Patent ID: 12228196

DETAILED DESCRIPTION OF THE DRAWINGS

In the depiction ofFIG.1, an electric drive system labelled1as a whole can be seen. This electric drive system has a first electric engine2and a second electric engine3. A rotor of the first electric engine2is non-rotatably connected to a first input shaft4and a rotor of the second electric engine3is non-rotatably connected to a second input shaft5. The input shafts4,5are part of a main group6of a group transmission7. An output shaft8of the main group6of the group transmission7is coupled with a range group9having a planetary gear set10. The output shaft8of the main group6is here connected to a sun shaft11of the planetary transmission10of the range group9. An output drive shaft13of the group transmission7is driven via a planetary carrier12, the output drive shaft meshing with a differential gear15via a gear wheel14, the differential gear being non-rotatably connected in turn to a differential cage of a differential transmission16. Two driven wheels17of an electrically driven axle of a vehicle, in particular a commercial vehicle, indicated in exemplary form, are finally driven via the differential transmission16. The differential transmission16can be attributed to general knowledge of the art, such that no further detail need be given regarding the differential transmission. The differential transmission is depicted here in exemplary form as a differential transmission16having a switchable differential lock.

The output drive shaft14, which is arranged coaxially to the sun shaft11, is preferably designed as a hollow shaft, and arranged surrounding the sun shaft11designed as a full shaft.

With regard to a torque flow starting from the electric engines2,3to the wheels17, the electric engines2,3, the main group6, the range group9, the differential gear15and the wheels17are arranged one after the other in the specified order.

A first idler wheel18and a second idler wheel19are arranged on the first input shaft4of the main group6. A third idler wheel20and a fourth idler wheel21are arranged on the second input shaft5. First switching elements S1or S1′ and second switching elements S2or S2′ are additionally arranged on the respective input shaft4,5such that they can respectively non-rotatably connect the idler wheels18,19or20,21arranged coaxially to the respective input shaft4,5to the respective input shaft4,5. The switching elements S1/S2and S1′/S2′ are preferably designed as dual switching elements having a neutral position as depicted here. They are actuated via a single actuator per dual switching element S1/S2.

The first idler wheel18and the third idler wheel20of the respective input shaft4,5mesh with a first fixed gear22on the output shaft. The second idler wheel19and the fourth idler wheel21mesh with a second fixed gear23on the output shaft8. The input shafts4,5and the output shaft8are exclusively connected to one another via these two fixed gears22,23. Unlike in the wheelset diagram shown here, they are not usually arranged in a plane. A third fixed gear24can thus be placed axially between the two fixed gears22,23, the third fixed gear meshing with a fourth fixed gear25on the sun shaft11of the planetary gear set10, and thus driving a sun26of the planetary gear set10when the output shaft8of the main group6of the group transmission7is driven. The fourth fixed gear25is permanently non-rotatably connected to the sun26of the planetary gear set10. The planetary gear set10used as a range group9is thus driven by the output shaft8of the main group6via the third gear wheel24and the fourth gear wheel25. In the depiction of the wheelset plan, the fact that the third fixed gear24permanently meshes with the fourth fixed gear25is correspondingly indicated by a dashed line.

The gear wheel14is advantageously arranged axially between the fourth fixed gear25and the planetary gear set10.

The fourth fixed gear25and either the first switching element S1, S1′ or the second switching element S2, S2′ are advantageously arranged axially overlapping one another, such that a very compact arrangement results overall.

The term “axial” relates in this case to an axial direction, and the axial direction is meant as the direction of an axis of rotation of the output shaft8or of the axis of rotation of the first input shaft4or of the axes of rotation of other shafts arranged in parallel hereto.

Planetary gears27on the planetary carrier12of the planetary gear set10correspondingly mesh with the sun26and a ring gear28as a third element of the planetary gear set10. The drive thus occurs via the sun26as a first element, the output drive via the planetary gears27or their planetary carrier12, which represents the second element of the planetary gear set. The ring gear28can be stalled via a brake switching element S3as required. The ring gear28is then non-rotatably connected to the housing of the group transmission7, for example, and correspondingly does not rotate. This yields a first transmission ratio of the range group9. It is also possible to connect the sun26as a first element of the planetary gear set10to the ring gear28or to block it via a blocking switching element S4, which can in turn be combined with the brake switching element S3as a dual switching element. Another transmission ratio thus results between the sun shaft11acting as an input shaft in the range group and the planetary gear carrier12connected to the output drive shaft13.

The planetary gear set10is advantageously arranged axially overlapping the first electric engine2and also axially overlapping the second electric engine3.

The term “axially overlapping” with regard to two axially overlapping components should be understood to mean that at least one part of the one component and at least one part of the other component are arranged in a same axial region. The same axial region is defined by a same axial coordinate.

The output shaft8, the sun shaft11and an axis of rotation of the differential gear15are advantageously substantially arranged in a shared plane. The two input shafts4,5are advantageously arranged in a further plane, wherein the further plane is arranged substantially perpendicularly to the shared plane.

In the depiction ofFIG.2, the four individual switchable gears are indicated in principle using a switching matrix. The respective gear is in the first column, the position of the first switching element S1or the first switching element S1′ on the respective input shaft4,5is in the second column. The second column correspondingly shows the second switching element S2or the second switching element S2′, the third column the state of the third switching element, and thus of the brake switching element S3, and the fourth column the state of the blocking switching element S4. In the first gear, the switching element S1and/or the switching element S1′ are engaged, and the first idler wheel18or the third idler wheel20are thus connected to the respective input shaft4or5, depending on which of the two electric engines2,3is driving, wherein both can also drive when required. The brake switching element S3is simultaneously switched, such that the ring gear28is thus non-rotatably stalled on the housing of the group transmission7, for example. It is now possible to change from the first gear into the second gear, even under load, by releasing the switching element S1or S1′ and engaging the switching element S2or S2′ without this switching position changing within the range group9, wherein this switching process can be synchronized as required via the electric engines2,3. It is thus possible to switch between the gears1,2or3,4very comfortably as required, and within the respective position of the range group9, to make it such that the two gears1,2or3,4dependent thereon can be switched under load. For this purpose, and this is a considerable advantage in relation to the prior art, no friction switching element is necessary, and instead, the switching elements S1and S2or S1′ and S2′ can be designed as form-fit switching elements, in particular as claw switching elements. For the third and fourth gear, this switching diagram repeats again, wherein unlike in gears1and2, the range group9is now switched such that the blocking switching element S4is active, and the brake switching element S3is correspondingly released.

By positioning the two electric engines2,3on different input shafts4,5, and thus ultimately on different gears, virtual intermediate gears can additionally be enabled by both electric engines2,3driving differently on the output shaft8. The intermediate gears that can thus be obtained can in particular improve the driving performance for heavy vehicles, such as in particular commercial vehicles. In the regular operation, which is very frequently a partial load operation, the operation of one of the two electric engines2,3is then sufficient, such that the respective other electric engine2,3and the parts of the main group6of the group transmission7connected thereto do not have to be used, such that wear can be reduced, efficiency can be increased and the lifespan of the structure can be lengthened.