Final drive for a motor vehicle and final drive device

Abstract

A final drive for a motor vehicle. A drive assembly having a drive shaft, the drive shaft is coupled via a gear stage to an output shaft of the final drive. The drive shaft is coupled to the gear stage via an intermediate shaft that is arranged offset with respect to it. The intermediate shaft is present on a first side of a conceptual plane that incorporates an axis of rotation of the drive shaft, and a power electronics unit is electrically connected to the drive assembly via connection terminals arranged at its front end on a second side of the plane, which lies opposite to the first side.

Claims

1. A final drive for a motor vehicle, comprising: a drive assembly having a drive shaft, wherein the drive shaft is coupled via a gear stage to an output shaft of a the final drive, wherein the drive shaft is coupled to the gear stage via an intermediate shaft that is arranged offset with respect to the drive shaft, wherein the intermediate shaft lies on a first side of a conceptual plane incorporating an axis of rotation of the drive shaft, and wherein a power electronics unit is electrically connected to the drive assembly via connection terminals arranged at the front end thereof on a second side, which lies opposite to the first side so that the power electronics unit and the gear stage are arranged in a single housing.

2. The final drive device for a motor vehicle according to claim 1, further comprising: a first final drive and a second final drive; a first drive assembly of the first final drive, which has a first drive shaft, and a second drive assembly of the second final drive, which has a second drive shaft, wherein the first drive shaft is coupled via the first gear stage to a first output shaft of the final drive device and the second drive shaft is coupled via a second gear stage to a second output shaft of the final drive device, wherein the first drive assembly and the second drive assembly are arranged symmetrically with respect to a plane of symmetry running between them, wherein the first drive shaft is coupled to the first gear stage via a first intermediate shaft, which is at an angle with respect to it, skewed with respect to it, and offset with respect to it in the direction facing away from the plane of symmetry, and the second drive shaft is coupled to the second gear stage via a second intermediate shaft, which is arranged at an angle with respect to it, skewed with respect to it, and offset with respect to it in the direction facing away from the plane of symmetry.

3. The final drive device according to claim 2, wherein the first gear stage and the second gear stage are each designed as a bevel gear stage, so that an axis of rotation of the first output shaft and an axis of rotation of the second output shaft are each at an angle with respect to the plane of symmetry or the first gear stage and the second gear stage are each designed as a spur gear stage.

4. The final drive device according to claim 2, wherein the first gear stage and the second gear stage are arranged in a common gear housing, in which the two output shafts are mounted.

5. The final drive device according to claim 2, wherein the first drive shaft is coupled to the first intermediate shaft via a first intermediate-shaft gear stage and the second drive shaft is coupled to the second intermediate shaft via a second intermediate-shaft gear stage.

6. The final drive device according to claim 5, wherein an intermediate-shaft gear wheel of the respective intermediate-shaft gear stage, which is connected to one of the intermediate shafts in a rotationally-resistant manner, is arranged on one side of a conceptual plane that incorporates the axis of rotation of the respective drive shaft and is arranged parallel to the plane of symmetry.

7. The final drive device according to claim 2, wherein between the first gear stage and the second gear stage, a power electronics unit mounting compartment is formed for the mounting of a power electronics unit for the first drive assembly and the second drive assembly, wherein at least portions of the power electronics unit mounting compartment are delimited by the first drive assembly and the second drive assembly.

8. The final drive device according to claim 7, wherein the power electronics unit mounting compartment is separated from a first gearbox mounting compartment, in which the first gear stage and the first intermediate-shaft gear stage are arranged, and from a second gearbox mounting compartment, in which the second gear stage and the second intermediate-shaft gear stage are arranged, by a dividing wall.

9. The final drive device according to claim 7, wherein a power electronics unit, which is arranged in the power electronics unit mounting compartment, is electrically connected via connection terminals arranged at the front end at the first drive assembly and the second drive assembly.

10. The final drive device according to claim 2, wherein the first drive assembly is arranged in a first motor housing and the second drive assembly is arranged in a second motor housing, wherein the first motor housing and the second motor housing are arranged directly at the gear housing.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The invention will be explained in detail below on the basis of the exemplary embodiments illustrated in the drawing, without any limitation of the invention thereby ensuing. Shown are:

(2) FIG. 1 a schematic illustration of a final drive for a motor vehicle, which has a drive assembly as well as an output shaft,

(3) FIG. 2 a schematic illustration of a first embodiment of a final drive device for a motor vehicle, which has a plurality of final drives, and

(4) FIG. 3 a schematic illustration of a second embodiment of the final drive device.

DETAILED DESCRIPTION OF THE FIGURES

(5) FIG. 1 shows a schematic illustration of a final drive 1 for a motor vehicle 2, only the final drive 1 and a wheel axle 3 of which are indicated here. The final drive 1 has a drive assembly 4, namely preferably an electric motor. The drive assembly 4 supplies a drive torque via a drive shaft 5, which is mounted rotatably in a motor housing 6 of the drive assembly 4. The drive shaft 5 is in mechanical operative connection with an output shaft 10 via a gear stage 7, which is composed of toothed gears 8 and 9, designed as spur gears. The output shaft 10 is coupled, in turn, preferably via an axle differential 11, to a first axle member 12 and a second axle member 13 of the wheel axle 3.

(6) The final drive 1 has an intermediate shaft 14, which is offset with respect to the drive shaft 5 and is coupled to the drive shaft 5 via an intermediate-shaft gear stage 15. The intermediate-shaft gear stage 15 is preferably composed of toothed gears 16 and 17, which mesh with each other. The toothed gear 16 is hereby arranged on the drive shaft 5 and, in particular, is connected to it rigidly and/or permanently. In contrast, the toothed gear 17 is present on the intermediate shaft 14 and is preferably likewise connected to it rigidly and/or permanently. Via the intermediate shaft 14, the toothed gear 17 and the toothed gear 8 are in this regard in permanent operative connection with each other.

(7) In summary, the drive shaft 5 is operatively connected mechanically via the intermediate shaft 14, which is arranged offset to it, to the gear stage 7 and via the latter to the output shaft 10. It can be seen that the intermediate shaft 14 is present on a first side of a conceptual plane that incorporates the axis of rotation of the drive shaft 5. The embodiment of the final drive 1 with the intermediate shaft 14 makes possible an especially compact design of the final drive 1, because a power electronics unit 18 can be arranged at the front end of the drive assembly 4 and can be electrically connected to it.

(8) The electrical connection is created, for example, by means of plug connectors 19, which are only indicated here. These plug connectors 19 represent connection terminals, which are present at the front end at the drive assembly 4, in particular at a bearing shield of the motor housing 6. The power electronics unit 8 in this regard overlaps, as viewed in the axial direction with respect to the axis of rotation of the drive shaft 5, at least with portions of the drive shaft 5 and the intermediate shaft 14.

(9) The wheel axle 3 illustrated here can be present as a front axle or a rear axle of a two-axle motor vehicle. If the motor vehicle 2 has a plurality of wheel axles 3, then only one of these wheel axles 3, a part of the wheel axles 3, or else all wheel axles 3 can each be associated with a final drive 1 of the described design. The drive shaft 5 of the drive assembly 4 is arranged in such a design at least approximately parallel to the wheel axle 3.

(10) FIG. 2 shows a schematic illustration of a first embodiment of a final drive device 20, which has a first final drive 21 and a second final drive 22. Each of the final drives 21 and 22 is constructed largely similar to the final drive 1. For this reason, the same reference characters are used for the final drives 21 and 22 as for the final drive 1. Reference is made fundamentally to the statements made above.

(11) The difference between the final drives 21 and 22 and the final drive 1 lies in the fact that, on the one hand, the drive assemblies 4 or their drive shafts 5 are at an angle with respect to the wheel axle 3. The drive assemblies 4 or the drive shafts 5 are hereby present essentially in the longitudinal direction of the motor vehicle 2 or in the main travel direction of the motor vehicle 2.

(12) Although the gear stage 7 is additionally composed of toothed gears 8 and 9, the latter are not designed as spur gears, but rather as crown gears. Each final drive 21 and 22 is also equipped with its own output shaft 10, wherein each of the output shafts 10 is linked to one of the axle members 12 and 13 in such a way as to transmit torque. In this regard, by use of the final drive device 20, an individual-wheel drive for the wheel axle 3 is realized.

(13) It can be seen that the two drive assemblies 4 are arranged symmetrically with respect to a plane of symmetry 23 running between them. The intermediate shafts 14 of the two final drives 21 and 22 are each arranged offset with respect to the corresponding drive shaft 5 in the direction facing away from the plane of symmetry 23. By use of such a design of the final drive device 20, a power electronics mounting compartment 24 for the power electronics unit 18 is created between the gear stages 7.

(14) At least portions of this power electronics unit mounting compartment 24 are delimited from the drive assemblies 4 in the axial direction. Accordingly, the connectivity of the power electronics unit 18 to the drive assemblies 4 can occur via the front ends of the motor housing 6 facing the power electronics unit mounting compartment 24. Preferably, the two gear stages 7 are arranged in a common gear housing 25, at and/or in which the output shafts 10 are also mounted.

(15) The power electronics unit mounting compartment 24 can also be present in the gear housing 25. Preferably, it is hereby delimited or separated by means of at least one dividing wall 26in the exemplary embodiment illustrated here, by two dividing walls 26from the gearbox mounting compartments 27, with the gear stages 7 and/or the intermediate-shaft gear stages 15 being arranged in the gearbox mounting compartments 27.

(16) It is possibleas illustrated hereto arrange each of the drive assemblies 4 in a separate motor housing 6. In this case, the two motor housings 6 are preferably joined to the gear housing 25 or fastened at it by means of screw connections, for example. Alternatively, it can be provided that the two drive assemblies 4 are present in a common motor housing 6, which is then likewise joined to the gear housing 25 or fastened to it.

(17) A final drive device 20, in which a single gear housing 25 is present, at which the drive assemblies 4 are fastened, is obtained in this case. The gear stages associated with the drive assemblies 4 are arranged in the gear housing 25 and serve for producing the operative connections between the drive shafts 5 and the output shafts 10. Achieved overall is an extremely compact design of the final drive device 20, for which the power electronics units 18 are also arranged in a space-saving manner through their mounting in the gear housing 25.

(18) It can be seen, in addition, that the two final drives 21 and 22, which are a component of the final drive device 20, have numerous identical parts, which, in particular, are also identical to those of the final drive 1 described above. An extremely modular construction made up of numerous identical parts is created in this case, so that the final drive 1 or the final drive device 20 can be employed for numerous drive configurations of the motor vehicle 2. The wheel axle 3 with which the final drive device 20 is associated can be, in turn, a front axle or a rear axle of the motor vehicle. Preferably, such a final drive device 20 is associated with both the front axle and the rear axle.

(19) Based on the alignment of the drive assemblies 4 in the longitudinal direction or main travel direction of the motor vehicle 2, it is possible to achieve any desired scaling of the drive assemblies 4 depending on the power demand of the motor vehicle 2. Thus, for example, it is possible to use a less-powerful embodiment of the final drive device 20 in drive assemblies 4 that have a shorter construction in the longitudinal direction, whereas the drive assemblies 4 can have a longer construction in the longitudinal direction for a more powerful final drive device 20, so that, overall, a modular system is created.

(20) FIG. 3 shows a schematic illustration of a second embodiment of the final drive device 20again with the first final drive 21 and the second final drive 22. In regard to the final drives 21 and 22, reference is made to the final drive 1. Once again, the same reference characters are used for the final drives 21 and 22 as for the final drive 1. The second embodiment of the final drive device 20 is constructed similarly to the first embodiment. Reference is therefore made to the foregoing statements and only the differences are noted below. These differences lie in the fact that the gear stage 7, in analogy to the final drive 1, has spur gears and not, for instance, crown gears, as is the case for the first embodiment. In contrast, the toothed gears 16 and 17 of the intermediate-shaft gear stages 15 are each designed as crown gears, so that the intermediate-shaft gear stages 15 in this case are present as crown gear stages.

(21) Such a design of the final drive device 20 results in a slightly different form of the power electronics unit mounting compartment 24, which is due essentially to the design of the intermediate-shaft gear stages 15 as crown gear stages.