Gear unit for an electric powertrain
A gear unit for a powertrain of a motor vehicle includes a drive shaft, a driven shaft, first and second planetary gearsets and first and second shifting elements. The first shifting element drivingly connects the drive shaft to an input of the first planetary gearset, and the second shifting element drivingly connects the drive shaft to an input of the second planetary gearset. An output element of the second planetary gearset is connected to the input of the first planetary gearset to be fixed with respect to rotation relative to it, and an output of the first planetary gearset is at least indirectly drivingly connected to the driven shaft. A shared element is fixed with respect to relative rotation and, with an inner toothing, forms a ring gear of the first planetary gearset and, with an outer toothing, forms a sun gear of the second planetary gearset.
1. A gear unit ( 100 , 200 , 300 , 400 ) for a powertrain ( 500 , 600 , 700 , 800 ) of a motor vehicle ( 900 ), having a drive shaft ( 1 ) and a driven shaft ( 2 ) and having a first planetary gearset ( 3 ) and a second planetary gearset ( 4 ) and at least a first shifting element (S 1 ) and a second shifting element (S 2 ), wherein the first shifting element (S 1 ) drivingly connects the drive shaft ( 1 ) to an input element of the first planetary gearset ( 3 ), and the second shifting element (S 2 ) drivingly connects the drive shaft ( 1 ) to an input element of the second planetary gearset ( 4 ), and wherein an output element of the second planetary gearset ( 4 ) is connected to the input element of the first planetary gearset ( 3 ) so as to be fixed with respect to rotation relative to it, and wherein an output element of the first planetary gearset ( 3 ) is at least indirectly drivingly connected to the driven shaft ( 2 ), and further comprising a shared element ( 5 ) fixed with respect to relative rotation and which, with an inner toothing ( 5 . 1 ), forms a ring gear of the first planetary gearset ( 3 ) and, with an outer toothing ( 5 . 2 ), forms a sun gear of the second planetary gearset ( 4 ).
2. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein the shared element ( 5 ) is integrally formed.
3. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein the first planetary gearset ( 3 ) and the second planetary gearset ( 4 ) are arranged one above the other in radial direction and at least overlapping in axial direction.
4. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein the input element of the first planetary gearset ( 3 ) is a sun gear ( 3 . 1 ), and the input element of the second planetary gearset ( 4 ) is a ring gear ( 4 . 1 ) or a planet carrier ( 4 . 2 ).
5. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein the second planetary gearset ( 4 ) has a lower stationary transmission ratio than the first planetary gearset ( 3 ).
6. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein at least one of the first and second planetary gearsets ( 3 , 4 ) is configured as a positive planetary gearset ( 3 ).
7. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , further comprising a third shifting element (S 3 ) configured to drivingly connect the drive shaft ( 1 ) to the driven shaft ( 2 ).
8. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein at least one of the shifting elements (S 1 , S 2 , S 3 ) is constructed as frictionally engaging shifting element (S 1 , S 2 , S 3 ).
9. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein at least one of the shifting elements (S 1 , S 2 , S 3 ) is constructed as positively engaging shifting element (S 1 , S 2 , S 3 ).
10. The gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 , wherein a third planetary gearset ( 17 ) is arranged between the drive shaft ( 1 ) and the shifting elements (S 1 , S 2 , S 3 ) or between the output element of the first planetary gearset ( 3 ) and the driven shaft ( 2 ) to form a fixed transmission ratio.
11. A powertrain ( 500 , 600 , 700 , 800 ) comprising:
the gear unit ( 100 , 200 , 300 , 400 ) according to claim 1 ; and
at least one electric machine ( 12 ).
12. The powertrain ( 500 , 600 , 700 , 800 ) according to claim 11 , wherein the at least one electric machine ( 12 ) is arranged coaxial to the first planetary gearset ( 3 ) and second planetary gearset ( 4 ).
13. The powertrain ( 500 , 600 , 700 , 800 ) according to claim 12 , wherein the driven shaft ( 2 ) acts on a first wheel shaft ( 15 . 1 ) and second wheel shaft ( 15 . 2 ) via a differential gear ( 14 ), and wherein the two wheel shafts ( 15 . 1 , 15 . 2 ) are arranged coaxial to or paraxial to the two planetary gearsets ( 3 , 4 ).
14. The powertrain ( 500 , 600 , 700 , 800 ) according to claim 13 , wherein at least one of the shifting elements (S 1 , S 2 , S 3 ) is arranged radially and axially inside of a rotor ( 12 . 2 ) of the at least one electric machine ( 12 ).
15. A motor vehicle ( 900 ) having the powertrain ( 500 , 600 , 700 , 800 ) according to claim 11 .