Transmission device for a motor vehicle

Abstract

A transmission device for a motor vehicle includes a first connecting shaft operatively connectable to a first subaxle of a wheel axle of the motor vehicle; a second connecting shaft operatively connectable to a second subaxle of the wheel axle; a coupling transmission having a drive shaft operatively connectable with a drive aggregate of the motor vehicle, and an output shaft operatively connectable with the first wheel axle, wherein via the coupling transmission the drive shaft is operatively connected with the output shaft and with the first and the second connecting shaft for torque distribution; and a superposition transmission, wherein the output shaft is operatively connectable with at least one of the first connecting shaft and the second connecting shaft via the superposition transmission by shifting the superposition transmission.

Claims

1. A transmission device for a motor vehicle having a first wheel axle and a second wheel axle, said second wheel axle comprising a first subaxle and a second subaxle, said transmission device comprising: a first connecting shaft operatively connectable to the first subaxle of the second wheel axle of the motor vehicle via a first transmission unit; a second connecting shaft extending parallel to the first connecting shaft and operatively connectable to the second subaxle of the second wheel axle of the motor vehicle via a second transmission unit; a coupling transmission having a drive shaft operatively connectable with a drive aggregate of the motor vehicle, and an output shaft extending parallel to the drive shaft and around the drive shaft and operatively connectable with the first wheel axle, wherein via the coupling transmission the drive shaft is operatively connected with the output shaft and with the first and the second connecting shaft for torque distribution; and a superposition transmission, said output shaft being operatively connectable with at least one of the first connecting shaft and the second connecting shaft via the superposition transmission by shifting the superposition transmission, wherein the coupling transmission comprises a first planetary transmission and a second planetary transmission directly operatively connected with the first planetary transmission, wherein the drive shaft and the output shaft are directly operatively connected with the first planetary transmission and the first and the second connecting shafts are directly operatively connected with the second planetary transmission.

2. The transmission device of claim 1, wherein the first planetary transmission includes a first sun gear, a first ring gear and a first planet carrier with at least one planet gear that meshes with the first sun gear and the first ring gear, said first planet carrier being operatively connected with the drive shaft and the first sun gear with the output shaft.

3. The transmission device of claim 2, wherein the second planetary transmission includes a second sun gear a second ring gear and a second planet carrier, wherein the second planet carrier is operatively connected with the first or the second connecting shaft and the second sun gear is operatively connected with the other connecting shaft.

4. The transmission device of claim 3, wherein the second planet carrier has at least one outer planet gear and at least one inner planet gear which mesh with each other, and wherein the outer planet gear meshes with the second ring gear and the inner planet gear meshes with the second sun gear.

5. The transmission device of claim 3, wherein the operative connection between the second connecting shaft and the second planet carrier is accomplished via a gear stage.

6. The transmission device of claim 3, wherein the operative connection between the second connecting shaft and the second sun gear is accomplished via a gear stage or via a rotation-direction maintaining coupling.

7. The transmission device of claim 6, wherein the rotation-direction maintaining coupling is a variable transmission or a rotation-direction maintaining gear stage.

8. The transmission device of claim 2, wherein the superposition transmission is configured as a planetary transmission via which the output shaft is operatively connected with at least one of the first ring gear and the second ring gear.

9. The transmission device of claim 3, wherein the superposition transmission includes a superposition transmission sun gear and a superposition transmission planet carrier, wherein a first superposition transmission planet gear supported on the superposition transmission planet carrier meshes with the superposition transmission sun gear that is coupled with the output shaft and a second superposition transmission planet gear supported on the superposition transmission planet carrier meshes with a superposition transmission gear which is coupled with at least one of the first ring gear and the second ring gear.

10. The transmission device of claim 9, further comprising at least one clutch adapted for fixing the second planet carrier or the second sun gear relative to the first planet carrier or relative to the superposition transmission planet carrier in a manner selected from the group consisting of partially fixing and completely fixing.

11. The transmission device of claim 1, wherein the second transmission unit is constructed identical to the first transmission unit.

12. The transmission device of claim 1, wherein the second connecting shaft extends in coaxial relation to the first connecting shaft.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the following the invention is explained in more detail by way of the exemplary embodiments shown in the drawing without limiting the invention. Hereby it is shown in:

(2) FIG. 1 a first embodiment of the transmission device,

(3) FIG. 2 a first variant of a second embodiment of the transmission device,

(4) FIG. 3 a second variant of the second embodiment,

(5) FIG. 4 a third variant of the second embodiment,

(6) FIG. 5 a fourth variant of the second embodiment,

(7) FIG. 6 a schematic representation of a drive train with the transmission device in a first variant of a third embodiment,

(8) FIG. 7 a detail view of the transmission device in the first variant of the third embodiment,

(9) FIG. 8 the transmission device in a second variant of the third embodiment, and

(10) FIG. 9 the transmission device in a third variant of the third embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(11) FIG. 1 shows a first embodiment of a transmission device 1 for a not further illustrated motor vehicle. The motor vehicle has a first wheel axle 2 and a second wheel axle 3 which is here only schematically indicated, wherein the second wheel axle 3 consists of at least one first subaxle 4 and a second subaxle 5. The transmission device 1, the first wheel axle 2 and the second wheel axle 3 form at least a part of a drive train of the motor vehicle. The transmission device 1 has a coupling transmission 6, which is formed essentially by a first planetary transmission 7 and a second planetary transmission 8. The coupling transmission 1 has a drive shaft 9, which can be operatively connected with a drive aggregate of the motor vehicle. The coupling transmission 6 also has an output shaft 10 to which via a gear stage 11 the first wheel axle 2 is connected. An operative connection of the coupling transmission 6 to the second wheel axle 3 or the first subaxle 4 assigned to the first wheel axle and the second subaxle 5 is accomplished via a first connecting shaft 12 and a second connecting shaft 13. The first connecting shaft 12 is operatively connected with the first subaxle 4 via a transmission unit 14, which is for example constructed as a gear stage, and the second connecting shaft is operatively connected with the second subaxle 5 via a second transmission unit 15, which is for example also constructed as a gear stage.

(12) The first planetary transmission 7 includes a first sun gear 16, a first ring gear 17 and a first planet carrier 18 with at least one planet gear 19. The second planetary transmission 8 on the other hand includes a second sun gear 20, a second ring gear 21 and a second planet carrier 22. On the second planet carrier 22 at least one outer planet gear 23 and at least one inner planet gear 24 are rotatably arranged. The planet gear 1,9 which is rotatably fastened on the first planet carrier 18, meshes with the first sun gear 16 as well as the first ring gear 17. Regarding the second planetary transmission 8 on the other hand it is provided that the outer planet gear 23 meshes with the inner planet gear 24 and with the second ring gear 21. The inner planet gear 24 on the other hand meshes with the outer planet gear 23 and with the second sun gear 20. An operative connection between the second sun gear 20 and the second ring gear 21 is thus established via the outer planet gear 23 and the inner planet gear 24.

(13) The planetary transmissions 7 and 8 are operatively connected with each other. In the present exemplary embodiment this is realized by configuring the ring gears 17 and 21 as a common ring gear 25. However, an operative connection between the ring gears 17 and 21 can also be established in a different manner. The drive shaft 9 and the output shaft 10 are directly operatively connected with the first planetary transmission 7 and the two connecting shafts 12 and 13 are directly operatively connected with the second planetary transmission 8. Hereby in the present exemplary embodiment the drive shaft 9 is directly operatively connected with the first planet carrier 18 and the output shaft 10 with the first sun gear 16. On the other hand the first connecting shaft 12 is directly operatively connected with the second sun gear 20 and the second connecting shaft 13 via gear stage 26 with the second planet carrier 22.

(14) FIG. 2 shows a first variant of a second embodiment of the transmission device 1. This variant is generally similar to the first embodiment so that insofar reference is made to the description above. In the following only the differences are discussed. These differences are mainly found in the second planetary transmission 8. The first connecting shaft 12 is directly connected to the second planet carrier 22 while the second connecting shaft 13 is connected to the second sun gear 20 via the gear stage 26.

(15) This arrangement offers the possibility to provide two clutches. By means of the clutch 27 the second planet carrier 22 can be fixed at least partially, in particular completely, relative to the first planet carrier 19. By means of the clutch 28 on the other hand the second sun gear 20 can be fixed at least partially, in particular completely, relative to the planet carrier 18. By means of the clutches 27 and 28 a torque can be redirected in a targeted manner form the first wheel axle 2 to either the first subaxle 4 (by means of the clutch 27) or to the second subaxle 5 (by means of the clutch 28). Correspondingly the transmission device 1 realizes a torque vectoring between the first wheel axle 2 and the second wheel axle 3 or the subaxles 4 and 5. Via the clutches 27 and 28 also an operative connection to the sun gear 16 can be generated instead of the operative connection to the first planet carrier 18.

(16) In the here shown first variant of the first embodiment of the transmission device 1 the transmission units 14 and 15 are configured mirror symmetrical. This is also the case for the first embodiment, which is shown in FIG. 1.

(17) FIG. 3 shows a second variant of the second embodiment. In the following only the differences are discussed. Insofar reference is made to the description above. In this case the transmission units 14 and 15 are configured identical. This has the advantage that the number of different parts that have to be provided can be reduced. In such a configuration of the transmission units 14 and 15 the connection for example of the second connecting shaft 13 to the second planetary transmission 6 has to be changed. For example in this case only one rotation-direction maintaining clutch 29 is provided, which in the present case is configured as a variable transmission.

(18) FIG. 4 shows a third variant of the second embodiment of the transmission device 1. Also in this case reference is made to the description above. The difference to the variants above is found in the arrangement of the transmission units 14 and 15 relative to each other. Due to the here selected design these can be arranged relative to each other in a very space-saving manner or can even be integrated in a transmission module.

(19) FIG. 5 shows a fourth variant of the second embodiment oft the transmission device 1. Again reference is made to the description above. While the connecting shafts 12 and 13 in the embodiments described so far were arranged parallel to each other, they are now arranged coaxial to each other. In this way a very space-saving arrangement of the transmission units 14 and 15 or an integration in a transmission module is possible.

(20) FIG. 6 shows a schematic representation of a drive train 30 of the motor vehicle. The drive train has a drive aggregate 31 for example an internal combustion engine and a transmission 32, in particular a manual transmission. The drive aggregate 31 is operatively connected with the transmission device 1, in particular via the transmission 32. The operative connection of the drive aggregate 31 is hereby established to the drive shaft 9 of the transmission device 1. Also in the here shown variant of a third embodiment the transmission device 1 has the coupling transmission 6, which is formed essentially by the first planetary transmission 7 and the second planetary transmission 8. The output shaft 10 of the coupling transmission 6 is connected to the first wheel axle 2, for example via the gear stage 11. The first wheel axle 2 can have an axle differential 33 via which subaxles 34 and 35 of the first wheel axle 2 are operatively connected with the gear stage 11 or the output shaft 10. The wheel axle 3, or the subaxles 4 and 5 assigned to this wheel axle, are operatively connected with the coupling transmission 6 via the first connecting shaft 12 and the second connecting shaft 13. The first connecting shaft 12 is operatively connected with the first subaxle 4 via the first transmission unit 14, which is for example constructed as a gear stage, and the second connecting shaft 13 with the second subaxle 5 via a second transmission unit 15, which is for example also constructed as a gear stage.

(21) The first planetary transmission 7 is formed by the first sun gear 16, the second ring gear 17 and the first planet carrier 18 with at least one planet gear 19. The second planetary transmission 8 is formed by the second sun gear 20, the second ring gear 21 and the second planet carrier 22. On the second planet carrier 22 the at least one outer planet gear 23 and the at least one inner planet gear 24 are rotatably arranged. The planet gear 19, which is rotatably arranged on the first planet carrier 18, meshes with the first sun gear 16 as well as with the first ring gear 17. In the case of the second planetary transmission 8 the outer planet gear 23 meshes with the inner planet gear 24 and also with the second ring gear 21. The inner planet gear 24 meshes with the outer planet gear 23 and the second sun gear 20. The operative connection between the second sun gear 20 and the second ring gear 21 is thus accomplished via the outer planet gear 23 and the inner planet gear 24. The above description can generally be used for understanding the transmission device 1.

(22) The planetary transmissions 7 and 8 are operatively connected with each other by virtue of the fact that the ring gears 17 and 21 are configured as a common ring gear 25. Of course the operative connection between the ring gears 17 and 21 can also be accomplished in a different manner. The drive shaft 9 and the output shaft 10 are directly operatively connected with the first planetary transmission 7 and the two connecting shafts 12 and 13 are directly operatively connected with the second planetary transmission 8. The operative connections are hereby preferably rigid and/or permanent. In the shown exemplary embodiment the drive shaft 9 is hereby directly operatively connected with the planet carrier 18 and the output shaft 10 with the first sun gear 16. The first connecting shaft 12 is directly operatively connected with the second planet carrier 22 and the second connecting shaft 13 with the second sun gear 20.

(23) Beside the coupling transmission 6 the transmission device 1 has a superposition transmission 36. This serves for the switchable operative connection of the output shaft 10 with the first connecting shaft 12 and/or the second connecting shaft 13. The superposition transmission 36 is configured as a planetary transmission, which has a superposition transmission planet carrier 38. On the superposition transmission planet carrier at least a first superposition transmission planet gear 39 and a second superposition transmission planet gear 40 are rotatably supported. The first superposition transmission planet gear 39 meshes with the superposition transmission sun gear 37 which is coupled with or rigidly fastened on the output shaft 10.

(24) The second superposition transmission planet gear 40 on the other hand meshes with a superposition transmission gear 41, which is here configured as a superposition transmission sun gear 41. The superposition transmission gear 41 is operatively connected with the first ring gear 17 and/or the second ring gear 21, in particular the common ring gear 25, in particular rigidly and/or permanently. Preferably the superposition transmission gear 41 is fastened on the common ring gear 25. Between the superposition transmission sun gear 37 and the first superposition transmission planet gear 39 a first transmission ratio of the superposition transmission is present. These transmission ratios are preferably different from each other so that in particular the superposition transmission planet gears 39 and 40 have different diameters. In the here shown exemplary embodiment the first transmission ratio of the superposition transmission is greater than the second transmission ratio of the superposition transmission.

(25) The superposition transmission planet carrier 38 is rigidly and/or permanently operatively connected with a first coupling element 42, which is commonly assigned to the clutches 27 and 28. The clutch 27 has a second coupling element 43 and the clutch 28 a second coupling element 44. The second coupling element 43 and also the second coupling element 44 can be selectively coupled with the first coupling element 42 for torque distribution. In a first switching state of the clutches 27 and 28 the second coupling elements 43 and 44 are thus completely separated from the first coupling element 42 so that no torque is transmitted. In a second operating mode of the clutch 27 on the other hand the second coupling element 43 is connected with the first coupling element 42 and in a second operating mode of the clutch 28 the second coupling element 44 is connected with the first coupling element 42 for torque distribution. Correspondingly via the clutches 27 and 28 an operative connection between the superposition transmission planet carrier 38 and the first connecting shat 12 the second connecting shaft 13 or both can be selectively generated.

(26) FIG. 7 shows a detail view of the first variant of the third embodiment of the transmission device 1 shown in FIG. 6. Insofar reference is made to the description above.

(27) FIG. 8 shows a second variant of the third embodiment of the transmission device 1. The only difference to the first variant is that the transmission ratios of the superposition transmission are different. In the shown variant the first transmission ratio of the superposition transmission is smaller than the second transmission ratio of the superposition transmission. Regarding the further configuration of the transmission device 1 reference is made to the description above.

(28) FIG. 9 shows a third variant of the third embodiment of the transmission device 1. Again reference is made to the description above regarding the first and second variant of the third embodiment. The difference to the first and second variants is a different configuration of the superposition transmission 36, which in this case is configured as a minus planetary transmission, while before a plus planetary transmission was described. The superposition transmission 36 has the superposition transmission sun gear 37, the superposition transmission planet carrier 38 with the at least one superposition transmission planet gear 39 and a superposition transmission ring gear 45.

(29) The superposition transmission ring gear 45 is rigidly and/or permanently operatively connected with the output shaft 10. The superposition transmission planet carrier 38 on the other hand is rigidly and/or permanently operatively connected with the first ring gear 17, the second ring gear 21 or the common ring gear 25. The first coupling element 42 is operatively rigidly and/or permanently coupled with or fastened to the superposition transmission sun gear 37. Also in this third variant the advantages of the further variants or the further embodiments can be realized. However, the third variant requires a large construction space.