CN116710308A

CN116710308A - Drive train for a motor vehicle

Info

Publication number: CN116710308A
Application number: CN202180091245.8A
Authority: CN
Inventors: S·贝克; M·赖施
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2021-01-21
Filing date: 2021-11-30
Publication date: 2023-09-05
Also published as: DE102021200527A1; WO2022156945A1

Abstract

The invention relates to a drive train (1 a) for a motor vehicle (1), comprising an internal combustion engine (2), a multi-speed transmission (4) and a one-piece differential (14), wherein the multi-speed transmission (4) is operatively connectable at least to the internal combustion engine (2) and is arranged upstream of the differential (14) in the power flow, wherein the differential (14) is configured with two planetary gearsets (13 a, 13 b), wherein each planetary gearset (13 a, 13 b) is operatively connected to a respective driven shaft (5 a, 5 b) in the drive, wherein the differential (14) and the respective driven shaft (5 a, 5 b) are arranged coaxially to a driven axle (6) of the motor vehicle (1), wherein the internal combustion engine (2) and the multi-speed transmission (4) are arranged axially parallel to the driven axle (6), wherein the multi-speed transmission (4) is operatively connected to a first input shaft (8) of the differential (14) via at least one first transmission stage (7), wherein a first torque can be transferred from the first driven shaft (13 a) to the second planetary gearset (13 a) by means of the driven shaft, wherein a torque can be transferred from the first planetary gearset (13 a) to the second planetary gearset (5 b) in the first torque transfer from the first planetary gearset (13 a) to the corresponding to the second torque. The invention also relates to a motor vehicle having such at least one drive train (1 a).

Description

Drive train for a motor vehicle

Technical Field

The present invention relates to a drive train for a motor vehicle and a motor vehicle having at least one such drive train.

Background

Patent document DE 10 2011 079 975 A1 discloses a transmission for a motor vehicle, comprising a surrounding housing and a differential transmission which is designed as a spur gear differential. A first spur gear accommodated therein and a second spur gear accommodated therein are arranged in the surrounding housing. Furthermore, a planetary gear stage is provided, which is kinematically coupled to the surrounding housing and has a sun gear, planet gears and a ring gear, wherein the planet gears of the planetary gear stage are configured in a stepped manner and each form a first planetary spur gear section and a second planetary spur gear section arranged coaxially and axially offset to the first planetary spur gear section. The first planetary spur gear section meshes with the sun gear and the second planetary spur gear section meshes with the ring gear, wherein the planetary gears rotate with the surrounding housing.

Disclosure of Invention

The object of the present invention is to provide a space-saving drive train for a motor vehicle. This object is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims, the following description and the figures.

The drive train for a motor vehicle according to the invention comprises an internal combustion engine, a multi-speed transmission and a one-piece differential, wherein the multi-speed transmission can be operatively connected to at least the internal combustion engine drive and is arranged upstream of the differential in the power flow, wherein the differential is configured with two planetary gear sets, wherein each planetary gear set is operatively connected to a respective driven shaft drive, wherein the differential and the respective driven shaft are arranged coaxially to a driven axle of the motor vehicle, wherein the internal combustion engine and the multi-speed transmission are arranged axially parallel to the driven axle, wherein the multi-speed transmission is operatively connected to a first input shaft of the differential by means of at least one first gear shift stage, wherein a first driven torque can be transmitted to a second driven shaft by means of the first planetary gear set, wherein a supporting torque (Abst tzmot) of the first planetary gear set can be converted in the second planetary gear set such that a second driven torque corresponding to the first driven torque can be transmitted to the first driven shaft. In other words, the sum of the two gear torques does not combine or combine in the component to form the total axle torque. Instead, drive power from the first gear stage is distributed in the differential and transmitted to the driven shaft according to the configuration of the planetary gear set. Thus, the components of the differential can be constructed to be thinner and narrower due to the correspondingly relatively small torque. The drive train thus constructed has the advantage, on the one hand, that an axial offset is achieved in order to save axial installation space along the driven axle, wherein at the same time an additional intermediate shaft can be dispensed with. In addition, torque increases and drive power distribution are preferably achieved by means of the differential. In addition, the weight is reduced.

An integrated differential is understood to be a differential having two planetary gear sets, wherein a first planetary gear set is in driving operative connection with a first input shaft of the differential and a second planetary gear set. The first planetary gear set is operatively connected with the second driven shaft drive and the second planetary gear set is operatively connected with the first driven shaft drive. The second planetary gear set is supported at least indirectly at the stationary housing of the differential or at the chassis of the motor vehicle. By means of such an integrated differential, the input torque of the first input shaft of the differential can be converted and distributed or transmitted in a defined ratio to the two driven shafts. Preferably, the input torques are transmitted to the output shaft in each case by 50%, i.e. half. Thus, the differential does not have a member to which the sum of the two slave torques is applied. Furthermore, when the driven rotational speeds of the driven shafts are the same, the differential does not have teeth that rotate as a unit, i.e., that rotate without rolling motion. In other words, there is always relative movement of the members of the respective planetary gear sets that mesh with each other, regardless of the driven speed of the driven shaft.

The multi-speed transmission is arranged to provide a plurality of different gear ratios between the internal combustion engine, more precisely the output shaft of the internal combustion engine or the input shaft of the multi-speed transmission and the output shaft of the multi-speed transmission. The output shaft of the internal combustion engine can be connected in one piece or in several parts to the input shaft of the multi-speed transmission in a rotationally fixed manner. The output shaft of the multi-speed transmission serves here as the input shaft of the first gear stage, which transmits the drive power, i.e. the drive torque and/or the drive rotational speed, from the internal combustion engine to the first input shaft of the differential. The output shaft of the multi-speed transmission is thus connected to the respective driven shaft via the first gear stage and the differential.

The output shaft of the internal combustion engine and the output shaft of the multi-speed transmission are arranged coaxially to a common main axis which is oriented parallel to the driven axle of the motor vehicle and thus transversely to the vehicle longitudinal axis. The output shaft of the multi-speed transmission is preferably configured as a hollow shaft, wherein the second input shaft of the multi-speed transmission passes axially through the output shaft of the multi-speed transmission. It is also conceivable to arrange the input shaft and the output shaft axially parallel to each other, depending on the available installation space.

The multi-speed transmission is preferably designed as a planetary gear having at least two planetary gear sets. In other words, the multi-speed transmission has an input shaft, an output shaft and at least one housing support to support torque acting at the chassis of the motor vehicle.

Preferably, the multi-speed transmission comprises at least one shift element. The switching element is used to set a shift ratio. This can be done manually according to the driver's wishes and/or at least partially automatically according to the operating state of the motor vehicle. Preferably, the shift element is arranged to shift between at least three gear ratios.

The first gear stage between the multi-speed transmission and the differential may be configured as a chain transmission, a belt transmission or a gear train with a plurality of gears in tooth engagement in order to transmit drive power to a first input shaft of the differential arranged substantially parallel to an output shaft of the internal combustion engine or an input shaft of the multi-speed transmission. By arranging the respective output shaft of the internal combustion engine or the input shaft of the multi-speed transmission in parallel with the input shaft of the differential, the drive train can be configured to save structural space in the axial direction, i.e. transverse to the longitudinal axis of the vehicle, since the internal combustion engine and the multi-speed transmission are arranged at least partially beside the differential.

An operative connection or a driving operative connection is understood to mean that two elements are connected directly, i.e. directly to each other, or indirectly to each other via at least one further element arranged therebetween. For example, other shafts and/or gears may be effectively disposed between the two shafts. The term "at least indirectly" is also understood to mean that two components are (effectively) connected to each other or are immediately connected to each other and thus directly connected to each other via at least one further component arranged between the two components. Thus, between the shafts or gears, further members may be arranged, which members are in operative connection with the shafts or gears.

The differential is preferably designed as a planetary gear, wherein the differential has one input shaft and two driven shafts. Each driven axle is connected at least indirectly to at least one wheel fixed at a driven axle of the motor vehicle. By means of the differential, on the one hand, the torque is increased and, on the other hand, the drive power is transmitted to the two driven shafts.

The two planetary gear sets of the differential may be arranged relative to each other in any manner so as to achieve a desired ratio of speed change. The planetary gear sets are drivingly connected to each other by a coupling shaft or wheel. Preferably, the two planetary gear sets are arranged side by side in the axial direction. Alternatively, two planetary gear sets are arranged radially one above the other. Each planetary gear set preferably includes a sun gear, a ring gear, and a planet gear carrier rotatably disposed thereon, wherein the planet gears mesh with both the sun gear and the ring gear. Furthermore, the differential has a connection fixed to the housing in order to support the torque acting at the housing or chassis of the motor vehicle. A radially overlapping arrangement is understood to mean that the planetary gear sets lie substantially jointly in a plane extending substantially perpendicular to the respective driven shaft or driven axle of the motor vehicle. Since the (integral) differential is arranged downstream of the multi-speed transmission in the power flow, the multi-speed transmission is subjected to relatively small loads, since a torque increase only occurs in the differential by means of the two planetary gear sets arranged in the differential. Thus, a multi-speed transmission can be constructed based on its relatively small size.

One of the two driven shafts passes through the differential and the first input shaft of the differential. One of the driven shafts thus passes through the differential and the first input shaft of the differential, so to speak, in-line, and is rotatably mounted relative thereto in order to transmit drive power from the differential to the respective wheel. In other words, the driven shaft extends in the opposite direction from the differential. The internal combustion engine and the multi-speed transmission preferably extend coaxially to the main axis above and to the driven axle of the differential, above which the first input shaft and the driven shaft are arranged, transversely to the longitudinal direction of the vehicle.

Preferably, the drive train further comprises at least one electric machine for generating electric drive power. The respective motor is preferably connected to a battery which supplies the respective motor with electrical energy. Furthermore, the respective motor is preferably controllable or adjustable by the power electronics. The respective electric machine has a stator fixed to the housing and a rotor rotatably arranged relative to the stator, the rotor having a rotor shaft, wherein the rotor shaft transmits drive power to the driven part directly or through at least one gear stage depending on the arrangement in the drive train.

According to one embodiment, at least one electric machine is arranged in the power flow between the internal combustion engine and the multi-speed transmission. The respective electric machine is thus connected at least indirectly to the output shaft of the internal combustion engine and/or to the second input shaft of the multi-speed transmission.

Preferably, the at least one electric machine and the internal combustion engine can be operatively connected together or in transmission with the second input shaft of the multi-speed transmission. In other words, the internal combustion engine and/or the corresponding electric machine is/are connected directly to the output, or a clutch unit is arranged in the power flow in order to decouple the internal combustion engine and/or the corresponding electric machine from the output. The motor vehicle can therefore be driven exclusively by means of the internal combustion engine or exclusively by means of the corresponding electric motor, wherein a common, hybrid drive of the motor vehicle is also possible.

The respective electric machine may be arranged coaxially with the second input shaft of the multi-speed transmission, for example. The electric motor is thereby arranged axially parallel to the first input shaft of the differential and to the driven axle. Preferably, the first gear stage is arranged axially between the internal combustion engine and the multi-speed transmission, wherein the respective electric machine can be arranged axially effectively between the internal combustion engine and the respective first gear stage or can be arranged axially effectively between the multi-speed transmission and the respective first gear stage. The drive power is thus summed at the corresponding first gear stage.

Alternatively, the respective electric machine is operatively connected to a second input shaft of the multi-speed transmission via at least one second gear stage. This saves axial installation space, since the rotor shaft of the respective electric machine can be arranged parallel to the second input shaft, and the respective electric machine can thus be arranged, for example, next to the internal combustion engine or next to the multi-speed transmission. The respective second gear stage can be configured, like the respective first gear stage, as a chain transmission, a belt transmission or a gear train with a plurality of gears in tooth engagement in order to transmit drive power to the second input shaft of the multi-speed transmission. Furthermore, alternatively, the second gear stage can also be configured as a planetary gear and thus serve as a pre-transmission.

According to a further embodiment, at least one electric machine is arranged in the power flow between the first gear stage and the differential. The respective electric machine likewise uses the gear change of the differential, and therefore in principle no further gear change step is required, as long as it is arranged directly on the first input shaft of the differential or the output shaft of the respective first gear change step. The respective electric machine is therefore preferably arranged coaxially with the input shaft of the differential and/or the respective driven shaft of the drive train, and is thus oriented parallel to the input shaft of the multi-speed transmission or the output shaft or main axis of the internal combustion engine.

Alternatively, the respective electric machine is operatively connected to the first input shaft of the differential via at least one second gear stage. In other words, the respective motor is arranged both axially parallel to the driven axle and to the main axis. As a result, additional axial installation space is saved, since the rotor shaft of the respective electric machine is arranged parallel to the first input shaft, and the respective electric machine can thus be arranged, for example, next to the differential and next to the internal combustion engine and the multi-speed transmission. The second gear stage may be constructed similarly to the previously described gear stages.

The invention comprises the following technical teachings: the clutch unit and/or the torsional damper are arranged in the power flow between the internal combustion engine and at least the first gear stage. If a clutch unit and a torsional damper are provided, it is advantageous if the clutch unit is arranged downstream of the torsional damper, preferably in the power flow. The clutch unit is preferably switchable at least between a closed state and a disengaged state in order to decouple the internal combustion engine from the driven part. In the disengaged state, no driving power of the internal combustion engine is transmitted to the corresponding first gear stage. However, the respective electric machine transmits drive power to the respective first input shaft of the differential at least indirectly via the first gear stage, so that the motor vehicle is driven at least temporarily by electric only. In the closed state of the clutch device, the motor vehicle is driven in hybrid fashion, wherein the internal combustion engine and the corresponding electric machine transmit drive power at least indirectly to the differential.

The motor vehicle according to the invention comprises at least one drive train according to the above-mentioned type. The motor vehicle is preferably a motor vehicle, in particular a car (for example a passenger car weighing less than 3.5 t), a bus, a truck or a commercial vehicle (for example a bus, a truck or a commercial vehicle weighing more than 3.5 t). The motor vehicle comprises at least two axles, wherein at least one of these axles, preferably all axles of the motor vehicle, is operatively connected at least indirectly to the driveline. It is also conceivable to provide such a drive train for each axle. Preferably, the drive train is constructed in a front transverse structure type such that the primary axis as well as the driven axle are oriented substantially transversely to the vehicle longitudinal direction. Hybrid drive of the motor vehicle is possible if at least one electric machine can be operatively connected to the respective driven shaft transmission or to it. In other words, the motor vehicle in this case is a hybrid vehicle.

The above limitations and the implementation of the technical effects, advantages and advantageous embodiments of the drive train according to the invention apply equally correspondingly to the motor vehicle according to the invention.

Drawings

Embodiments of the present invention are explained in more detail below with reference to the schematic drawings, in which identical or similar elements are provided with the same reference symbols. Wherein:

fig. 1 shows a very schematic top view of a motor vehicle with a drive train according to the invention according to a first embodiment;

fig. 2 shows a very schematic illustration of the drive train according to the invention according to fig. 1;

fig. 3 shows a very schematic illustration of a drive train according to the invention according to a second embodiment;

fig. 4 shows a very schematic illustration of a drive train according to the invention according to a third embodiment;

fig. 5 shows a very schematic illustration of a drive train according to the invention according to a fourth embodiment;

fig. 6 shows a very schematic illustration of a drive train according to the invention according to a fifth embodiment;

fig. 7 shows a very schematic illustration of a drive train according to the invention according to a sixth embodiment;

fig. 8 shows a very schematic illustration of a drive train according to the invention according to a seventh embodiment;

fig. 9 shows a very schematic illustration of a drive train according to the invention according to an eighth embodiment; and

fig. 10 shows a very schematic illustration of a drive train according to the invention according to a ninth embodiment.

Detailed Description

According to fig. 1, a motor vehicle 1 according to the invention is shown with two axles 17a, 17b, wherein the drive train 1a according to the invention is effectively arranged at the first axle 17 a. The drive train 1a is operatively connected to the two driven shafts 5a, 5b of the first axle 17, at the ends of which wheels 18 are each coupled in a drivable manner for driving the motor vehicle 1. Thus, the first axle 17a forms the driven axle 6. The axles 17a, 17b are arranged transversely to the vehicle longitudinal axis L.

According to fig. 2 to 10, the drive train 1a comprises an internal combustion engine 2, which is arranged on a main axis 21 and has a first output shaft 15, and a multi-speed transmission 4, which has a second input shaft 9 and a second output shaft 16. The second output shaft 16 of the multi-speed transmission 4 is configured as a hollow shaft, wherein the second input shaft 9 passes through the second output shaft 16. The second output shaft 16 is operatively connected to a first gear stage 7 which transmits drive power, i.e. drive torque and/or drive rotational speed, to the first input shaft 8 of the integrated differential 14. The first input shaft 8 is configured as a hollow shaft and is arranged coaxially to the driven shafts 5a, 5b and the driven axle 6, wherein the second driven shaft 5b axially passes through the first input shaft 8. The driven axle 6 and the main axis 21 are thus arranged transversely to the vehicle longitudinal axis L.

According to fig. 2 to 10, in addition to fig. 4, the first gear stage 7 is designed as a chain drive, which comprises a first gearwheel 23 which is connected to the second output shaft 16 in a rotationally fixed manner and a second gearwheel 24 which is connected to the first input shaft 8 in a rotationally fixed manner, wherein the two gearwheels 23, 24 are in driving operative connection with one another via a first chain 22. According to fig. 4, the first gear stage 7 is configured as a spur gear pair, wherein the first gear 23 and the second gear 24 are directly in toothed engagement. The first gear stage 7 can have a ratio of 1:1, wherein virtually any gear ratio can also be provided, which is introduced into the differential 14.

A torsional damper 11 is arranged in the power flow between the internal combustion engine 2 and the multi-speed transmission 4, wherein torque peaks of the internal combustion engine 2 and operational irregularities of the output shaft 15 of the internal combustion engine 2 are absorbed by means of the torsional damper 11.

According to fig. 2 to 5, the drive power is generated only by the internal combustion engine 2, and is transmitted to the wheels 18 according to the embodiment. The drive train 1a further comprises an electric motor 3 for generating electric drive power according to fig. 6 to 10, wherein the electric motor 3 is effectively arranged in the drive train 1a in a different manner in the embodiment according to fig. 6 to 10.

The electric motor 3 is supplied with electric energy by a battery, not shown here, which is operatively connected to a stator 19 fixed to the housing. Furthermore, the motor 3 is connected to power electronics, not shown here, for control and regulation. By energizing the stator 19, a rotor 20, which is rotatably arranged relative to the stator, is placed in a rotational movement relative to the stator 19, which in turn is connected in a rotationally fixed manner to the rotor shaft 20 a. The arrangement of the motor is described in more detail in the respective embodiments. The mechanical power of the internal combustion engine 2 and the electrical power of the electric machine 3 can thus be used in parallel and thus in hybrid fashion for driving the motor vehicle 1. Alternatively, the motor vehicle 1 can be driven at least temporarily only electrically.

For this purpose, the drive train 1a according to fig. 6 to 10 has a clutch unit 10 which is arranged downstream of the torsional damper 11 in the power flow and upstream of the electric machine 3 and the multi-speed transmission 4. Depending on the operating state of the drive train 1a or the current driving situation of the motor vehicle 1, the internal combustion engine 2 can be decoupled from the driven part by the clutch unit 10, so that the motor vehicle 1 can be driven at least temporarily purely electrically, depending on the situation and/or depending on the operating state.

The multi-speed transmission 4 is currently constructed as a planetary gear transmission, which may have two or more planetary gear sets, not shown here, if desired. Furthermore, the multi-speed transmission 4 comprises a plurality of shift elements, not shown here, in order to switch arbitrarily between two or more gear ratios depending on the situation and/or depending on the operating state. Furthermore, the multi-speed transmission 4 is supported at the housing 30 of the motor vehicle 1 as is the differential 14.

The differential 14 is designed as a one-piece differential with two planetary gear sets 13a, 13b, wherein the two planetary gear sets 13a, 13b are arranged axially next to one another or radially one above the other, depending on the requirements of the differential 14, in particular the transmission ratio of the differential 14 to be achieved. The first drive torque can be transmitted to the second output shaft 5b by means of the first planetary gear set 13 a. The support torque of the first planetary gear set 13a, which acts against the first secondary torque, is transmitted to the second planetary gear set 13b and can be converted in the second planetary gear set 13b, so that a second secondary torque corresponding to the first secondary torque can be transmitted to the first driven shaft 5a. Thus, differential 14 is configured as a planetary gear.

The differential 14 is operatively connected to the first gear stage 7 via its input shaft 8. The driven at the integrated differential 14 is made by two driven shafts 5a, 5b. In other words, the drive power is distributed via the differential 14 across the two driven shafts 5a, 5b. In the present case, the first driven shaft 5a extends away from the drive train 1a, and the second driven shaft 5b passes through the differential 14 and the first input shaft 8 of the differential 14 to axially opposite sides of the drive train 1 a. By arranging the torque-raising differential 14 at the end of the drive train 1a, the components arranged upstream thereof in the power flow can be constructed relatively small and slim, whereby the costs of manufacture are lower and the total weight of the drive train 1a is reduced.

The driven shafts 5a, 5b, the differential 14 and the input shaft 8 thereof are arranged coaxially with the driven axle 6 of the motor vehicle 1, wherein the internal combustion engine 2 and the multi-speed transmission 4 are arranged axially parallel to the driven axle 6 on the main axis 21. This saves axial installation space for the drive train 1a, and in particular because the internal combustion engine 2 is arranged at least partially next to one another together with the multi-speed transmission 4 and the differential 14.

According to the first exemplary embodiment according to fig. 2, the two planetary gear sets 13a, 13b of the differential 14 are arranged radially one above the other in order to save additional axial installation space on the driven axle 6. In other words, the planetary gear sets 13a, 13b lie in a common plane, which is perpendicular to the driven shafts 5a, 5b or the driven axle 6. Thus, the differential 14 is in the present case constructed as a radially nested structure type.

The first input shaft 8 of the differential 14 is connected to the first sun gear 25a of the first planetary gear set 13a in a rotationally fixed manner. The power transfer from the first planetary gear set 13a to the second planetary gear set 13b takes place via a coupling shaft 27 which is connected, on the one hand, in a rotationally fixed manner to the first ring gear 26a of the first planetary gear set 13a and, on the other hand, in a rotationally fixed manner to the second sun gear 25b of the second planetary gear set 13 b. Thus, the coupling shaft 27, the first ring gear 26a, and the second sun gear 25b are integrally connected to each other. Spatially between the first sun gear 25a and the first ring gear 26a, a plurality of first planet gears 28a are arranged, which in the present case are rotatably arranged on a rotatably mounted first planet carrier 29 a. Furthermore, in the same plane extending radially and radially outside the first planetary gear set 13a, a plurality of second planetary gears 28b are spatially arranged between the second sun gear 25b and the second ring gear 26b of the second planetary gear set 13b, which are rotatably arranged in the present case on a second planet gear carrier 29b fixed to the housing. The first driven on the first driven shaft 5a is performed by the second ring gear 26b fixed in a non-rotatable manner therewith, and the second driven on the second driven shaft 5b is performed by the first carrier 29a connected in a non-rotatable manner therewith.

The second embodiment according to fig. 3 is implemented substantially identically to the first embodiment according to fig. 2. The main difference here is that the two planetary gear sets 13a, 13b of the differential 4b are arranged axially next to one another.

The first input shaft 8 is in the present case connected in a rotationally fixed manner to the first sun gear 25a of the first planetary gear set 13 a. The power transfer from the first planetary gear set 13a to the second planetary gear set 13b takes place via a coupling shaft 27 which is connected, on the one hand, in a rotationally fixed manner to the first ring gear 26a of the first planetary gear set 13a and, on the other hand, in a rotationally fixed manner to the second sun gear 25b of the second planetary gear set 13 b. The connection fixed to the housing is made by means of a second planet carrier 29b, which second planet carrier 29b is thus arranged so as to be non-rotatable with respect to each other. The first driven on the first driven shaft 5a is performed by the second ring gear 26b non-rotatably connected thereto, and the second driven on the second driven shaft 5b is performed by the first carrier 29a non-rotatably connected thereto.

With the differential 4b thus constructed according to the embodiment of fig. 2 and 3, a transmission ratio between i=5 and i=10 can be achieved.

The third embodiment according to fig. 4 is constructed substantially identically to the second embodiment according to fig. 3. The main difference is the different construction and arrangement of the two planetary gear sets 13a, 13b of the differential 14.

In this embodiment, the first input shaft 8 is non-rotatably connected with the first sun gear 25a of the first planetary gear set 13 a. The power transfer from the first planetary gear set 13a to the second planetary gear set 13b takes place via a coupling shaft 27 which is connected, on the one hand, in a rotationally fixed manner to the first planet carrier 29a of the first planetary gear set 13a and, on the other hand, in a rotationally fixed manner to the second ring gear 26b of the second planetary gear set 13 a. The connection fixed to the housing is made by means of a second planet carrier 29b, which is thus arranged so as to be non-rotatable with respect to each other. The first driven on the first driven shaft 5a is made by the second sun gear 25b which is non-rotatably connected thereto, and the second driven on the second driven shaft 5b is made by the first ring gear 26a which is non-rotatably connected thereto. By the differential 14 thus constructed, a gear ratio between i= -3 and i= -8 can be achieved.

The current differential 14 has a reversal of the direction of rotation between the first input shaft 8 and the driven shafts 5a, 5b. Thus, another difference from the embodiment according to fig. 2 is that, as already described previously, the first gear stage 7 has two gears 23, 24 that are in toothed engagement with each other in order to achieve a second rotation direction reversal that eliminates or compensates for the first rotation direction reversal of the differential 14. In the present case, therefore, the first gear stage 7 is configured as a spur gear stage, whereby the reversal of the rotational direction is achieved. As an alternative to this, the first gear stage 7 may be provided with an odd number of meshed gear trains in order to transmit drive power to the differential 14 and to effect reversal of the direction of rotation.

The fourth embodiment shown in fig. 5 is essentially identical in design to the embodiment according to fig. 3, with the main difference being the alternative design of the integrated differential 14. The transmission ratio between i=2.5 and i=3.5 can be realized with the current differential 4 b.

In the present case, the first input shaft 8 is connected in a rotationally fixed manner to the first ring gear 26a of the first planetary gear set 13 a. The power transfer from the first planetary gear set 13a to the second planetary gear set 13b takes place via a coupling shaft 27 which is connected to the first sun gear 26a in a rotationally fixed manner, on the one hand, and to the second sun gear 25b in a rotationally fixed manner, on the other hand. The differential 4b is fixed to the housing via a second planetary carrier 29b, which is thus arranged so as to be non-rotatable with respect to each other. The first driven on the first driven shaft 5a is performed by the second ring gear 26b non-rotatably connected thereto, and the second driven on the second driven shaft 5b is performed by the first carrier 29a non-rotatably connected thereto.

According to the fifth exemplary embodiment according to fig. 6, the electric machine 3 and the internal combustion engine 2 are arranged jointly with the multi-speed transmission 4 and thus coaxially on the main axis 21, wherein the rotor shaft 20a of the electric machine 3 is connected in a rotationally fixed manner to the second input shaft 9 of the multi-speed transmission 4. The clutch unit 10 is arranged in the power flow between the internal combustion engine 2 and the electric machine 3, wherein the electric machine 3 is arranged in the power flow between the internal combustion engine 2 and the multi-speed transmission 4. Depending on the desired operating state, the internal combustion engine 2 can be connected to the second input shaft 9 in a driving manner via the clutch unit 10 or can be decoupled from the second input shaft 9. The drive train 1a and in particular the differential 14 are otherwise constructed identically to the first embodiment according to fig. 2.

Fig. 7 to 9 show a further connection possibility at the second input shaft 9 of the multi-speed transmission for connecting the electric machine 3, wherein the electric machine 3 is operatively connected to the second input shaft 9 by means of a second gear stage 12.

According to fig. 7, the second gear stage 12 is designed as a planetary gear set with a planetary gear set in order to transmit drive power to the second input shaft 9 in a specific gear ratio. The planetary gear arrangement may also be configured with two or more planetary gear sets.

The rotor 20 of the electric machine 3 is connected in a rotationally fixed manner to the third ring gear 26c of the second gear stage 12, wherein the transmission of drive power to the rotor shaft 20a or the second input shaft 9 is effected by a third planetary gear carrier 29c connected in a rotationally fixed manner thereto, on which a plurality of third planetary gears 28c are arranged in a rotatable manner. The third planetary gear 28c is in tooth mesh with and spatially arranged between the third ring gear 26c and the third sun gear 25c, wherein the third sun gear 25c is arranged fixed to the housing. Thus, a pre-shift between i=1.5 and i=1.7 can be achieved by means of the second gear stage 12 a. Furthermore, the drive train 1a is configured similarly to fig. 6. In the embodiment according to fig. 6 and 7, the motor 3 is arranged coaxially to the main axis 21.

Fig. 8 shows a seventh embodiment of the drive train 1a, which is essentially identical to the embodiment according to fig. 7. The main difference here is that the electric machine 3 is arranged axially parallel to the main axis 21 and is in operative drive connection with the second input shaft 9 by means of the second gear stage 12. In other words, the rotor shaft 20a of the electric machine 3 is arranged axially parallel to the main axis 21 and the driven axle 6, wherein the parallel axes mentioned are radially superimposed to each other merely for reasons of clarity. In practice, it is conceivable to arrange the rotor shaft 20a and the driven axle 6 at the same or almost the same distance parallel to the main axis 21. This saves additional axial and radial installation space, since, unlike the previous embodiments, the electric machine 3 is not arranged axially adjacent to the internal combustion engine 2, the first gear stage 7 and the multi-speed transmission 4, but laterally next to it.

The second gear stage 12 is in the present case configured as a chain drive, similar to the first gear stage 7, wherein a third gear wheel 31, which is connected to the second input shaft 9 in a rotationally fixed manner, is operatively connected to a fourth gear wheel 32, which is connected to the rotor shaft 20a in a rotationally fixed manner, by means of a chain 33. In other words, the rotor shaft 20a is in the present case configured as the input shaft of the second gear stage 12 b.

According to fig. 9, the second gear stage 12 is configured as a spur gear stage, unlike the embodiment according to fig. 8. The second gear stage 12 has a third gear 31 which is connected to the second input shaft 9 in a rotationally fixed manner, and a fourth gear 32 which is connected to the rotor shaft 20a in a rotationally fixed manner. The third gear 31 and the fourth gear 32 are in tooth engagement with a fifth gear 35 arranged on the intermediate shaft 34. The remaining construction of the drive train 1a is similar to the embodiment according to fig. 8.

Fig. 10 shows a ninth embodiment of a drive train 1a, which is essentially identical to the embodiment according to fig. 6. The main difference here is that the electric machine 3 is arranged in the power flow between the first gear stage 7 and the differential 34, i.e. the transmission is effectively arranged at the first input shaft 8 of the differential 14. The rotor shaft 20a is integrally connected with the first input shaft 8 such that the motor 3 is arranged coaxially with the first input shaft 8 of the differential 14. In this case, the advantage is that the electric machine 3 can also use the entire transmission ratio of the differential 14. It is conceivable to connect the electric machine 3 to the first input shaft 8 via the second gear stage 12 in a manner similar to the embodiment according to fig. 8 or 9, whereby the axial installation space on the driven axle 6 is saved. The remaining construction of the drive train 1a is similar to the embodiment according to fig. 8.

The present invention is not limited to only the embodiments described herein. Rather, these embodiments can be combined with each other in any manner. Thus, for example, the first gear stage 7 and/or the corresponding second gear stage 12 can be embodied as spur gear stages, chain drives and/or belt drives. Furthermore, the planetary gear sets 13a, 13b can be configured arbitrarily and connected in a driving-effective manner to each other in order to set a desired gear ratio in particular.

List of reference numerals

1. Motor vehicle

1a drive train

2. Internal combustion engine

3. Motor with a motor housing

4. Multi-gear transmission device

5a first driven shaft

5b second driven shaft

6. Driven axle

7. First gear stage

8. First input shaft of differential

Second input shaft of 9-multi-speed transmission

10. Clutch unit

11. Torsional damper

Second speed change stage at input shaft of 12-speed multi-gear transmission

13a first planetary gear set

13b second planetary gear set

14. Differential mechanism

15. First output shaft of internal combustion engine

Second output shaft of 16 multi-gear transmission

17a first axle

17b second axle

18. Wheel of vehicle

19. Stator

20. Rotor

20a rotor shaft

21. A main axis

22. First chain

23. First gear

24. Second gear

25a first sun gear of the first planetary gear set

25b second sun gear of the second planetary gear set

25c third sun gear of the second gear stage

26a first ring gear of a first planetary gear set

26b second ring gear of second planetary gear set

26c second gear stage third ring gear

27. Coupling shaft

28a first planetary gear of the first planetary gear set

28b second planetary gear of the second planetary gear set

28c second speed change stage third planetary gear

29a first planet carrier of a first planetary gear set

29b second planet carrier of the second planetary gear set

29c third planetary gear carrier of the second gear stage

30. Shell body

31. Third gear

32. Fourth gear

33. Second chain

34. Intermediate shaft

35. Fifth gear

L vehicle longitudinal axis.

Claims

1. A drive train (1 a) for a motor vehicle (1), comprising an internal combustion engine (2), a multi-speed transmission (4) and a one-piece differential (14), wherein the multi-speed transmission (4) is at least operatively connectable to the internal combustion engine (2) and is arranged in the power flow upstream of the differential (14), wherein the differential (14) is configured with two planetary gearsets (13 a, 13 b), wherein each planetary gearset (13 a, 13 b) is operatively connected to a respective driven shaft (5 a, 5 b) in a driving manner, wherein the differential (14) and the respective driven shaft (5 a, 5 b) are arranged coaxially to a driven axle (6) of the motor vehicle (1), wherein the internal combustion engine (2) and the multi-speed transmission (4) are arranged axially parallel to the driven axle (6), wherein the multi-speed transmission (4) is operatively connectable to the first planetary gearset (8) via at least one first transmission stage (7) to the first planetary gearset (13 a) by means of which a torque can be transferred from the first planetary gearset (13 a) to the second planetary gearset (13 b) in a first planetary gearset (13 b), so that a second secondary torque corresponding to the first secondary torque can be transmitted to the first driven shaft (5 a).

2. A drive train (1 a) according to claim 1, wherein the drive train further comprises at least one electric machine (3) for generating electric drive power.

3. A drive train (1 a) according to claim 2, wherein the at least one electric machine (3) is arranged in the power flow between the internal combustion engine (2) and the multi-speed transmission (4).

4. A drive train (1 a) according to claim 3, wherein the at least one electric machine (3) and the internal combustion engine (2) can be operatively connected together with the second input shaft (9) of the multi-speed transmission (4) or together with the second input shaft (9) of the multi-speed transmission (4).

5. A drive train (1 a) according to claim 3 or 4, wherein the respective electric machine (3) is in driving operative connection with the second input shaft (9) via at least one second gear stage (12).

6. A drive train (1 a) according to claim 2, wherein the at least one electric machine (3) is arranged in the power flow between the first gear stage (7) and the differential (14).

7. A drive train (1 a) according to claim 6, wherein the respective electric motor (3) is in driving connection with the first input shaft (8) of the differential (14) through at least one second gear stage (12).

8. A drive train (1 a) according to any of the preceding claims, wherein a clutch unit (10) is arranged in the power flow between the internal combustion engine (2) and the multi-speed transmission (4).

9. A drive train (1 a) according to any of the preceding claims, wherein a torsional damper (11) is arranged in the power flow between the internal combustion engine (2) and the multi-speed transmission (4).

10. A drive train (1 a) according to any of the preceding claims, wherein the two planetary gear sets (13 a, 13 b) are arranged side by side in the axial direction.

11. A drive train (1 a) according to any of claims 1 to 9, wherein the two planetary gear sets (13 a, 13 b) are arranged radially one above the other.

12. A transmission (1 a) according to any one of the preceding claims, wherein the multi-speed transmission (4) is configured as a planetary gear transmission having at least two planetary gear sets.

13. Motor vehicle (1) comprising at least one drive train (1 a) according to any one of claims 1 to 12.