Drive system for a vehicle

Abstract

The present invention relates to a drive unit (2) for a vehicle (100) comprising a drive (6) and an output (5). The drive unit (2) includes a transmission assembly (7) with a variator (10) for providing multiple driving ranges, a central shaft (36), and an output shaft (42). Furthermore, the drive unit (2) comprises a gearshift transmission (8) with a forward shift element (46) for mechanically connecting the output shaft (42) to the output (5) with a first gear ratio (48) for forward travel. It also includes a shift device (55) for selectively switching between a second gear ratio (53) for forward travel and a gear ratio (49) for reverse travel. The drive unit (2) also includes a reverse shift element (47) for mechanically connecting the output shaft (42) to the shift device (55).The forward switching element (46) and the reverse switching element (47) are each designed as individual switching elements.

Description

Technical field

[0001] The present invention relates to a drive system for a vehicle. Furthermore, the present invention relates to a vehicle with such a drive system. The vehicle may be a work machine or a commercial vehicle. State of the art

[0002] Continuously variable transmissions (CVTs) are used in construction machinery and commercial vehicles. Such transmissions can have multiple driving ranges, in which different mechanical gear ratios can exist between a transmission input and a transmission output. The transmissions can also include a variator, by means of which the gear ratio can be continuously varied in the respective driving ranges. A drive train for a commercial vehicle with a CVT is known, for example, from DE 10 2009 002 808 A1. Description of the invention

[0003] The present invention relates to a drive unit for a vehicle. The drive unit comprises a drive for mechanical connection with a motor unit. The motor unit can be one or more internal combustion engines and, alternatively or additionally, electric motors. The drive unit further comprises an output for mechanical connection with a propulsion element. The propulsion element can be one or more wheels, tracks, or other propulsion elements of the vehicle. The output of the drive unit can be mechanically connected to the propulsion element via one or more differentials, for example, via a longitudinal and a transverse differential. The drive and the output of the drive unit can be arranged parallel to each other.The drive unit also includes a torque transmission path for transmitting torque from the drive unit to the output of the drive unit. The vehicle can be a working machine, such as a construction or agricultural machine, or a commercial vehicle.

[0004] In one embodiment, the vehicle is, for example, a work machine or utility vehicle designed as a universal motor unit. This embodiment can also be used in other applications. The vehicle can be designed to travel on roads and / or railways. The vehicle can have a maximum speed greater than 50 km / h, for example, greater than 70 km / h. In one embodiment, the vehicle has a maximum speed of approximately 120 km / h. The vehicle can be designed as an all-wheel-drive vehicle and, in one embodiment, may have portal axles. Furthermore, the vehicle can be designed as a vehicle with a ladder frame supported by portal axles guided by torque tubes and wishbones, which may be sprung with coil springs. This allows for a very large axle articulation, enabling the vehicle to have excellent off-road capability.

[0005] Furthermore, the drive unit comprises a transmission assembly for providing multiple driving ranges and a variator. The transmission assembly is designed as a continuously variable, power-split transmission with a variator. The transmission assembly can, for example, provide four driving ranges. Within each driving range, a fixed mechanical gear ratio between the input and output of the transmission can be provided, whereby the gear ratio within the respective driving range can be continuously varied by adjusting the variator. The variator can be a hydraulic variator, for example, a hydrostatic variator. Alternatively or additionally, it can be an electrically operated variator. The transmission assembly can have one or more planetary gear sets and one or more switching elements, whereby some or all of these components can be arranged coaxially.The gearbox assembly can be designed as a so-called planetary roller. The drive can be arranged parallel to the axis and thus spaced apart from a central shaft of the gearbox assembly. The central shaft can be a shaft with which the gearbox assembly can be coaxial. Furthermore, the gearbox assembly includes an output shaft, which can be designed to be coaxial with the central shaft.

[0006] The transmission assembly includes a gearbox, which is integrated into the torque transmission path along with the transmission assembly. In other words, torque supplied to the drive unit is transmitted via the transmission assembly and the gearbox to the output of the drive unit. In this torque transmission path from the drive unit to the output, the gearbox can be located downstream of the transmission assembly. Positioning the gearbox downstream of the transmission assembly helps to avoid high rotational speeds within the assembly.

[0007] The transmission has a forward shift element for mechanically connecting the output shaft to the output shaft with a first gear ratio for forward travel and high tractive forces. Furthermore, the transmission has a shift mechanism for selectively switching between a second gear ratio for forward travel at high speeds and a reverse gear ratio. Additionally, the transmission has a reverse shift element for mechanically connecting the output shaft to the shift mechanism. Besides these shift positions, the shift mechanism may also have other positions, such as a neutral position. The transmission can have any configuration, as long as it provides the required functionalities. The transmission can have one or more spur gear stages and, alternatively or additionally, one or more planetary gear stages.The gearbox can provide additional gears in the forward direction and, alternatively or additionally, in reverse, besides the gears already described. In one embodiment, the gearbox has only the two forward gears described and the single reverse gear described.

[0008] In this design, the forward and reverse shift elements are each configured as individual shift elements. They are therefore designed separately from one another, for example, both functionally and spatially. For instance, each shift element has its own control mechanism for actuating the respective shift element and, alternatively or additionally, its own housing. Thus, the forward and reverse shift elements are not configured as dual shift elements. This allows for a drive unit, and especially a gearbox, with a particularly compact design. The configuration of the forward and reverse shift elements as individual shift elements, for example, enables a particularly compact axial design of the drive unit.

[0009] The drive system, for example, the gearbox, can be designed such that the vehicle can reach suitable speeds for transport, such as highway speeds, in the high-speed gear. For example, speeds greater than 50 km / h, such as greater than 70 km / h, and in one embodiment approximately 90 km / h, can be achieved in this gear. The drive system, for example, the gearbox, can also be designed such that the high-traction gear provides sufficient power to pull heavy loads, such as loaded or empty freight trains with multiple trailers. The drive system can also include a generator that can provide power assistance, for example, in the form of a boost function.In this case, the drive system can enable hybrid operation with an internal combustion engine and an electric motor that also functions as a generator.

[0010] By incorporating a gearbox, a drive unit with a particularly wide gear ratio spread can be provided without requiring a particularly complex and robust design for the transmission assembly. As a result, a continuously variable, power-split transmission with a wide gear ratio spread can be provided in a relatively simple and cost-effective manner. At the same time, the gearbox design allows for a compact construction and a drive unit with effective and efficient shifting behavior.

[0011] If two elements are mechanically connected, they are coupled to each other directly or indirectly in such a way that a movement of one element causes a reaction of the other. For example, a mechanical connection can be provided by a positive-locking or friction-locking connection. The mechanical connection can correspond to the meshing of corresponding gear teeth on the two elements. Further elements, such as one or more spur gear stages, can be provided between the elements. A permanently rotationally fixed connection between two elements, on the other hand, is understood to be a connection in which the two elements are rigidly coupled to each other in all intended states. The elements can be individual components connected in a rotationally fixed manner or even as a single piece.However, a switching element, such as a clutch or brake, can be used to selectively establish or break a rotationally fixed connection between two elements.

[0012] In one embodiment, the drive unit further comprises an auxiliary drive unit. The auxiliary drive unit can be mechanically connected to the central shaft. The auxiliary drive unit can have one or more auxiliary drives, which can drive various auxiliary drive components of the vehicle. For example, the auxiliary drive unit can drive a pump, a generator, or any other type of auxiliary component. Connecting the auxiliary drive unit to the central shaft of the transmission assembly allows for a compact design of the drive unit. In one embodiment, the auxiliary drive unit can have a first and a second power take-off, which can be designed to provide different rotational speeds.

[0013] In one embodiment, the forward and reverse shift elements are each designed as friction-fit shift elements, and the shifting device is designed as a synchronous shifting device. For example, the forward and reverse shift elements are each designed as multi-plate clutches. The shifting device can, for example, be a synchronizer. This allows for particularly simple switching in the transmission between second gear for forward travel and the gear for reverse travel. The synchronizer can, for example, selectively connect an intermediate shaft, which can be mechanically connected to the transmission assembly via the reverse shift element, either to the second gear ratio for forward travel or to the gear ratio for reverse travel with the output shaft.In one embodiment, the first forward gear ratio, the second forward gear ratio, and the reverse gear ratio are each provided by a spur gear chain. The forward gear ratios can be single-stage spur gear chains, and the reverse gear ratio can be a two-stage spur gear chain. The design of the shifting device as a synchronizer and the forward and reverse shift elements as friction-fit shift elements allows for load-shifting in the transmission from first to second forward gear. If second forward gear is pre-selected in the synchronizer, a change can be made, for example, by opening the forward shift element and closing the reverse shift element under load.

[0014] In one embodiment, the reverse shift element and the shifting device are arranged coaxially to each other and spaced parallel to the central shaft of the transmission assembly and the forward shift element. The forward shift element can, in turn, be arranged parallel to the central shaft. For example, it is located on the side of the shifting device facing away from the transmission assembly. The transmission can have an input shaft that may be coaxial with the intermediate shaft described above. The reverse shift element and the shifting device can be arranged coaxially with the input shaft. Thus, the transmission can, for example, be mechanically connected to the transmission assembly via the input shaft and a single- or multi-stage spur gear stage.

[0015] The coaxial design of the switching device and reverse switching element, and the axially parallel arrangement of these components to the gearbox assembly, allows for a drive system that can be integrated particularly well into a machine, such as a universal motor unit, in terms of installation space. At the same time, the axially parallel arrangement of the forward switching element to the switching device enables a particularly compact design in the axial direction. In an alternative embodiment, however, the forward switching element can also be arranged coaxially to the switching device.

[0016] In one embodiment, the reverse shift element and the forward shift element are arranged on opposite sides of the shifting device in the direction of the central shaft. This allows for a highly variable transmission that can be particularly well integrated into the installation space of a vehicle, such as a universal motor unit. In one embodiment, viewed from the transmission assembly in the direction of the central shaft, the forward shift element is arranged upstream of the shifting device, which is located upstream of the reverse shift element. In an alternative embodiment, viewed from the transmission assembly in the direction of the central shaft, the reverse shift element is arranged upstream of the shifting device, which is located upstream of the forward shift element. In one embodiment, the transmission and the transmission assembly do not overlap in the direction of the central shaft.In an alternative embodiment, the two components can slightly overlap, while still being arranged one behind the other.

[0017] In one embodiment, the drive is arranged parallel to the axis and spaced apart from the central shaft. This allows the drive to be connected to the central shaft, for example, via a reduction gear, which can positively impact the installation space required for a motor unit mechanically linked to the drive. The central shaft can be mechanically linked to the variator of the planetary assembly via a gear element, such as a spur gear chain, which can be two-stage. The gear element can be an intermediate gear of the spur gear chain. In the present embodiment, the drive can be mechanically linked to the gear element, for example, by being permanently and rotationally fixed. This allows for a particularly compact design, as the drive is integrated into the variator connection.In an alternative embodiment, the drive is mechanically connected to the central shaft via a separate spur gear stage, which is separate from the variator connection.

[0018] In one embodiment, a driving range available via the first gear ratio of the transmission in the forward direction overlaps with a driving range available via the second gear ratio of the transmission in the forward direction. This can mean that specific vehicle speeds, i.e., specific gear ratios, such as reciprocal ratios, can be set using both driving ranges. During a shift in the drive unit, when switching from one of the overlapping driving ranges to the other, both driving ranges can have the same variator position. For example, during the shift in the overlapping range, both driving ranges can have a variator position corresponding to a neutral position, in which, for example, no power can be transmitted via the variator.This allows switching between the two overlapping driving ranges without adjusting the variator. Therefore, the present embodiment enables fast switching with low power loss.

[0019] In one embodiment, the transmission assembly comprises at least one planetary gear set, for example, several planetary gear sets, and at least one switching element, for example, several switching elements, for switching a driving range. In another embodiment, the transmission assembly is configured to provide four different driving ranges with four planetary gear sets and five switching elements. The planetary gear set and the switching element can be coaxial with each other. Viewed from the drive unit, the switching element of the transmission assembly is arranged along the central shaft upstream of the planetary gear set of the transmission assembly. In another embodiment, the transmission assembly comprises several planetary gear sets, for example, three planetary gear sets, and several switching elements, for example, four switching elements, wherein the four switching elements are arranged upstream of the three planetary gear sets in the direction of the central shaft, viewed from the drive unit.

[0020] In one embodiment, the gear assembly comprises a first planetary gear set with a first sun gear, a first planet carrier with a planet gear rotatably mounted thereon, and a first ring gear. Furthermore, in this embodiment, the gear assembly comprises a second planetary gear set with a second sun gear, a second planet carrier with a planet gear rotatably mounted thereon, and a second ring gear. In addition, in this embodiment, the gear assembly comprises a third planetary gear set with a third sun gear, a third planet carrier with a planet gear rotatably mounted thereon, and a third ring gear. Furthermore, the gear assembly in this embodiment comprises a fourth planetary gear set with a fourth sun gear, a fourth planet carrier with a planet gear rotatably mounted thereon, and a fourth ring gear. All of the planetary gear sets can be configured as negative planetary gear sets.Furthermore, the planetary gear sets can all be arranged coaxially with each other.

[0021] In this embodiment, the transmission assembly can have a first switching element, a second switching element, a third switching element, a fourth switching element, and a fifth switching element. Some or all of the switching elements can be designed as friction-fit switching elements, for example, as multi-plate clutches. In this embodiment, the transmission assembly can have a central shaft that is mechanically connected to the drive of the drive unit via a spur gear stage, for example, a single-stage spur gear stage. Furthermore, the transmission assembly can have an output shaft that is mechanically connected to the transmission, for example, via a spur gear stage, which can be single-stage. In this embodiment, the central shaft of the transmission assembly can be permanently and rotationally fixed to the second planet carrier and the first ring gear.Furthermore, the first sun gear can be mechanically connected to the central shaft via the variator. For this purpose, a first spur gear stage, for example a single-stage spur gear stage, can be provided, which is mechanically connected to a constant unit of the variator. An adjustment unit of the variator, which is mechanically connected to the constant unit, can be mechanically connected to the central shaft of the transmission assembly via a single-stage or two-stage spur gear stage.

[0022] The first planet carrier can be permanently and non-rotatably connected to the second ring gear and the third planet carrier. The second sun gear can be permanently and non-rotatably connected to the third sun gear. The third ring gear can be non-rotatably connected to the fourth sun gear via the first switching element. Furthermore, the third sun gear can be non-rotatably connected to the fourth sun gear via the second switching element. The third planet carrier can be non-rotatably connected to the fourth planet carrier via the third switching element. Furthermore, the fourth planet carrier can be non-rotatably connected to the fourth sun gear via the fourth switching element to lock the fourth planet gear set. In addition, the fourth ring gear can be non-rotatably fixed to a housing of the drive unit, for example, a housing of the gearbox assembly, via the fifth switching element. The fourth planet carrier can, in turn, be permanently and non-rotatably connected to the output shaft.This allows for a transmission assembly that efficiently and effectively offers four different driving ranges, in each of which the gear ratio can be continuously varied by means of the variator. The gearbox provides driving ranges in both forward and reverse directions. Furthermore, it allows for a wider gear ratio spread in the forward direction by providing a gear for high speeds and another gear for high tractive effort.

[0023] In one embodiment, the drive unit includes a control device that may have one or more separately provided control units. The control device can be configured, i.e., specifically set up, for example, programmed, to open the forward shift element and close the reverse shift element when the shift ratio described above is present. This opening and closing can occur simultaneously and, for example, under load. The shifting device can already be set so that the second gear ratio for the forward direction is preselected. By opening and closing the forward and reverse shift elements, it is therefore possible, for example, to shift from first gear to second gear in the forward direction in the transmission under load.Simultaneously or alternatively, with a time delay, the control unit can also actuate at least one of the switching elements of the transmission assembly described above to change the driving range provided by the transmission assembly. It is possible to actuate the variator during the changeover. However, it is also possible that the variator is not actuated during the changeover. Consequently, this enables simple, fast, and efficient switching between forward gears in the transmission within this embodiment.

[0024] Furthermore, the present invention relates to a vehicle with a drive unit according to one of the embodiments described above. The vehicle may be a work or agricultural machine or a commercial vehicle, for example, a universal motor unit, which may be configured according to the above descriptions. The present invention may also relate to a drive train for a vehicle, which may include a drive unit according to one of the embodiments described above and a motor unit, for example, an internal combustion or electric motor. The drive train may also include a front and / or rear axle mechanically connected to the output of the drive unit via a differential. For details regarding the design and advantages of the individual features, reference is made to the above descriptions in connection with the drive unit. Brief description of the characters Fig. Figure 1 shows a drive device for a vehicle according to an embodiment of the present invention. Fig. 2 shows a vehicle with a drive unit to Fig. 1. Fig. Figure 3 shows a connection of a drive to the drive unit according to one embodiment. Fig. Figure 4 shows a circuit diagram of the drive unit according to Fig. 1. Fig. 5 shows the driving ranges of the drive unit Fig. 1. Detailed description of embodiments

[0025] Fig. Figure 2 shows a vehicle 100 according to an embodiment of the present invention. In the present embodiment, the vehicle 100 is a work machine or commercial vehicle, for example, in the form of a universal motor unit. The vehicle 100 has a drive train 1 with a drive unit 2. The drive unit 2 has a drive 6 and an output 5. In addition to the drive unit 2, the drive train 1 comprises a motor unit 3, which in the present embodiment is designed as an internal combustion engine. In an alternative embodiment, the motor unit 3 is designed as an electric motor. The drive 6 of the drive unit 2 is permanently and rotationally fixed to the motor unit 3. Furthermore, the drive train 1 comprises propulsion elements 4, which are designed as wheels. The wheels 4 are mechanically connected to the output 5 of the drive unit 2.In the present embodiment, the wheels 4 are connected via a transverse differential (shown in . Fig. 1) mechanically connected to the output 5. A torque transmission path is formed between the input 6 and the output 5 of the drive unit 2, in which a gear assembly 7 and a gearshift 8 are provided one after the other in this sequence, as shown in Fig. 1 shown.

[0026] The transmission assembly 7 is designed as a continuously variable, power-split transmission with a variator 10. In the present embodiment, the variator 10 is designed as a hydrostatic variator. In an alternative embodiment, the variator 10 is designed as an electric variator. The variator 10 has a constant-speed unit 10.1 and an adjustment unit 10.2, which in the present embodiment are hydraulically interconnected. Furthermore, the transmission assembly 7 of the drive unit 2 comprises a first planetary gear set 11 with a first sun gear 12, a first planet carrier 13 with planet gears 14 rotatably mounted thereon, and a first ring gear 15. The transmission assembly 7 also comprises a second planetary gear set 16 with a second sun gear 17, a second planet carrier 18 with planet gears 19 rotatably mounted thereon, and a second ring gear 20.Furthermore, the gear assembly 7 comprises a third planet gear set 21 with a third sun gear 22, a third planet carrier 23 with planet gears 24 rotatably mounted thereon, and a third ring gear 25. The gear assembly 7 also comprises a fourth planet gear set 26 with a fourth sun gear 27, a fourth planet carrier 28 with planet gears 29 rotatably mounted thereon, and a fourth ring gear 30. The first 11, second 16, third 21, and fourth planet gear sets 26 are each designed as negative planet gear sets.

[0027] Furthermore, the transmission assembly 7 comprises a first switching element 31, a second switching element 32, a third switching element 33, a fourth switching element 34, and a fifth switching element 35. The first 31, second 32, third 33, and fourth 34 switching elements are each designed as friction-fit switching elements, in this case as multi-plate clutches. The fifth switching element 35 is designed as a brake, in this case as a friction-fit brake. The four planetary gear sets 11, 16, 21, and 26, as well as the five switching elements 31, 32, 33, 34, and 35, are each coaxial with each other and coaxial with a central shaft 36 of the transmission assembly 7. The first switching element 31 and the second switching element 32 are located at the same axial height. Likewise, the third switching element 33 and the fourth switching element 34 are located at the same axial height.Viewed from the motor-side end in the direction of the central shaft 36, the fourth planetary gear set 26 follows the fifth switching element 35. The fourth planetary gear set 26 is followed by the third and fourth switching elements 33, 34, which in turn are followed by the first and second switching elements 31, 32. The third planetary gear set 21 follows the first and second switching elements 31, 32, followed by the second planetary gear set 16. The first planetary gear set 11 follows the second planetary gear set 16. A single-stage spur gear stage 37 follows the first planetary gear set 11, via which the constant unit 10.1 of the variator 10 is mechanically connected to the first sun gear 12 of the first planetary gear set 11.Between the motor device 3 and the fifth switching element 35, a two-stage spur gear stage 38 is provided with an intermediate gear 39 forming a gear element, which meshes with a fixed gear 40 provided on the central shaft 36 and a fixed gear 41 permanently connected to the adjusting unit 10.2 in a rotationally fixed manner.

[0028] In the present embodiment, the motor assembly 3 is permanently and rotationally fixedly connected to the intermediate gear 39 of the two-stage spur gear stage 38. Thus, the drive 6 of the drive assembly 2 is arranged axially parallel to the central shaft 36 and permanently and rotationally fixedly connected to the intermediate gear 39. Furthermore, the drive assembly 2 comprises an output shaft 42, which is designed as a hollow shaft and is arranged coaxially with the central shaft 36. The output shaft 42 is arranged in the direction of the central shaft 36 between the two-stage spur gear stage 38 and the fourth planetary gear set 26. The gearshift 8 is mechanically connected to the output shaft 42 by means of a single-stage spur gear stage 43, as described below.

[0029] In the present embodiment, the central shaft 36 is permanently and non-rotatably connected to the second planet carrier 18 of the second planet gear set 16 and to the first ring gear 15 of the first planet gear set 11. The first planet carrier 13 of the first planet gear set 11 is permanently and non-rotatably connected to the second ring gear 20 of the second planet gear set 16. The second sun gear 17 of the second planet gear set 16 is permanently and non-rotatably connected to the third sun gear 22 of the third planet gear set 21. The third planet carrier 23 of the third planet gear set 21 is permanently and non-rotatably connected to the second ring gear 20 of the second planet gear set 16. The third ring gear 25 of the third planet gear set 21 can be non-rotatably connected to the fourth sun gear 27 of the fourth planet gear set 26 via the first switching element 31.Furthermore, the third sun gear 22 of the third planetary gear set 21 can be non-rotatably connected to the fourth sun gear 27 of the fourth planetary gear set 26 via the second switching element 32. The third planet carrier 23 of the third planetary gear set 21 can be non-rotatably connected to the fourth planet carrier 28 of the fourth planetary gear set 26 via the third switching element 33. Furthermore, the fourth planet carrier 28 of the fourth planetary gear set 26 can be non-rotatably connected to the fourth sun gear 27 of the fourth planetary gear set 26 via the fourth switching element 34 to lock the fourth planetary gear set 26. The fourth ring gear 30 of the fourth planetary gear set 26 can be non-rotatably fixed to a housing 44 of the drive unit 2 via the fifth switching element 35. The fourth planet carrier 28 of the fourth planetary gear set 26 is in turn permanently non-rotatably connected to the output shaft 42.As previously described, the variator 10 is mechanically connected to the first sun gear 12 of the first planet gear set 11 via the first spur gear stage 37 and to the central shaft 36 via the two-stage spur gear stage 38.

[0030] The gearshift 8 comprises an input shaft 45, a forward shift element 46, a reverse shift element 47, a first single-stage spur gear stage 48, a two-stage spur gear stage 49, a second single-stage spur gear stage 53, and an output shaft 50. The single-stage spur gear stage 43, for mechanically connecting the output shaft 42 of the transmission assembly 7 to the gearshift 8, has a fixed gear 51 provided on the output shaft 42, which meshes with a mating gear 52 permanently fixed to rotation on the input shaft 45 of the gearshift 8. The forward shift element 46 and the reverse shift element 47 are each designed as friction-fit shift elements. By actuating the forward or reverse shift element 46, 47, the direction of rotation of the output shaft 50 can be selectively set for a specific direction of rotation of the input shaft 45.In the present embodiment, the forward switching element 46 and the reverse switching element 47 are each designed as individual switching elements and are provided separately from each other both locally and functionally.

[0031] The input shaft 45 is mechanically connected to the output shaft 50 via the first single-stage spur gear stage 48 and the forward shift element 46. In the present embodiment, the forward shift element 46 is arranged coaxially with the output shaft 50. In the torque transmission path between the output shaft 42 and the output shaft 50, the forward shift element 46 is thus located downstream of the first single-stage spur gear stage 48. Furthermore, the input shaft 45 is mechanically connected to an intermediate shaft 54 ​​via the reverse shift element 47, which is arranged coaxially with the input shaft 45. The reverse shift element 47 is also arranged coaxially with the input shaft 45 in this embodiment. In addition, the transmission 8 includes a shifting device 55, which in this embodiment is designed as a synchronizer.In the direction of the input shaft 45 and thus in the direction of the central shaft 36, the reverse switching element 47 and the forward switching element 46 are arranged on opposite sides of the switching device 55.

[0032] The intermediate shaft 54 ​​can be selectively connected to the output shaft 50 via the synchronizer 55, either via the second single-stage spur gear stage 53 or via the two-stage spur gear stage 49. In the present embodiment, the second single-stage spur gear stage 53 has a gear ratio of less than 1, for example, between 0.5 and 0.9. The gear engaged via this stage is therefore a gear for high driving speeds. The first single-stage spur gear stage 48, in the present embodiment, has a gear ratio greater than 1, for example, between 1.5 and 1.9. The gear engaged via this stage is therefore a gear for high tractive forces. A fixed gear is provided on the output shaft 50, which in this embodiment forms the output 5 of the drive unit 2. As described above, the output 5 is mechanically connected to the wheels 4 of the vehicle 100 via a transverse differential.

[0033] In the present embodiment, the transmission assembly 7 and the gearshift 8 of the drive unit 2 are arranged parallel to each other. The shifting device 55 and the reverse shifting element 47 are arranged coaxially, while the forward shifting element 46 is arranged parallel to the shifting device 55 and the reverse shifting element 47. This allows for a drive unit 2 that is optimized for installation space in a universal motor device. The shifting elements 31, 32, 33, 34, and 35 of the transmission assembly 7 can provide a plurality of driving ranges, for example, four driving ranges, in which different fixed gear ratios can be engaged between the central shaft 36 and the output shaft 42. Within the different driving ranges, the gear ratio can be continuously varied by means of the variator 10.The forward shift element 46 of the gearbox allows all these travel ranges of the gearbox assembly 7 to be provided with the gear described above for high tractive forces in the forward direction. Furthermore, the shift device 55 and the reverse shift element 47 allow all these travel ranges of the gearbox assembly 7 to be provided with the gear described above for high forward speeds. This enables the drive unit 2 to achieve an optimal balance between high tractive forces at low speeds and high speeds. Such a drive unit 2 is particularly advantageous when used in a universal motor device. Moreover, the shift device 55 and the reverse shift element 47, with the two-stage spur gear stage 49 described above, also allow all these travel ranges of the gearbox assembly 7 to be provided in reverse.

[0034] Furthermore, the drive unit 2 includes a power take-off unit 60, which is mechanically operatively connected to the central shaft 36 of the transmission assembly 7. The power take-off unit 60 comprises a first power take-off 61, a second power take-off 62, and a friction-fit switching element 63. The friction-fit switching element 63 is mechanically operatively connected to the central shaft 36 via a single-stage spur gear stage 64. The switching element 63 is also rotationally fixed to a fixed gear 65. By actuating the switching element 63, the fixed gear 65 can be mechanically operatively connected to the central shaft 36 via the single-stage spur gear stage 64. An intermediate gear 66 meshes with the fixed gear 65, to which the second power take-off 62 is permanently rotationally fixed. A mating gear 67 meshes with the intermediate gear 66, to which the first power take-off 61 is permanently rotationally fixed.The gears 65, 66 and 67 are designed such that the auxiliary drives 61 and 62 rotate at different speeds, in this case such that the second auxiliary drive 62 rotates at a higher speed than the first auxiliary drive 61.

[0035] In the Fig. In the drive unit 2 shown in Figure 1, the gearshift 8 and the transmission assembly 7 are arranged one behind the other in the direction of the central shaft 36 and do not essentially overlap. This allows for a space-optimized drive unit 2. Viewed from the transmission assembly 7, the first single-stage spur gear stage 48 is arranged in the direction of the central shaft 36 upstream of the two-stage spur gear stage 49, which is located upstream of the second single-stage spur gear stage 53. Furthermore, viewed from the transmission assembly 7 in the direction of the central shaft 36, the forward shift element 46 is located upstream of the shift device 55, which is located upstream of the reverse shift element 47.

[0036] At the in Fig. In the embodiment shown in Figure 1, the drive 6 is permanently and rotationally fixedly connected to the gear element 39, which is designed as an intermediate gear. In an alternative embodiment, Fig. In the embodiment shown in Figure 3, the central shaft 36 is mechanically connected to the variator 10 via a single-stage spur gear stage 38'. A fixed gear 40' is arranged on the central shaft 36, which meshes with a mating gear 41' that is permanently and rotationally fixed to the adjusting unit 10.2 of the variator 10. Furthermore, on the side of the spur gear stage 38' facing away from the adjusting unit 10.2, another fixed gear 39.1' is provided on the central shaft 36, which meshes with a mating gear 39'. The drive 6 is permanently and rotationally fixed to the mating gear 39' and is thus also arranged axially parallel to the central shaft 36. The rest of the Fig. 3 embodiment shown as in Fig. 1. The embodiment shown is designed as shown.

[0037] By actuating the various switching elements 31, 32, 33, 34 and 35 of the transmission assembly 7, different driving ranges can be provided by the transmission assembly 7. More precisely, the drive unit 2 can be used to select the following: Fig. The 4 driving ranges shown can be selected. Driving ranges I, II, III and IV are forward driving ranges in which the gear for high tractive effort is engaged in the gearbox 8. Driving ranges V and VI are forward driving ranges in which the gear for high speeds is engaged in the gearbox 8. The in Fig. The control unit 9 shown is configured to switch the switching elements of the drive unit 2 described above for switching the travel ranges I-VI in the forward direction and the travel ranges I-IV in the reverse direction described below. For this purpose, the control unit 9 has interfaces to be able to communicate with the respective switching elements accordingly.

[0038] To shift into driving range I, the first shift element 31, the fifth shift element 35, and the forward shift element 46 are actuated. The shifting device 55 can be in position 55-1, in which it shifts the gear for high driving speeds even though no torque is transmitted through it. To shift into driving range II, the second shift element 32, the fifth shift element 35, and the forward shift element 46 are actuated. The shifting device 55 can be in position 55-1, in which it shifts the gear for high driving speeds even though no torque is transmitted through it. To shift into driving range III, the second shift element 32, the third shift element 33, and the forward shift element 46 are actuated. The shifting device 55 can be in position 55-1, in which it shifts the gear for high driving speeds even though no torque is transmitted through it.To engage the fourth driving range IV, the second shift element 32, the fourth shift element 34, and the forward shift element 46 are actuated. The shifting device 55 can be in position 55-1, in which it shifts the gear for high driving speeds, even though no torque is transmitted through it.

[0039] In Fig.Figure 5 shows the forward travel ranges I-VI plotted against the reciprocal transmission ratio irez, which correlates with the travel speed. Also shown are some efficiency curves η of the drive unit 2 in the respective travel ranges I-VI. As can be seen from the diagram, the efficiency η fluctuates within each travel range, with an efficiency maximum occurring approximately in the middle of each range. This is because, as described above, the drive unit 2 switches a fixed mechanical transmission ratio between the drive 6 and the output 5 in each travel range. Within the respective travel ranges I-VI, however, the transmission ratio is continuously adjusted by pivoting the adjustment unit 10.2 of the variator 10. At the beginning and end of each travel range, the adjustment unit 10.2 is essentially in a maximum deflection position, which is associated with a minimum efficiency.The adjustment unit 10.2 is in a zero position approximately in the middle of each driving range, so that the hydraulic power path via the variator 10 has a minimal influence on the overall transmission ratio and therefore a maximum efficiency is achieved.

[0040] Driving ranges IV and V are now coordinated such that they overlap with respect to the reciprocal ratio irez. In the present embodiment, driving ranges IV and V overlap in such a way that they exhibit a maximum efficiency at essentially the same reciprocal ratio irezm. This means that the adjusting unit 10.2 of the variator 10 has a zero position in driving ranges IV and V at essentially the same reciprocal ratios irezm.

[0041] If the drive unit 2 is accelerating in the fourth driving range IV and is to be shifted into the fifth driving range V, the control unit 9 opens the forward shift element 46 and simultaneously closes the reverse shift element 47 upon reaching the reciprocal gear ratio irezm. The shifting device 55 is already in the pre-selected position 55-1 for shifting the gear in the forward direction for high speeds. At the same time, the control unit 9 shifts the transmission assembly 7 from the shift position in the fourth driving range IV to the shift position of the third driving range III described above. The shift from driving range IV to driving range V is a power shift, which is possible due to the shift elements 31, 32, 33, 34, 35, 46 and 47, which are designed as multi-plate clutches.Furthermore, switching is efficient without changing the position of the variator 10, since the variator 10 is in the zero position in both driving ranges IV and V. To switch to the sixth driving range VI, the gearshift 8 and the reverse shift element 47 remain in the position of the fifth driving range V. The shift elements 31, 32, 33, 34, and 35 are switched to the shift positions of the fourth driving range IV as described above. To switch driving ranges I-IV in reverse, the shift elements 31, 32, 33, 34, and 35 of the transmission assembly 7 are switched in the forward direction according to the respective driving ranges. Additionally, the shift device 55 is in position 55-2, and the reverse shift element 47 is actuated. Reference sign 1 Powertrain 2 Drive unit 3 Motor unit 4 wheels 5 Drive 6 Drive 7 Gearbox assembly 8-speed manual transmission 9 Control unit 10 Variator 10.1, 10.2 Constant or adjusting unit 11, 16, 21, 26 Planetary gear set 12, 17, 22, 27 Sun wheel 13, 18, 23, 28 Planetary carriers 14, 19, 24, 29 planetary gear 15, 20, 25, 30 ring gear 31, 32, 33, 34, 35, 63 Switching element 36 Central shaft 37, 38, 38', 43, 48, 49, 53, 64 Spur gear stage 39, 66 intermediate wheel 40, 41, 51, 52, 65, 67, 39', fixed or counter wheel 39.1', 40', 41' 42 Output wave 44 Gearbox housing 46, 47 Forward and reverse switching element 45 Input shaft 50th issue wave 54 Intermediate shaft 55 Synchronization 60 Auxiliary drive unit 61, 62 Auxiliary drive 100 vehicles I, II, III, IV, V, VI driving range reciprocal translation irezm Maximum reciprocal translation 55-1, 55-2 Switch position Synchronization η efficiency QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2009 002 808 A1

[0002]

Claims

[1] Drive unit (2) for a vehicle (100) comprising a drive (6) for mechanical connection with a motor unit (3), an output (5) for mechanical connection with a propulsion element (4), a torque transmission path for transmitting torque from the drive (6) to the output (5), a transmission assembly (7) comprising a variator (10) for providing multiple driving ranges, wherein the transmission assembly (7) comprises a central shaft (36) and an output shaft (42), and a gearshift transmission (8) comprising a forward shift element (46) for mechanically connecting the output shaft (42) to the output (5) with a first gear ratio (48) for forward travel and high tractive forces,a switching device (55) for selectively switching between a second gear ratio (53) for the forward direction for high driving speeds and a gear ratio (49) for a reverse direction, and a reverse switching element (47) for mechanically connecting the output shaft (42) to the switching device (55), wherein the transmission assembly (7) and the gearshift mechanism (8) are provided in the torque transmission path and the forward switching element (46) and the reverse switching element (47) are each designed as individual switching elements. [2] Drive device (2) according to claim 1, characterized by , that the forward switching element (46) and the reverse switching element (47) are each designed as friction-locked switching elements and the switching device (55) as a synchronous switching device. [3] Drive device (2) according to claim 1 or 2, characterized by, that the reverse switching element (47) and the switching device (55) are arranged coaxially to each other and spaced parallel to the central shaft (36) of the transmission assembly (7) and the forward switching element (46). [4] Drive device (2) according to one of the preceding claims, characterized by , that in the direction of the central shaft (36) the reverse switching element (47) and the forward switching element (46) are arranged on opposite sides of the switching device (55). [5] Drive device (2) according to one of the preceding claims, characterized by , that the drive (6) is arranged parallel to the axis at a distance from the central shaft (36), the central shaft (36) is mechanically connected to the variator (10) via a gear element (39), and by the fact that the drive (6) is mechanically connected to the gear element (39). [6] Drive device (2) according to any of the preceding claims, characterized by, that a driving range (IV) available in the forward direction via the first gear ratio of the gearshift (8) and a driving range (V) available in the forward direction via the second gear ratio of the gearshift (8) overlap in such a way that both driving ranges (IV, V) have the same variator position when the drive unit (2) is switched (irezm), so that switching between the driving ranges (IV, V) can take place without adjusting the variator (10). [7] Drive device (2) according to one of the preceding claims, characterized by , that the transmission assembly (7) has at least one planetary gear set (11; 16; 21; 26) and at least one switching element (31; 32; 33; 34; 35) for switching a driving range, wherein, viewed from the drive (6), the switching element (31; 32; 33; 34; 35) of the transmission assembly (7) is arranged along the central shaft (36) in front of the planetary gear set (11; 16; 21; 26) of the transmission assembly (7). [8] Drive device (2) according to one of the preceding claims, characterized by, that the transmission assembly (7) comprises a first planetary gear set (11) with a first sun gear (12), a first planet carrier (13) with a planet gear (14) rotatably mounted thereon and a first ring gear (15), a second planetary gear set (16) with a second sun gear (17), a second planet carrier (18) with a planet gear (19) rotatably mounted thereon and a second ring gear (20), a third planetary gear set (21) with a third sun gear (22), a third planet carrier (23) with a planet gear (24) rotatably mounted thereon and a third ring gear (25), a fourth planetary gear set (26) with a fourth sun gear (27), a fourth planet carrier (28) with a planet gear (29) rotatably mounted thereon and a fourth ring gear (30), a first switching element (31), a second switching element (32), a third switching element (33), a fourth switching element (34) and a fifth switching element (35) exhibitswherein the central shaft (36) is mechanically operatively connected to the drive (6) via a spur gear stage (38; 39', 39.1') and permanently non-rotatably connected to the second planet carrier (18) and the first ring gear (15), the first sun gear (12) is mechanically operatively connected to the central shaft (36) via the variator (10), the first planet carrier (13) is permanently non-rotatably connected to the second ring gear (20) and the third planet carrier (23), the second sun gear (17) is permanently non-rotatably connected to the third sun gear (22), the third ring gear (25) can be non-rotatably connected to the fourth sun gear (27) via the first switching element (31), the third sun gear (22) can be non-rotatably connected to the fourth sun gear (27) via the second switching element (32), the third planet carrier (23) can be non-rotatably connected to the fourth planet carrier via the third switching element (33). (28) can be connected in a rotationally fixed manner,the fourth planet carrier (28) can be connected to the fourth sun gear (27) via the fourth switching element (34) in a rotationally fixed manner, the fourth ring gear (30) can be fixed to a gearbox housing (44) via the fifth switching element (35), and the fourth planet carrier (28) is permanently connected to the output shaft (42) in a rotationally fixed manner. [9] Drive device (2) according to claims 6 and 8, characterized by , that the drive device (2) has a control device (9) which is configured to open the forward switching element (46), close the reverse switching element (47) and actuate at least one of the switching elements (31; 32; 33; 34; 35) of the transmission assembly (7) when the switching ratio (irezm) is present. [10] Vehicle (100) with a drive unit (2) according to one of the preceding claims.

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