DE102022203135A1 - Drive assembly for a work machine - Google Patents

Abstract

The invention relates to a drive assembly (10) for a work machine, having a drive shaft (18), a first output shaft (20), a second output shaft (22), a reversing group (12), a longitudinal differential (14) and a differential lock (16). . The drive assembly (10) is designed to transmit drive power from the drive shaft (18) to the two output shafts (20, 22). The reversing group (12) is designed to change a direction of rotation when transmitting the drive power. The longitudinal differential (14) is designed to divide the drive power during transmission from the drive shaft (18) to the first output shaft (20) and the second output shaft (22). The drive shaft (18), the first output shaft (20) and the second output shaft (22) extend parallel in an axial direction. The reversing group (12) extends in a first axial region (38) in the axial direction. The differential lock (16) extends at least partially in the first axial region. The invention also relates to a work machine.

Description

Technical area

The present invention relates to a drive assembly for a work machine with a longitudinal differential and a differential lock. The invention also relates to a work machine.

State of the art

Drive assemblies for work machines must enable efficient and reliable operation of the work machine under various ground conditions and work cycles. For this it may be necessary, for example, to provide a four-wheel drive with a longitudinal differential, whereby the differential can be locked depending on the ground conditions. However, this can result in a large space requirement.

In the DE 10 2012 216 046 A1 a drive train of an agricultural or municipal utility vehicle is described, wherein a differential effect of a transfer case can be locked via a clutch.

Presentation of the invention

A first aspect of the invention relates to a drive assembly for a work machine. A drive assembly can, for example, form part of a drive train. The work machine can be used as an agricultural machine, e.g. B. be designed as a tractor, as a construction machine or as a special vehicle. An example of a work machine is a wheel loader, in which the respective wheels can be driven by the drive power.

The drive assembly has a drive shaft, a first output shaft and a second output shaft. Drive power from the work machine can be supplied to the drive assembly on the drive shaft. The drive power can be used to drive the work machine. For example, a portion of the drive power supplied can be output at the first output shaft and the second output shaft, for example to a respective assigned drive axle of the work machine. The two output shafts are, for example, each mechanically operatively connected to the associated drive axle via an axle differential. Alternatively or additionally, for example, a mechanical active connection via respective bevel gears is also possible. The two output shafts can each form an output shaft of the drive assembly. For example, the drive assembly only has two output shafts. The drive shaft may form an input shaft or a drive power transmission shaft of the drive assembly. The drive assembly is designed to transmit drive power from the drive shaft to the two output shafts.

The drive assembly also has a reversing group. The reversing group is designed to change a direction of rotation when transmitting the drive power to the two output shafts. For this purpose, the reversing group can, for example, have one or more switching elements, by actuating which a direction of rotation can be reversed. In addition, the reversing group can also have, for example, one or more spur gear stages or one or more planetary gear sets. The reversing group can also be designed to provide idling. When idling, torque transmission from the drive shaft to the two output shafts can be interrupted.

The drive assembly also has a longitudinal differential. The longitudinal differential is designed to divide the drive power during transmission from the drive shaft to the first output shaft and the second output shaft. The longitudinal differential may allow the first output shaft to rotate at a different speed than the second output shaft. The longitudinal differential can, for example, improve cornering and off-road driving by speed compensation. The longitudinal differential can, for example, enable automatic speed adjustment. The longitudinal differential can, for example, couple a front axle and a rear axle of the work machine.

The drive assembly also has a differential lock with a switching element. The differential lock can be designed to determine a speed ratio of the two output shafts of the longitudinal differential and thus also of the two output shafts of the drive assembly in a locked state. This can prevent a drive axle from spinning on slippery surfaces such as snow or ice. The differential lock can at least inhibit the increased slip of a drive axle. In the locked state, a speed-fixed connection between the two output shafts can be set or only one output shaft speed can be inhibited compared to a release state. The longitudinal differential can also be locked for emergency braking, since on many machines a service brake is only provided on one drive axle. The differential lock can be adjusted to the release state, for example, by actuating the switching element. This can improve braking behavior, especially in the event of a defect. In the non-actuated state the switching element of the differential lock is held in the closed state, for example with a plate spring. Other switching elements of the drive assembly are open, for example, when they are not actuated. The differential lock can, for example, also be adjusted to the locked state by actuating the switching element. In this case, however, when the switching element is not actuated, the differential lock can be in a release state.

A switching element can, for example, be designed to be frictionally or positively locking. An example of a frictional switching element is a multi-plate clutch. An example of a positive switching element is a claw clutch. A switching element can be closed by actuation. For example, a switching element can be actuated with oil pressure to enable torque transmission between two elements.

The input shaft, the first output shaft and the second output shaft extend in parallel in an axial direction. For example, at least the first output shaft and the second output shaft are spaced axially parallel to one another and are therefore not arranged coaxially to one another. The drive shaft can, for example, be arranged axially parallel to the first output shaft and alternatively or in addition to the second output shaft. The axial direction can correspond to a longitudinal extent of these waves.

The reversing group extends in a first axial region of the axial direction. The first axial region can be defined by a first end and an axially opposite second end of the reversing group. The first end can, for example, face a drive shaft and thus define a drive-side end. The opposite end can form an output-side end. The drive-side end and the output-side end of the axial region can also be defined by a torque flow. The reversing group may extend parallel with respective shafts to the input shaft, the first output shaft and the second output shaft.

The differential lock extends at least partially in the first axial region, so that it is partially arranged in the axial region. An axial extent of the differential lock has, for example, an at least partial overlap with the axial extent of the reversing group. For example, the switching element of the differential lock can have an at least partial axial overlap with the axial extent of the reversing group. The switching element of the differential lock can extend parallel to the reversing group and spaced axially parallel to it in the axial direction.

Such a design allows the axial installation space of the drive group to be significantly reduced. The switching element of the differential lock is, for example, arranged on a different axle than the longitudinal differential. For example, the switching element of the differential lock and the longitudinal differential are not arranged coaxially with one another. A free space radial to the reversing group can be used in order to provide the differential lock in a space-saving manner. This allows the drive group to be particularly compact.

In a further embodiment of the drive assembly, it can be provided that the switching element of the differential lock extends completely in the first axial region and is therefore completely arranged in this. This allows the drive assembly to be particularly compact. The switching elements of the differential lock can be arranged radially instead of axially next to the reversing group. Respective spur gears of the differential lock and the reversing group can be arranged axially next to the switching element of the differential lock and can also be in engagement with one another without the switching element of the differential lock hindering this.

In a further embodiment of the drive assembly, it can be provided that the switching element of the differential lock is arranged in a drive-side end region of the first axial region. This can make assembly of the drive assembly considerably easier and overall result in a drive assembly that is compact but still easy to assemble. For example, the differential lock, or at least its switching element, can already be installed in a housing. The reversing group can thus be pivoted past the switching element and inserted into the housing on the drive side. For example, an intermediate shaft of the reversing group can be moved past the switching element, even though the intermediate shaft is in engagement with a spur gear stage of the differential lock in its fully assembled position. The drive-side end region can, for example, extend away from the drive-side end into the first axial region. The end region can be another axial region. The drive shaft can, for example, extend into the drive-side end region of the first axial region.

In a further embodiment of the drive assembly, it can be provided that the switching element of the differential lock is arranged coaxially with the second output shaft. This allows the switching element of the differential lock to be locked be mounted on the second output shaft in a tens-saving and space-efficient manner and, alternatively or additionally, be mounted together with the second output shaft on a housing of the drive assembly. The longitudinal differential can, for example, be arranged coaxially with the first output shaft. As a result, the longitudinal differential can be mounted on the first output shaft in a cost-saving and space-efficient manner and, alternatively or additionally, can be mounted together with the first output shaft on a housing of the drive assembly.

In a further embodiment of the drive assembly, it can be provided that the reversing group has an intermediate shaft, a first spur gear stage and a second spur gear stage. The result is a simple, cost-effective and reliable reversing group. An intermediate shaft can be a rotatably mounted shaft. The intermediate shaft can be a shaft which is involved in the drive power transmission from the reversing group to the two output shafts.

A spur gear stage can, for example, be designed in one or more stages. A single-stage spur gear stage can, for example, have two gears that mesh with one another. A two-stage spur gear stage can, for example, have three gears that mesh with each other in pairs.

The drive shaft can be mechanically operatively connected to the intermediate shaft via the first spur gear stage or the second spur gear stage in order to change the direction of rotation when transmitting the drive power to the two output shafts. Accordingly, when the direction of rotation is reversed, the direction of rotation of the intermediate shaft can also be reversed. For example, the first spur gear stage can have an even number of stages and the second spur gear stage can have an odd number of stages. The reversing group can, for example, have a first reversing switching element and a second reversing switching element. A reversing switching element can be a normal switching element, which is only referred to as such to associate it with the reversing assembly. By actuating the first reversing switching element, for example, a gear of the first spur gear stage can be connected to the drive shaft in a rotationally fixed manner in order to engage a forward travel range. By actuating the second reversing switching element, for example, a gear of the second spur gear stage can be connected to the drive shaft in a rotationally fixed manner in order to engage a reverse travel range. The two reversing switching elements can be designed together as a double switching element, which can have a neutral position. A first switching position of this double switching element can correspond to an actuation of the first reversing switching element and a second switching position to an actuation of the second reversing switching element.

The respective switching elements of the reversing assembly can be arranged coaxially with the drive shaft. As a result, respective switching elements of the reversing assembly can be mounted on the drive shaft in a cost-saving and space-efficient manner and, alternatively or additionally, can be mounted together with the drive shaft on a housing of the drive assembly. The intermediate shaft can extend axially parallel to the drive shaft. The intermediate shaft can, for example, be arranged axially parallel to the drive shaft. The intermediate shaft can be arranged coaxially with one of the two output shafts or offset from both output shafts.

If two elements are mechanically connected, they are directly or indirectly coupled to one another in such a way that a movement of one element causes a reaction of the other element. For example, a mechanical active connection can be provided by a positive or frictional connection. For example, the mechanical active connection can correspond to a meshing of corresponding toothings of two elements. Additional elements, for example one or more spur gear stages, can be provided between the elements. A permanently rotationally fixed connection between two elements is understood to be 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 unwanted slippage can occur. Elements that are permanently connected in a rotationally fixed manner can be present as individual components that are connected to one another in a rotationally fixed manner or in one piece. A connection between two elements via another element can mean that this additional element is involved in an indirect active connection between the two elements. For example, this element can be arranged in the flow of force between these two elements. A connection between two elements via two or more elements can mean that these additional elements are all involved in an indirect active 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 essentially interrupt this torque transmission in another state. For this purpose, a corresponding switching element can be provided between the two elements.

The intermediate shaft can be mechanically operatively connected to an input shaft of the longitudinal differential. This allows the drive power to be transferred from the reversing assembly to the longitudinal differential. The differential lock can have a third spur gear stage and a fourth spur gear stage. The numbering is only used for clear assignment and does not imply that the differential lock has additional spur gear stages. The differential lock can, for example, only have two spur gear stages. The switching element of the differential lock can be mechanically operatively connected to the intermediate shaft by means of the third spur gear stage, for example on a first switching element side. The switching element of the differential lock can be mechanically operatively connected to an output shaft of the longitudinal differential by means of the fourth spur gear stage, for example on a second switching element side. The third spur gear stage and the fourth spur gear stage can each form a winding spur gear stage for the differential lock, which can enable an axially parallel spacing between the switching element of the spur gear stage and the longitudinal differential. By closing the switching element of the differential lock, two rotating elements of the longitudinal differential can be mechanically connected to one another and the longitudinal differential can thus be locked. For example, the longitudinal differential can be locked by actuating the switching element of the differential lock, since two rotating elements of the longitudinal differential are then connected to one another. An output shaft of the longitudinal differential can be mechanically operatively connected to the second output shaft by means of the fourth spur gear stage. When the switching element of the longitudinal differential is closed, the output shaft is then mechanically operatively connected to the intermediate shaft via the fourth spur gear stage and the third spur gear stage. Due to the mechanical active connection of the intermediate shaft with the input shaft of the longitudinal differential, when the switching element of the longitudinal differential is closed, there is a mechanical active connection between the two output shafts of the longitudinal differential and the input shaft of the longitudinal differential. In this way, the longitudinal differential can be locked using simple means with an axially compact design.

In a further embodiment of the drive assembly, it can be provided that the longitudinal differential has a negative planetary gear set. A planetary gear set has a ring gear, a planet carrier and a sun gear. These elements can also be referred to as rotating elements. One or more planet gears can be mounted on the planet carrier. For example, three planet gears can be rotatably mounted on the planet carrier. The planet gears can mesh with the ring gear and the sun gear. A minus planetary gear set can have a negative stationary gear ratio. For example, a minus planetary gear set only has one set of planetary gears. If a negative planetary gear set is provided, a connection of the fourth spur gear stage to the longitudinal differential can be particularly simple. In the minus planetary gear set, the intermediate shaft can be mechanically operatively connected to the input shaft of the longitudinal differential, which is designed as a planet carrier, for example via the second spur gear stage. In the negative planetary gear set, the second output shaft can be mechanically operatively connected to the output shaft of the longitudinal differential, which is designed as a sun gear, via the fourth spur gear stage. The result is a simple connection, which can be implemented, for example, with a compact hollow shaft arranged radially on the inside.

In a further embodiment of the drive assembly, it can be provided that the longitudinal differential has a plus planetary gear set. A plus planetary gear set can have a positive stationary gear ratio. A plus planetary gear set can, for example, have two sets of planet gears, each of which meshes with one another in pairs. Respective planet gears of a first set can mesh with the sun gear and respective planet gears of a second set can mesh with the ring gear. A plus planetary gear set can provide particularly low gear ratios. For example, with a plus planetary gear set, a stationary transmission can be realized in a structurally simple and compact manner, in which a front axle is allocated between 35% and 45%, for example 40%, of the drive torque and a rear axle between 55% to 65%, for example 60% Drive torque is allocated, which can be advantageous for the driving characteristics of the work machine. In the plus planetary gear set, the intermediate shaft can be mechanically operatively connected to the input shaft of the longitudinal differential, which is designed as a ring gear. In the case of the plus planetary gear set, the second output shaft can be mechanically operatively connected to the output shaft of the longitudinal differential, which is designed as a sun gear, via the fourth spur gear stage. The first output shaft can be easily mounted on a housing wall.

In a further embodiment of the drive assembly, it can be provided that the fourth spur gear stage is arranged axially on the output side of the first axial region. This can simplify assembly. In addition, the fourth spur gear stage can be supported, for example, on a housing of the longitudinal differential.

In a further embodiment of the drive assembly it can be provided that the fourth spur gear stage is arranged axially on the drive side of the longitudinal differential. This makes a connection to the longitudinal differential possible in a radially compact and simple manner, for example if the longitudinal differential has a negative planetary gear set.

In a further embodiment of the drive assembly, it can be provided that the fourth spur gear stage is arranged axially on the output side of the longitudinal differential. This allows the first output shaft and the fourth spur gear stage to be mounted on a housing wall of the drive group. In addition, the connection to the longitudinal differential can easily be guided past the longitudinal differential to the switching element of the differential lock, for example if the longitudinal differential has a plus planetary gear set.

In a further embodiment of the drive assembly, it can be provided that a first spur gear and a second spur gear are each connected to the intermediate shaft in a rotationally fixed manner. For example, the first spur gear, the second spur gear and the intermediate shaft can form a one-piece double gear shaft. The drive assembly has so few parts and is robust. The first spur gear can form a spur gear of both the first spur gear stage and the third spur gear stage. As a result, the drive assembly has few spur gears and can require few bearings. For example, the first spur gear can mesh with both a further spur gear of the first spur gear stage and with a further spur gear of the third spur gear stage. The second spur gear stage can, for example, be designed in two stages. The second spur gear can then form a middle spur gear or a spur gear of the second spur gear stage on the output side in the torque flow.

In a further embodiment of the drive assembly, it can be provided that the third spur gear stage and the fourth spur gear stage have a different gear ratio, so that a differential planetary gear set of the longitudinal differential rolls in the locked state of the differential lock during operation of the drive group. Rolling of the longitudinal differential can mean a relative movement between respective rotating elements of the longitudinal differential. This can prevent there being any relative movement of the gears installed in the longitudinal differential to one another in the locked state. Otherwise, if the longitudinal differential is operated for a long time in the locked state, this can lead to a lubricant film separating between contacting tooth flanks and the teeth starting to seize. Due to the different gear ratio, the difference being, for example, very small, there is a relative speed between the rotating elements of the longitudinal differential due to the winding spur gear stages to the switching element of the differential lock, which can continuously renew the lubricating film.

In a further embodiment of the drive assembly, it can be provided that the drive assembly has an oil pipe for supplying oil to the longitudinal differential. The oil pipe can extend centrally at least partially through the planetary gear set of the longitudinal differential. The oil pipe can enable a supply of lubricating oil to the planetary gear set. The oil pipe can, for example, have radial bores. At least one of these radial bores can be arranged axially within an oil groove of the planet carrier. This means that all planetary bearings can be supplied with lubricating oil. The oil pipe can, for example, be permanently connected to the intermediate shaft in a rotationally fixed manner. The intermediate shaft can be arranged coaxially with the planetary gear set of the longitudinal differential. The rotation-proof connection between the oil pipe and the intermediate shaft can be provided, for example, by means of teeth. The intermediate shaft can have a central oil channel, which is fluidly connected to the oil pipe. The oil pipe can thus supply all planet carriers with sufficient lubricating oil.

In a further embodiment of the drive assembly, it can be provided that the drive assembly has a power-split continuously variable transmission.

With a continuously variable transmission, the ratio is continuously adjustable. The power split can be, for example, a hydrostatic-mechanical power split. Alternatively or additionally, for example, an electrical-mechanical power split is possible. The gearbox enables a high gear ratio spread with high efficiency. The transmission can have a drive on which the variable to be translated is fed into the transmission. The drive can have a shaft and a drive motor of the drive assembly can be connected to the drive at a drive-side end of this shaft. The shaft of the drive can extend through the transmission and enable a power take-off at an end facing away from the drive motor, for example to drive a working device of the working machine. The gearbox can also have an output at which the variable translated by the gearbox is output. For example, the drive power can be provided at the output. The respective driving ranges can be reversed using the reversing assembly. In the respective forward travel ranges, a work machine can, for example, move forward drive and reverse in the respective reversing areas.

The power-split continuously variable transmission has a variator. The variator can be set up to continuously vary a gear ratio of the transmission, 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 input and output of the transmission, the transmission ratio of the transmission being able to be varied continuously within the driving range by the variator. The variator can have two energy converters that are coupled to one another and designed, for example, as a hydrostat. The energy converters of the variator can also be designed as electrical machines. For example, the first energy converter can be a hydraulic machine with a fixed displacement volume and the second energy converter can be a hydraulic machine with an adjustable displacement volume.

The transmission may further include a planetary assembly, a first shift element, a second shift element, a third shift element, a fourth shift element and a fifth shift element. The planetary assembly can have four planetary gear sets. The transmission can be designed to transmit torque and speed from the drive to the output via the planetary assembly. In order to transmit torque and speed, it may be necessary for one or more of the gearshift elements to be actuated. An input shaft of the planetary assembly may be connected to the drive. An output shaft of the planetary assembly can be connected to the drive shaft, for example by means of a permanent, rotation-proof connection, and thus transmit the drive power to the reversing group.

The planetary assembly has, for example, a first sun gear, a first planet carrier and a first ring gear, which form a first planetary gear set. The planetary assembly has, for example, a second sun gear, a second planet carrier and a second ring gear, which form a second planetary gear set. The planetary assembly has, for example, a third sun gear, a third planet carrier and a third ring gear, which form a third planetary gear set. The planetary assembly has, for example, a fourth sun gear, a fourth planet carrier and a fourth ring gear, which form a fourth planetary gear set. The numbering only serves to assign the rotating elements to the respective planetary gear set. The second planetary gear set, for example, only has one ring gear, one sun gear and one planet carrier. One or more sets of planet gears can be rotatably mounted on each of the planet carriers. Each planetary gear set of the planetary assembly can be designed, for example, as a minus planetary gear set.

The drive can be permanently connected in a rotationally fixed manner to the first ring gear and the second planet carrier. The first planet carrier can be permanently connected to the second ring gear in a rotationally fixed manner. The second ring gear can be permanently connected to the third planet carrier in a rotationally fixed manner. The second sun gear can be permanently connected to the third sun gear in a rotationally fixed manner. The variator can be mechanically operatively connected to the drive and the first sun gear. 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 third sun gear can be connected in a rotationally fixed manner to the fourth sun gear by means of the second switching element. The first planet carrier can be connected in a rotationally fixed manner to the fourth planet carrier by means of the third 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 ring gear can be fixed by means of the fifth switching element. For this purpose, the fourth ring gear can be connected in a rotationally fixed manner to a stationary component of the drive group by means of the fifth switching element. The fourth planet carrier can be permanently connected to the drive shaft in a rotationally fixed manner. The fourth planet carrier can form an output of the planetary assembly, at which the translated drive torque and the translated drive speed are transmitted to the reversing assembly. The fourth planet carrier can form the output of the transmission.

The power-split transmission allows many driving ranges to be provided with just a few switching elements and has a large transmission spread. In addition, space-saving integration of the differential lock is possible.

A second aspect concerns a work machine. The work machine has a drive assembly according to the first aspect. Respective advantages and further features can be found in the description of the first aspect, with embodiments of the first aspect also forming embodiments of the second aspect and vice versa.

The work machine has a first drive axle and a second drive axle. The first drive axle is designed, for example, as the rear axle of the work machine. The second drive axle is designed, for example, as the front axle of the work machine. For example, wheels are arranged at opposite ends on each drive axle. Every drive axle can have an axle differential. The first drive axle can be mechanically connected to the first output shaft. The second drive axle can be mechanically connected to the second output shaft. The work machine can have a driving brake, which is arranged, for example, on the rear axle.

Short description of the characters

• 1 schematically illustrates a first embodiment of a drive assembly of a work machine.
• 2 schematically illustrates a second embodiment of a drive assembly of a work machine.
• 3 schematically illustrates a third embodiment of a drive assembly of a work machine.
• 4 schematically illustrates a fourth embodiment of a drive assembly of a work machine.
• 5 schematically illustrates the first embodiment of the drive assembly with a power-split continuously variable transmission.
• 6 schematically illustrates the second embodiment of the drive assembly with the one already in 5 power-split continuously variable transmission shown.

Detailed Description of Embodiments

1 schematically illustrates a first embodiment of a drive assembly 10 of a work machine. The drive assembly 10 has a reversing group 12, a longitudinal differential 14 and a differential lock 16. The drive assembly 10 has a drive shaft 18, a first output shaft 20 and a second output shaft 22. The first output shaft 20 is mechanically connected to a rear axle of the work machine. The second output shaft 22 is mechanically connected to a front axle of the work machine. The drive assembly 10 is designed to transmit drive power from the drive shaft 18 to the two output shafts 20, 22. For example, drive power generated by a motor is fed into the reversing group 12 on the drive shaft 18. During transmission, the longitudinal differential 14 divides the drive power between the first output shaft 20 and the second output shaft 22. The reversing group 12 is designed to change a direction of rotation when transmitting the drive power to the two output shafts 20, 22.

The reversing group 12 has a forward clutch KV and a reverse clutch KR, which are designed as a double switching element and are arranged coaxially to the drive shaft 18. In addition, the reversing group 12 has a first spur gear stage ST1, which is designed in one stage. Furthermore, the reversing group 12 has a second spur gear stage ST2, which is designed in two stages. When the forward clutch KV is closed, the drive power is transmitted from the drive shaft 18 via the first spur gear stage ST1 to an intermediate shaft 24 of the reversing group 12. When the reverse clutch KR is closed, the drive power is transmitted from the drive shaft 18 via the second spur gear stage ST2 to the intermediate shaft 24 of the reversing group 12, whereby the direction of rotation is reversed. The intermediate shaft 24 is permanently connected in a rotationally fixed manner to a coaxially arranged input shaft of the longitudinal differential 14.

The longitudinal differential 14 has a differential planetary gear set 26. The differential planetary gear set 26 has a sun gear 28, a planet carrier 30 and a ring gear 32. A plurality of planet gears 34 are rotatably mounted on the planet carrier 30 of the longitudinal differential 14, each of which meshes with the sun gear 28 and the ring gear 32 of the longitudinal differential 14. The differential planetary gear set 26 is designed as a minus planetary gear set. The planet carrier 30 forms an input shaft of the longitudinal differential 14. The ring gear 32 forms a first output shaft of the longitudinal differential 14 and is permanently connected to the first output shaft 20 in a rotationally fixed manner. The sun gear 28 forms a second output shaft of the longitudinal differential 14 and is mechanically operatively connected to the second output shaft 22.

The differential lock 16 has a switching element 36, a third spur gear stage ST3 and a fourth spur gear stage ST4. By actuating the switching element 36 of the differential lock 16, the longitudinal differential 14 is locked by operatively connecting two rotating elements of the differential planetary gear set 26 to one another. The fourth spur gear stage ST4 connects the second output shaft 22 with the sun gear 28 as the output shaft of the longitudinal differential 14. The third spur gear stage ST3 and thus the intermediate shaft 24 and the planet carrier 30 connected to it in a rotationally fixed manner as the input shaft of the longitudinal differential 14 are connected to the second output shaft 22 by means of the switching element 36 mechanically connectable. Correspondingly, by closing the switching element 36 of the differential lock 16, the planet carrier 30 and the sun gear 28 of the differential planetary gear set 26 are mechanically operatively connected to one another via the third spur gear stage ST3 and the fourth spur gear stage ST4.

The drive shaft 18, the first output shaft 20 and the second output shaft 22 extend axially parallel and spaced apart from one another in an axial direction. The reversing assembly 12 extends in a first axial region, which is illustrated by the arrow 38. A drive-side end of the first axial region facing the drive shaft 18 and the motor is limited by the first spur gear stage ST1. An opposite output-side end of the first axial region 38 is limited by the second spur gear stage ST2. The switching element 36 of the differential lock 16 is arranged completely in the first axial region 38 in a drive-side end region. The fourth spur gear stage is arranged between the first axial region 38 and the longitudinal differential 14 in the axial direction. As a result, the drive assembly 10 is compact in the axial direction and the intermediate shaft 24 is easy to assemble even when the differential lock 16 is already installed. The intermediate shaft 24 extends parallel to the drive shaft 18 and the two output shafts 20, 22 in the axial direction 38, in the embodiment shown coaxial to the first output shaft 20.

The intermediate shaft 24 is permanently connected in a rotationally fixed manner to a gear of the first spur gear stage ST1 and the second spur gear stage ST2. The gear of the first spur gear stage ST1, which is permanently connected to the intermediate shaft 24 in a rotationally fixed manner, also forms a gear of the third spur gear stage ST3. This gear meshes with both a gear of the first spur gear stage ST1 and a gear of the third spur gear stage ST3. As a result, the drive assembly 10 requires few parts. The third spur gear stage ST3 and the fourth spur gear stage ST4 have a different transmission ratio, so that the differential planetary gear set 26 of the longitudinal differential 14 rolls in the locked state of the differential lock 16 during operation of the drive assembly 10. This continues to enable continuous lubrication of the differential planetary gear set 26 during operation of the drive assembly 10.

In 2 A second embodiment of the drive assembly 10 is shown schematically. The basic functionality is the same as the other embodiments and the structure is similar. Therefore, only essential differences from the first embodiment will be discussed.

In the second embodiment of the drive assembly 10, the differential planetary gear set 26 is designed as a plus planetary gear set, which has two sets of planetary gears 40, 42 instead of just one set of planetary gears 34. The planet gears 40 and 42 mesh with each other in pairs. The outer planetary gears 40 each mesh with the ring gear 32. The inner planetary gears 42 each mesh with the sun gear 28. By using a plus planetary gear set in the longitudinal differential 14, a translation that is favorable for driving characteristics can be achieved in a structurally simple manner.

According to this design, the input shaft of the differential planetary gear set 26 is formed by the ring gear 32, which is permanently connected to the intermediate shaft 24 in a rotationally fixed manner. The planet carrier 30 forms the first output shaft of the longitudinal differential 14, which is permanently connected to the first output shaft 20 in a rotationally fixed manner. The sun gear 28 forms a second output shaft of the longitudinal differential 14, which is mechanically connected to the second output shaft 22 via the fourth spur gear stage ST4. The fourth spur gear stage ST4 is arranged on a side facing away from the reversing assembly 12 in the axial direction on the output side of the longitudinal differential 14. Accordingly, the second output shaft 22 extends axially past the differential planetary gear set 26, whereby the winding stage formed by the fourth spur gear stage ST4 is guided past the longitudinal differential 14. The fourth spur gear stage ST4 is mounted on the same housing wall as the first output shaft 20. No additional separate housing wall is necessary. This design is made possible by the arrangement of the fourth spur gear stage ST4 on the output side of the longitudinal differential 14.

In 3 A third embodiment of the drive assembly 10 is shown schematically. The basic functionality is the same as the other embodiments and the structure is similar. Therefore, only essential differences from the first embodiment will be discussed.

In the third embodiment, the reversing assembly 12 is designed differently compared to the first embodiment. In the case of the spur gear stage ST2, the intermediate shaft 24 is not permanently connected in a rotationally fixed manner to the planet carrier 30, which is designed as the input shaft of the longitudinal differential 14. Instead, a further shaft 44, to which a central gear 46 of the two-stage spur gear stage ST2 is permanently connected in a rotationally fixed manner, is permanently connected in a rotationally fixed manner to the planet carrier 30. The third spur gear stage ST3 is designed in two stages with three gears. A gear of the first spur gear stage ST1, which is permanently connected to the intermediate shaft 24 in a rotationally fixed manner, also forms a gear of the third spur gear stage ST3. The third spur gear stage ST3 has an additional shaft 48, which also extends parallel in the axial direction to the intermediate shaft 24, the drive shaft 18 and the two output shafts 20, 22. This results in a modified spur gear chain. The intermediate shaft 24 is offset parallel to the first Output shaft 20 arranged in the third embodiment.

In 4 A fourth embodiment of the drive assembly 10 is shown schematically. The basic functionality is the same as the other embodiments and the structure is similar. Therefore, only essential differences from the first embodiment will be discussed.

In the fourth embodiment, the structure of the reversing group 12 according to the third embodiment was combined with the structure of the longitudinal differential 14 according to the second embodiment.

5 additionally shows a power-split continuously variable transmission 60 and an internal combustion engine 62 in the drive assembly 10 according to the first embodiment. The transmission 60 has a drive 64 as a central shaft, which is operatively connected to the internal combustion engine 62 on the drive side and forms a power take-off 66 on the output side, which is connected to a power take-off shaft transmission. In another embodiment, the PTO 66 can be connected to the PTO transmission. The transmission 60 also has an output 78, which is permanently connected in a rotationally fixed manner to the drive shaft 18 of the reversing assembly 12 and is designed as a hollow shaft. Furthermore, the transmission 62 has a variator 68, a planetary assembly 70, a first switching element K1, a second switching element K2, a third switching element K3, a fourth switching element K4 and a fifth switching element K5 and is designed to provide different driving ranges.

The planet assembly 70 has a first sun gear 100, a first planet carrier 102 with first planet gears 104 rotatably mounted thereon and a first ring gear 106, which form a first planetary gear set P1. The planet assembly 70 has a second sun gear 110, a second planet carrier 112 with second planet gears 114 rotatably mounted thereon and a second ring gear 116, which form a second planetary gear set P2. The planet assembly 70 has a third sun gear 120, a third planet carrier 122 with third planet gears 124 rotatably mounted thereon and a third ring gear 126, which form a third planetary gear set P3. The planet assembly 70 has a fourth sun gear 130, a fourth planet carrier 132 with fourth planet gears 134 rotatably mounted thereon and a fourth ring gear 136, which form a fourth planetary gear set P4. The planetary gear sets P1 to P4 of the planetary assembly 70 are designed as negative planetary gear sets. The planetary assembly 70 is designed as a planetary roller which is arranged coaxially with the reversing group 12 and the drive shaft 18.

The drive 64 is permanently connected in a rotationally fixed manner to the first ring gear 106 and the second planet carrier 112. The first planet carrier 102 is permanently connected to the second ring gear 116 in a rotationally fixed manner. The second ring gear 116 is permanently connected to the third planet carrier 122 in a rotationally fixed manner. The second sun gear 110 is permanently connected to the third sun gear 120 in a rotationally fixed manner. The variator 68 is mechanically operatively connected to the drive 64 by means of a two-stage spur gear stage 72, which is at least partially arranged in the same axial region as the fourth spur gear stage ST4. In addition, the variator 68 is mechanically operatively connected to the first sun gear by means of a single-stage spur gear stage 74.

The third ring gear 126 can be connected in a rotationally fixed manner to the fourth sun gear 130 by means of the first switching element K1. The third sun gear 120 can be connected in a rotationally fixed manner to the fourth sun gear 130 by means of the second switching element K2. The first planet carrier 102 can be connected in a rotationally fixed manner to the fourth planet carrier 132 by means of the third switching element K3. The fourth sun gear 130 can be connected in a rotationally fixed manner to the fourth planet carrier 132 by means of the fourth switching element K4, whereby the fourth planetary gear set P4 of the planetary assembly 70 can be blocked. The fourth ring gear 136 can be fixed to a stationary component 76 of the drive assembly 10 by means of the fifth switching element K5.

6 additionally shows a power-split continuously variable transmission 60 and an internal combustion engine 62, in which the drive assembly 10 is designed according to the second embodiment. The transmission 60 and the internal combustion engine 62 are essentially the same as in 5 educated. Only the spur gear stage 72, which connects the variator 68 to the drive 64 in two stages, has an axial offset. For this purpose, the spur gear stage 72 has an extended shaft 78 in the middle with two gear wheels permanently attached to it in a rotationally fixed manner. At least a part of the spur gear stage 72 facing away from the variator 68 extends in the same axial region as the fourth spur gear stage ST4.

Reference symbols

10

Drive assembly

12

Reversing group

14

Longitudinal differential

16

Differential lock

18

drive shaft

20

first output shaft

22

second output shaft

24

Intermediate shaft

26

Differential planetary gear set

28

Sun gear of the differential planetary gear set

30

Planet carrier of the differential planetary gear set

32

Ring gear of the differential planetary gear set

34, 40, 42

Planetary gears

36

Differential lock switching element

38

Double arrow / first axial area

44, 48

Wave

46

gear

60

transmission

62

Internal combustion engine

64

drive

66

PTO output

68

variator

70

Planet assembly

72, 74

Spur gear stages of the gearbox

76

stationary component

78

downforce

100, 110, 120, 130

sun gear

102, 112, 122, 132

Planet carrier

104, 114, 124, 134

Planetary gears

106, 116, 126, 136

ring gear

KV

Forward clutch

KR

Reverse clutch

ST1-ST4

spur gear stages

K1-K5

switching elements

P1-P4

Planetary gear sets of the transmission

QUOTES INCLUDED IN THE DESCRIPTION

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

Cited patent literature

• DE 102012216046 A1 [0003]

Claims (15)

Drive assembly (10) for a work machine, the drive assembly (10) having a drive shaft (18), a first output shaft (20), a second output shaft (22), a reversing group (12), a longitudinal differential (14) and a differential lock (16 ) with a switching element (36), the drive assembly (10) being designed to transmit drive power from the drive shaft (18) to the two output shafts (20, 22), the reversing group (12) being designed to be a To change the direction of rotation when transmitting the drive power to the two output shafts (20, 22), the longitudinal differential (14) being designed to change the drive power when transmitting it from the drive shaft (18) to the first output shaft (20) and the second output shaft (22), wherein the drive shaft (18), the first output shaft (20) and the second output shaft (22) extend parallel in an axial direction, the reversing group (12) extending in a first axial region (38) of the axial direction and wherein the differential lock (16) is at least partially arranged in the first axial region. drive assembly (10). Claim 1 , characterized in that the switching element (36) of the differential lock (16) is arranged completely in the first axial region (38). drive assembly (10). Claim 1 or 2 , characterized in that the switching element (36) of the differential lock (16) is arranged in a drive-side end region of the first axial region (38). Drive assembly (10) according to one of the preceding claims, characterized in that the switching element (36) of the differential lock (16) is arranged coaxially with the second output shaft (22). Drive assembly (10) according to one of the preceding claims, characterized in that the reversing group (12) has an intermediate shaft (24), a first spur gear stage (ST1) and a second spur gear stage (ST2), the drive shaft (18) optionally via the first Spur gear stage (ST1) or the second spur gear stage (ST2) can be mechanically operatively connected to the intermediate shaft (24) in order to change the direction of rotation when transmitting the drive power to the two output shafts (20, 22), the intermediate shaft (24) being connected to an input shaft of the longitudinal differential (14) is mechanically operatively connected, and the differential lock (16) has a third spur gear stage (ST3) and a fourth spur gear stage (ST4), the switching element (36) of the differential lock (16) being connected to the by means of the third spur gear stage (ST3). Intermediate shaft (24) is mechanically operatively connected and the switching element (36) of the differential lock (16) is mechanically operatively connected to an output shaft of the longitudinal differential (14) by means of the fourth spur gear stage (ST4). drive assembly (10). Claim 5 , characterized in that the longitudinal differential (14) has a minus planetary gear set, the intermediate shaft (24) is mechanically operatively connected to the input shaft of the longitudinal differential (14) designed as a planet carrier (30) and the second output shaft (22) via the fourth spur gear stage ( ST4) is mechanically operatively connected to the output shaft of the longitudinal differential (14), which is designed as a sun gear (28). drive assembly (10). Claim 5 , characterized in that the longitudinal differential (14) has a plus planetary gear set, the intermediate shaft (24) is mechanically operatively connected to the input shaft of the longitudinal differential (14) designed as a ring gear (32) and the second output shaft (22) via the fourth spur gear stage ( ST4) is mechanically operatively connected to the output shaft of the longitudinal differential (14), which is designed as a sun gear (28). Drive assembly (10) according to one of the preceding Claims 5 until 7 , characterized in that the fourth spur gear stage (ST4) is arranged axially on the output side of the first axial region (38). drive assembly (10). Claims 6 and 8th , characterized in that the fourth spur gear stage (ST4) is arranged axially on the drive side of the longitudinal differential (14). drive assembly (10). Claims 7 and 8th , characterized in that the fourth spur gear stage (ST4) is arranged axially on the output side of the longitudinal differential (14). Drive assembly (10) according to one of the preceding Claims 5 until 10 , characterized in that a first spur gear and a second spur gear are each connected in a rotationally fixed manner to the intermediate shaft (24) and the first spur gear forms a spur gear of both the first spur gear stage (ST1) and the third spur gear stage (ST3). Drive assembly (10) according to one of the preceding Claims 5 until 11 , characterized in that the third spur gear stage (ST3) and the fourth spur gear stage (ST4) have a different gear ratio, so that a differential planetary gear set (26) of the longitudinal differentials (14) rolls in the locked state of the differential lock (16) during operation of the drive group. drive assembly (10). Claim 12 , characterized in that the drive assembly has an oil pipe for supplying oil to the longitudinal differential (14), the oil pipe extending centrally into the longitudinal differential (14) and the oil pipe being permanently connected to the intermediate shaft (24) in a rotationally fixed manner. Drive assembly (10) according to one of the preceding claims, characterized in that the drive assembly (10) has a power-split continuously variable transmission (60), the transmission (60) having a drive (64), an output (78), a variator (68 ), a planetary assembly (70), a first switching element (K1), a second switching element (K2), a third switching element (K3), a fourth switching element (K4) and a fifth switching element (K5) and is designed to have different driving ranges to provide, wherein the planet assembly (70) has a first sun gear (100), a first planet carrier (102) and a first ring gear (106), which form a first planetary gear set (P1), a second sun gear (110), a second planet carrier (112 ) and a second ring gear (116), which form a second planetary gear set (P2), a third sun gear (120), a third planet carrier (122) and a third ring gear (126), which form a third planetary gear set (P3), and a fourth sun gear (130), a fourth planet carrier (132) and a fourth ring gear (136), which form a fourth planetary gear set (P4), the drive (64) having the first ring gear (106) and the second planet carrier (112 ), the first planet carrier (102) is permanently connected in a rotationally fixed manner to the second ring gear (116), the second ring gear (116) to the third planet carrier (122), and the second sun gear (110) to the third sun gear (120), whereby the variator (68) is mechanically operatively connected to the drive (64) and the first sun gear (100), the third ring gear (126) being rotatably connected to the fourth sun gear (130) by means of the first switching element (K1), the third Sun gear (120) can be connected in a rotationally fixed manner to the fourth sun gear (130) by means of the second switching element (K2), wherein the first planet carrier (102) can be connected in a rotationally fixed manner to the fourth planet carrier (132) by means of the third switching element (K3), the fourth Sun gear (130) can be connected in a rotationally fixed manner to the fourth planet carrier (132) by means of the fourth switching element (K4), the fourth ring gear (136) being fixable by means of the fifth switching element (K5) and the fourth planet carrier (132) being permanently rotationally fixed to the Drive shaft (18) is connected. Work machine with a first drive axle, a second drive axle and a drive assembly (10) according to one of the preceding Claims 1 until 14 , wherein the first drive axle is mechanically operatively connectable to the first output shaft (20) and wherein the second drive axle is mechanically operatively connectable to the second output shaft (22).

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