WO2024188575A1

WO2024188575A1 - Drive train for a motor vehicle

Info

Publication number: WO2024188575A1
Application number: PCT/EP2024/053800
Authority: WO
Inventors: Martin FELLMANN
Original assignee: Zf Friedrichshafen Ag
Priority date: 2023-03-14
Filing date: 2024-02-15
Publication date: 2024-09-19
Also published as: DE102023202278B3

Abstract

The invention relates to a drive train for a motor vehicle, said drive train comprising an engine (10), a variator (12), a planetary assembly (14), a drive shaft (16), and an output shaft (18). The planetary assembly has a first planetary gear set (20), a second planetary gear set (30), a third planetary gear set (40), and a fourth planetary gear set (50). The second planetary gear set (30) is arranged axially on the engine side next to the first planetary gear set (20). The third planetary gear set (40) is arranged axially on the engine side next to the second planetary gear set (30). The fourth planetary gear set (50) is arranged axially on the engine side next to the third planetary gear set (40).

Description

Drivetrain for a motor vehicle

Technical area

The present invention relates to a drive train for a motor vehicle. The invention also relates to a motor vehicle.

State of the art

Old transport vehicles, such as the Unirnog, usually have gearboxes with stepped gear ratios. However, the discrete gears limit driving efficiency. In addition, it is not always possible to provide the desired gear ratio for every driving situation. Overall, using the transport vehicle can be difficult. However, due to the limited installation space, installing a gearbox with continuously variable gear ratios can be difficult.

DE 10 2009 002 806 A1 describes a drive train of a motor vehicle with a short wheelbase and switchable or permanent all-wheel drive. A planetary assembly is used.

DE 10 2009 002 807 A1 describes a drive train of a motor vehicle, comprising a continuously variable transmission and a longitudinal transfer case. The longitudinal transfer case has a bevel gear differential for power distribution to the cardan shaft connection flanges to the driven axles of the motor vehicle.

DE 10 2009 002 808 A1 describes a drive train of a utility vehicle, comprising a continuously variable transmission and a PTO transmission. The PTO transmission is designed as a spur gear transmission and is integrated into the continuously variable transmission.

Description of the invention A first aspect relates to a drive train for a motor vehicle. A motor vehicle can be designed, for example, as a van, passenger car, off-road vehicle or work machine. A motor vehicle can, for example, have a frame and, alternatively or additionally, a body to which the drive train is attached. The drive train can be designed to provide propulsion for the motor vehicle. The drive train can be designed to provide different forward and reverse driving ranges. The drive train can be continuously variable and power-split. In a continuously variable drive train, a gear ratio between an input shaft and an output shaft can be continuously adjustable. The power split can, for example, be a hydrostatic-mechanical power split. Alternatively or additionally, an electro-mechanical power split is possible, for example. The drive train enables a high gear spread with high efficiency.

The drive train has a drive shaft to which a variable to be translated can be fed into the transmission. The drive train has a motor which can, for example, provide drive power, a speed and alternatively or additionally a torque. The motor can, for example, be designed as an electric motor or an internal combustion engine. The motor can, for example, have a motor shaft to which drive power can be output. The drive train has an output shaft to which, for example, the translated variable is output. The output shaft can, for example, be connected to a driven axle of the motor vehicle, for example via a transmission differential. The drive shaft can extend through the drive train and, at an end facing away from the motor, enable a power take-off to be taken, for example to drive an implement of a work machine. The drive train can, however, also be free of a power take-off shaft.

In the respective reverse driving ranges, an output of the transmission rotates, for example, in the opposite direction to a direction of rotation in the respective forward driving ranges. In the respective forward driving ranges, a work machine can, for example, drive forwards and in the respective reverse driving ranges areas. The drive shaft and the output shaft are arranged parallel to each other. However, another design is also possible.

The drive train has a variator. The variator can be designed to continuously vary a transmission ratio of the drive train, for example within a driving range. A driving range of the transmission can be understood as a state in which there is a fixed mechanical transmission ratio between the drive shaft and the output shaft, whereby the transmission ratio of the drive train can be continuously varied within the driving range by the variator. The variator can have two energy converters that are coupled to one another and are designed as a hydrostatic drive, for example. The energy converters of the variator can also be designed as electrical machines. The energy converters can be arranged coaxially or axially parallel to the drive shaft, for example. For example, the first energy converter can be a hydraulic machine with a fixed displacement and the second energy converter can be a hydraulic machine with an adjustable displacement. A hydraulic machine with a fixed displacement can be a constant pump. A hydraulic machine with an adjustable displacement can be a variable displacement pump.

The drive train has a planetary assembly. The planetary assembly can, for example, have one or more planetary gear sets. In addition, the planetary assembly can additionally have one or more switching elements, wherein one or more of these switching elements can be designed as a brake. The drive train can be designed to transmit a torque from the drive shaft via the planetary assembly to the output shaft. To transmit a torque, it may be necessary for one or more switching elements to be actuated. An input shaft of the planetary assembly can be coupled to the drive shaft. An output shaft of the planetary assembly can be coupled to the output shaft. Another input shaft of the planetary assembly can be coupled to the variator. A coupling can, for example, be switchable and direct or indirect. The planetary assembly can be designed as a planetary roller. All parts of the planetary assembly can be arranged coaxially. The planetary assembly can be arranged coaxially with the drive shaft. The planetary assembly has a first switching element, a second switching element, a third switching element, a fourth switching element and a brake. A switching element can connect two parts to one another in a closed state. In an open state, a switching element can release this connection. A switching element can be designed, for example, as a frictional or positive switching element. A positive switching element can be designed, for example, as a claw clutch or synchronous clutch. A frictional switching element can be designed, for example, as a multi-disk clutch. If a switching element is provided between two elements of the drive train, these rotating elements are not permanently connected to one another in a rotationally fixed manner, for example, but can be connected to one another in a rotationally fixed manner via the clutch. A rotationally fixed connection is only brought about by actuating the switching element in between. Actuating the switching element means, for example, that it is transferred to a closed state, so that the components directly coupled to the switching element are aligned with one another in their rotational movements. The respective switching elements can be switched, for example, at least between an open and a closed state. A brake, for example, is a switching element that can connect a part to a stationary component, such as a housing, in a rotationally fixed manner.

The drive train has a first planetary gear set with a first sun gear, a first planet carrier and a first ring gear, a second planetary gear set with a second sun gear, a second planet carrier and a second ring gear, a third planetary gear set with a third sun gear, a third planet carrier and a third ring gear and a fourth planetary gear set with a fourth sun gear, a fourth planet carrier and a fourth ring gear. The planetary assembly and the drive train as a whole can, for example, be free of further planetary gear sets. The numbering of the rotating elements can merely serve to assign them to the respective planetary gear set. The second planetary gear set can, for example, be free of further rotating elements, such as, for example, another sun gear or another ring gear. The drive train may be free of elements other than those listed here.

For example, the drive train may not have any additional rotating elements, switching elements, planetary gear sets and motors.

A planetary gear set can, for example, be designed as a minus planetary gear set or as a plus planetary gear set. A planetary gear set can have three rotating elements, a sun gear, a planet carrier and a ring gear. One or more planet gears can be rotatably mounted on a planet carrier of a planetary gear set. For example, a planetary gear set can have three planet gears arranged on the same diameter around the sun gear. A sun gear can have external teeth with which respective planet gears mesh. A ring gear can have internal teeth with which respective planet gears also mesh. In a minus planetary gear set, the planet gears mesh with both the sun gear and the ring gear, for example. A minus planetary gear set has a negative stationary gear ratio. Alternatively, a planetary gear set can be designed as a plus planetary gear set. A plus planetary gear set has a positive stationary gear ratio. In a plus planetary gear set, for example, several sets of planet gears are provided. In the case of two sets of planet gears, each planet gear of a first set meshes with a sun gear and a planet gear of a second set. The planet gears of the second set in this case mesh with a ring gear.

The first sun gear is mechanically connected to the variator. The first sun gear can form an input shaft of the planetary assembly. The first planet carrier is permanently connected to the second ring gear in a rotationally fixed manner. The first ring gear is permanently connected to the second planet carrier in a rotationally fixed manner. The first ring gear is permanently connected to the drive shaft in a rotationally fixed manner. The first ring gear can form another input shaft of the planetary assembly, as can the second planet carrier which is connected to it in a rotationally fixed manner. The second sun gear is permanently connected to the third sun gear in a rotationally fixed manner. The second ring gear is permanently connected to the third planet carrier in a rotationally fixed manner. The third sun gear can be connected to the fourth sun gear in a rotationally fixed manner by means of the second switching element. The third planet carrier can be connected to the fourth planet carrier in a rotationally fixed manner by means of the third switching element. can be connected in a rotationally fixed manner. The third ring gear can be connected in a rotationally fixed manner to the fourth sun gear by means of the first switching element. The fourth sun gear can be connected in a rotationally fixed manner to the fourth planet carrier by means of the fourth switching element. The fourth switching element can thus block the fourth planetary gear set. The fourth planet carrier can be mechanically operatively connected to the output shaft. The fourth planet carrier can form an output shaft of the planetary assembly. The fourth ring gear can be secured by means of the brake, for example to a gearbox housing. The motor can be mechanically operatively connected to the drive shaft. For example, the motor shaft can be permanently connected in a rotationally fixed manner to the drive shaft. The variator can be mechanically operatively connected to the drive shaft. The drive train can be designed for continuously variable transmission between the drive shaft and the output shaft of the drive train. The drive train can be designed as a continuously variable power-split transmission.

If two elements are mechanically operatively connected, they can be directly or indirectly coupled to one another in such a way that a movement of one element can cause a reaction in the other element. For example, a mechanical operative connection can be provided by a positive or frictional connection. A mechanical operative connection can be established and also separated by a switching element. A mechanical operative connection, on the other hand, can exist permanently. For example, the mechanical operative connection can correspond to a meshing of corresponding teeth of two elements. Additional elements can be provided between elements that are mechanically operatively connected to one another.

A permanently non-rotatable connection between two elements is understood to mean a connection in which the two elements are essentially rigidly coupled to one another in all intended states. This also includes a frictional connection in which intentional or unintentional slippage can occur. Permanently non-rotatably connected elements can, for example, be present as individual components connected to one another in a rotationally fixed manner or as a single piece. A connection between two elements via a further element can mean that this further element can be involved in an indirect operative connection between the two elements. For example, this element can be arranged in the power flow between these two elements. A connection between two elements via two or more elements can mean that these further elements are all involved in an indirect operative connection between the two elements. A switchable connection can enable torque transmission between two elements in one state, for example through a rigid coupling, and in another state essentially interrupt this torque transmission. For this purpose, a corresponding switching element can be provided between the two elements.

For example, a fixed component cannot be rotated. For example, a rotating element can be detachably connected to a stationary component, such as a gearbox housing, by the brake. The housing can, for example, be permanently connected to the body in a rotationally fixed manner.

The second planetary gear set is arranged axially on the engine side next to the first planetary gear set. Engine side can mean that a part or assembly is arranged on a side that faces the engine. The second planetary gear set is therefore, for example, placed closer to the engine than the first planetary gear set. The third planetary gear set is arranged axially on the engine side next to the second planetary gear set. The third planetary gear set is therefore, for example, placed closer to the engine than the second planetary gear set. The fourth planetary gear set is arranged axially on the engine side next to the third planetary gear set. The fourth planetary gear set is therefore, for example, placed closer to the engine than the third planetary gear set. This results in a compact design that can be particularly easily integrated later even in the limited installation space of older motor vehicles. In addition, the connection of the variator can be particularly simple. This means that the drive train can also be easily installed in motor vehicles that were not originally designed for a continuously variable and power-split drive train. The first planetary gear set can be arranged axially at an end of the planetary gear facing away from the engine. The fourth planetary gear set can be arranged axially at the motor-side end region of the planetary gear, wherein the brake can be arranged further to the motor side. The fourth planetary gear set can be arranged axially adjacent to the motor.

In one embodiment of the drive train, it is provided that the four switching elements are arranged axially between the third planetary gear set and the fourth planetary gear set. This results in simple integration and a compact design. The first switching element and the second switching element can, for example, be arranged axially at least partially in the same area. The third switching element and the fourth switching element can, for example, be arranged axially at least partially in the same area. The third switching element and the fourth switching element can be arranged axially on the motor side to the first switching element and the second switching element.

In one embodiment of the drive train, it is provided that the brake is arranged axially on the motor side next to the fourth planetary gear set. The brake can form the component of the planetary assembly that is axially most on the motor side. The brake can thus be arranged particularly easily for connection to the housing.

In one embodiment of the drive train, it is provided that the first switching element and the second switching element are designed as a first double switching element. Alternatively or additionally, the third switching element and the fourth switching element are designed as a second double switching element. The second double switching element can be arranged axially on the motor side next to the first double switching element. A double switching element can, for example, provide the function of two switching elements. A double switching element can be compact and structurally simple. A double switching element can be easily operated, for example by means of a common single actuator. The first double switching element can alternatively provide an operative connection according to the closed first or the closed second switching element as switching states. The second double switching element can alternatively provide an operative connection according to the closed third or the closed fourth switching element as switching states. A double switching element can optionally also have a neutral position All switching elements can be arranged coaxially with each other and alternatively or additionally to the planetary gear sets.

In one embodiment of the drive train, the variator is arranged axially on the engine side next to the planetary assembly. This allows the drive train to be particularly compact radially.

In one embodiment of the drive train, it is provided that the variator is arranged axially in at least partial overlap with the planetary assembly. This allows the drive train to be particularly compact axially.

In one embodiment of the drive train, the variator is designed as a hydrostatic device with a variable displacement pump and a constant displacement pump. Such a drive train is particularly robust and reliable. The variable displacement pump can be mechanically connected to the drive shaft. The constant displacement pump can be mechanically connected to the first sun. This makes it possible to connect the variator with very few stages when connected using spur gear stages. For example, the variable displacement pump and the constant displacement pump can each be connected to the drive shaft or the first sun gear with just one set of two meshing spur gears. The variable displacement pump can be arranged axially on the motor side next to the constant displacement pump. The variable displacement pump can thus be arranged in an area with more radial installation space, whereby the variable displacement pump may require more installation space than the constant displacement pump.

In one embodiment of the drive train, it is provided that the variator is mechanically connected to the drive shaft by means of a single-stage first spur gear stage. Alternatively or additionally, the variator is mechanically connected to the first sun gear by means of a single-stage second spur gear stage. As a result, the drive train has few spur gears and can be highly efficient. A spur gear stage can have one or more stages. Each stage is formed, for example, by two meshing spur gears, whereby in the case of multi-stage spur gear stages, one spur gear can be involved in two stages. In one embodiment of the drive train, it is provided that the first spur gear stage is arranged axially on the motor side next to the planetary assembly. Alternatively or additionally, the planetary assembly is arranged axially on the motor side next to the second spur gear stage. This results in a radially compact design. The first spur gear stage is arranged axially between the motor and the planetary gear, for example. A direction change assembly can be arranged between the planetary assembly and the first spur gear stage, for example.

In one embodiment of the drive train, the drive shaft ends axially in front of an end of the planetary assembly facing away from the engine. For example, the drive shaft does not extend completely through the planetary gear. The drive train can be free of a power take-off shaft. The drive train can thus be easily retrofitted into a motor vehicle that is designed for a drive train without a power take-off shaft. In addition, the drive train can be particularly compact. Alternatively, the drive shaft extends through the planetary assembly and forms a power take-off shaft, for example, on a side facing away from the engine.

In one embodiment of the drive train, it is provided that the drive train has a direction change assembly which is designed to mechanically connect the fourth planet carrier to the output shaft selectively with a reversal of the direction of rotation. The direction change assembly can therefore provide a connection of the fourth planet carrier to the output shaft in a first switching state, in which a direction of rotation of the fourth planet carrier causes a rotation of the output shaft in a first direction of rotation. In a second switching state of the direction change assembly, a connection of the fourth planet carrier to the output shaft is then provided, in which a direction of rotation of the fourth planet carrier causes a rotation of the output shaft in a second direction of rotation opposite to the first direction of rotation. In this way, a reversal of the direction of rotation can be effected using simple means in order to change a direction of travel with the motor vehicle. In one embodiment of the drive train, it is provided that the direction change assembly is arranged axially on the motor side next to the planetary assembly. This allows the drive train to be particularly compact radially. The direction change assembly is arranged axially between the motor and the planetary assembly, for example. The first spur gear stage is arranged axially on the motor side next to the direction change assembly, for example.

In one embodiment of the drive train, it is provided that the direction change assembly is arranged axially at least partially in overlap with the variator. The drive train can thus be particularly compact axially. Alternatively, the direction change assembly is arranged axially without overlap with the variator.

In one embodiment of the drive train, the direction change assembly is designed to provide a first forward driving range, a second forward driving range and a reverse driving range. This allows the planetary assembly to be particularly compact and still achieve high forward driving speeds. For example, the direction change assembly can be designed to mechanically connect the fourth planet carrier to the output shaft with two different gear ratios while maintaining the same direction of rotation. In motor vehicles, however, a maximum reverse driving speed that corresponds to a maximum forward driving speed is often not desired. The drive train can thus provide particularly needs-based driving ranges in a compact manner.

In one embodiment of the drive train, it is provided that the direction change assembly has a first forward switching element, a second forward switching element and a reverse switching element. The designation as forward switching element and reverse switching element can serve to assign the direction change assembly and alternatively or additionally to its function. These switching elements can otherwise be designed like other switching elements. For example, the first forward switching element, the second The forward shift element and the reverse shift element can be designed as synchronizers, which means that drag losses can be particularly low. For example, the first forward shift element, the second forward shift element and the reverse shift element can also be designed as multi-plate clutches, which means that the drive train can be particularly cost-effective.

The direction change assembly can have a third spur gear stage, a fourth spur gear stage and a fifth spur gear stage. The numbering can be used for assignment. For example, the direction change assembly can be free of further spur gear stages. The fourth planet carrier can be mechanically connected to the output shaft via the first forward switching element and the third spur gear stage in the first forward driving range. The fourth planet carrier can be mechanically connected to the output shaft via the second forward switching element and the fourth spur gear stage in the second forward driving range. The third spur gear stage can, for example, have a higher gear ratio than the fourth spur gear stage. The number of stages can be the same for the third and fourth spur gear stages. For example, the third and fourth spur gear stages can be designed as one stage. The fourth planet carrier can be mechanically connected to the output shaft via the reverse switching element and the fifth spur gear stage in the reverse driving range. The number of stages can be different for the fifth spur gear stage than for the third and fourth spur gear stages. For example, the fifth spur gear stage can have an even number of stages if the third and fourth spur gear stages have an odd number of stages, and vice versa. For example, the fifth spur gear stage can be designed with two stages. The direction change assembly can thus provide the two forward driving ranges and the one reverse driving range in a mechanically simple and highly efficient manner.

In one embodiment of the drive train, it is provided that the fifth spur gear stage is arranged axially on the motor side next to the planetary assembly. Alternatively or additionally, the fourth spur gear stage can be arranged axially on the motor side next to the fifth spur gear stage. Alternatively or additionally, the third spur gear stage can be arranged axially on the motor side next to the fourth spur gear stage. This results in a A favorable arrangement with regard to bearing loads and radial installation space requirements, which, for example, in conjunction with the described axial arrangements of the planetary gear sets, enables a particularly compact, lightweight and cost-effective drive train.

A second aspect relates to a motor vehicle. The motor vehicle can have a drive train according to the first aspect. Respective features and advantages of the first aspect accordingly equally represent features and advantages of the second aspect and vice versa.

The motor vehicle can have a driven axle. For example, wheels can be attached to the axle. The driven axle can be mechanically connected to the output shaft of the drive train, for example via a differential. The differential can be designed as a limited-slip differential.

Short description of the characters

Fig. 1 shows a schematic diagram of a drive train for a motor vehicle.

Detailed description of embodiments

Fig. 1 shows a schematic of a drive train for a motor vehicle with an engine 10, a variator 12, a planetary assembly 14, a drive shaft 16 and an output shaft 18. The variator has a variable displacement pump 70 and a constant displacement pump 72. The planetary assembly has a first switching element K1, a second switching element K2, a third switching element K3, a fourth switching element K4 and a brake B. The four switching elements K1, K2, K3, K4 and the brake B are arranged coaxially with the drive shaft 16 and are designed as multi-plate clutches. The first switching element K1 and the second switching element K2 form a common first double switching element. The third switching element K3 and the fourth switching element K4 form a common second double switching element. The planetary assembly 14 has a first planetary gear set 20 with a first sun gear 22, a first planet carrier 24 and a first ring gear 26. A set of first planet gears 28 are rotatably mounted on the first planet carrier 24, each of which meshes with the first sun gear 22 and the first ring gear 26. The planetary assembly 14 has a second planetary gear set 30 with a second sun gear 32, a second planet carrier 34 and a second ring gear 36. A set of second planet gears 38 are rotatably mounted on the second planet carrier 34, each of which meshes with the second sun gear 32 and the second ring gear 36. The planetary assembly 14 has a third planetary gear set 40 with a third sun gear 42, a third planet carrier 44 and a third ring gear 46. A set of third planet gears 48 are rotatably mounted on the third planet carrier 44, each of which meshes with the third sun gear 42 and the third ring gear 46. The planetary assembly 14 has a fourth planetary gear set 50 with a fourth sun gear 52, a fourth planet carrier 54 and a fourth ring gear 56. A set of fourth planet gears 58 are rotatably mounted on the fourth planet carrier 54, each of which meshes with the fourth sun gear 52 and the fourth ring gear 56.

The first sun gear 22 is mechanically connected to the variator 12 on the constant pump 72 by means of a single-stage second spur gear stage 74. The first planet carrier 24 is permanently connected in a rotationally fixed manner to the second ring gear 36. The first ring gear 26 is permanently connected in a rotationally fixed manner to the second planet carrier 34. The first ring gear 26 is permanently connected in a rotationally fixed manner to the drive shaft 16. The second sun gear 32 is permanently connected in a rotationally fixed manner to the third sun gear 42. The second ring gear 36 is permanently connected in a rotationally fixed manner to the third planet carrier 44. The third sun gear 42 can be connected in a rotationally fixed manner to the fourth sun gear 52 by means of the second switching element K2. The third planet carrier 44 can be connected in a rotationally fixed manner to the fourth planet carrier 54 by means of the third switching element K3. The third ring gear 46 is rotatably connected to the fourth sun gear 52 by means of the first switching element K1. The fourth sun gear 52 is rotatably connected to the fourth planet carrier 54 by means of the fourth switching element K4. The fourth planet carrier 54 is mechanically operatively connected to the output shaft 18 via a direction change group 80. The fourth ring gear 56 is connected to a stationary component. The motor 10 can be mechanically connected to the drive shaft 16. In the example shown, a motor shaft of the motor 10 is permanently connected to the drive shaft 16. The variator 12 is mechanically connected to the drive shaft 16 with its variable displacement pump by means of a single-stage first spur gear stage 76.

The direction change assembly 80 is designed to mechanically connect the fourth planet carrier 54 to the output shaft 18 selectively with a reversal of the direction of rotation. For this purpose, the direction change assembly 80 can provide a first forward driving range, a second forward driving range and a reverse driving range. The direction change assembly has a first forward switching element KV1, a second forward switching element KV2, a reverse switching element KR, a third spur gear stage 82, a fourth spur gear stage 84 and a fifth spur gear stage 86. The first forward switching element KV1, the second forward switching element KV2 and the reverse switching element KR are designed as synchronizers and arranged coaxially with the drive shaft 16. The two forward switching elements KV1, KV2 are designed as a common third double switching element. In another embodiment, these switching elements are designed as multi-plate clutches. The fifth spur gear stage 86 has three spur gears that mesh in pairs and form two stages. The fourth spur gear stage 84 and the third spur gear stage 82 each have two spur gears that mesh in pairs and form one stage each. The spur gear on the most output side of the fifth spur gear stage 86, the fourth spur gear stage 84 and the third spur gear stage 82 is each permanently connected to the output shaft 18 in a rotationally fixed manner.

The fourth planet carrier 54 is mechanically connected to the output shaft 18 via the first forward shifting element KV1 and the third spur gear stage 82 in the first forward driving range. The fourth planet carrier 54 is mechanically connected to the output shaft 18 via the second forward shifting element KV2 and the fourth spur gear stage 84 in the second forward driving range. The fourth planet carrier 54 is mechanically connected to the output shaft 18 via the Reverse switching element KR and the fifth spur gear stage 86 are mechanically connected in the reverse driving range.

The output shaft 18 is connected to a limited-slip differential 90 of a driven axle 92 of the motor vehicle. Drive power can be transmitted to respective wheels 94 of the driven axle 92 via the limited-slip differential. In another embodiment, the motor vehicle has several driven axles which are mechanically operatively connected to the output shaft 18 via the limited-slip differential 90.

The motor 10 forms a motor-side end of the drive train. The second spur gear stage 74 is arranged at an end facing away from the motor 10. The first planetary gear set 20 is arranged axially next to it on the motor side. The second planetary gear set 30 is arranged axially next to the first planetary gear set 20. The third planetary gear set 40 is arranged axially next to the second planetary gear set 30 on the motor side. The fourth planetary gear set 50 is arranged axially next to the third planetary gear set 40 on the motor side. The four switching elements K1, K2, K3 and K4 of the planetary assembly 14 are arranged axially between the third planetary gear set 40 and the fourth planetary gear set 50. The first double switching element is arranged axially next to the third planetary gear set 40 on the motor side. The second double switching element is arranged axially next to the first double switching element on the motor side. The brake B is arranged axially on the motor side to the fourth planetary gear set 50. The direction change assembly 80 is arranged axially on the motor side to the brake B. The first spur gear stage 76 is arranged axially on the motor side next to the direction change assembly 80. The motor 10 is then arranged axially on the motor side next to the first spur gear stage 76.

The variator 12 is arranged axially at least partially overlapping with the direction change assembly 80. The variable displacement pump 70 is arranged axially on the engine side to the constant displacement pump 72.

In the direction change assembly, the fourth spur gear stage 84 is arranged axially on the motor side to the fifth spur gear stage 86. The third spur gear stage 82 is arranged axially on the motor side to the fourth spur gear stage 84. The Reverse switching element KR is arranged axially between the fifth spur gear stage 86 and the fourth spur gear stage 84. The two forward switching elements KV1, KV2 are arranged axially between the fourth spur gear stage 84 and the third spur gear stage 82. The first forward switching element KV1 is arranged axially on the motor side to the second forward switching element KV2.

Reference symbol

10 Engine

12 Variators

14 Planetary assembly

16 Drive shaft

18 Output shaft

20, 30, 40, 50 planetary gear set

22, 32, 42, 52 Sun gear

24, 34, 44, 54 planet carrier

26, 36, 46, 56 ring gear

28, 38, 48, 58 planetary gears

70 Variable displacement pump

72 Constant pump

74, 76, 82, 84, 86 spur gear stage

80 Direction change group

90 limited-slip differential

92 driven axle

94 wheels

K1, K2, K3, K4 switching element

B Brake

KV1 , KV2 forward switching element

KR reverse switching element

Claims

Patent claims

1 . Drive train for a motor vehicle with an engine (10), a variator (12), a planetary assembly (14), a drive shaft (16) and an output shaft (18), wherein the planetary assembly (14) has a first switching element (K1), a second switching element (K2), a third switching element (K3), a fourth switching element (K4), a brake (B), a first planetary gear set (20) with a first sun gear (22), a first planet carrier (24) and a first ring gear (26), a second planetary gear set (30) with a second sun gear (32), a second planet carrier (34) and a second ring gear (36), a third planetary gear set (40) with a third sun gear (42), a third planet carrier (44) and a third ring gear (46) and a fourth planetary gear set (50) with a fourth sun gear (52), a fourth planet carrier (54) and a fourth ring gear (56), wherein the first sun gear (22) is mechanically operatively connected to the variator (12), wherein the first planet carrier (24) is permanently connected to the second ring gear (36) in a rotationally fixed manner, wherein the first ring gear (26) is permanently connected to the second planet carrier (34) in a rotationally fixed manner, wherein the first ring gear (26) is permanently connected to the drive shaft (16) in a rotationally fixed manner, wherein the second sun gear (32) is permanently connected to the third sun gear (42) in a rotationally fixed manner, wherein the second ring gear (36) is permanently connected to the third planet carrier (44), wherein the third sun gear (42) is rotationally fixedly connected to the fourth sun gear (52) by means of the second switching element (K2), wherein the third planet carrier (44) is rotationally fixedly connected to the fourth planet carrier (54) by means of the third switching element (K3), wherein the third ring gear (46) is rotationally fixedly connected to the fourth sun gear (52) by means of the first switching element (K1) is rotatably connected, wherein the fourth sun gear (52) is rotatably connected to the fourth planet carrier (54) by means of the fourth switching element (K4), wherein the fourth planet carrier (54) is mechanically operatively connected to the output shaft (18), wherein the fourth ring gear (56) can be fixed by means of the brake (B), wherein the motor (10) is mechanically operatively connected to the drive shaft (16), wherein the variator (12) is mechanically operatively connected to the drive shaft (16), wherein the second planetary gear set (30) is arranged axially on the motor side next to the first planetary gear set (20), wherein the third planetary gear set (40) is axially on the motor side next to the second planetary gear set (30) is arranged, wherein the fourth planetary gear set (50) is arranged axially on the engine side next to the third planetary gear set (40).

2. Drive train according to claim 1, characterized in that the four switching elements (K1, K2, K3, K4) are arranged axially between the third planetary gear set (40) and the fourth planetary gear set (50) and the brake (B) is arranged axially on the engine side next to the fourth planetary gear set (50) and the first switching element (K1) and the second switching element (K2) are designed as a first double switching element and the third switching element (K3) and the fourth switching element (K4) are designed as a second double switching element and the second double switching element is arranged axially on the engine side next to the first double switching element.

3. Drive train according to claim 1 or 2, characterized in that the variator (12) is arranged axially on the engine side next to the planetary assembly (14).

4. Drive train according to claim 1 or 2, characterized in that the variator (12) is arranged axially at least in partial overlap with the planetary assembly (14).

5. Drive train according to one of the preceding claims, characterized in that the variator (12) is designed as a hydrostatic unit with a variable displacement pump (70) and a constant displacement pump (72), wherein the variable displacement pump (70) is mechanically operatively connected to the drive shaft (16), wherein the constant displacement pump (72) is mechanically operatively connected to the first sun (22) and wherein the variable displacement pump (70) is arranged axially on the engine side next to the constant displacement pump (72).

6. Drive train according to one of the preceding claims, characterized in that the variator (12) is mechanically operatively connected to the drive shaft (16) by means of a single-stage first spur gear stage (76) and the variator (12) is mechanically operatively connected to the first sun gear (22) by means of a single-stage second spur gear stage (74).

7. Drive train according to claim 6, characterized in that the first spur gear stage (76) is arranged axially on the engine side next to the planetary assembly (14) and the planetary assembly (14) is arranged axially on the engine side next to the second spur gear stage (74).

8. Drive train according to one of the preceding claims, characterized in that the drive shaft (16) ends axially in front of an end of the planetary assembly (14) facing away from the engine.

9. Drive train according to one of the preceding claims, characterized in that the drive train has a direction change assembly (80) which is designed to mechanically connect the fourth planet carrier (54) to the output shaft (18) selectively with a reversal of the direction of rotation.

10. Drive train according to claim 9, characterized in that the direction change assembly (80) is arranged axially on the engine side next to the planetary assembly (14).

11. Drive train according to claim 9 or 10, characterized in that the direction change assembly (80) is arranged axially at least partially in overlap with the variator (12).

12. Drive train according to one of claims 9 to 11, characterized in that the direction change assembly (80) is designed to provide a first forward driving range, a second forward driving range and a reverse driving range.

13. Drive train according to claim 12, characterized in that the direction change assembly (80) comprises a first forward switching element (KV1), a second forward switching element (KV2), a reverse switching element (KR), a third spur gear stage (82), a fourth spur gear stage (84) and a fifth spur gear stage (86)

21

REVISED SHEET (RULE 91) ISA/EP wherein the fourth planet carrier (54) is mechanically operatively connected to the output shaft (18) via the first forward shifting element (KV1) and the third spur gear stage (82) in the first forward driving range, wherein the fourth planet carrier (54) is mechanically operatively connected to the output shaft (18) via the second forward shifting element (KV2) and the fourth spur gear stage (84) in the second forward driving range, and wherein the fourth planet carrier (54) is mechanically operatively connected to the output shaft (18) via the

Reverse switching element (KR) and the fifth spur gear stage (86) are mechanically operatively connected in the reverse driving range.

14. Drive train according to claim 13, characterized in that the fifth spur gear stage (86) is arranged axially on the motor side next to the planetary assembly (14), the fourth spur gear stage (84) is arranged axially on the motor side next to the fifth spur gear stage (86) and the third spur gear stage (82) is arranged axially on the motor side next to the fourth spur gear stage (84).

15. Motor vehicle with a drive train according to one of the preceding claims and a driven axle, wherein the driven axle (92) is mechanically operatively connectable to the output shaft (18) of the drive train.

22

REVISED SHEET (RULE 91) ISA/EP