Multistage transmission for a motor vehicle
A multistage transmission, in particular for a motor vehicle, is provided at least structurally for selecting at least twelve forward transmission gears with different step-up ratios. This multistage transmission has four operatively interconnected planetary gear stages, a transmission input shaft for attaching to an internal combustion engine, a transmission output shaft, for attaching to drive wheels, four clutch units, each of which includes two clutch elements, and three brake units, each of which includes one clutch element.
1. A multistage transmission, comprising:
a transmission input shaft for attaching to an internal combustion engine, a transmission output shaft for attaching to drive wheels, four clutch units, each of which comprises two clutch elements, and three brake units, each of which comprises one clutch element;
wherein a first sun gear and a fourth planet gear carrier are permanently and non-rotatably connected with one of the clutch elements and to the transmission input shaft;
wherein a second ring gear, a third sun gear and a fourth sun gear are permanently and non-rotatably connected with one of the clutch elements;
wherein a first planet gear carrier is permanently and non-rotatably connected with three of the clutch elements;
wherein a second sun gear is permanently and non-rotatably connected with two of the clutch elements;
and wherein a third planet gear carrier is permanently and non-rotatably connected with two of the clutch elements and to the transmission output shaft;
wherein one of the clutch units is provided for non-rotatably connecting to each other one of the clutch elements non-rotatably connected with the second sun gear and one of the clutch elements which is non-rotatably connected with the third planet gear carrier, so that a selection of at least twelve forward transmission gears with different step-up ratios is structurally provided.
2. The multistage transmission according to claim 1 , wherein a first ring gear and a second planet gear carrier are permanently and non-rotatably connected to each other.
3. The multistage transmission according to claim 1 , wherein a third ring gear is permanently and non-rotatably connected with one of the clutch elements and wherein one of the brake units is provided for attaching the clutch element, which is non-rotatably connected with the third ring gear, to a housing.
4. The multistage transmission according to claim 1 , wherein a fourth ring gear is permanently and non-rotatably connected with one of the clutch elements.
5. The multistage transmission according to claim 4 , wherein one of the clutch units is provided for non-rotatably connecting to each other one of the clutch elements non-rotatably connected with the third planet gear carrier and the clutch element non-rotatably connected with the fourth ring gear.
6. The multistage transmission according to claim 1 , wherein one of the clutch units is provided for non-rotatably connecting to each other the clutch element non-rotatably connected with the first sun gear and one of the clutch elements non-rotatably connected with the first planet gear carrier.
7. The multistage transmission according to claim 1 , wherein one of the brake units is provided for fastening one of the clutch elements non-rotatably connected with the first planet gear carrier to a housing.
8. The multistage transmission according to claim 1 , wherein one of the clutch units is provided for non-rotatably connecting to each other one of the clutch elements non-rotatably connected with the first planet gear carrier and the clutch element non-rotatably connected with the second ring gear, the third sun gear and the fourth sun gear.
9. The multistage transmission according to claim 1 , wherein one of the brake units is provided for fixing one of the clutch elements, which is non-rotatably connected with the second sun gear, to the housing.