Multi-Speed Gearbox for an Electrically Drivable Vehicle, and Vehicle Having Such a Multi-Speed Gearbox

Abstract

A multi-speed gearbox for a vehicle has fewer than 4 shiftable gears and has a gearbox input shaft, a gearbox output shaft, a gearbox housing and a planetary gearbox. The planetary gearbox has a planetary gearbox gear set, which has the following planetary gearbox elements: a sun gear, a first ring gear, and a second ring gear, at least one first planetary gear, which is engaged with both the sun gear and the first ring gear, at least one second planetary gear, which is engaged with the second ring gear, and with a planetary gear carrier, on which the at least one first planetary gear is rotatably mounted. The planetary gearbox gear set has multiple shift elements, which are designed to selectively connect one of the planetary gearbox elements to a further one of the planetary gearbox elements or to the gearbox housing for conjoint rotation and therefore to provide different gears. The at least one second planetary gear is mounted rotatably on the planetary gear carrier and is engaged with the first planetary gear, and the second ring gear can be selectively connected by way of a first of the shift elements to the gearbox housing for conjoint rotation, and the sun gear can be selectively connected by way of a second of the shift elements to the gearbox housing for conjoint rotation.

Claims

1. A multi-speed gearbox having fewer than four shiftable gears for a vehicle, comprising: a gearbox input shaft; a gearbox output shaft; a gearbox housing; and an epicyclic gearbox, the epicyclic gearbox comprising an epicyclic gearbox gear set with gearbox elements of: a sun gear, a first ring gear and a second ring gear, at least one first planetary gear, which is in engagement both with the sun gear and with the first ring gear, at least one second planetary gear, which is in engagement with the second ring gear, and with a planetary gear carrier, on which the at least one first planetary gear is rotatably mounted, wherein the epicyclic gearbox gear set has multiple shifting elements for selectively connecting one of the epicyclic gearbox elements to a further one of the epicyclic gearbox elements or to the gearbox housing for conjoint rotation to provide different gears, the at least one second planetary gear is rotatably mounted on the planetary gear carrier and is in engagement with the first planetary gear, the second ring gear is selectively connectable to the gearbox housing for conjoint rotation by a first of the shifting elements, and the sun gear is selectively connectable to the gearbox housing for conjoint rotation by a second of the shifting elements.

2. The multi-speed gearbox according to claim 1, wherein the first ring gear is selectively connectable to the second ring gear for conjoint rotation by a third of the shifting elements.

3. The multi-speed gearbox according to claim 1, wherein drive power is fed via the gearbox input shaft and said drive power is transmitted in the direction of the gearbox output shaft via the epicyclic gearbox and is delivered by the gearbox output shaft, and in said transmission, the drive power is fed to the first ring gear, as the first of the epicyclic gearbox elements, and said drive power is fed from the planetary gear carrier, as the last of the epicyclic gearbox elements, to the gearbox output shaft.

4. The multi-speed gearbox according to claim 1, wherein with respect to torque transmission, a first spur-gear gearbox is arranged between the gearbox input shaft and the first ring gear, so that drive power is fed directly to the first ring gear from the gearbox input shaft via this first spur-gear gearbox.

5. The multi-speed gearbox according to claim 4, wherein with respect to the torque transmission, a second spur-gear gearbox is arranged between the planetary gear carrier and the gearbox output shaft, so that drive power is fed directly to the gearbox output shaft from the planetary gear carrier via this second spur-gear gearbox.

6. The multi-speed gearbox according to claim 1, wherein the multi-speed gearbox has precisely three shifting elements and is shiftable into precisely three different gears by said three shifting elements.

7. A vehicle comprising a multi-speed gearbox according to claim 1.

8. The vehicle according to claim 7, further comprising: at least one electric motor, which is connectable to the gearbox input shaft for transmission of electric motor drive power.

9. The vehicle according to claim 8, wherein the multi-speed gearbox has precisely three shifting elements and precisely three gears, and the electric motor is the only drive source of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 shows a schematized section of a multi-speed gearbox.

[0031] FIG. 2 shows a schematized drive train with such a multi-speed gearbox.

DETAILED DESCRIPTION OF THE DRAWINGS

[0032] The multi-speed gearbox is designed for transmitting drive power from a driving motor (not shown) via the gearbox input shaft 1 for overcoming driving resistances of the motor vehicle in the drive train of which this multi-speed gearbox is used. This drive power is transmitted by a first spur-gear gearbox having a first spur gear 13 and a second spur gear 14 to the first ring gear 4 of the epicyclic gearbox 3.

[0033] The first ring gear 4 belongs to the epicyclic gearbox gear set of the epicyclic gearbox 3, and this epicyclic gearbox gear set has the sun gear 5, the planetary gear carrier 6, the first planetary gear 7 and the second planetary gear 8, which are mounted rotatably on the planetary gear carrier 6, and the second ring gear 9. On account of the representation, only one first planetary gear 7 and one second planetary gear 8 are shown, but the epicyclic gearbox gear set has multiple of these planetary gears 7, 8. For power transmission, the first ring gear 4 is in engagement with the first planetary gear 7, and the first planetary gear 7 is engagement with the second planetary gear 8. In order that these two planetary gears 7, 8 can be in engagement with one another, the first planetary gear 7 is offset with respect to the second planetary gear 8 in the circumferential direction; in order to represent this, the first planetary gear 7 is shown by dashed lines. For power transmission, the second planetary gear 8 is in engagement with the second ring gear 9. Furthermore, the first planetary gear 7 is in engagement with the sun gear 5.

[0034] In order to be able to provide different transmission ratios between the gearbox input shaft 1 and the gearbox output shaft 2, the multi-speed gearbox has the first shifting element 10, the second shifting element 11 and also the third shifting element 12. With the first shifting element 10, the second ring gear 9 can be selectively connected to the gearbox housing 0 for conjoint rotation. By the second shifting element 11, the sun gear 5 can be selectively connected to the gearbox housing 0 for conjoint rotation. By the third shifting element 12, the first ring gear 4, and consequently the first spur gear 13 of the first spur-gear gearbox, can be selectively connected to the second ring gear 9 for conjoint rotation.

[0035] The drive power provided by the driving motor can be fed to the gearbox output shaft 2 via the planetary gear carrier 6 and a second spur-gear gearbox having a first spur gear 15 and a second spur gear 16.

[0036] In the embodiment shown, the first ring gear 4 is configured at least partly as a gear wheel rings which has the ring gear toothing for the first ring gear 4 and an external toothing for the first spur gear 13 of the first spur-gear gearbox. In particular by means of such a configuration, a small installation space requirement in the axial direction can be achieved.

[0037] In FIG. 2, a schematized drive train having a multi-speed gearbox 18 of the type described above is shown. The multi-speed gearbox 18 can be fed drive power from the electric motor 17 via the gearbox input shaft 1 for overcoming driving resistances.

[0038] Depending on the shifting state, the multi-speed gearbox 18 delivers this drive power from the gearbox input shaft 1 via the gearbox output shaft 2 with a certain transmission ratio. Furthermore, the drive train has a drivable vehicle axle 19, which is connected to the gearbox output shaft 2 for conjoint rotation. Arranged on the drivable vehicle axle 19 are the drivable wheels 20, with which the drive power delivered by the gearbox output shaft 2 can be transmitted to the roadway surface (not shown).

LIST OF DESIGNATIONS

[0039] 1 Gearbox input shaft [0040] 2 Gearbox output shaft [0041] 3 Epicyclic gearbox [0042] 4 First ring gear [0043] 5 Sun gear [0044] 6 Planetary gear carrier [0045] 7 First planetary gear [0046] 8 Second planetary gear [0047] 9 Second ring gear [0048] 10 First shifting element [0049] 11 Second shifting element [0050] 12 Third shifting element [0051] 13 First spur gear of the first spur-gear gearbox [0052] 14 Second spur gear of the first spur-gear gearbox [0053] 15 First spur gear of the second spur-gear gearbox [0054] 16 Second spur gear of the second spur-gear gearbox [0055] 17 Electric motor [0056] 18 Multi-speed gearbox [0057] 19 Drivable vehicle axle [0058] 20 Drivable wheel

[0059] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.