GEARBOX, DRIVETRAIN, AND VEHICLE WITH GEARBOX

Abstract

A gearbox includes: an input shaft; a first output shaft; a second output shaft; a first planetary gearset; and a second planetary gearset connected to the first planetary gearset. The input shaft, the first and second output shafts, and the first and second planetary gearsets are configured such that a torque introduced via the input shaft is converted and distributed in a defined ratio to the first and second output shafts, so as to prevent formation of a sum torque. The first planetary gearset is configured as a minus planetary gearset, and the second planetary gearset is configured as a plus planetary gearset.

Claims

1. A gearbox (G) comprising: an input shaft (10); a first output shaft (11); a second output shaft (12); a first planetary gearset (P1); and a second planetary gearset (P2) connected to the first planetary gearset, wherein the input shaft (10), the first and second output shafts (11, 12), and the first and second planetary gearsets (P1, P2) are configured such that a torque introduced via the input shaft (10) is converted and distributed in a defined ratio to the first and second output shafts (11, 12), so as to prevent formation of a sum torque, wherein at least a third element (E31) of the first planetary gearset (P1) is connected by a shaft (3) to a first element (E12) of the second planetary gearset (P2) so as to be fixed with respect to rotation relative to it, and a second element (E22) of the second planetary gearset (P2) is secured to a component element (GG) which is fixed against relative rotation, wherein the first planetary gearset (P1) is configured as a minus planetary gearset, and the second planetary gearset (P2) is configured as a plus planetary gearset, and wherein the first planetary gearset (P1) and/or the second planetary gearset (P2) comprises a stepped planet (SP1, SP2).

2. The gearbox (G) according to claim 1, wherein the input shaft (10) is connected to a first element (E11) of the first planetary gearset (P1) so as to be fixed with respect to rotation relative to it; the first output shaft (11) is connected to a second element (E21) of the first planetary gearset (P1) so as to be fixed with respect to rotation relative to it; the third element (E31) of the first planetary gearset (P1) is connected to the first element (E12) of the second planetary gearset (P2) so as to be fixed with respect to rotation relative to it; the second element (E22) of the second planetary gearset (P2) is secured to the component element (GG) of the gearbox (G) that is fixed with respect to relative rotation; and the second output shaft (12) is connected to a third element (E32) of the second planetary gearset (P2) so as to be fixed with respect to rotation relative to it.

3. The gearbox (G) according to claim 2, wherein the first planetary gearset (P1) comprises a first stepped planet gear (SP1).

4. The gearbox (G) according to claim 3, wherein the second planetary gearset (P2) comprises a second stepped planet gear (SP2).

5. The gearbox (G) according to claim 4, wherein the second stepped planet gear (SP2) has two sun gear connections (SO2-1, SO2-2).

6. The gearbox (G) according to claim 4, wherein the second stepped planet gear (SP2) has two ring gear connections (HO2-1, HO2-2).

7. The gearbox (G) according to claim 2, wherein the first planetary gearset (P1) and the second planetary gearset (P2) each have a stepped planet gear (SP1, SP2).

8. The gearbox (G) according claim 2, wherein the first planetary gearset (P1) is arranged radially inwardly of the second planetary gearset (P2).

9. The gearbox (G) according to claim 2, wherein the first planetary gearset (P1) is arranged axially adjacent to the second planetary gearset (P2).

10. A drivetrain having the gearbox according to claim 1.

11. A vehicle having the drivetrain according to claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In the drawings:

[0043] Advantageous embodiments of the invention which are described in the following are shown in the drawings. The drawings show:

[0044] FIGS. 1A-E a schematic view of a motor vehicle drivetrain;

[0045] FIG. 2 stationary gear ratio of the individual embodiments; and

[0046] FIGS. 3 to 7 schematic views of several preferred embodiments of the invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0047] FIGS. 1A to 1E show schematic views of a gearbox G of a motor vehicle drivetrain 100 of a vehicle 1000 in the form of a passenger car.

[0048] The drivetrain 100 according to FIG. 1A shows an electric drive which drives the rear axle A of the vehicle 1000. The drivetrain comprises a gearbox G which distributes the drive torque of the electric machine EM to two output shafts 11 and 12. The gearbox G and the electric machine are arranged in a common housing. The forward driving direction is shown by arrow 99. As will also be appreciated from FIG. 1A, the gearbox G and the electric machine EM are oriented transverse to the driving direction of the vehicle.

[0049] The drivetrain 100 according to FIG. 1B shows an internal combustion engine drive which drives the rear axle A of the vehicle 1000. The drivetrain comprises a gearbox G which distributes the drive torque of the internal combustion engine VM to two output shafts 11 and 12. A further gearbox, for example, an automatic transmission of the vehicle, is arranged between gearbox G and internal combustion engine VM. The forward driving direction is shown by arrow 99. As will also be appreciated from FIG. 1B, the gearbox G and the internal combustion engine VM are oriented longitudinal to the driving direction of the vehicle.

[0050] The drivetrain 100 according to FIG. 1C shows an internal combustion engine drive which drives the rear axle A and the front axle B of the vehicle 1000. The drivetrain comprises a gearbox G which distributes the drive torque of the internal combustion engine VM to axles A and B, a further gearbox, for example, an automatic transmission of the vehicle, being arranged between gearbox G and internal combustion engine VM. The gearbox G can then be connected to an axle differential of the rear wheel axle A via an output shaft 11 and to an axle differential of the front axle B via an output shaft 12. The forward driving direction is indicated by arrow 99. As will further be appreciated from FIG. 1C, the gearbox G and the internal combustion engine VM are oriented longitudinal to the driving direction of the vehicle.

[0051] The drivetrain 100 according to FIG. 1D shows an electric drive which drives the front axle B of the vehicle 1000, i.e., an electric front-transverse drive. The drivetrain comprises a gearbox G which distributes the drive torque of the electric machine EM to two output shafts 11 and 12. The gearbox G and the electric machine are arranged in a common housing. The forward driving direction is shown by arrow 99. As will also be appreciated from FIG. 1D, the gearbox G and the electric machine EM are oriented transverse to the driving direction of the vehicle.

[0052] The drivetrain 100 according to FIG. 1E shows an electric all-wheel drive which drives the rear axle A and the front axle B of the vehicle 1000. This is a gearbox constructed as longitudinal distributor. The drivetrain comprises a gearbox G which distributes the drive torque of the electric machine EM to two output shafts 11 and 12. Output shaft 11 transmits the torque to the front axle B, while output shaft 12 transmits the torque to the rear axle A. The respective torques are then introduced in turn into respective axle differentials. The gearbox G and the electric machine are arranged in a common housing. The forward driving direction is shown by arrow 99. As will also be appreciated from FIG. 1E, the gearbox G and the electric machine EM are oriented transverse to the driving direction of the vehicle.

[0053] FIG. 2 shows the calculation specification for the stationary gear ratio. This brings about an output torque at the same level and with the same mathematical sign at both output shafts 11, 12 without taking into account gear losses. The stationary gear ratio of the first planetary gearset P1 is designated by i.sub.01. The stationary gear ratio of the second planetary gearset P2 is designated by i.sub.02.

[0054] FIGS. 3 to 7 show embodiments of the gearbox G, the first planetary gearset being formed as a minus planetary gearset, and the second planetary gearset being formed as a plus planetary gearset, and the first planetary gearset and/or the second planetary gearset comprises a stepped planet gear.

[0055] FIG. 3 shows a drivetrain 100 of a vehicle with a gearbox G in a first preferred embodiment. The gearbox G comprises an input shaft 10, a first output shaft 11, a second output shaft 12, a first planetary gearset P1 and a second planetary gearset P2 connected to the first planetary gearset P1.

[0056] The first planetary gearset P1 is formed as a minus planetary gearset, while the second planetary gearset P2 is formed as a plus planetary gearset. The planetary gearsets P1, P2 comprise in each instance a plurality of elements E11, E21, E31, E12, E22, E32. The first element E11 is a sun gear SO1, the second element E21 is a planet carrier PT1, and the third element E31 of the first planetary gearset P1 is a ring gear HO1.

[0057] In the second planetary gearset P2, the first element E12 is a sun gear SO2, the third element E32 is a planet carrier PT2, and the second element E22 is a ring gear HO2.

[0058] The first planetary gearset P1 further comprises a stepped planet gear SP1 with two toothed wheels Z1 and Z2 of different sizes and, therefore, with two different transmission ratios. The first toothed wheel Z1 is smaller than the second toothed wheel Z2. The first toothed wheel Z1 meshes with the ring gear HO1. The second toothed wheel Z2 meshes with the sun gear SO1.

[0059] The planet carrier PT2 supports a plurality of inner and outer planet gears PR2-i and PR-2a, respectively. The inner planet gears PR2-i mesh with the radially inner sun gear SO2. The outer planet gears PR2-a mesh with the surrounding ring gear HO2. The inner and outer planet gears mesh with one another in addition.

[0060] In the present case, the input shaft 10 is connected to the sun gear SO1 so as to be fixed with respect to rotation relative to it. The first output shaft 11 is connected to the planet carrier PT1 of the first planetary gearset P1 so as to be fixed with respect to rotation relative to it. The second output shaft 12 is connected to the ring gear HO2 of the second planetary gearset P2 so as to be fixed with respect to rotation relative to it. The ring gear HO1 of the first planetary gearset P1 is connected to the sun gear SO2 of the second planetary gearset P2 so as to be fixed with respect to rotation relative to it, while the planet carrier PT2 of the second planetary gearset P2 is secured to a component element GG which is fixed against relative rotation. The component element GG which is fixed against relative rotation is a gearbox housing of the gearbox G.

[0061] The ring gear HO1 of the first planetary gearset P1 and the sun gear SO2 of the second planetary gearset P2 form a common structural component part which is a shaft 3 in the present case.

[0062] As can be seen from FIG. 3, the input shaft 10, the first output shaft 11 and the second output shaft 12 are arranged coaxial to one another. The two planetary gearsets P1, P2 are likewise arranged coaxial to one another. The two planetary gearsets P1, P2 are arranged to be axially spaced apart from one another according to this embodiment.

[0063] Further, it is clearly shown how the first output shaft 11 is guided through the input shaft 10 formed as hollow shaft. The two output shafts 11, 12 are each connected to a drive wheel 20 of the vehicle. Constant velocity joints 15 are provided to enable wheel movements such as steering movement and/or deflection.

[0064] The input shaft 10 is connected to a prime mover in the form of an electric machine EM to introduce an input torque into the gearbox G. This means that the input shaft 10 and the output shafts 11, 12 rotate in the same direction.

[0065] Because the two planetary gearsets P1, P2 are connected to one another and because the planetary gear carrier PT2 is supported at the gearbox GG, the introduced input torque can be distributed to the two output shafts 11, 12. The gearbox G takes over not only the function of a transmission but also, additionally, that of a differential gearbox. That is, the introduced torque is not only converted but is also distributed to different output shafts. In this embodiment, there is no reversal of rotational direction.

[0066] FIG. 4 shows a further embodiment of the invention. In contrast to the embodiment according to FIG. 3, the second planetary gearset P2 likewise has a stepped planet gear, namely, a second stepped planet gear SP2. The latter comprises two sun gear connections. The stepped planet gear SP2 has a third toothed wheel Z3 and a fourth toothed wheel Z4, the third toothed wheel Z3 being smaller than the fourth toothed wheel Z4. The third toothed wheel Z3 meshingly engages with a first sun gear SO2-1. The sun gear SO2-1 is in turn secured to the gearbox housing GG and is accordingly permanently prevented from rotating. The sun gear SO2-1 accordingly represents the second element E22 of the second planetary gearset P2. The fourth toothed wheel Z4 meshingly engages with a second sun gear SO2-2. The sun gear SO2-2 is connected via the shaft 3 to the ring gear HO1 of the first planetary gearset P1 so as to be fixed with respect to rotation relative to it. The sun gear SO2-2 represents the first element E12 of the second planetary gearset P2. The planet carrier PT2 which supports the toothed wheels Z3 and Z4 is connected to the second output shaft 12 so as to be fixed with respect to rotation relative to it. The planet carrier PT2 represents the third element E32 of the second planetary gearset P2. As is clearly shown in FIG. 4, the two planetary gearsets P1 and P2 are arranged axially adjacent to one another, and the first planetary gearset P1 is arranged radially inwardly of the electric machine EM. In other respects, reference is made to the statements referring to the FIG. 3.

[0067] FIG. 5 shows a further preferred embodiment of the invention. In contrast to FIG. 4, the planetary gearsets P1, P2 of the embodiment according to FIG. 5 are not arranged axially adjacent to one another but rather radially one above the other. According to FIG. 5, the second planetary gearset P2 is arranged radially outwardly of the first planetary gearset P1. In other respects, reference is made to the statements referring to FIG. 4.

[0068] FIG. 6 shows a further preferred embodiment of the invention. In contrast to FIG. 4, the second stepped planet gear SP2 is now constructed with two ring gear connections. The third toothed wheel Z3 meshingly engages with a first ring gear HO2-1, the latter being secured to the housing GG. The ring gear HO2-2 accordingly represents the second element E22 of the second planetary gearset P2. The fourth toothed wheel Z4 meshingly engages with a second ring gear HO2-2. Ring gear HO2-2 is in turn connected via the shaft 3 to ring gear HO1 so as to be fixed with respect to rotation relative to it. Accordingly, ring gear HO2-1 represents the first element E12 of the second planetary gearset P2. As is clearly shown in FIG. 6, the two planetary gearsets P1, P2 are arranged axially adjacent to one another, the first planetary gearset P1 being arranged radially inwardly of the rotor R of the electric machine EM. In other respects, reference is made to the comments referring to FIG. 4.

[0069] FIG. 7 shows a further preferred embodiment of the invention. In contrast to FIG. 5, the first planet carrier P1 is constructed as a conventional minus planetary gearset and accordingly has no stepped planet gear. The sun gear SO1 is connected to the input shaft 10 so as to be fixed with respect to rotation relative to it, the planet carrier PT1 is connected to the first output shaft 11 so as to be fixed with respect to rotation relative to it, and the ring gear HO1 is connected to the sun gear SO2-2 so as to be fixed with respect to rotation relative to it. The two planetary gearsets P1, P2 are arranged radially one above the other, the second planetary gearset P2 being arranged radially outwardly of the first planetary gearset P1 as is also shown in FIG. 5.

[0070] The invention has been described and explained in some detail referring to the drawings and description. The description and explanation are exemplary and not intended to be limiting. The invention is not limited to the disclosed embodiment forms. Other embodiment forms or variations will be apparent to the person skilled in the art in the use of the present invention from an accurate analysis of the drawings, the disclosure and the following patent claims.

[0071] In the patent claims, the words “comprise” and “with” are not intended to exclude other elements or steps. The indefinite article “a” does not exclude a plurality. An individual element or an individual unit may carry out the functions of a plurality of units mentioned in the patent claims. The mere mention of some steps in a plurality of different dependent patent claims should not be construed to mean that a combination of these steps cannot likewise be advantageous.

[0072] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of configuration choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.