vehicle has at least or exactly two axles, also referred to as vehicle axles, which follow one another in the longitudinal direction of the vehicle, ie are arranged one behind the other. The respective axle has, for example, at least or exactly two vehicle wheels, also referred to simply as wheels. The vehicle wheels are ground contact elements, by means of which the motor vehicle can be or is supported on a ground downwards in the vertical direction of the vehicle. In particular, by means of the drive device 10, in particular by means of the electric machine 12, the vehicle wheels can be driven electrically, in particular purely, on exactly one of the axles, as a result of which the motor vehicle is driven, in particular purely electrically. The vehicle wheels that can be driven by the electric machine 12 are also referred to as drivable wheels, drivable vehicle wheels, driven wheels or driven vehicle wheels. The rotor 16 can be driven by the stator 14 and is therefore rotatable about a machine axis of rotation 18 relative to the stator 14 and in particular relative to a housing 20 of the drive device 10 . For example, the electrical machine 12 is at least partially arranged in the housing 20 .

The drive device 10 also includes a first planetary gear set 22 and a second planetary gear set 24, which are also simply referred to as planetary gear sets. The first planetary gear set 22 has a first sun gear 26 , a first planet carrier 28 and a first ring gear 30 . Furthermore, the first planetary gearset 22 includes at least one first planetary gear 32, which is rotatably mounted on the first planet carrier 28, which is also referred to as the first carrier, and at the same time meshes with the sun gear 26 and with the ring gear 30. The planetary gear set 22 preferably has a plurality of first planetary gears.

The second planetary gear set 24 has a second sun gear 34, a second planet carrier 36, which is also referred to as the second carrier, and a second ring gear 38. In addition, the second planetary gear set 24 includes at least one second planetary gear 40 which is rotatably mounted on the second carrier and simultaneously meshes with the sun gear 34 and with the ring gear 38 . For example, the second planetary gearset 24 includes a plurality of second planetary gears. The sun gears 26 and 34, the planet carriers 28 and 36 and the ring gears 30 and 38 are transmission elements of the planetary gear sets 22 and 24. The respective transmission element, if it is not rotationally fixed to the housing 20, in which the planetary gear sets 22 and 24 are each at least partially arranged are connected to be rotatable about a gear element axis of rotation relative to the housing 20 . In the present case, the planetary gear sets 22 and 24 are arranged coaxially with one another, so that the transmission element axis of rotation is a transmission element axis of rotation that is common to the or all transmission elements of the planetary gear sets 22 and 24, about which the respective transmission element can be rotated relative to the housing 20 when it is not rotationally fixed to the housing 20 connected is.

The first shifting element B03 is advantageously designed as a first brake shifting element, which is provided to connect one of the elements of the first planetary gear set 22 to the housing 20 in a torque-proof manner. The first switching element B03 is particularly advantageously provided for connecting the first ring gear 30 to the housing in a rotationally fixed manner. The second shifting element B04 is advantageously designed as a second brake shifting element, which is intended to connect one of the elements of the second planetary gearset 22 to the housing in a torque-proof manner. The second switching element B04 is particularly advantageously provided for connecting the second ring gear 38 to the housing 20 in a rotationally fixed manner.

The electric drive device 10 also includes a differential gear 42, also referred to simply as a differential, which is in particular a component of the axle, the wheels of which are driven by the electronic drive device 10 and thus via the planetary gear sets 22 and 24 by the electric machine 12 and in particular by the rotor 16 can be driven. The planetary gear sets 22 and 24 are components of a transmission, also referred to as a planetary gear, whose gears G1 and G2 are implemented by the planetary gear sets 22 and 24 . The transmission can provide an output torque which results from an input torque which is provided by the electric machine 12 via its rotor 16 and, in particular via the planetary gear set 22, is introduced into the transmission. The output torque provided by the transmission or a torque resulting from the output torque can be transmitted to the differential gear 42, as a result of which the differential gear 42 can be driven or is driven. By means of the differential gear 42, the output torque or a further torque resulting from the output torque—as in FIG 1 illustrated by arrows 44 - transferred or divided to the drivable vehicle wheels. The drivable vehicle wheels can thus be driven electrically by the differential gear 42 and by the gear via the differential gear 42 and by the electric machine 12 , in particular by the rotor 16 , via the gear.
The differential gear 42 has a differential input shaft 46, also referred to simply as an input shaft, via which the output torque or the torque resulting from the output torque for driving the differential gear 42 can be introduced into the differential gear 42 in order to thereby drive the differential gear 42 and, via this, the drivable vehicle wheels. The differential gear 42 has differential gears 48 and output gears 50 meshing directly with the differential gears 48 and which are connected in a torque-proof manner to output shafts 52 of the differential gear 42 . The respective, drivable vehicle wheel can be driven by the respective output shaft 52 . As is already well known from the general state of the art, the differential gear 42 is designed in particular to allow different speeds of the drivable vehicle wheels when the motor vehicle is cornering, so that the drivable vehicle wheel on the outside of the curve rotates or can rotate at a higher speed than the inside of the curve , drivable vehicle wheel.

It can be seen that the first sun gear 26 is connected to the rotor 16 in a torque-proof manner. In addition, the first planetary carrier 28, the second planetary carrier 36 and the differential input shaft 46 are non-rotatably connected to one another. In addition, it is provided in the drive device 10 that that the second sun gear 34 is non-rotatably connected to the first sun gear 26 and is thus non-rotatably connected to the rotor 16 .

It is conceivable that the shifting elements B03 and B04 are designed as frictional shifting elements and thus advantageously as friction brakes. Furthermore, it is particularly advantageous that the first shifting element B03 is designed as a claw shifting element and the second shifting element B04 is designed as a friction clutch.

The electric drive device 10 advantageously comprises a parking lock 54 provided in addition to the switching elements B04 and B04, by means of which, in particular when the parking lock 54 is in an engaged state, the differential input shaft 46 and thus the planet carriers 28 and 36 can be connected to the housing 20 in a rotationally fixed manner. As a result, the drivable vehicle wheels can be prevented from rotating, as a result of which, for example when the motor vehicle is parked on a slope, an undesired rolling away of the motor vehicle caused by gravity can be avoided. The parking lock 54 includes a parking lock gear 56 which is non-rotatably connected to the differential input shaft 46 and to the webs. The webs and the differential input shaft 46 can be positively connected to the housing 20 in a torque-proof manner by means of the parking lock wheel 56 . The parking lock gear 56 is connected to the second planet carrier 36 in a torque-proof manner. This means in particular that the parking lock gear 56 is arranged on a side of the planetary gearset 24 that faces away from the first planetary gearset 22 in the axial direction of the planetary gearsets 22 and 24 . Based on the in 2 It can be seen from the switching table of the electric drive device 10 shown that the first switching element B03 is activated for engaging the first gear G1, that is to say it is closed, while the second switching element B04 is open. As a result, ring gear 30 is non-rotatably connected to housing 20 by means of first shifting element B03, while second shifting element B04 allows ring gear 38 to rotate relative to housing 20 about the transmission element axis of rotation, which in this case coincides with machine axis of rotation 18. In order to engage the second gear G2 while the first gear G1 is disengaged, the second shifting element B04 is closed while the first shifting element B03 is open. As a result, ring gear 38 is non-rotatably connected to housing 20 by means of second shifting element B04, while first shifting element B03 allows ring gear 30 to rotate relative to housing 20 about the transmission element axis of rotation, i.e. about machine axis of rotation 18. Since, in the exemplary embodiment shown in the figures, the electric machine 12, in particular its rotor 16, is arranged coaxially with the planetary gear sets 22 and 24, the axis of rotation of the transmission element coincides with the axis of rotation 18 of the machine.

the 3 and 4 show an inventive embodiment of an electric drive device (10a), wherein objects that are already in the embodiment of 1 and 2 are shown and are used here unchanged are denoted by the same reference numerals.

For one thing, that contains in the 3 and 4 shown further embodiment, a modified first switching element B03a. The modified shifting element B03a has a claw shifting element 57 and a freewheeling shifting element 58 arranged parallel to the claw shifting element 57 .

A use of the modified switching element B03a can also in the embodiment of 1 be beneficial.

The claw shifting element 57 is designed to connect the first ring gear 30 to the housing in a torque-proof manner. For this purpose, the claw switching element 57 has an electromechanical or hydraulic or pneumatic actuator which is not shown in more detail. The freewheel switching element 58 is designed to connect the first ring gear 30 to the housing when the first ring gear 30 rotates in a specific direction.

On the other hand, this includes in the 3 and 4 shown further embodiment, a third switching element K1, by means of which a third gear G3 can be realized. The third shifting element K1 is designed to block the first planetary gear set 22 . The third switching element K1 is advantageously designed to connect the first sun gear 26 to the first planet carrier 28 in a torque-proof manner. When the third shifting element K1 is closed and the first shifting element B03a is open and the second shifting element B04 is open, the third transmission gear G3 is implemented. The transmission gears G1, G2, G3 shown have a decreasing translation in the order mentioned here.

reference list

10, 10a

electric drive device

12

electric machine

14

stator

16

rotor

18

machine axis of rotation

20

Housing

22

first planetary gear set

24

second planetary gear set

26

first sun wheel

28

first planet carrier

30

first ring gear

32

first planet wheel

34

second sun wheel

36

second planet carrier

38

second ring gear

40

second planet gear

42

differential gear

44

Arrow

46

differential input shaft

48

balance wheel

50

output gear

52

output shaft

54

parking lock

56

parking lock wheel

57

claw shift element

58

freewheel switching element

B03

first switching element

B03a

modified first switching element

B04

second switching element

G1

first gear

G2

second gear

G3

third gear

K1

third switching element

Claims (2)

Electrical drive device (10a) for a motor vehicle with a housing (20), with a first switching element (B03a) and a second switching element (B04) for shifting three gears (G1, G2, G3) of the drive device (10a), with an electrical Machine (12), with a first planetary gear set (22) which has a first sun gear (26), a first planet carrier (28) and a first ring gear (30), with a second planetary gear set (24) which has a second sun gear (34 ), a second planet carrier (36) and a second ring gear (38), and with a differential gear (42) which has a differential input shaft (46) and two output shafts (52), the first sun gear (26) being non-rotatably connected to a rotor (16) of the electrical machine (12), and wherein the first planet carrier (28), the second planet carrier (36) and the differential input shaft (46) are connected to one another in a rotationally fixed manner, the second sun gear (34) being rotationally fixed to de m first sun gear (26), the first shifting element (B03a) being provided to connect the first ring gear (30) to the housing (20) in a torque-proof manner, the second shifting element (B04) being provided to connect the second ring gear (38) to be connected to the housing (20) in a torque-proof manner, characterized by a third shifting element (K1), which is intended to block the first planetary gear set (22), the first shifting element (B03a) having a claw shifting element (57) and a Has freewheel switching element (58) and the second switching element (B04) is designed as a friction clutch. Electrical drive device (10a) after claim 1 , characterized by a parking lock wheel (56) which is non-rotatably connected to the second planet carrier (36).

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