drive train of a work machine

Abstract

The invention relates to a drive train of a machine, wherein the drive train comprises a first axle assembly (12) and a first PTO drive. A first motor shaft (62) of a first electric machine (60) is mechanically connected to two output shafts (64, 66) via the differential gear (20). The first motor shaft (62) is arranged coaxially with the output shafts (64). The first differential gear (20) comprises a first differential lock (50), a first planetary gear set (30), and a second planetary gear set (40). A first ring gear (36) is permanently and rotationally fixed to a second sun gear (42), and the two planetary gear sets (30, 40) are radially stacked. A first PTO connection (98) extends from a first PTO motor shaft (94) to a first PTO shaft (96) transversely to the two output shafts (64) between the first electric machine (60) and the differential gear (20) in an axial direction of the two output shafts (64).Furthermore, the invention relates to a working machine with a drive train.

Description

[0001] The present invention relates to a drive train of a work machine. The invention also relates to a work machine. State of the art

[0002] A work machine's drivetrain can provide both driving power via an output shaft and working power, for example, via a power take-off shaft. Electrification can often significantly reduce the complexity of the drivetrain. Furthermore, the environmental impact of operating the work machine can be significantly reduced. Therefore, many previously conventionally powered work machines are being retrofitted with an electrified drivetrain. However, an energy storage unit for operating an electrified drivetrain is typically much larger than the fuel tank of conventionally powered work machines. This can make integrating an electrified drivetrain difficult. Description of the invention

[0003] A first aspect relates to a drive train of a work machine. The drive train can, for example, be designed to provide drive power for driving the work machine. Alternatively or additionally, the drive train can optionally also provide work power, for example for moving or otherwise operating respective tools of the work machine. The work power can, for example, be provided as mechanical work power to one or more power take-off shafts. The work power can also, for example, be provided as hydraulic work power. The drive power can, for example, be provided to one or more driven axles. The work machine can, for example, be designed as an agricultural machine or a construction machine. An example of an agricultural machine is a tractor. An example of a construction machine is a wheel loader.

[0004] The drivetrain has a first axle assembly. An axle assembly can include a drive motor and an output shaft, which drives the work machine for travel. The drivetrain has a first power take-off drive. A power take-off drive can include a drive motor and a power take-off shaft, which can drive an attachment there. For example, the drivetrain can provide drive power to the attachment. A power take-off drive is also known as a power take-off (PTO) or auxiliary drive.

[0005] The first axle arrangement has a first electric machine with a first motor shaft, a first differential gear, a first output shaft, a second output shaft, a first output element, and a second output element. An electric machine can be designed, for example, as a synchronous motor or asynchronous motor. The electric machine can, for example, convert electrical energy into mechanical energy. The electric machine can, for example, have only one motor shaft, which is set in rotation when the electric machine is operated. The electric machine can also be designed for recuperation. A differential gear can be designed to translate an input variable into an output variable. For example, the differential gear can translate into fast or slow gears. The differential gear can optionally be designed to provide different gears.The differential gear can be designed to provide a differential function. The differential gear can have an input shaft and two output shafts. The output shafts can rotate at different speeds, for example, depending on a torque applied to the output shafts. The differential gear can transmit engine power from the first engine shaft to the two output shafts. The first output shaft and the second output shaft can, for example, each form an output shaft or be connected thereto in a rotationally fixed manner. An output element can be an element by means of which the drive train can transmit drive power to a surface on which the work machine is standing. For example, the output elements can be designed as wheels or pinions for driving a track.The first output element and the second output element can be arranged on opposite sides of the work machine. For example, the first output element can form a left wheel and the second output element a right wheel of a driven axle of the work machine.

[0006] The first PTO drive has a first PTO electric machine with a first PTO motor shaft and a first PTO shaft. The designation “PTO electric machine” can serve for identification purposes. The PTO electric machine can be designed like other electric machines. The PTO electric machine can be configured for lower power than the first electric machine. The designation “PTO motor shaft” can also serve for identification purposes. The PTO motor shaft can be a motor shaft of a PTO electric machine. The PTO shaft can be a shaft at which PTO power can be provided externally by the work machine. For example, the PTO shaft can protrude from the front or rear of the work machine. The PTO shaft can be designed for connecting and driving an attachment. The first PTO shaft can, for example, be arranged adjacent to the first axle arrangement, in particular its first output shaft and its second output shaft.For example, the first axle assembly, with its first output shaft and its second output shaft, can form a driven rear axle or front axle of the work machine. For example, the first power take-off shaft can then form a rear or front power take-off shaft of the work machine. The first power take-off electric machine can, for example, be arranged in front of or behind the first axle assembly in the vehicle's longitudinal direction.

[0007] The first motor shaft is mechanically operatively connected to the first output shaft and the second output shaft via the differential gear. This allows drive power from the first motor shaft to be transmitted to the two output shafts via the differential gear. The first motor shaft is arranged coaxially to the first output shaft and alternatively or additionally to the second output shaft. The first output shaft and the second output shaft can be arranged coaxially to one another. The two output shafts can extend, for example, in the transverse direction of the vehicle. The first electric machine can thus form a coaxial axle drive, making the drive arrangement particularly compact and easy to integrate into the motor vehicle. The first output shaft is mechanically operatively connected to the first output element.This allows the drive power to be transmitted compactly to the ground, and optionally a further transmission ratio can be provided in the connection from the first output shaft to the first output element. The first output shaft and the first output element can be arranged coaxially with one another. The second output shaft is mechanically operatively connected to the second output element. This allows the drive power to be transmitted compactly to the ground, and optionally a further transmission ratio can be provided in the connection from the second output shaft to the second output element. The second output shaft and the second output element can be arranged coaxially with one another.

[0008] The first differential gear has a first differential lock, a first planetary gear set with a first sun gear, a first planet carrier, and a first ring gear, and a second planetary gear set with a second sun gear, a second planet carrier, and a second ring gear. The planetary gear set can provide a transmission ratio from the first electric motor to the output of the work machine as well as the differential function in a compact design with few components. The first differential lock can be designed to connect the two output shafts of the differential gear in a rotationally fixed manner. This allows the differential lock to be integrated with little effort. The first differential lock is designed, for example, as a switching element by means of which the first output element and the second output element can be rotationally fixedly connected. The first ring gear is permanently rotationally fixedly connected to the second sun gear.The two planetary gear sets are radially stacked. The second planetary gear set can, for example, extend in the same axial region as the first planetary gear set. For example, all rotating elements of the second planetary gear set can be arranged radially outward to the first planetary gear set. This results in a very compact axial design, whereby the differential gear and the first electric machine can be arranged coaxially to one another next to one another in the transverse direction of the vehicle in the work machine. The first ring gear and the second sun gear can, for example, be formed in one piece. An internal toothing can form a first ring gear region and an external toothing a second sun gear region. Each planetary gear set can, for example, have only one sun gear, one planet carrier and one ring gear. For example, the second planetary gear set can have only a single sun gear.For example, the first motor shaft is permanently connected to the input shaft of the differential gear in a rotationally fixed manner.

[0009] The numbering of the rotating elements can be used to assign them to a planetary gear set. For example, designating them as the second sun gear can serve to clearly assign this sun gear to the second planetary gear set. In general, the numbering and, alternatively or additionally, the designation of components according to their assembly group can be used for assignment.

[0010] The first PTO motor shaft is mechanically operatively connected to the first PTO shaft. For example, the first PTO motor shaft can be or can be mechanically operatively connected to the first PTO shaft via a spur gear stage and alternatively or additionally a bevel gear stage or a planetary stage. The first PTO motor shaft can be connected to the first PTO shaft, for example, via a first PTO switching element. The first PTO switching element can be arranged, for example, in front of or behind the first axle arrangement in the vehicle's longitudinal direction. The first PTO switching element can be arranged, for example, in the vehicle's longitudinal direction relative to the first axle arrangement and alternatively or additionally the first motor shaft can be arranged on the PTO electric machine side or on the PTO side. The first PTO switching element can be designed as a conventional switching element, for example as a frictional or positive coupling.The first PTO shaft and the first PTO shaft can be connected via a first PTO gearbox. The PTO gearbox can, for example, be designed to provide two gears for the connection. A connection between the first PTO shaft and the first PTO shaft can be referred to as a first PTO connection. For example, the first PTO connection can have shafts for torque transmission. The first PTO connection can be designed to transmit torque from the first PTO shaft to the first PTO shaft. The PTO shaft can, for example, extend transversely, for example orthogonally, or parallel to the first output shaft, the second output shaft, and alternatively or additionally to the first engine shaft.

[0011] The first power take-off connection from the first power take-off motor shaft to the first power take-off shaft extends transversely to the first output shaft and alternatively or additionally transversely to the second output shaft between the first electric motor and the differential gear in an axial direction of the first output shaft. This arrangement allows the differential gear and the first electric motor to be well integrated into the work machine, and the first power take-off shaft to be arranged at an easily accessible location in the work machine. For example, at least one connecting shaft of the first power take-off connection extends orthogonally to the first output shaft and alternatively or additionally to the first motor shaft. This connecting shaft can extend, for example, in the longitudinal direction of the work machine.The connecting shaft can, for example, extend centrally in the vehicle's transverse direction, which can correspond to the axial direction of the first output shaft. For example, the first differential gear can be arranged to the left of the connecting shaft and the first electric motor to the right of the connecting shaft. The first power take-off connection crosses, for example, the first output shaft, the second output shaft and, alternatively or additionally, a connection between the first motor shaft and the first differential gear in a plan view of the work machine. For example, the first power take-off connection is routed below the output shaft, past the output shaft. Due to the typically large diameters of output elements in work machines, sufficient installation space can be available and sufficient ground clearance can be ensured, resulting in a compact design.An axial extent of the first electric machine can be defined by its rotor and, alternatively or additionally, its stator. The first rotor and, alternatively or additionally, the first stator can be arranged on one side of the first power take-off connection in the vehicle's transverse direction or in a direction along an axial extent of the output shaft, and the differential gear can be arranged on an opposite side of the power take-off connection in the vehicle's transverse direction or in the direction along an axial extent of the two output shafts. The first differential lock can, for example, be arranged on a side of the differential gear facing away from the first electric motor.

[0012] The second PTO shaft can be mechanically connected to a pump device. The pump device can be designed, for example, to supply pressure to the working hydraulics of the work machine. The pump device can also comprise a plurality of pumps, one of which is designed, for example, to supply pressure to the working hydraulics of the work machine and another to supply pressure to a steering power assistance system. The PTO electric machine can thus also drive the pump device and, for example, enable the pressure supply to a hydraulic system. The drive train can also have further electric motors for driving further pump devices. These further pump devices can, for example, be designed to supply pressure to a steering hydraulics, hydraulic switching elements and, alternatively or additionally, a transmission lubrication system. The pressure supply to the working hydraulics can also be provided by an electric machine separate from the PTO electric machine.

[0013] The first output shaft can be operatively connected to the first output element, for example, via a planetary gear set or a spur gear stage. This allows for a further gear ratio to be provided there. Likewise, the second output shaft can be operatively connected to the second output element via a planetary gear set or a spur gear stage. For example, such a planetary gear set can be arranged within the associated output element.

[0014] A non-rotatable connection between two elements is defined as a connection in which the two elements are essentially rigidly coupled to each other under all intended conditions. This also includes a frictional connection, which may result in intentional or unintentional slippage. Permanently non-rotatable elements can, for example, be formed as individual components permanently connected to each other in a non-rotatable manner, or even as a single piece.

[0015] 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 essentially interrupt this torque transmission in another state. For this purpose, a corresponding switching element can be provided between the two elements. If two elements can be connected in a rotationally fixed manner, these two elements can be connected to one another in a rotationally fixed manner, for example via a switching element.If two elements can be mechanically connected, these two elements can be connected, for example, via a switching element for torque transmission.

[0016] A planetary gear set is designed, for example, as a negative planetary gear set or a positive planetary gear set. The sun gears, planet carrier, and ring gears of a planetary gear set, for example, form its rotating elements. Each planetary gear set can have one or more planet gears that are rotatably attached to the planet carrier. For example, the planet gears of a planetary gear set each mesh with a sun gear and a ring gear of a planetary gear set. Each planetary gear set can be free of rotating elements other than those mentioned here. An axis of rotation of a planetary gear set can correspond to an axis of rotation of the rotating elements.

[0017] In one embodiment of the drive train, it can be provided that the drive train has an all-wheel drive switching element and a second axle arrangement. The first motor shaft can be mechanically operatively connected to the second axle arrangement by means of the all-wheel drive switching element. This allows a second axle with, for example, two output elements to be driven by the first electric motor. This allows all-wheel drive to be provided with little effort. An all-wheel drive connection from the first motor shaft to the second output shaft can be connected between the first electric motor and the differential gear in an axial direction of the first output shaft to the first output shaft or the second output shaft.For example, a spur gear or bevel gear of the all-wheel drive connection can be arranged in the axial direction of the first output shaft between the first electric motor and the differential gear on the first output shaft or the second output shaft. The all-wheel drive connection can, for example, have connecting shafts, spur gear stages, bevel gear stages, and alternatively or additionally the all-wheel drive switching element, for example to transmit torque from the first axle arrangement to the second axle arrangement. The all-wheel drive connection can be provided alternatively or in addition to the first power take-off connection. Due to the typically large diameters of output elements in work machines, sufficient installation space can be available and sufficient ground clearance can be ensured, resulting in a compact design.

[0018] In one embodiment of the drive train, the all-wheel drive connection may comprise a bevel gear stage and a spur gear stage. This allows a simple cross connection to be provided. A bevel gear stage can connect two shafts, for example, at an angle of 90° to each other.

[0019] A first bevel gear of the bevel gear stage can be permanently connected to the first motor shaft in a rotationally fixed manner. A second bevel gear of the bevel gear stage can be permanently connected to a spur gear of the spur gear stage in a rotationally fixed manner. The design of the connection can be simple. For example, the spur gear stage can pass below the first output shaft.

[0020] Alternatively, a first spur gear of the spur gear stage can be permanently connected to the first motor shaft in a rotationally fixed manner. A second spur gear of the spur gear stage can be permanently connected to a bevel gear of the bevel gear stage in a rotationally fixed manner. This design allows the bevel gear to operate at a reduced speed. Furthermore, assembly can be simplified, for example, via pins on the second planet carrier. Furthermore, manufacturing the gearing of the first spur gear can be easier, as the diameter can be small. The bevel gear stage, another spur gear stage, or a shaft can, for example, pass below the first output shaft.

[0021] In one embodiment of the drive train, it can be provided that the second axle arrangement has at least one of the following components, wherein these components can be designed like the first axle arrangement. For example, the second axle arrangement can have a second electric machine with a second motor shaft as a component, which is constructed and connected like the first electric machine. For example, the second axle arrangement can have a second differential gear as a component, which is constructed and connected like the first differential gear. For example, the second axle arrangement can have a third output shaft as a component, which has the same axial length as the first output shaft. For example, the second axle arrangement can have a fourth output shaft as a component, which has the same axial length as the second output shaft.For example, the axial length of the two axle arrangements can be the same and can be selected modularly by selecting the two associated output shafts. The second axle arrangement can have a structure similar to or identical to the first axle arrangement. The aforementioned components can be modularly modified, for example in order to be able to adapt a track width and power to different work machines. For example, the second axle arrangement can also have a second PTO as a component, whereby this second PTO can be designed like the first PTO and arranged in relation to the second axle arrangement. The second PTO can be arranged at an end of the work machine opposite the first PTO. The second PTO can be designed like the first PTO and operatively connected.The second PTO drive may comprise a second PTO electric machine and a second PTO shaft, which can be driven by the second PTO electric machine.

[0022] The second axle arrangement can be similar or identical to the first axle arrangement, but for example without an electric motor. The second axle arrangement can have a third output shaft, a fourth output shaft, and a second differential gear. These parts can be designed as in the first axle arrangement, allowing many identical parts to be used. The first motor shaft can be mechanically operatively connected to the third output shaft and the fourth output shaft by means of the all-wheel drive shifting element via the second differential gear. The first motor shaft is, for example, mechanically operatively connected or operatively connected to an input shaft of the second differential gear. In an operatively connected configuration, the all-wheel drive shifting element can be omitted, and permanent all-wheel drive can be provided.

[0023] Alternatively, the second axle assembly has a second electric motor. This second electric motor can be designed like the first electric motor. For example, the same axle assembly can be installed multiple times in the work machine in a modular fashion. For example, a second motor shaft of the second electric motor is mechanically connected to the input shaft of the second differential gear. This allows high drive power to be provided cost-effectively. The all-wheel drive connection can be omitted. However, the all-wheel drive connection can still be provided for joint braking of both axle assemblies.

[0024] In one embodiment of the drivetrain, it can be provided that the all-wheel drive connection passes the first output shaft and, alternatively or additionally, the second output shaft below the first output shaft. "Below" can be defined by a vertical direction of the vehicle. Alternatively or additionally, the all-wheel drive connection can pass the first power take-off connection below the first power take-off connection.

[0025] In one embodiment of the drive train, it can be provided that the first axle arrangement has a modular design in which at least one of the following components is modularly interchangeable for adaptation to the work machine. For each modularly interchangeable component, there can be at least two variants, for example. The first output shaft and, alternatively or additionally, the second output shaft can be interchangeable, for example for adaptation to a track width. The variants can therefore be of different lengths, for example. The connection from the first output shaft to the first output element and, alternatively or additionally, the connection from the second output shaft to the second output element can be interchangeable. As a result, different gear ratios can be provided there for adaptation to a travel speed range of the work machine. In addition, the connection can be steered or unsteered.This allows for a steered or unsteered axle to be provided. The first differential gear can be modularly interchangeable, for example, for different gear ratios. Likewise, the second axle arrangement can have a modular design, with the equivalent components being modularly interchangeable for adaptation to the working machine.

[0026] In one embodiment of the drive train, it can be provided that the first sun gear is permanently connected to the first motor shaft in a rotationally fixed manner. The first sun gear can, for example, form the input shaft of the first differential gear. The first planet carrier can be permanently connected to the first output shaft in a rotationally fixed manner. The first planet carrier can, for example, form the first output shaft of the planetary gear. The second planet carrier can be fixed to a stationary component, such as a vehicle frame or a transmission housing. The second ring gear can be permanently connected to the second output shaft in a rotationally fixed manner. The second ring gear can, for example, form the second output shaft of the planetary gear.By selecting the appropriate gear ratio, an identical gear ratio can be easily provided for both output shafts of the differential gear, provided, for example, that the machine is traveling straight ahead and both output elements have the same slip. This also allows for easy integration of the first differential lock.

[0027] In one embodiment of the drive train, it can be provided that the differential lock is designed to connect the first planet carrier to the second ring gear in a rotationally fixed manner.

[0028] In one embodiment of the drive train, it can be provided that the drive train has a first service brake, which is designed to brake the first output element. Alternatively or additionally, the drive train can have a second service brake, which is designed to brake the second output element. This allows the output elements to be braked individually, whereby additional functions can be implemented. For example, the two service brakes can be designed as disc brakes or drum brakes on the wheels. Likewise, a third service brake and a fourth service brake can be provided in the second axle arrangement, which are designed analogously to the first service brake and the second service brake.

[0029] In one embodiment of the drivetrain, it can be provided that the drivetrain has a central service brake designed to brake the all-wheel drive connection between the first axle arrangement and the second axle arrangement. This allows all axles to be braked centrally together. This allows more space between the output elements to be available for other components. When the central service brake is applied, for example, the all-wheel drive switching element can be automatically engaged. However, the all-wheel drive switching element can also engage automatically when the brake is applied, even if individual service brakes are applied to the output elements.

[0030] The drivetrain can have an energy storage device for supplying power to the respective electric motors. The energy storage device can be arranged centrally in the vehicle's longitudinal direction, for example. The energy storage device can be arranged in front of the first axle assembly, for example, in the vehicle's longitudinal direction. The energy storage device can be arranged between the first axle assembly and the second axle assembly, for example, in the vehicle's longitudinal direction. The energy storage device can be designed, for example, as a battery or fuel cell.

[0031] A second aspect relates to a work machine. The work machine has the drive train 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. A drive force of the work machine can be provided electrically by means of the drive train. Short description of the characters Fig. 1 schematically illustrates in a side view a first embodiment of a work machine with an electrified drive train. Fig. 2 schematically illustrates in a plan view a second embodiment of a work machine with an electrified drive train. Fig. Figure 3 schematically illustrates a differential gear. Fig. 4 schematically illustrates a first embodiment of a drive train. Fig. 5 schematically illustrates a second embodiment of a drive train. Fig. 6 schematically illustrates an arrangement of components of a powertrain in a plan view. Fig. 7 schematically illustrates an arrangement of components of a powertrain in a side view. Fig. Figure 8 schematically illustrates a front axle of a drive train. Fig. Figure 9 schematically illustrates a modular design of a powertrain. Fig. 10 schematically illustrates a modular structure of a powertrain. Fig. 11 schematically illustrates a third embodiment of a drive train. Fig. 12 schematically illustrates a fourth embodiment of a powertrain. Fig. 13 schematically illustrates a fifth embodiment of a powertrain. Fig. 14 schematically illustrates a sixth embodiment of a drive train Detailed description of embodiments

[0032] Fig. Figure 1 illustrates a schematic side view of a first embodiment of a working machine designed as a tractor. This working machine has two axles with wheels 10 attached to each axle at one end, which form output elements of a drive train. In the embodiment of Fig. 1 shows a first axle assembly 12 arranged at the rear. A second axle assembly 14 is shown at the front. Since a drive motor is arranged coaxially with the associated wheels 10 in the first axle assembly 12 and optionally in the second axle assembly 14, there is ample installation space 16 between the two axle assemblies 12, 14 in the vehicle's longitudinal direction and above the second axle assembly 14 for arranging an energy storage device for the drive train.

[0033] In Fig. Figure 2 shows a top view of a second embodiment of the work machine designed as a tractor. This differs from the first embodiment in the additional all-wheel drive connection 18 between the first axle assembly 12 and the second axle assembly 14. This allows all-wheel drive to be provided. This allows the first axle assembly 12 to drive the second axle assembly 14, allowing a single drive motor to provide all-wheel drive. Furthermore, centralized braking of all wheels 10 is possible.

[0034] In Fig. Figure 3 schematically illustrates a differential gear 20, which is used in the two axle assemblies 12, 14 and enables a space-saving coaxial arrangement. The differential gear has an input shaft 22, a first output shaft 24 and a second output shaft 26, which are arranged coaxially to one another. The two output shafts 24, 26 are operatively connected to opposite wheels 10 on the work machine. The input shaft 22 is driven by a drive motor, which, in the embodiments shown here, is permanently connected to the input shaft 22 in a rotationally fixed manner. The differential gear has a first planetary gear set 30 with a first sun gear 32, a first planet carrier 34 and a first ring gear 36, as well as a second planetary gear set 40 with a second sun gear 42, a second planet carrier 44 and a second ring gear 46.First planet gears 38 are rotatably attached to the first planet carrier 34 and mesh with the first sun gear 32 and the first ring gear 36. Second planet gears 48 are rotatably attached to the second planet carrier 44 and mesh with the second sun gear 42 and the second ring gear 46. The first ring gear 36 is permanently connected to the second sun gear 42 in a rotationally fixed manner, whereby these are formed integrally by a hollow gear which has an internal toothing and an external toothing. The two planetary gear sets 30, 40 are radially stacked, whereby the second planetary gear set 40 is arranged radially outwardly of the first planetary gear set 30. The second planet carrier 44 is fixed to a stationary component. The first planet carrier 34 forms the first output shaft 24 or is permanently connected to it in a rotationally fixed manner. The second ring gear 46 forms the second output shaft 26 or is permanently connected to it in a rotationally fixed manner.The first sun gear 32 forms the input shaft 22 or is permanently connected to it in a rotationally fixed manner.

[0035] The differential gear 20 has a differential lock 50, which is designed as a friction-engaging shifting element. The differential lock 50 connects the first planetary carrier 34 and the second ring gear 46, and thus also the two output shafts 24, 26, to one another in a rotationally fixed manner.

[0036] Fig. Figure 4 schematically illustrates a first embodiment of a drive train for the previously discussed embodiments of a work machine. The drive train includes the first axle assembly 12. The first axle assembly 12 includes a first electric machine 60 with a first motor shaft 62, a first differential gear 20, which, like the one shown in Fig. 3, a first output shaft 64, a second output shaft 66, a first output element 68, and a second output element 70. The first output element 68 forms the right rear wheel 10, and the second output element 70 forms the left rear wheel 10. The first motor shaft 62 is mechanically operatively connected to the first output shaft 64 and the second output shaft 66 via the differential gear 20, wherein the first motor shaft 62 is permanently connected in a rotationally fixed manner to the first sun gear 32. The first sun gear 32 is permanently connected in a rotationally fixed manner to the first output shaft 64, and the second ring gear 46 is permanently connected in a rotationally fixed manner to the second output shaft 66. The first motor shaft 62, the first output shaft 64, and the second output shaft 66 are arranged coaxially to one another.

[0037] The first output shaft 64 is mechanically operatively connected to the first output element 68, in the embodiment shown, via a further planetary gear 72. The second output shaft 66 is mechanically operatively connected to the second output element 70, in the embodiment shown, via a further planetary gear 72. The first output element 68 can be braked via a first service brake 74, which is connected to the associated planetary gear 72 and is designed as a disc brake. The second output element 70 can be braked via a second service brake 76, which is connected to the associated planetary gear 72 and is designed as a disc brake.

[0038] The drive train of Fig. 4 optionally has an all-wheel drive switching element 80 and, likewise optionally, an all-wheel drive operative connection 18. This allows the first motor shaft 62 to be mechanically operatively connected to the second axle arrangement 14. The all-wheel drive switching element 80 is designed as a multi-plate clutch. The all-wheel drive operative connection 18 has a spur gear stage 84 and a bevel gear stage 82. A first bevel gear 86 of the bevel gear stage 82 is permanently connected in a rotationally fixed manner to the first motor shaft 62. A second bevel gear 88 of the bevel gear stage 82 is permanently connected in a rotationally fixed manner to a spur gear of the spur gear stage 84. The spur gear stage 84 has a gear 90 which meshes with a spur gear at one axial end region and with another spur gear at an opposite axial end region. As a result, the all-wheel drive connection 18 can be easily guided on the first motor shaft 62 in the vehicle longitudinal direction to the second axle arrangement 14.The all-wheel drive connection 18 is arranged in the axial direction of the first axle assembly 12 and thus in the transverse direction of the vehicle between the first electric motor 60 and the differential gear 20. The axial direction of the first axle assembly 12 corresponds to an axial direction of the first output shaft 64.

[0039] In Fig. 4, the second axle arrangement 14 is not shown. A possible design of this second axle arrangement 14 is shown in Fig. 8, which will be described later.

[0040] The drive train has a first power take-off drive. The power take-off drive has a first PTO electric machine 92 with a first PTO motor shaft 94 and a first PTO shaft 96. The first PTO electric machine 92 is arranged in front of the first axle assembly 12 in the vehicle's longitudinal direction, and the first PTO shaft 96 is arranged behind the first axle assembly 12. This allows for optimal use of the available installation space. The first PTO shaft 96 protrudes from the rear of the work machine for connecting an attachment. The first PTO motor shaft 94 is mechanically operatively connected to the first PTO shaft 96 via a PTO connection 98. The PTO connection 98 has several spur gear stages, a planetary gear set 104, a PTO switching element 100, and connecting shafts. The PTO switching element 100 allows the first PTO electric machine 92 to be decoupled from the first PTO shaft 96.The first power take-off electric machine 92 drives a main hydraulic pump 102 via spur gear stages, whereby the main hydraulic pump 102 can continue to operate even when the first power take-off shaft 96 is to be stationary due to the power take-off switching element 100. The first power take-off connection 98 extends from the first power take-off motor shaft 94 to the first power take-off shaft 96 orthogonal to the first axle assembly 12 and thus to the axial direction of the first output shaft 64 between the first electric machine 60 and the differential gear 20. This allows the first power take-off connection 98 to pass through the axle assembly 12 in a space-saving manner.

[0041] The drive arrangement has three additional electric motors 110, each driving an associated pump 112. This allows pressure to be supplied to a control hydraulic system, a lubrication system, and the respective switching elements, independent of the drive power and the work output.

[0042] Fig. Figure 5 schematically illustrates a second embodiment of the drive train, which differs from the first embodiment only in the design of the all-wheel drive connection 18. Therefore, only these differences will be explained.

[0043] Specifically, the all-wheel drive connection 18 also has a spur gear stage 84 and a bevel gear stage 82, which are, however, connected differently. Instead of the bevel gear stage 82, the spur gear stage 84 is now directly connected to the first motor shaft 62. A first spur gear 120 of the spur gear stage 84 is permanently connected in a rotationally fixed manner to the first motor shaft 62. A second spur gear 122 of the spur gear stage 84 is permanently connected in a rotationally fixed manner to a bevel gear 124 of the bevel gear stage 82. This reduces the speed applied to the bevel gear stage 82 during operation.

[0044] The Fig. 6 illustrates a possible spatial arrangement of the parts and components of the drive assembly in a plan view. Fig. Figure 7 illustrates the possible spatial arrangement of the parts and components of the drive assembly in a side view. This spatial arrangement can be used in all embodiments of the drive train and the working machine. The arrow 154 illustrates Fig. 6 and Fig. 7 each one forward direction with the working machine. In Fig. 6, a part of a connection to the power take-off shaft 96 is only symbolically shown by an arrow. In Fig. 7, part of the connection of the power take-off shaft 96 to the power take-off machine 92 is only symbolically shown by an arrow. The power take-off machine 92 is in Fig. 7 is not shown. Likewise, Fig. 7 the main hydraulic pump 102 is not shown.

[0045] As can be seen, the all-wheel drive connection 18 and the power take-off connection 98 are arranged in an axial extension of the first axle arrangement 12 between the differential gear 20 and the first electric machine 60. The differential lock 50 is arranged on a side of the differential gear 20 facing away from the first electric machine 60, although a reverse arrangement is also possible. A connection 150 between the first output shaft 64 and the first output element 68, as well as a connection 150 between the second output shaft 66 and the second output element 70, can be modified modularly, which will be explained below. For example, the connection can be designed to be articulated instead of rigid as previously shown.

[0046] In Fig. 7 shows that both the all-wheel drive connection 18 and the power take-off connection 98 pass an axis 160 of the first axle assembly 12, which axis of rotation of the first output shaft 64, the second output shaft 66 and the first motor shaft 62, in the vertical direction of the vehicle. To simplify the illustration, Fig. 7 not all shafts of the first axle arrangement 12 are shown.

[0047] Fig. Figure 8 schematically illustrates an embodiment of the second axle arrangement 14. As can be seen, the second axle arrangement 14 is almost identical to the first axle arrangement 12 according to Fig. 4. Identical components are therefore given the same reference numerals, even if they are designated differently for identification purposes. In this exemplary embodiment, no power take-off drive is provided at the front, although a second power take-off drive for a front PTO shaft can also be provided. The second axle arrangement 14 therefore also has a differential gear 20, which is referred to here as the second differential gear 20. In addition, the second axle arrangement 14 has a second electric machine 60 with a second motor shaft 62. The two output elements 68, 70 are each mechanically connected to the second differential gear 20 by a planetary gear 72. The all-wheel drive connection 18 of the second axle arrangement 14 also extends orthogonally between the second electric machine 60 and the differential gear 20 in the transverse direction of the vehicle.

[0048] The two output shafts 64, 66 are also permanently connected in a rotationally fixed manner to the two output shafts 24, 26 of the differential gear 20 in the second axle arrangement 14. However, the two output shafts 64, 66 are not rigidly connected to the two output elements 68, 70, but rather are articulated. For this purpose, a joint 160 is arranged in the rotationally fixed connection between the two output shafts 64, 66 and an input shaft 22 of the associated planetary gear 72. This joint 160 allows the output elements 68, 70, or the left front wheel and the right front wheel 10, to pivot about an axis of the joints 160 running in the vertical direction of the vehicle. This enables steering on the front axle. No all-wheel drive switching element 80 is provided adjacent to the second axle arrangement 14, since one all-wheel drive switching element 80 is sufficient for connecting the two axle arrangements 12, 14.

[0049] Fig. 9 and Fig. 10 illustrate a modular structure. Fig. 9 illustrates three variants of the first axle arrangement 12 and the second axle arrangement 14. In Fig. 9 above, in a first variant 200, the two output shafts 64, 66 and, alternatively or additionally, the connection 150 to the output elements 68, 70 are axially shorter. This allows a drive train with a narrow track width to be provided, while a central part 210 remains identical. In the middle of the Fig. 9, a second variant 202 is shown, in which the two output shafts 64, 66 and alternatively or additionally the connection 150 to the output elements 68, 70 have a normal axial length. This allows a drive train with a normal track width to be provided, while a central part 210 remains identical. The track width in the first variant 200 is therefore narrower than in the second variant 202. The axial extent of the central part 210 remains the same. Below, in Fig. 9 shows a third variant 204, which has the same track width as the second variant 202. However, the connection 150 to the output elements 68, 70 of the two output shafts 64, 66 has a joint 160, as the second axle arrangement 14 in Fig. 8. This allows for modular selection of which axles of the work machine are steered. For example, rear-axle steering can be provided as an alternative or in addition to front-axle steering. To ensure sufficient installation space for the joints 160, shorter output shafts 64, 66 of the first variant 200 can be used. This further reduces the number of component variants.

[0050] In Fig. Figure 10 illustrates how the modular design can be used in a work machine. It shows a first axle assembly 12 with a power take-off drive and thus a power take-off shaft 96. This first axle assembly 12 can optionally have joints 160 for rear-wheel steering, which are therefore shown in dashed lines. The second axle assembly 14 can be coupled to the first axle assembly 12 via the optional all-wheel drive connection 18 and has joints 160.

[0051] In Fig. Figure 11 shows a narrow-gauge variant, or the first variant 200, of the first axle assembly 12, schematically illustrated in detail as a third embodiment of the drive train. The third embodiment of the drive train differs from the first embodiment only in the design of the brake system and the length of the two output shafts 64, 66. Therefore, only these differences will be explained, and otherwise the same reference numerals will be used. Fig. 11, the optional electric machines 110 and pumps 112 were not shown.

[0052] In the third embodiment, the two service brakes 74, 76 are omitted. Instead, the drive train has a central service brake 300, which is designed to brake the all-wheel drive connection 18 between the first axle arrangement 12 and the second axle arrangement 14. The all-wheel drive connection 18 is permanently connected to at least one of the two axle arrangements 12, 14, with the central service brake 300 acting on a corresponding shaft. In addition, when the central service brake 300 is activated, the all-wheel drive switching element 80 is automatically closed. As a result, the central service brake 300 acts on both the rear axle and the front axle and on all output elements 68, 70. The central service brake 300 requires less axial installation space for the two axle arrangements 12, 14, whereby the central part 210 can have the wide track width design despite the narrower track width.

[0053] In Fig. Figure 12 schematically illustrates a fourth embodiment of the drive train. The fourth embodiment of the drive train differs from the first embodiment only in that the all-wheel drive connection 18 is omitted. Furthermore, both the first axle assembly 12 and the second axle assembly 14 are shown, along with how they are arranged on a frame 400 of the work machine, shown in dashed lines. In one embodiment, this frame 400 also forms a housing for the central part 210.

[0054] In Fig. 13 schematically shows a fifth embodiment of the drive train. The fifth embodiment of the drive train differs from the first embodiment in the design of the first power take-off connection 98. The power take-off switching element 100 is now arranged on the PTO shaft 96 side, not on the PTO electric machine 92 side in relation to the first axle arrangement 12, in the vehicle's longitudinal direction. In addition, the number of spur gears for operatively connecting the PTO motor shaft 94 and the main hydraulic pump 102 is reduced. A central gear of the spur gear stage connecting these is permanently and non-rotatably connected to an axle that extends below the first axle arrangement 12 in the vehicle's longitudinal direction. This axle is no longer connected to the PTO shaft 96 via the planetary gear set 104, but via a simple spur gear stage.The axial position of the power take-off switching element 100 at the rear in the vehicle's longitudinal direction can allow for the placement of an oil tank in a front area. Component complexity can be reduced because a hollow shaft design for the all-wheel drive connection 18 is no longer necessary. Furthermore, an increase in efficiency can be possible due to a smaller number of gear meshes. Furthermore, a lower gear ratio can allow for overspeed on the power take-off shaft 96.

[0055] Furthermore, in the fifth embodiment, the design of the planetary gears 72, one of which mechanically connects each of the two output elements 68, 70 with the second differential gear 20, is different. Instead of a planetary gear with planetary gears with simple toothing, stepped planetary gears are now provided. The stepped planetary gears have a first toothing which meshes only with the sun gear. The stepped planetary gears have a second toothing which meshes only with the ring gear and which has a smaller effective diameter than the first toothing. With the same radial diameter, this design of the planetary gear 72 can have a larger transmission ratio. Furthermore, in the fifth embodiment, the all-wheel drive connection is the same as in the second embodiment or the Fig. 5 trained.

[0056] In Fig.14 schematically shows a sixth embodiment of the drive train. The sixth embodiment of the drive train differs from the fifth embodiment in a design of the operative connection between the power take-off motor shaft 94 and the main hydraulic pump 102. In the sixth embodiment, this operative connection is not provided by three spur gears, with a middle one of these spur gears meshing with both an engine-side and a pump-side spur gear, as in the fifth embodiment. Instead, this operative connection is provided by four spur gears, with two of these spur gears meshing with each other and two of these spur gears in the middle of the power flow being permanently connected to each other in a rotationally fixed manner. In the fifth embodiment, the number of spur gears is small and thus the efficiency in driving the main hydraulic pump 102 is also high.In the sixth embodiment, the radial installation space required for the operative connection to the main hydraulic pump 102 is small, and an axial offset can be easily provided. Furthermore, a high transmission ratio for driving the main hydraulic pump 102 can be provided with a small installation space requirement. Reference symbol 10 front and rear wheels 12 first axle arrangement 14 second axle arrangement 16 installation space 18 All-wheel drive connection 20 differential gears 22 Input shaft 24 first output shaft 26 second output shaft 30, 40, 104 planetary gear set 32 first sun gear 34 first planet carrier 36 first ring gear 38 first planetary gears 42 second sun gear 44 second planet carrier 46 second ring gear 48 second planetary gears 50 differential lock 60, 110 electric machine(s) 62 Motor shaft 64 first output shaft 66 second output shaft 68 first output element 70 second output element 72 planetary gears 74, 76, 300 service brake 80 all-wheel drive switching element 82 bevel gear stage 84 Spur gear stage 86, 88, 124 bevel gear 90 gear 92 electric tap machine 94 PTO shaft 96 PTO 98 PTO connection 100 tap switching element 102 Main hydraulic pump 112 pump(s) 120 first spur gear 122 second spur gear 150, 152 connection 154 Arrow 160 axes / joints 200, 202, 204 variant 210 Central part 400 frames

Claims

[1] Drive train of a work machine, wherein the drive train has a first axle arrangement (12) and a first power take-off drive, wherein the first axle arrangement (12) has a first electric machine (60) with a first motor shaft (62), a first differential gear (20), a first output shaft (64), a second output shaft (66), a first output element (68) and a second output element (70), wherein the first power take-off drive has a first power take-off electric machine (92) with a first power take-off motor shaft (94) and a first power take-off shaft (96), wherein the first motor shaft (62) is mechanically operatively connected to the first output shaft (64) and the second output shaft (66) via the differential gear (20), wherein the first motor shaft (62) is arranged coaxially to the first output shaft (64), wherein the first output shaft (64) is mechanically connected to the first output element (68) is effectively connected,wherein the second output shaft (66) is mechanically operatively connected to the second output element (70), wherein the first differential gear (20) has a first differential lock (50), a first planetary gear set (30) with a first sun gear (32), a first planetary carrier (34) and a first ring gear (36) and a second planetary gear set (40) with a second sun gear (42), a second planetary carrier (44) and a second ring gear (46), wherein the first ring gear (36) is permanently connected in a rotationally fixed manner to the second sun gear (42) and the two planetary gear sets (30, 40) are radially stacked, wherein the first power take-off motor shaft (94) is mechanically operatively connectable to the first power take-off shaft (96), wherein a first power take-off connection (98) extends from the first power take-off motor shaft (94) to the first power take-off shaft (96) transversely to the first output shaft (64) between the first electric machine (60) and the differential gear (20) in an axial direction of the first output shaft (64)., [2] Drive train according to claim 1, characterized by in that the drive train has an all-wheel drive switching element (80) and a second axle arrangement (14), wherein the first motor shaft (62) can be mechanically operatively connected to the second axle arrangement (14) by means of the all-wheel drive switching element (80), wherein an all-wheel drive operative connection (18) from the first motor shaft (62) to the second output shaft (66) between the first electric machine (60) and the differential gear (20) is connected to the first output shaft (64) in an axial direction of the first output shaft (64). [3] Drive train according to claim 2, characterized by that the all-wheel drive connection (18) passes the first output shaft (64) below the first output shaft (64). [4] Drive train according to claim 2 or 3, characterized byin that the all-wheel drive connection (18) has a bevel gear stage (82) and a spur gear stage (84), wherein a first bevel gear (86) of the bevel gear stage (82) is permanently connected in a rotationally fixed manner to the first motor shaft (62) and wherein a second bevel gear (88) of the bevel gear stage (82) is permanently connected in a rotationally fixed manner to a spur gear of the spur gear stage (84). [5] Drive train according to claim 2 or 3, characterized by in that the all-wheel drive connection (18) has a bevel gear stage (82) and a spur gear stage (84), wherein a first spur gear (120) of the spur gear stage (84) is permanently connected in a rotationally fixed manner to the first motor shaft (62) and wherein a second spur gear (122) of the spur gear stage (84) is permanently connected in a rotationally fixed manner to a bevel gear (124) of the bevel gear stage (82). [6] Drive train according to one of the preceding claims 2 to 5, characterized by that the second axle arrangement (14) comprises at least one of the following components: - A second electric machine (60) with a second motor shaft (62) which is constructed and connected like the first electric machine (60); - A second differential gear (20) constructed and connected in the same way as the first differential gear (20); - A third output shaft having an axial length equal to the first output shaft (64); and - A fourth output shaft having an axial length equal to the second output shaft (66). [7] Drive train according to one of the preceding claims, characterized by that the first axle arrangement (12) has a modular structure in which at least one of the following components is modularly interchangeable for adaptation to the working machine: - The first output shaft (64); - The second output shaft (66); - The connection (150) from the first output shaft (64) to the first output element (68) and the connection (152) from the second output shaft (66) to the second output element (70); and - The first differential gear (20). [8] Drive train according to one of the preceding claims, characterized by that the first sun gear (32) is permanently connected in a rotationally fixed manner to the first motor shaft (62), the first planet carrier (34) is permanently connected in a rotationally fixed manner to the first output shaft (64), the second planet carrier (44) is fixed to a stationary component, and the second ring gear (46) is permanently connected in a rotationally fixed manner to the second output shaft (66). [9] Drive train according to one of the preceding claims, characterized by that the differential lock (50) is designed to connect the first planet carrier (34) to the second ring gear (46) in a rotationally fixed manner. [10] Drive train according to one of the preceding claims, characterized by that the drive train has a first service brake (74) which is designed to brake the first output element (68), and the drive train has a second service brake (76) which is designed to brake the second output element (70). [11] Drive train according to one of the preceding claims 2 to 9, characterized by that the drive train has a central service brake (300) which is designed to brake the all-wheel drive connection (18) between the first axle arrangement (12) and the second axle arrangement (14). [12] Working machine with a drive train according to one of the preceding claims, characterized by that the driving force of the working machine can be provided electrically by means of the drive train.

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