Axle drive device for a work machine

Abstract

The present invention relates to an axle drive device (1) for a work machine (100) comprising an electric traction motor (4). The axle drive device (1) comprises a transfer case (8; 8'; 8") having a first output shaft (9) for driving a first wheel (2) and a second output shaft (10) for driving a second wheel (3). The axle drive device (1) comprises a transmission (19) for providing two gears having different transmission ratios. The transmission (19) is designed as a spur-gear mechanism and comprises a transmission input (18), a transmission output (20), a first shifting element (31) and a second shifting element (32). The transmission input (18) can be mechanically operatively connected to the transmission output (20) by means of the first shifting element (31) via a first gear ratio (34, 35), and by means of the second shifting element (32) via a second gear ratio.

Description

[0001] ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14

[0002] Axle drive device for a work machine

[0003] Technical field

[0004] The present invention relates to an axle drive device for a working machine. Furthermore, the present invention relates to a working machine with such an axle drive device.

[0005] State of the art

[0006] As part of the electrification of drive trains for construction machinery, axle drives with an electric traction motor have been developed. A disadvantage of the solutions known from the prior art is that these drives cannot simultaneously provide high tractive forces and high travel speeds with a comparatively simple design.

[0007] Description of the invention

[0008] The present disclosure relates to an axle drive device for a working machine. The working machine may be a construction or agricultural machine or a commercial vehicle. For example, the working machine may be a municipal vehicle or a tractor. In addition to the axle drive device, the working machine may have a further axle drive device, which may be identical or of a different design. In one embodiment, the working machine has a further axle which is driven by the axle drive device of the present disclosure. Thus, the axle drive device of the present disclosure may, for example, provide all-wheel drive for the working machine. The axle drive device may be a drive unit that can be integrated into an axle of the working machine.For example, the axle drive unit can be designed to be at least partially coaxial with an axle of the machine. In one embodiment, the axle drive unit is designed such that it is spatially and functionally integrated with an axle of the machine (ZF Friedrichshafen AG File 303451, Friedrichshafen, August 14, 2024), for example, by sharing a common housing. The axle drive unit can have a main direction of extension, which can be parallel, for example, coaxial, with an axle of the machine. In one embodiment, the axle drive unit is designed as a drive unit for a rear axle of the machine.

[0009] The axle drive unit comprises an electric traction motor, which is designed, for example, to provide sufficient power to drive the drive system of the machine, thus accelerating the machine to the required speeds with the necessary tractive forces. Furthermore, the axle drive unit comprises a distribution gearbox with a first output shaft for driving a first wheel of the machine and a second output shaft for driving a second wheel of the machine opposite the first wheel. The first wheel can, for example, be a right wheel and the second wheel a left wheel of the machine. The two opposing wheels of the machine can be driven simultaneously by the axle drive unit of this disclosure.Between the first output shaft and, alternatively or additionally, the second output shaft and the respective wheel, a further gear stage, for example a hub gear, can be provided. This further gear stage can provide an additional reduction and may, for example, be designed as a planetary gear set.

[0010] The electric traction motor can be supplied with the electrical energy required for its operation, for example, from a battery storage system, a fuel cell, or via a diesel-powered generator. A combination of these electrical supply options is also conceivable and preferred; in particular, the electric traction motor can be supplied electrically by a battery storage system and a diesel-powered generator, or by a battery storage system and a fuel cell. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14

[0011] The transfer case can provide a transmission function between the electric traction motor and the first and second output shafts, for example, a transmission with a ratio greater than 1. Thus, the transfer case can, for instance, be designed as a reduction gearbox to reduce the speed of the electric traction motor. Alternatively or additionally, the transfer case can provide a differential function to allow the first and second wheels of the machine to rotate at different speeds. The transfer case can be a single integrated unit that can provide both the transmission and differential functions.Alternatively or additionally, the transfer case can also have two separate units: one unit for providing the transmission functionality and another unit for providing the differential functionality. In one embodiment, both functionalities are provided by a planetary gear transfer case. In an alternative embodiment, the transmission functionality is provided by a planetary gear set and the differential functionality by a separate bevel gear differential. Other configurations are also possible within the scope of this disclosure, provided that the transfer case distributes power from the electric traction motor to both the first and second output shafts. The transfer case can also include a differential lock to disable the differential functionality.

[0012] Furthermore, the axle drive unit includes a transmission for providing at least two gears with different gear ratios. The transmission can be located in the torque transmission path from the electric traction motor to the first and second output shafts upstream of the transfer case. In addition to the two gears, the transmission can provide further gears. The transmission can be a unit that is physically and functionally separate from the transfer case. At least one gear of the transmission can be a reduction gear, i.e., a gear with a gear ratio greater than 1. Alternatively, one gear of the transmission can be a direct drive gear with a gear ratio of 1.The axle drive unit is designed to drive the first and second output shafts via the transmission (for example, first or second gear) and the transfer case using the electric traction motor. In one embodiment, the torque of the electric traction motor can thus be converted, for example, by the transmission and the transfer case, for example by reducing it.

[0013] The transmission is designed as a spur gear transmission and comprises a transmission input, a transmission output, a first shift element, and a second shift element. The transmission input is mechanically connected to the transmission output via a first gear ratio by means of the first shift element and via a second gear ratio by means of the second shift element. The first and second shift elements can be configured as a dual shift element or as separate shift elements, both spatially and functionally. If the shift elements are configured as a dual shift element, a single actuator can be used to actuate the dual shift element. Furthermore, such a dual shift element can have a neutral position in addition to the gear-shifting positions.If, however, the switching elements are designed as individual switching elements, a separate actuator can be provided for each switching element. By providing the gear transmission, an axle drive system with a wide gear ratio can be provided, capable of delivering both high tractive forces at low speeds and high tractive forces at high speeds.

[0014] High top speeds are made possible. At the same time, such an axle drive system with a high gear ratio spread can be provided relatively easily and cost-effectively due to the spur gear design of the transmission.

[0015] If two elements are mechanically connected, they are coupled directly or indirectly, such that a movement of one element causes a reaction in the other. A mechanical connection can be established, for example, by friction or positive engagement. The mechanical connection can correspond to a gear mesh between the corresponding gears of the two elements. Additional elements, such as a ZF Friedrichshafen AG file 303451 Friedrichshafen 2024-08-14 or several spur gear stages, may be present between the elements. A permanent, non-rotatable connection, on the other hand, is a connection in which the two elements are rigidly coupled. The elements can be designed as separate, non-rotatably connected components or as a single piece. A non-rotatable connection between two elements can also be established by a switching element, such as a clutch or a brake.The rotationally fixed connection can be established when the switching element is actuated. The rotationally fixed connection can be released when the switching element is no longer actuated.

[0016] In one embodiment, the electric traction motor has a rotor shaft designed as a hollow shaft, which can be arranged coaxially with and radially within a stator of the electric traction motor. The transfer case and the traction motor, for example, the hollow shaft of the traction motor, can be arranged coaxially with each other. Furthermore, the transfer case and the traction motor can be arranged coaxially with the first and second output shafts. The first output shaft can extend from the transfer case through the hollow shaft of the traction motor. Thus, the first output shaft can extend from the transfer case toward the electric traction motor and be arranged radially within the hollow rotor shaft.Such a design allows, for example, the first output shaft to reach a wheel of the driven machine, which can be located on the side of the electric traction motor facing away from the transfer case. The second output shaft can extend away from the transfer case and the electric traction motor. This design provides an axle drive arrangement that is particularly compact, especially in the radial direction. In an alternative embodiment, the electric traction motor is spaced parallel to the transfer case and, alternatively or additionally, from the first or second output shaft. In such an embodiment, the rotor shaft can be connected to the transmission and, alternatively or additionally, to the transfer case via a spur gear stage and / or a continuous recirculating element, such as a chain or belt.ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14.

[0017] In one embodiment, the spur gear transmission has a countershaft that can be arranged parallel to and spaced apart from one of the output shafts. Furthermore, in this embodiment, the spur gear transmission can have a first spur gear stage and a second spur gear stage to provide the first gear ratio. The first spur gear stage and the second spur gear stage can each be designed as single-stage spur gear stages. The countershaft can be mechanically connected to one of the transmission inputs and outputs via the first spur gear stage and the first switching element. In addition, the countershaft can be mechanically connected to the other of the transmission inputs and outputs via the second spur gear stage.When the first switching element is closed, the transmission input can be mechanically connected to the transmission output via the first spur gear stage, the countershaft, and the second spur gear stage in this embodiment. While the first spur gear stage can, for example, have a gear ratio greater than 1, the second spur gear stage can have a gear ratio approximately equal to 1. Thus, the first gear ratio can be designed entirely as a reduction.

[0018] In one embodiment, the countershaft forms an all-wheel drive output, via which another axle of the machine, for example a front axle, can be mechanically coupled to the axle drive unit. For this purpose, a bevel gear transmission is provided, for example, whereby one bevel gear of the bevel gear transmission can be permanently fixed to the countershaft. The first spur gear stage, via which the transmission input can be mechanically connected to the countershaft, for example by means of the first shift element, can therefore also be used simultaneously for the all-wheel drive to drive another axle of the machine. This enables a particularly simple and cost-effective implementation of an all-wheel drive system. The other axle of the machine can be coupled to the all-wheel drive formed on the countershaft, for example by means of a shift element such as a multi-plate clutch.The electric traction motor can be configured to drive both the first and second output shafts as well as the further axle of the working machine via the all-wheel drive at the countershaft. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14.

[0019] In one embodiment, the gearbox input and output are rotationally fixed via the second switching element to provide the second gear ratio. In such an embodiment, the second gear ratio is therefore designed as a through-drive and can have a gear ratio of 1. This design allows for a second gear ratio with particularly low complexity. In an alternative embodiment, the spur gear transmission has a further countershaft, which can be arranged parallel to the axis and spaced apart from the first or second output shaft. The further countershaft can be located on the opposite side of the first output shaft from the other countershaft. The further countershaft can be mechanically connected to the gearbox input and output via a third spur gear stage and the second switching element.Furthermore, the additional intermediate shaft can be mechanically connected to the other input and output shafts via a fourth spur gear stage. Accordingly, the second gear ratio of the spur gear transmission can be provided by either the third or the fourth spur gear stage. The values ​​of the third and fourth spur gear stages can differ from those of the first and second spur gear stages, so that both the first and second gear ratios can be freely selected. Within this embodiment, an axle drive unit can be provided that exhibits particularly high flexibility in the configuration of the gears.

[0020] In one embodiment, the first and second switching elements are arranged coaxially. For example, the first and second switching elements are arranged coaxially with the first output shaft and, alternatively or additionally, with the second output shaft. As described above, in such an embodiment, the first and second switching elements can, for example, be configured as a double switching element. In an alternative embodiment, the first and second switching elements are spaced apart along their axis. For example, one of the switching elements is arranged coaxially with the first output shaft, and the other switching element is spaced along its axis, for example, coaxially with the countershaft described above.In one embodiment, the first switching element is arranged coaxially with the intermediate shaft described above (ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14), and the second switching element is arranged coaxially with the intermediate shaft described above. While the coaxial design of the two switching elements allows for simpler operation, the axially parallel design of the switching elements offers an advantage in terms of axial installation space.

[0021] The switching elements can each be designed as a positive-locking or friction-locking switching element. In one embodiment, one or both switching elements are designed as synchronizers. In a positive-locking configuration, the switching element can be designed as a dog clutch, which is compact, cost-effective, and has low drag torque. In a friction-locking configuration, the switching element can be designed as a multi-plate clutch, which enables load-shifting. In one embodiment, the first switching element is designed as a positive-locking switching element and the second as a friction-locking switching element, so that, for example, during acceleration, upshifting from first to second gear is possible by closing the second switching element under load.

[0022] In one embodiment, the transfer case has a first planetary gear set comprising a first element, a second element, and a third element. Furthermore, in this embodiment, the transfer case can have a second planetary gear set comprising a first element, a second element, and a third element. The first element of the first planetary gear set can be mechanically connected to the transmission output of the gearbox. The second element of the first planetary gear set can be mechanically connected to the first output shaft, for example, by being permanently and non-rotatably connected. The third element of the first planetary gear set can be non-rotatably connected to the first element of the second planetary gear set, for example, via a component designed as a sun gear. The second element of the second planetary gear set can be non-rotatably fixed to a stationary component, for example, the housing described above.The third element of the second planetary gear set can be mechanically connected to the second output shaft, for example, permanently and rotationally fixed. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14.

[0023] In one embodiment, the first elements of the planetary gear sets are each sun gear, the second elements are each planet carrier, and the third elements are each ring gear. In an alternative embodiment, the first elements of the planetary gear sets are each sun gear, the second elements are each ring gear, and the third elements are each planet carrier. In this embodiment, the first and second planetary gear sets can be arranged at the same axial height but radially one behind the other. In an alternative embodiment, the first and second planetary gear sets are arranged axially one behind the other. A transfer case configured in this way can simultaneously provide both differential functionality and a

[0024] The transfer case provides reduction functionality with a reduction ratio of, for example, around 10. This allows for the simple implementation of a compact axle drive unit with a wide gear ratio spread. In an alternative embodiment, the transfer case can have a third planetary gear set and be configured to provide reduction ratios significantly greater than 10.

[0025] In one embodiment, the transfer case comprises a bevel gear differential to provide differential functionality between the output shafts and a planetary gear set to provide reduction functionality between the traction motor and the output shafts. The planetary gear set can have two planetary gear sets, which can be arranged coaxially to each other and coaxially to the first and second output shafts of the axle drive unit. In the axial direction of the axle drive unit, the planetary gear sets can be arranged one behind the other. The first planetary gear set can have a sun gear, a planet carrier, and a ring gear. Similarly, the second planetary gear set can have a sun gear, a planet carrier, and a ring gear. The sun gear of the first planetary gear set can be mechanically coupled to the traction motor, for example, permanently and rotationally fixed.The planet carrier of the first planet gear set can be permanently rotationally fixed to the sun gear of the second ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14.

[0026] The planetary gear set can be connected. The planet carrier of the second planetary gear set can be permanently and rotationally fixed to the bevel gear differential. The ring gears of the first and second planetary gear sets can be permanently and rotationally fixed to a stationary component.

[0027] In one embodiment, the transfer case comprises a first planetary gear set with a first element, a second element, and a third element, as well as a second planetary gear set with a first element, a second element, and a third element. Furthermore, the transfer case comprises a third planetary gear set with a first element, a second element, and a third element. Torque from the traction motor can be transmitted to the first element of the first planetary gear set. The second element of the first planetary gear set can be permanently and rotationally fixed to the third element of the third planetary gear set. The third element of the first planetary gear set can be permanently and rotationally fixed to the first element of the second planetary gear set. The second element of the second planetary gear set can be permanently and rotationally fixed to a stationary component.The third element of the second planetary gear set can be permanently and non-rotatably connected to the second output shaft. The first element of the third planetary gear set can also be permanently and non-rotatably connected to the second output shaft. Furthermore, the second element of the third planetary gear set can be permanently and non-rotatably connected to the first output shaft. The first elements of the first, second, and third planetary gear sets can each be sun gears; the second elements of the first, second, and third planetary gear sets can be planet carriers; and the third elements of the first, second, and third planetary gear sets can be ring gears.

[0028] In one embodiment, the axle drive unit has an auxiliary drive with an auxiliary drive motor for driving an attachment of the machine. The auxiliary drive motor can be provided separately from the electric traction motor. The axis of rotation of the auxiliary drive motor can be arranged orthogonally to the first and second output shafts. A hydraulic pump for lubricating and actuating the axle drive unit, for example, the shift elements of the transmission, can be driven by the auxiliary drive motor. Furthermore, a coupling device can be selectively mechanically connected to the auxiliary drive motor, for example, via a shift element. The attachment can be mechanically coupled to the coupling device and can then, in turn, be driven by the auxiliary drive motor.The coupling device and the auxiliary drive motor can be arranged on opposite sides of the first and second output shafts.

[0029] Furthermore, the present disclosure relates to a working machine with an axle drive device according to one of the embodiments described above. In addition to the axle drive device, the working machine may have another axle, for example a front axle, which can be driven via the axle drive device. Regarding the designs and advantages of the individual features, reference is made to the above descriptions in connection with the axle drive device for a working machine.

[0030] Brief description of the characters

[0031] Figure 1 shows an axle drive device for a working machine according to one embodiment.

[0032] Figure 2 shows an axle drive device for a working machine according to one embodiment.

[0033] Figure 3 shows an axle drive device for a working machine according to one embodiment.

[0034] Figure 4 shows an axle drive device for a working machine according to one embodiment.

[0035] Figure 5 shows an axle drive unit for a machine according to one embodiment. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14

[0036] Figure 6 shows an axle drive device for a working machine according to one embodiment.

[0037] Figure 7 shows an axle drive device for a working machine according to one embodiment.

[0038] Figure 8 shows an axle drive device for a working machine according to one embodiment.

[0039] Figure 9 shows a working machine with an axle drive device according to one of the embodiments of Figures 1 to 8.

[0040] Detailed description of embodiments

[0041] Figure 1 shows an axle drive unit 1 for a work machine 100 according to one embodiment. In the present embodiment, the work machine 100 is a tractor. In this embodiment, the axle drive unit 1 is designed as a rear axle drive unit. As described below, the axle drive unit 1 shown in Figure 1 can also drive a front axle 101 of the work machine 100, which is not shown in Figure 1. The rear axle drive unit 1 comprises a right wheel 2 and a left wheel 3, which can be driven by the axle drive unit 1 to propel the tractor 100. Furthermore, the axle drive unit 1 has an axis of symmetry that coincides with the axes of rotation of the wheels 2 and 3. The axle drive unit 1 is designed coaxially with this axis of symmetry.The axle drive unit 1 comprises an electric traction motor 4 with a stator 5 and a rotor 6 located radially inside it.

[0042] The rotor 6 of the electric traction motor 4 is permanently and rotationally fixedly connected to a rotor shaft 7 designed as a hollow shaft. The electric traction motor 4, and thus both the stator 5 and the rotor 6, are arranged coaxially with respect to the axis of symmetry described above. The electric traction motor 4 is designed to propel the tractor 100. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14

[0043] Furthermore, the axle drive unit 1 comprises a distribution gearbox 8 with a first output shaft 9 and a second output shaft 10. The first output shaft 9 and the second output shaft 10 are each mechanically connected to the wheels 2 and 3, respectively, via a wheel hub gearbox 11. The wheel hub gearboxes 11 are each of planetary design and have a sun gear 12, a planet carrier 13 with planet gears 14 rotatably mounted thereon, and a ring gear 15. The sun gear 12 is permanently and non-rotatably connected to the first 9 and second output shaft 10, respectively. The ring gear 15 is permanently and non-rotatably connected to a stationary component 16, in this case a housing of the axle drive unit 1. The stator 5 of the electric traction motor 4 is also permanently and non-rotatably connected to this housing 16.The planet carrier 13 of the respective hub gear 11 is permanently and rotationally fixed to the respective wheel 2 or 3. Furthermore, the planet carrier 13 can be selectively locked to the stationary component 16 via a brake 17 in order to brake the associated wheel 2 or 3.

[0044] The hollow-shafted rotor shaft 7 of the electric traction motor 4 is permanently and rotationally fixedly connected to a gear input 18 of a transmission 19. A gear output 20 of the transmission 19 is permanently and rotationally fixedly connected to an input shaft 21 of the transfer case 8. Torque from the electric traction motor 4 can be transmitted to the transfer case 8 via the transmission 19 with different gear ratios, which then distributes the torque to the first output shaft 9 and the second output shaft 10. As explained below, the transmission 19 is designed as a spur gear transmission. Viewed from the left wheel 3, in the present embodiment the wheel hub gear 11 of the left wheel 3 is arranged in the direction of the axis of symmetry of the axle drive unit 1 upstream of the transfer case 8, which in turn is located upstream of the transmission 19.The electric traction motor 4 follows the transmission 19 and is located in front of the right wheel hub gear 11 of the right wheel 2. In the present embodiment, the wheel hub gear 11, the transfer case 8, and the electric traction motor 4 are all arranged coaxially with respect to the axis of symmetry described above. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14.

[0045] The transfer case 8 comprises a first planetary gear set 22 and a second planetary gear set 23, which are arranged at the same axial height but radially one behind the other. A first element 24, in this case a sun gear, of the first planetary gear set 22 is permanently and rotationally fixed to the input shaft 21. A second element 25, in this case a planet carrier of the first planetary gear set 22, is permanently and rotationally fixed to the first output shaft 9. A third element 26, in this case a ring gear, of the first planetary gear set 22 is permanently and rotationally fixed to a first element 27, in this case a sun gear, of the second planetary gear set 23. In the present embodiment, the ring gear 26 of the first planetary gear set 22 and the sun gear 27 of the second planetary gear set 23 are designed as a sun gear, which can be monolithic and consist of a single component.A second element 28, in this case a planet carrier, of the second planet gear set 23 is permanently fixed against rotation to the stationary component 16. A third element 29, in this case a ring gear, of the second planet gear set 23 is permanently connected against rotation to the second output shaft 10. Planet gears are provided on the planet carrier 25 of the first planet gear set 22 and on the planet carrier 28 of the second planet gear set 23, respectively, which mesh with the respective sun gear and ring gear of the first 22 and second planet gear set 23.

[0046] As can be seen in Figure 1, the planet carrier 25 of the first planet gear set 22 extends away from the associated planet gears in the direction of the wheel hub gear 11 of the left wheel 3. The first output shaft 9, which is permanently and rotationally fixed to this planet carrier 25 of the first planet gear set 22, extends through the input shaft 21, which is designed as a hollow shaft, and the rotor shaft 7 of the electric traction motor 4, which is also designed as a hollow shaft, to the wheel hub gear 11 of the right wheel 2. The first output shaft 9 and the second output shaft 10 are arranged coaxially with each other and coaxially with the axis of symmetry of the axle drive unit 1 described above. Furthermore, the axle drive unit 1 has a differential lock 30, by means of which the planet carrier 25 of the first planet gear set 22 can be rotationally fixedly connected to the ring gear 29 of the second planet gear set 23.According to the differential lock 13, the first output shaft 9 and the second ZF Friedrichshafen AG file 303451 Friedrichshafen 2024-08-14.

[0047] The output shaft 10 is connected to each other in a rotationally fixed manner. The transfer case 8 of the present embodiment provides a reduction gear, for example with a gear ratio of approximately 10, and also a differential function. Thus, the transfer case 8 can enable a differential speed between the right wheel 2 and the left wheel 3. By engaging the differential lock 30, the differential function of the transfer case 8 can be locked, and consequently, a differential speed between the right wheel 2 and the left wheel 3 can be prevented.

[0048] In the present embodiment, the transmission 19 has two gears with different gear ratios. It comprises a first shift element 31 and a second shift element 32. In the present embodiment, the first and second shift elements are designed as a double shift element 31, 32. The double shift element 31, 32 is configured as a double synchronizer, which, in addition to a shift position for engaging first gear and a shift position for engaging second gear, also has a neutral position. The double synchronizer 31, 32 is arranged coaxially with the axis of symmetry of the axle drive unit 1, i.e., coaxially with the first 9 and second output shaft 10.

[0049] Furthermore, the transmission 19 comprises a countershaft 33, which is arranged parallel to the axis of symmetry of the axle drive unit 1 and can be mechanically connected to the transmission input 18 via a first spur gear stage 34 by actuating the first shift element 31. The transmission 19 also has a second spur gear stage 35, through which the countershaft 33 is mechanically connected to the transmission output 20. The first spur gear stage 34 and the second spur gear stage 35 are each designed as single-stage spur gear stages. In the present embodiment, the first spur gear stage 34 has a gear ratio greater than 1, while the second spur gear stage 35 has a gear ratio of approximately 1. Therefore, by actuating the first shift element 31 and thus by engaging first gear in the transmission 19, the rotational speed of the electric traction motor 4 can be reduced.By actuating the second switching element 32, in the present embodiment of ZF Friedrichshafen AG file 303451 Friedrichshafen 2024-08-14.

[0050] The gearbox input 18 is connected to the gearbox output 20 in a rotationally fixed manner. In this second gear, the speed of the electric traction motor 4 can therefore be transmitted directly, i.e., without reduction, to the transfer case 8. In the present embodiment, viewed from the left wheel 3, the transfer case 8 is positioned in the direction of the axis of symmetry upstream of the second spur gear stage 35, which in turn is arranged upstream of the double shift element 31, 32. The first spur gear stage 34 follows the double shift element 31, 32 and is again arranged upstream of the electric traction motor 4.

[0051] The countershaft 33 also forms an all-wheel drive output 36, which in the present embodiment is designed as a bevel gear. A front axle 101 of the tractor 100 (not shown in Figure 1) can be selectively mechanically coupled to the bevel gear 36. For this purpose, a further bevel gear 37 meshing with the all-wheel drive output 36 is provided, which can be mechanically connected to the front axle via a switching element 38. A torque can be transmitted from the axle drive unit 1 to the front axle 101 via the bevel gear transmission 36, 37. For this purpose, a cardan shaft extending transversely to the axis of symmetry of the axle drive unit 1 can be provided, via which the bevel gear transmission 36, 37 can be mechanically coupled to the front axle 101 via the switching element 38.

[0052] Furthermore, the axle drive unit 1 of the present embodiment comprises a power take-off with its own electric power take-off motor 40, the axis of rotation of which is arranged transversely, for example orthogonally, to the first and second output shafts 9, 10. A hydraulic pump 42 for lubricating and actuating the axle drive unit 1, for example the switching elements 31 and 32, can be driven by the power take-off motor 40 via a spur gear transmission 41. In addition, a coupling device 44 can be selectively mechanically connected to the power take-off motor 40 via a switching element 43. An implement of the tractor 100 can be mechanically coupled to the coupling device 44, which can then in turn be driven by the power take-off motor 40.In the present embodiment, the coupling device 44 and the auxiliary drive motor 40 are arranged on opposite sides of the first and second output shafts 9, 10. The auxiliary drive motor 40 can be arranged on the side of the output shafts 9, 10 that faces the front axle 101 of the tractor 100.

[0053] To accelerate the tractor 100 with the axle drive unit 1 of the embodiment shown in Figure 1, first gear is engaged by closing the first shift element 31. In this first gear, the torque of the electric traction motor 4 is reduced via the transmission 19 and the transfer case 8 to provide high torques at the first and second output shafts 9, 10 for starting the tractor 100. Once the tractor 100 reaches higher speeds, the second shift element 32 is engaged and the first shift element 31 is opened. In this case, a through-drive is engaged between the electric traction motor 4 and the transfer case 8 in the present embodiment, so that reduction is only achieved by the transfer case 8. Therefore, high speeds can be reached with the tractor in this second gear.

[0054] Figure 2 shows an axle drive unit 1 for a working machine 100 according to a further embodiment. The axle drive unit 1 in Figure 2 is designed according to the axle drive unit 1 in Figure 1, with the exception of the differences described below. As in the embodiment of Figure 1, in the embodiment of Figure 2 the first switching element 31 and the second switching element 32 are designed as a double switching element 31, 32. In contrast to the embodiment of Figure 1, however, the first 31 and the second switching element 32 in the embodiment of Figure 2 are designed as friction-fit switching elements, in this case as multi-plate clutches. Otherwise, the embodiment of Figure 2 is identical to the embodiment of Figure 1.

[0055] Figure 3 shows an axle drive device 1 for a machine 100 according to a further embodiment of the present invention. The embodiment of Figure 3 is similar to the embodiment of Figure 1 except for the differences described below. In contrast to the embodiment of Figure 1, the first switching element 31 and the second switching element 32 in the embodiment of Figure 3 (ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14) are not designed as a double switching element, but as individual switching elements 31 and 32, respectively. The first switching element 31 is arranged coaxially to the countershaft 33 and thus spaced parallel to the axis of the first output shaft 9. The second switching element 32 is arranged coaxially to the first output shaft 9, as in the embodiment of Figure 1.As in the embodiment of Figure 1, the transmission input 18 can be mechanically connected to the countershaft 33 via the first spur gear stage 34 by means of the first switching element 31. Otherwise, the embodiment of Figure 3 is identical to the embodiment of Figure 1. This means, for example, that the first switching element 31 and the second switching element 32 are each designed as positive-locking switching elements, in this case as synchronizers.

[0056] Figure 4 shows another embodiment of an axle drive device 1 for a machine 100. The axle drive device 1 from Figure 4 is designed like the axle drive device 1 from Figure 3, with the exception of the differences described below. In contrast to the embodiment of Figure 3, in the embodiment of Figure 4 the first switching element 31 and the second switching element 32 are each designed as friction-fit switching elements, in this case as multi-plate clutches. Otherwise, the embodiment of Figure 4 is identical to the embodiment of Figure 3.

[0057] Figure 5 shows another embodiment of an axle drive unit 1 for a machine 100. The axle drive unit 1 from Figure 5 is designed like the axle drive unit 1 from Figure 1, except for the differences described below. Unlike the axle drive unit 1 from Figure 1, in the axle drive unit 1 from Figure 5 the electric traction motor 4 is not arranged coaxially to the first output shaft 9, but rather parallel to it at a distance. The rotor shaft 7 of the electric traction motor 4 is connected to the transmission input 18 of the gearbox 19 via a spur gear stage 45. Otherwise, the axle drive unit 1 from Figure 5 is designed like the axle drive unit 1 from Figure 1. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14

[0058] Figure 6 shows an axle drive unit 1 for a working machine 100 according to a further embodiment. The axle drive unit 1 from Figure 6 is designed like the axle drive unit 1 from Figure 1, with the exception of the differences described below. In the embodiment of Figure 6, the transfer case 8' is designed differently from the transfer case 8 of the embodiment of Figure 1. The transfer case 8' of the embodiment of Figure 6 also has a reduction gear and a differential function. To provide the differential function, the transfer case 8' of the embodiment of Figure 6 has a bevel gear differential 46' with a differential carrier 47' and two output shafts 48', each of which is permanently and rotationally fixedly connected to an output shaft 9, 10. Compensating gears are rotatably mounted within the differential carrier 47', via which the output shafts 48' are mechanically operatively connected.

[0059] In the present embodiment, the reduction function of the transfer case 8' is provided by two planetary gear sets 22' and 23', which are arranged coaxially to each other and coaxially to the first and second output shafts 9, 10 of the axle drive unit 1. In the axial direction of the axle drive unit 1, the planetary gear sets 22' and 23' are arranged one behind the other. The first planetary gear set 22' comprises a sun gear 24', a planet carrier 25', and a ring gear 26'. Similarly, the second planetary gear set 23' comprises a sun gear 27', a planet carrier 28', and a ring gear 29'. The sun gear 24' of the first planetary gear set 22' is permanently and rotationally fixed to the input shaft 21. The planet carrier 25' of the first planetary gear set 22' is permanently and rotationally fixed to the sun gear 27' of the second planetary gear set 23'.The planet carrier 28' of the second planet gear set 23' is permanently and rotationally fixed to the differential housing 47' of the bevel gear differential 46'. The ring gears 26' and 29' of the first 22' and second planet gear sets 23' are permanently and rotationally fixed to the stationary component 16. Furthermore, the transfer case 8' includes a differential lock 30', by means of which the planet carrier 28' of the second planet gear set 23' can be selectively and rotationally fixed to the first output shaft 9. Otherwise, the embodiment of Figure 6 is identical to the embodiment of Figure 1. ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14.

[0060] Figure 7 shows another embodiment of an axle drive unit 1 for a working machine 100. The axle drive unit 1 from Figure 7 is designed like the axle drive unit 1 from Figure 1, except for the differences described below. In contrast to the drive unit 1 from Figure 1, the transfer case 8" of the embodiment of Figure 7 has a different configuration than that in Figure 1. In the embodiment in Figure 7, the transfer case 8" comprises a first planetary gear set 22" with a first sun gear 24", a first planet carrier 25", and a first ring gear 26". Furthermore, the transfer case 8" comprises a second planetary gear set 23" with a second sun gear 27", a second planet carrier 28", and a second ring gear 29". In addition, the transfer case 8" comprises a third planetary gear set 46" with a third sun gear 47", a third planet carrier 48", and a third ring gear 49".

[0061] The first sun gear 24" is permanently and rotationally fixed to the input shaft 21. Furthermore, the first planet carrier 25" of the first planet gear set 22" is permanently and rotationally fixed to the third ring gear 49" of the third planet gear set 46". The first ring gear 26" of the first planet gear set 22" is permanently and rotationally fixed to the second sun gear 27" of the second planet gear set 23". The second planet carrier 28" of the second planet gear set 23" is permanently and rotationally fixed to the stationary component 16. The second ring gear 29" of the second planet gear set 23" is permanently and rotationally fixed to the second output shaft 10. Furthermore, the third sun gear 47" of the third planet gear set 46" is permanently and rotationally fixed to the second output shaft 10. The third planet carrier 48" of the third planet gear set 46" is permanently and rotationally fixed to the first output shaft 9.Furthermore, the third ring gear 49" of the third planet gear set 46" can be connected to the second ring gear 29" of the second planet gear set 23" via a differential lock 30" in a rotationally fixed manner.

[0062] Viewed from the left wheel, in the direction of the axis of symmetry of the axle drive unit 1, the third planetary gear set 46" is arranged in front of the first planetary gear set 22", which in turn is arranged in front of the second planetary gear set 23". The transmission 19 follows the second planetary gear set 23" of the transfer case 8". In contrast to the transfer case 8 of the embodiment ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14 of Figure 1, a higher absolute reduction ratio, for example significantly greater than 10, can be achieved with the transfer case 8" of the embodiment of Figure 7. Otherwise, the axle drive unit 1 of the embodiment of Figure 7 is designed like the axle drive unit 1 of the embodiment of Figure 1.

[0063] Figure 8 shows an axle drive unit 1 for a machine 100 according to a further embodiment. The axle drive unit 1 in Figure 8 is designed like the axle drive unit 1 in Figure 1, with the exception of the differences described below. In contrast to the embodiment of Figure 1, in the embodiment of Figure 8 the transmission 19 is designed such that the first switching element 31 and the second switching element 32 are provided separately from each other as individual switching elements. The first switching element 31 is arranged coaxially to a countershaft 33, which is spaced parallel to the axis of the first output shaft 9. Via the first switching element 31, the countershaft 33 can be mechanically connected to the transmission input 18 via the first spur gear stage 34. Via the second spur gear stage 35, the countershaft 33 is mechanically connected to the transmission output 20.

[0064] In the embodiment of Figure 8, the countershaft 33 does not form the all-wheel drive 36, as is the case in the embodiment of Figure 1.

[0065] Instead, the embodiment of Figure 8 has a further countershaft 50, which is also arranged parallel to the axis of the first output shaft 9. In the present embodiment, the countershaft 33 and the further countershaft 50 are arranged on opposite sides of the first output shaft 9. The second switching element 32 is provided coaxially with the further countershaft 50. Via the second switching element 32, the further countershaft 50 is mechanically connected to the transmission input 18 via a third spur gear stage 51. Furthermore, the further countershaft 50 is mechanically connected to the transmission output 20 via a fourth spur gear stage 52. In the present embodiment, the further countershaft 50 forms the all-wheel drive output 36 according to the embodiment of Figure 1.In contrast to the embodiment of Figure 1, in the embodiment of Figure 8, both the first and second gears in the transmission 18 are not designed as through-drives, but rather their gear ratios are freely selectable. (ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14) Otherwise, the embodiment of Figure 8 is designed like the embodiment of Figure 1.

[0066] Figure 9 shows a working machine 100 according to one embodiment. In the present embodiment, the working machine 100 is designed as a tractor. The working machine 100 comprises an axle drive unit 1 according to one of the previously described embodiments, which is designed as a rear axle drive unit. Furthermore, the working machine 100 comprises a front axle 101, which can be driven via the rear axle drive unit 1 by closing the switching element 38 described above.

[0067] ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14

[0068] Reference mark

[0069] 1 axle drive unit

[0070] 2, 3 wheel

[0071] 4.40 electric motor

[0072] 5 Stator

[0073] 6, 7 Rotor, rotor shaft

[0074] 8, 8', 8" transfer case

[0075] 9, 10, 48' Output shaft

[0076] 11 Wheel hub gears

[0077] 12, 24, 27, 24', 27', 24", 27", 47" sun wheel

[0078] 13, 25, 28, 25', 28', 25", 28", 48" Planetary carrier

[0079] 14 planetary gear

[0080] 15, 26, 29, 26', 29', 26", 29", 49" hollow gear

[0081] 16 stationary component

[0082] 17 Brake

[0083] 18 Gearbox input

[0084] 19-speed gearbox

[0085] 20 Gearbox output

[0086] 21 Input wave

[0087] 22, 23, 22', 23' , 22", 23", 46" planetary gear set

[0088] 30, 30', 30" differential lock

[0089] 31, 32, 38, 43 Switching element

[0090] 33, 50 Countershaft

[0091] 34, 35, 41, 45, 51, 52 Spur gear stage

[0092] 36 All-wheel drive

[0093] 37 Bevel gear

[0094] 42 Hydraulic pump

[0095] 44 Coupling device

[0096] 46' bevel gear differential

[0097] 47' Differential basket

[0098] 100 working machines

[0099] 101 Front axle

Claims

ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14 Patent claims 1. Axle drive device (1 ) for a working machine (100) comprising an electric traction motor (4), a distribution gearbox (8; 8'; 8") with a first output shaft (9) for driving a first wheel (2) of the working machine (100) and a second output shaft (10) for driving a second wheel (3) of the working machine (100) opposite the first wheel (2), and a gear transmission (19) for providing two gears with different gear ratios, wherein the axle drive device (1 ) is configured to communicate with the electric traction motor (4) via the gear transmission (19) and the distribution gearbox (8; 8';8”) to drive the first (9) and the second output shaft (10), and wherein the transmission (19) is designed as a spur gear transmission and has a transmission input (18), a transmission output (20), a first switching element (31) and a second switching element (32), wherein the transmission input (18) is mechanically connected to the transmission output (20) by means of the first switching element (31) via a first transmission (34, 35) and by means of the second switching element (32) via a second transmission.; 2. Axle drive device (1 ) according to claim 1 , characterized in that the electric traction motor (4) has a rotor shaft (7) designed as a hollow shaft, the distribution gearbox (8; 8'; 8") and the electric traction motor (4) are arranged coaxially to each other, and the first output shaft (9) of the distribution gearbox (8; 8'; 8") extends through the hollow shaft (7) of the traction motor (4).

3. Axle drive device (1 ) according to claim 1 or 2, characterized in that the spur gear transmission (19) has a countershaft (33), a first spur gear stage (34) and a second spur gear stage (35) for providing the first gear ratio, wherein the countershaft (33) is mechanically connected via the first spur gear stage (34) and the first switching element (31 ) to one of the transmission input (18) and the transmission output (20) and is mechanically connected via the second spur gear stage (35) to the other of the transmission input (18) and the transmission output (20). ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14 4. Axle drive device (1 ) according to claim 3, characterized in that the countershaft (33) forms an all-wheel drive (36) via which a further axle (101 ) of the working machine (100) can be driven by means of the electric traction motor (4).

5. Axle drive device (1 ) according to claim 3 or 4, characterized in that the transmission input (18) can be connected to the transmission output (20) via the second switching element (32) to provide the second gear ratio.

6. Axle drive device (1 ) according to claim 3 or 4, characterized in that the spur gear transmission (19) has a further countershaft (50), a third spur gear stage (51 ) and a fourth spur gear stage (52), wherein the further countershaft (50) is mechanically connected via the third spur gear stage (51 ) and the second switching element (32) to one of the transmission input (18) and the transmission output (20) and is mechanically connected via the fourth spur gear stage (52) to the other of the transmission input (18) and the transmission output (20).

7. Axle drive device (1 ) according to one of the preceding claims, characterized in that the first switching element (31 ) and the second switching element (32) are arranged coaxially or parallel to each other.

8. Axle drive device (1) according to one of the preceding claims, characterized in that the transfer case (8) has a first planetary gear set (22) with a first element (24), a second element (25) and a third element (26) and a second planetary gear set (23) with a first element (27), a second element (28) and a third element (29), wherein the first element (24) of the first planetary gear set (22) is mechanically operatively connected to the transmission output (20) of the gear transmission (19), the second element (25) of the first planetary gear set (22) is permanently rotationally fixed to the first output shaft (9), the third element (26) of the first planetary gear set (22) is permanently rotationally fixed to the first element (27) of the second planetary gear set (23), the second element (28) of the second planetary gear set (23) is mounted on a stationary ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14 Component (16) is fixed in a rotationally fixed manner, and the third element (29) of the second The planetary gear set (23) is permanently and rotationally fixedly connected to the second output shaft (10).

9. Axle drive device (1 ) according to claim 8, characterized in that the first elements (24, 27) of the first and second planet gear set (22, 23) are each designed as sun gears, the second elements (25, 28) of the first and second planet gear set (22, 23) are each designed as planet carriers and the third elements (26, 29) of the first and second planet gear set (22, 23) are each designed as ring gears.

10. Axle drive device (1 ) according to one of claims 1 to 7, characterized in that the transfer case (8') has a bevel gear differential (46') for providing differential functionality between the output shafts (9, 10) and a planetary gear set (22', 23') for providing reduction functionality between the traction motor (4) and the output shafts (9, 10).

11. Axle drive device (1) according to any one of claims 1 to 7, characterized in that the transfer case (8) comprises a first planetary gear set (22) with a first element (24), a second element (25) and a third element (26), a second planetary gear set (23) with a first element (27), a second element (28) and a third element (29), and a third planetary gear set (46) with a first element (47), a second element (48) and a third element (49), wherein a torque of the traction motor (4) can be transmitted to the first element (24) of the first planetary gear set (22), the second element (25) of the first planetary gear set (22) is permanently rotationally fixed to the third element (49) of the third planetary gear set (46), and the third element (26) of the first planetary gear set (22) is permanently rotationally fixed to the first element (27) of the second planetary gear set (23") is connectedthe second element (28") of the second planetary gear set (23") is permanently fixed in a rotationally fixed manner to a stationary component (16), the third element (29") of the second planetary gear set (23") is permanently connected in a rotationally fixed manner to the second output shaft (10), the first element (47") of the third planetary gear set (46") is permanently connected in a rotationally fixed manner to the second output shaft (10), and the second element (48") of the third, ZF Friedrichshafen AG File 303451 Friedrichshafen 2024-08-14 The planetary gear set (46") is permanently and rotationally fixed to the first output shaft (9).

12. Axle drive device (1 ) according to one of the preceding claims, characterized in that the axle drive device (1 ) has an auxiliary drive with an auxiliary drive motor (40) for driving an attachment of the working machine.

13. Working machine (100) with an axle drive device (1 ) according to one of the preceding claims.

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