DE102004046009A1 - Power transmission arrangement for four-wheel drive front-engined vehicle has clutch to bevelled gear located close to front axle - Google Patents

Abstract

An automotive drive train has powered front and rear axles, one of which is permanently driven and the other selected as required. The vehicle has a transverse engine with a side-mounted gearbox and clutch with a power take-off point at the interface to the permanently driven axle. The power take-off point further has a bevelled gear that is engaged when required and coupled to a longitudinal drive shaft to the rear axle.

Description

The The present invention relates to a drive train for a motor vehicle, which has a front axle and a rear axle, one of which is constantly and the other is driven on demand, with a drive unit, the front is installed across the vehicle and on a Output member provides drive torque, wherein the output member with the constantly driven axle is connected, an angular gear, in the Area of the front axle is arranged and with a cardan shaft connected, which serves to drive torque to the rear axle transferred to, and a friction clutch assembly for engaging the on demand driven one Axis.

Further The present invention relates to a transfer case for a Powertrain, with a housing, from the laterally a first and a second drive shaft emerge and from the longitudinal direction a propeller shaft exits, with an angle gear arranged in the housing and with a friction clutch assembly, which by means of a clutch actuator actuated is.

at Motor vehicles, the four-wheel drive was originally almost exclusively all-terrain vehicles used. In recent years, however, are also vehicles that predominantly for the road traffic are designed (such as passenger cars in the form of Sedans, station wagons, SUVs) frequently equipped with four-wheel drive, namely to increase the Driving safety, especially in unfavorable traction conditions.

at Four-wheel drive vehicles are generally differentiated between Differential controlled systems and clutch controlled systems. at differential controlled systems, the drive torque of the Drive unit by means of a differential on the front axle and split the rear axle. For clutch controlled systems In general, only one axle is driven and the other axle becomes driven as needed. Here, in the simplest case, a hand-switched Coupling be provided, which is actuated from the passenger compartment. However, modern four-wheel drive vehicles of this type use automatic actuated clutches (e.g., Haldex couplings) which then turn on the second axis, if a differential speed builds up between the axles or has built up. These systems are also referred to as "hang-on" systems.

at Differential-controlled systems are known for lack of traction the longitudinal differential over a Clutch lock so that torque is transmitted to the axle with the higher coefficient of friction.

at Clutch-controlled systems distinguish between systems with hang-on to the rear axle. This is generally about front-wheel drive vehicles, the rear axle in the absence Traction at the front axle torque is allocated.

One such powertrain is installed, for example, in the Audi TT. Here, in the rear area of the cardan shaft, in front of the rear axle differential, a friction clutch arrangement in the form of a Haldex coupling is provided, with the rear axle is switched on when needed.

Vice versa are also known systems in which generally driven the rear axle is and the front axle is designed as a slope-on axle.

Under a drive unit becomes a unit in the present context for providing drive torque understood. It can do this to an engine such as an internal combustion engine or a Electric motor act, either as such or in combination with a gearbox.

The Gear can be a manual gearbox, a torque converter, a dual-clutch transmission, an automated manual transmission, a continuously variable transmission, etc.

at Transfer cases for Four-wheel drive vehicles are known in a number of concepts.

From the DE 37 21 628 C2 For example, it is known to arrange coaxially with the front axle a transverse differential and a longitudinal differential, both of which are designed as bevel gear differential. In this case, an output of a transversely mounted front drive unit is connected via a hollow shaft construction with an input member of the longitudinal differential. This in turn is connected on the outer circumference with a ring gear of an angle gear, which drives a propeller shaft for the rear axle.

Out WO 02/28678 A1, it is also known, coaxial with the front axle a longitudinal and to provide a transverse differential, each as Planetenraddifferentiale are formed. The planetary gear differentials are in one gearbox added. A housing for receiving a bevel gear for the output to the rear axle is on the side of the gearbox flanged.

From the DE 103 13 386 A1 is another transfer case for a transversely mounted front drive unit known. In this case, a trained as a planetary gear longitudinal differential is provided, whose output member is in engagement with a gear of a hollow shaft stub, which is arranged parallel to the front axle. At another end of the hollow shaft stub a bevel gear is fixed, which drives a propeller shaft for the rear axle.

at The Hang-On systems are subject to vibrations caused by the Friction clutch assembly for connecting the driven on demand Axis triggered become. The transfer cases are also special, as a rule Constructions exclusively for one certain powertrain are suitable.

It Against this background, the object of the present invention is an improved powertrain for a motor vehicle and a specify improved transfer case.

These Task is in the aforementioned drive train for a motor vehicle solved by that the friction clutch assembly with the angular gear in the area the front axle is integrated.

at the above-mentioned transfer case is the above object solved by that the case a basic housing for receiving the angular gear, one in the lateral direction of the casing Flanged housing cover for receiving the friction clutch assembly and an intermediate housing, that between the basic housing and the housing cover is arranged and to which the clutch actuator is fixed.

This Actuator is preferably operated fluidically, e.g. hydraulic or pneumatically, but is also purely mechanically actuated.

at the drive train according to the invention It is advantageous that the friction clutch assembly now with the angle gear connected or integrated. This has a positive effect on the the friction clutch assembly triggered vibrations, since the mass to be excited is much larger. Farther are in angular gear usually much lower speeds which has a positive effect on the stimulating forces.

at the transfer case according to the invention is advantageous in that the friction clutch assembly in a lateral Direction flanged housing cover is included. This is in a comparatively simple way a modular change the transfer case possible. In other words, the transfer case is constructed so that with many identical parts and few changes several transfer case variants are feasible. More precisely can in the transfer case different friction clutch assemblies will be realized.

As a result, it is preferred in a corresponding manner, when in the drive train according to the invention the friction clutch assembly integrated into a housing of the angle gear is.

The Task is thus completely solved.

at the drive train according to the invention It is also advantageous if the friction clutch assembly on a Side of the angular gear, which is opposite to the side, on which the output member of the drive unit is arranged.

hereby the space available in the area of the front axle can be optimal be exploited.

From It is particularly advantageous if the front axle is constantly driven is.

at this embodiment Consequently, the rear axle is connected as needed as a "slope-on" axis.

in this connection it is of particular advantage if the output member of the drive unit connected to an input member of a transverse differential gear is whose output members with a left or a right Side shaft of the front axle are connected.

The Transverse differential can in the case of a transmission of the drive unit be integrated, but can also in a housing of the distributor or angle gear be integrated.

The Transverse differential gear is preferably as a bevel gear differential trained, but can also be realized as Planetenraddifferential.

Further it is advantageous if the friction clutch as Coupling coupling for the Rear axle is formed, if further the input member of the transverse differential gear is connected to a hollow shaft assembly which is connected to an input member the Zuschaltkupplung is connected, and if an output member of the Coupling is connected to the angle gear.

Due to the connection between the transverse differential gear and the input member of the connection coupling via a Hohlwellenanord voltage of Be in Be rich the front axle existing space can be optimally utilized.

there it is particularly advantageous if the connection clutch a multi-plate clutch is and if the input member of the connection clutch is an outer disc carrier.

This favored an arrangement of a Hydraulikaktuators inside a housing of the angular gear.

Further In this case, it is advantageous if the connection coupling is a multi-plate clutch is and if the output member of the connection clutch is an inner disc carrier.

This allows a cheap one Connection of the angle gear to the output member (the inner disk carrier).

Further It is advantageous if the output member of the coupling via a further hollow shaft assembly is connected to the angular gear.

By This measure can be the positioning of slip clutch and bevel gear in Side direction selected be that the space is optimally utilized. It is further possible, in between to arrange a clutch actuator.

From It is particularly advantageous if the further hollow shaft arrangement the first hollow shaft assembly, the transverse differential gear and the connection coupling connects, encloses. This way you can the further hollow shaft assembly in a structurally simple manner a crown gear of the angular gear are fixed.

According to one Overall preferred embodiment is the input member of the transverse differential with a further Hollow shaft assembly connected to an input member of a transverse lock-up clutch is connected, wherein an output member of the transverse lock with one of the side shafts of the front axle is connected.

at this embodiment is an additional in the angular gear in a modular way Cross-locking clutch integrated.

The Quersperrkupplung can preferably in the housing of the Be integrated angular gear, preferably in the housing cover hereof.

From It is particularly advantageous if the connection clutch and the transverse lock-up clutch have a common input member.

This In particular, an outer disk carrier for two adjacent Be multi-plate clutches.

Further the transverse lock-up clutch can be actuated by means of a clutch actuator, in the housing cover is stored.

According to one Overall preferred, alternative embodiment of the drive train according to the invention is the rear axle constantly driven.

at this embodiment Thus, the front axle is a "hang-on" axle via a friction clutch assembly switchable.

From It is particularly advantageous if the output member of the drive unit via a hollow shaft arrangement connected to the angular gear.

hereby is achieved that drive torque from the drive unit directly constantly is delivered to the rear axle.

Further it is advantageous if the output member of the drive unit with the input member of the friction clutch assembly is connected, the as Zuschaltkupplungsanordnung for the front axle is formed.

there is it generally possible that the Aufsetzkupplungsanordnung for the front axle on an input member a Vorderachsdifferentialgetriebes acts. This corresponds to one Hang-on system for the front axle.

From However, it is particularly advantageous if the Zuschaltkupplungsanordnung is formed by two side friction clutches, which are independent of each other are controllable, wherein the output members of the two side friction clutches connected to a left and a right side shaft of the front axle are.

On this way it is possible while cornering a front wheel (preferably the outside front wheel) a bigger torque to assign as the other front wheel. This allows the yaw moment to be reversed To influence the vehicle's vertical axis, in particular to be more sporty Cornering to prevent understeering driving behavior.

there It is particularly advantageous if the side friction clutches designed as multi-plate clutches are and when their common input member formed by an outer disk carrier is.

This allows in a comparatively simple way, the respective inner disk carrier with the to connect left or right side shaft of the front axle.

Of the The term friction clutch is to be understood broadly in the present context. It can be e.g. dry rubble couplings and particularly preferred but are wet-running multi-plate clutches. The term friction clutch However, it should also include alternative coupling systems, such as Magnetic particle clutches.

It it is understood that the above and the following yet to be explained features not only in the specified combination, but also in other combinations or alone, without to leave the scope of the present invention.

embodiments The invention are illustrated in the drawings and in the following description explained. Show it:

1 a schematic plan view of a drive train according to a first embodiment of the present invention;

2 a plan view of a front part of a drive train according to another embodiment of the present invention;

3 a plan view of a front part of a drive train according to another embodiment of the present invention;

4 a sectional view through a constructive embodiment of a transfer case of the drive train of 1 ;

5 one of the 4 corresponding partial view of a section through a constructive embodiment of a transfer case of the drive train of 2 ; and

6 a sectional view through a constructive embodiment of a transfer case of the drive train of 3 ,

In 1 is a first embodiment of the drive train according to the invention generally with 10 designated.

The powertrain 10 is realized in a motor vehicle, more precisely a passenger car with two driven axles.

The Motor vehicle has a front axle VA and a rear axle HA on. The left and right front wheels of the front axle VA are denoted VL or VR. The rear wheels of the rear axle are HA designated HL or HR.

The powertrain 10 has a drive unit 12 on, which is transversely mounted in the area of the front axle VA.

The drive unit 12 has an engine 14 , For example, an internal combustion engine, and a transmission 16 For example, a manual transmission, a dual-clutch transmission, an automated transmission, a continuously variable transmission, an automatic transmission, etc., on.

An exit 18 the drive unit 12 is realized in the form of a "Final drive" wheelset, with a first gear that is connected to an output shaft of the gearbox 16 is connected, and a gear meshing therewith, which is arranged coaxially with the front axle.

The powertrain 10 has a cardan shaft (output shaft) 20 on, the front axle VA with a rear axle differential, more precisely a bevel gear differential 22 combines.

The output links of the bevel gear differential 22 are with a drive shaft 24 for the left rear wheel HL or a drive shaft 26 connected for the right rear wheel HR.

In the region of the front axle VA is for the purpose of distribution of the drive torque of the drive unit 12 a transfer case 28 intended. The transfer case 28 includes a bevel gear 29 that drive the cardan shaft 20 serves.

Furthermore, includes the transfer case 28 a friction clutch assembly 30 , which serves to drive the drive unit 12 if necessary to guide the rear axle HA.

The transfer case 28 has a housing 32 on, the side of a housing of the transmission 16 is flanged.

The exit 18 the drive unit 12 is with a Vorderachsdifferentialgetriebe 34 connected. The front axle differential gear 34 is arranged coaxially with the front axle VA, and its output links are provided with a drive shaft 36 for the left front wheel VL or a drive shaft 40 connected to the right front wheel VR. More specifically, the Vorderachsdifferentialgetriebe 34 designed as Kegelraddifferentialgetriebe and is immediately adjacent to the output 18 arranged, in the illustrated embodiment, within the transmission housing.

The input member of the Vorderachsdifferentialgetriebes 34 is also a hollow shaft arrangement 42 with an input member of the friction clutch assembly 30 connected. The friction clutch arrangement 30 is in relation to the angular gear 29 arranged so that they are the exit 18 or the Vorderachsdifferentialgetriebe 34 opposite. The hollow shaft arrangement 42 penetrates the angular gear 29 and is coaxial with the drive shaft 40 arranged for the right front wheel VR.

An output member of the friction clutch assembly 30 is with a ring gear 44 of the angular gear 29 connected. The ring gear 44 is coaxial with the front axle VA and is engaged with a bevel gear 46 the cardan shaft 20 ,

With the drive train 10 becomes the front axle VA over the Vorderachsdifferentialgetriebe 34 constantly driven.

The rear axle HA is switched on when needed, via the friction clutch arrangement 30 , The connection of the rear axle HA by means of known control or control algorithms, for example, monitor the rotational speeds of the axes VA, HA and the rear axle HA switch on when no sufficient traction on the front axle can be achieved.

Out establish a clearer Presentation will be given on the details of these control algorithms not received.

By the measure to arrange the friction clutch assembly in the region of the front axle, in particular with the angular gear 29 to perform integrated, various advantages are achieved. For example, it is not necessary for the friction clutch arrangement 30 to provide a separate housing. The rear differential 22 can be designed as a conventional Hinterachsdifferentialgetriebe. Further, by means of the friction clutch assembly 30 excited mass larger, so that the risk of building up vibrations is lower. In addition, in the range of the angular gear 29 (or the input) significantly lower speeds than in the propshaft 20 so that the friction clutch assembly 30 can work with smaller differential speeds and thus the imbalance problem is significantly reduced.

In addition, it is due to the arrangement of the friction clutch 30 at an axial the output 18 opposite end possible, the drive train, and in particular its transfer case 28 to expand modular.

An example of this is in 2 shown. 2 shows an alternative embodiment of a drive train according to the invention, which generally with 10 ' is designated. The powertrain 10 ' is identical in terms of structure and function to the drive train of 1 , In the following, only differences will be discussed. The same elements are provided with the same reference numerals.

In addition to the friction clutch arrangement 30 ' indicates the drive train 10 ' a transverse lock-up clutch 48 on, which acts on the front axle VA (front axle differential).

The transverse lockup clutch 48 is laterally adjacent to the friction clutch assembly 30 ' arranged. Accordingly, it is possible, despite the additional inclusion of such a transverse lock-up clutch 48 keep essential components and assemblies identical. Thus, the transverse lock can be 48 offer in a simple way as an accessory or optional equipment of the motor vehicle. The transverse lockup clutch 48 is between the input member of the friction clutch 30 ' and the right drive shaft 40 ' connected. More specifically, friction clutch assembly share 30 ' and the transverse lock-up clutch 48 a common input member in the form of an outer disk carrier.

3 shows a further alternative embodiment of a drive train according to the invention, which generally there with 10 '' is designated.

The powertrain 10 '' is in many ways identical to the powertrain 10 of the 1 , Therefore, in terms of its structure and function generally to the description of the drive train 10 Referenced.

The powertrain 10 '' however, it is fundamentally different from the powertrain 10 of the 1 because of the powertrain 10 '' the rear axle HA '' is constantly driven and the front axle VA '' is switched on when needed.

The rear axle HA '' is generally identically constructed as the rear axle HA of the drive train 10 of the 1 ,

In the area of the front axle VA '' is the output 18 the drive unit 12 with a hollow shaft section 50 connected. The hollow shaft section 50 bridges within the gear housing a space that is otherwise occupied by a Vorderachsendifferential. The hollow shaft section 50 is rotatably with the hollow shaft assembly 42 '' connected. The hollow shaft arrangement 42 '' is non-rotatable with the ring gear 44 '' of the angular gear 29 '' connected so that the rear axle HA '' via the propshaft 20 '' from the drive unit 12 is constantly supplied with drive torque.

To connect the front axle VA '' when needed is a friction clutch assembly 30 '' provided that a left side friction clutch 52 and a right side friction clutch 54 having.

The side friction clutches 52 . 54 have a common input member, which in the illustrated embodiment with the ring gear 44 '' of the angular gear 29 '' connected is. However, it is also possible, the input member of the side friction clutches 52 . 54 in other ways constantly with the output 18 the drive unit 12 connect to.

An output member of the left side friction clutch 52 is with the left drive shaft 36 '' connected to the left front wheel VL. An output member of the right side friction clutch 54 is in a similar way with the right drive shaft 40 '' connected to the right front wheel VR.

The side friction clutches 52 . 54 are independently controllable. As a result, drive torque can be individually transmitted to the front wheels VL, VR.

For example when cornering, the outside front wheel with more drive torque than the inside wheel to understeer prevent.

To prevent oversteer, for example during a load change during cornering, both side friction clutches 52 . 54 equally driven, or it can be supplied to the inside front wheel with a larger drive torque.

4 shows a constructive realization of the transfer case 28 of the drive train 10 of the 1 ,

The transfer case 28 has a housing 60 on, the side of a transmission housing 70 is flanged.

More specifically, the housing has 60 a basic housing 62 on, that is essentially the angular gear 29 receives. Furthermore, the housing has 60 a housing cover 66 and an intermediate housing 64 on that between the base housing 62 and the housing cover 66 is arranged.

Furthermore, the housing has 60 a propeller shaft housing 68 on where the propshaft 20 is mounted by means of two rolling bearings (preferably in O arrangement).

The basic housing 62 is on the gearbox 70 appropriate. A hollow shaft section 72 that with the front axle differential 34 and with the exit 18 is connected (not shown here), extends to the base housing 62 , Inside the basic housing 62 is a second hollow shaft section 74 mounted rotatably with the first hollow shaft section 72 is connected, for example by means of a toothing or the like. The first hollow shaft section 72 and the second hollow shaft portion 74 form the hollow shaft assembly 42 ,

The second hollow shaft section 74 extends coaxially with the drive shaft 40 for the right front wheel, through the housing cover 66 therethrough. In the area of the housing cover 66 is the second hollow shaft section 74 with an outer disc carrier 76 the friction clutch assembly 30 connected. The Außenla mellenträger extends radially adjacent to the housing cover 66 and is radially outward toward the intermediate housing 64 directed.

The outer disc carrier 76 is at the second hollow shaft portion 74 by means of an axial lock 78 established.

An inner disc carrier 80 the friction clutch assembly 30 is with a carrier sleeve 82 connected, extending through the intermediate housing 64 through into the basic housing 62 extends into it.

The carrier sleeve 82 is designed as a further hollow shaft and is by means of a first bearing 84 and a second camp 86 on the basic housing 62 or on the intermediate housing 64 rotatably mounted. Because the carrier sleeve 82 coaxial with the second hollow shaft portion 74 is arranged, the bearings serve 84 . 86 also for storage of the second hollow shaft section 74 ,

The ring gear 44 of the angular gear 29 is rotationally fixed to the carrier sleeve 82 established.

In the intermediate housing 64 is a first clutch actuator 88 arranged in the form of a Hydraulikaktuators, which is adapted to the friction clutch assembly 30 to press. The clutch actuator 88 acts in a direction laterally outwards, towards the housing cover 66 ,

Upon actuation of the clutch actuator 88 supports the outer disk carrier 76 via the axial lock 78 on the second hollow shaft section 74 from.

The second hollow shaft section 74 is supported in the axial direction by a needle bearing 90 on the carrier sleeve 82 off, over the two camps 84 . 86 is axially supported.

In this way, in the Reibkupp development arrangement 30 exerted axial forces of the bearing of the ring gear 44 be recorded.

5 shows a constructive realization of the drive train 10 ' of the 2 , for reasons of a clearer presentation, only the differences from the transfer case 28 of the 4 are shown.

It can be seen that the outer disk carrier 76 ' of the transfer case 28 ' in the radially outer area not only towards the intermediate housing 64 extends, but also also towards the housing cover 66 ' ,

The housing cover 66 ' is elongated and not only takes the friction clutch assembly 30 ' but also the transverse lock-up clutch 48 of the front axle differential 34 on. In the housing cover 66 ' is also a second clutch actuator 92 for actuating the transverse lock-up clutch 48 arranged.

An inner disc carrier 94 the transverse lock-up clutch 48 is non-rotatable with the drive shaft 40 ' connected.

In 6 is a constructive realization of the drive train 10 '' of the 3 shown.

It can be seen that the second hollow shaft section 74 '' rotatably with the carrier sleeve 82 '' for the ring gear 44 '' is connected, so that the rear axle HA '' is constantly driven.

Furthermore, an outer disk carrier 100 the friction clutch assembly 30 '' rotatably with the carrier sleeve 82 '' connected.

An inner disc carrier 102 the left side friction clutch 52 is with the drive shaft 36 '' connected. An inner disc carrier 104 the right side friction clutch 54 is with the drive shaft 40 '' connected.

In the intermediate housing 64 '' is a first clutch actuator 106 for actuating the left side friction clutch 52 intended. In the housing cover 66 '' is a second hydraulic actuator 108 to operate the right side friction clutch 54 arranged.

It can be seen that the structural embodiments of the three drive trains 10 . 10 ' . 10 '' of the 4 to 6 are identical in many respects and can resort to many identical parts, although functionally different drive trains can be realized.

It can be a technically simple way a modular transfer case realized with integrated angular gear and friction clutch become.

Claims (17)

Powertrain ( 10 ) for a motor vehicle having a front axle (VA) and a rear axle (HA), one driven continuously and the other driven as required, comprising: - a drive unit ( 12 ), which is installed at the front transversely in the motor vehicle and via an output member ( 18 ) Provides drive torque, wherein the output member ( 18 ) is connected to the constantly driven axle, - a bevel gear ( 29 ), which is arranged in the region of the front axle (VA) and with a cardan shaft ( 20 ), which serves to transmit drive torque to the rear axle (HA), and - a friction clutch arrangement ( 30 ) for connecting the on-demand driven axle, characterized in that the friction clutch assembly ( 30 ) with the angular gear ( 28 . 29 ) is integrated in the area of the front axle (VA). Drive train according to claim 1, characterized in that the friction clutch arrangement ( 30 ) in a housing ( 60 ) of the angular gear ( 28 . 29 ) is integrated. Drive train according to claim 1 or 2, characterized in that the friction clutch arrangement ( 30 ) on one side of the angular gear ( 28 . 29 ), which is opposite to the side on which the output member ( 18 ) of the drive unit ( 12 ) is arranged. Drive train according to one of claims 1-3, characterized characterized in that the front axle (VA; VA ') is constantly is driven. Drive train according to claim 4, characterized in that the output member ( 18 ) of the drive unit ( 12 ) with an input member of a transverse differential gear ( 34 ) whose output members are connected to a left or a right side wave ( 36 . 40 ) of the front axle (VA) are connected. Drive train according to claim 5, characterized in that the friction clutch arrangement ( 30 ; 30 ' ) as a connection coupling ( 30 ; 30 ' ) is designed for the rear axle (HA), that the input member of the transverse differential gear ( 34 ) further comprising a hollow shaft arrangement ( 42 ) connected to an input member ( 76 ) of the connection coupling ( 30 ; 30 ' ), and that an output member ( 80 ) of the connection coupling ( 30 ; 30 ' ) with the Winkelgetrie be ( 28 . 29 ) connected is. Drive train according to claim 6, characterized in that the Zuschaltkupplung ( 30 ; 30 ' ) is a multi-plate clutch and that the input member ( 76 ) of the connection coupling ( 30 ; 30 ' ) an outer disc carrier ( 76 ). Drive train according to claim 6 or 7, characterized in that the Zuschaltkupplung ( 30 ; 30 ' ) is a multi-plate clutch and that the output member ( 80 ) of the connection coupling ( 30 ; 30 ' ) an inner disc carrier ( 80 ). Drive train according to one of claims 6-8, characterized in that the output member ( 80 ) of the connection coupling ( 30 ; 30 ' ) via a further hollow shaft arrangement ( 82 ) with the angular gear ( 28 . 29 ) connected is. Drive train according to one of claims 5-9, characterized in that the input member of the transverse differential gear is further provided with a hollow shaft arrangement ( 74 ' ) connected to an input member ( 76 ' ) a transverse lock-up clutch ( 48 ), and that an output member ( 90 ) of the transverse lock-up clutch ( 48 ) with a ( 40 ' ) of the side shafts of the front axle (VA) is connected. Drive train according to claim 6 and 10, characterized in that the Zuschaltkupplung ( 30 ' ) and the transverse lock-up clutch ( 48 ) a common input element ( 76 ' ) exhibit. Drive train according to one of claims 1-3, characterized characterized in that the rear axle (HA '') constantly is driven. Drive train according to claim 12, characterized in that the output member ( 18 ) of the drive unit ( 12 ) via a hollow shaft arrangement ( 42 '' ) with the angular gear ( 29 '' ) connected is. Drive train according to claim 13, characterized in that the output member ( 18 ) of the drive unit ( 12 ) with an input member of the friction clutch assembly ( 30 '' ) connected as a connection coupling arrangement ( 30 '' ) is designed for the front axle (VA). Drive train according to claim 14, characterized in that the Zuschaltkupplungsanordnung ( 30 '' ) by two side friction clutches ( 52 . 54 ) is formed, which are independently controllable, wherein the output members ( 102 . 104 ) of the two side friction clutches ( 52 . 54 ) with a left or a right side wave ( 36 '' . 40 '' ) of the front axle (VA '') are connected. Drive train according to claim 15, characterized in that the side friction clutches ( 52 . 54 ) as multi-plate clutches ( 52 . 54 ) and that their common input element ( 100 ) by an outer disc carrier ( 100 ) is formed. Transfer case ( 28 ), in particular for a drive train ( 10 ) according to any one of claims 1-16, with a housing ( 60 ), from the side in a first and a second drive shaft ( 36 . 40 ; 24 . 26 ) emerge and from the longitudinal direction of a propeller shaft ( 20 ), with one in the housing ( 60 ) arranged angular gear ( 29 ) and with a friction clutch assembly ( 30 ), which by means of a clutch actuator ( 88 ; 106 ) is actuated, characterized in that the housing ( 60 ) a basic housing ( 62 ) for receiving the angular gear ( 29 ), one in the lateral direction of the housing ( 60 ) flanged housing cover ( 66 ) for receiving the friction clutch assembly ( 30 ) and an intermediate housing ( 64 ), which between the basic housing ( 62 ) and the housing cover ( 66 ) is arranged and on which the clutch actuator ( 88 ; 106 ).