Electrical Axle Drive for a Vehicle

Abstract

An electric axle drive and a vehicle having an electric axle drive are provided. The electric axle drive includes an electric machine (EM) and a differential (10), which couples the electric machine to an axle output. The axle output includes a first output shaft (1) and a second output shaft (2). An axis (B) of the electric machine is arranged at an angle (α) with respect to an axis (A) of the output shafts (1, 2).

Claims

1-9: (canceled)

10. An electric axle drive (100) for a vehicle (1000), comprising: an electric machine (EM); an axle output including a first output shaft (1) and a second output shaft (2); a differential (10) coupling the electric machine (EM) to the axle output, wherein an axis (B) of the electric machine (EM) is arranged at an angle (α) with respect to an axis (A) of the axle output, and wherein the angle (α) is acute and is no less than four degrees and no greater than thirty degrees.

11. The electric axle drive (100) of claim 10, wherein a drive shaft (11) of the electric machine (EM) is rotationally fixed to a gearwheel (12) in mesh with a drive element (13) of the differential (10), and the meshing of the gearwheel (12) and the drive element (13) of the differential (10) comprises an oblique toothing, a beveloid gear, or a bevel gear cutting configured for forming the angle (α).

12. The electric axle drive (100) of claim 10, wherein: at least one joint (21) connects a drive shaft (11) of the electric machine (EM) to an intermediate shaft (12a) rotationally fixed to a gearwheel (12), and the drive shaft (11) is arranged at an angle with respect to the intermediate shaft (12a); the gearwheel (12) is in mesh with a drive element (13) of the differential (10); and the at least one joint (21) is configured for transmitting an angular speed and a torque from the drive shaft (11) to the intermediate shaft (12a).

13. The electric axle drive (100) of claim 12, wherein two joints (21, 22) are provided between the gearwheel (12) and the drive shaft (11), and the gearwheel (12) and the drive shaft (11) are connected by an additional intermediate shaft (23).

14. The electric axle drive (100) of claim 10, wherein the axis (B) of the electric machine (EM) and the axis (A) of the axle output are situated in a common plane.

15. The electric axle drive (100) of claim 10, wherein the axis (B) of the electric machine (EM) is arranged askew relative to the axis (A) of the axle output.

16. A vehicle (1000), comprising the electric axle drive (100) of claim 10.

17. The vehicle (1000) of claim 16, wherein the differential (10) is arranged essentially in a center of the vehicle.

18. The vehicle (1000) of claim 17, wherein the electric machine (EM) is arranged on one of the two sides with respect to a vehicle longitudinal axis (X).

19. The vehicle (1000) of claim 16, wherein the differential (10) is arranged on one of the two sides with respect to a vehicle longitudinal axis (X).

Description

BRIEF DESCRIPTION OF THE DRAWING

[0025] Advantageous example embodiments of the invention, which are explained in the following, are represented in the drawings, in which:

[0026] FIGS. 1-4 show preferred example embodiments of an axle drive; and

[0027] FIG. 5 shows a vehicle having an axle drive from FIGS. 2 through 4.

DETAILED DESCRIPTION

[0028] Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

[0029] FIG. 1 shows an electric axle drive of a vehicle in a first preferred example embodiment of the invention.

[0030] The electric axle drive 100 includes an electric machine EM, an axle output in the form of two output shafts 1, 2, and a differential 10, which couples the electric machine EM to the axle output.

[0031] The differential designed as a bevel gear differential 10 has two wheel-side output elements, which are designed as a first output gear 15 and a second output gear 16. The output gears 15, 16 each mesh with a compensating element 17 designed as a spur gear. The compensating elements 17 are mounted in a differential cage 14 so as to be rotatable about respective axes. The first output gear 15 is rotationally fixed to the output shaft 1, which, in turn, is connected via a shaft joint 18a to a first sideshaft 1a. The second output gear 16 is rotationally fixed to the output shaft 2, which, in turn, is connected via a shaft joint 18c to a second sideshaft 2a. A drive element 13 designed as a spur gear is rotationally fixed to the differential cage 14 and can be driven by a gearwheel designed as a bevel gear 12, which is rotationally fixed to a drive shaft 11 of the electric machine.

[0032] The differential bevel gears 17, which operate between the spur gear 13 and the two output gears 15, 16, can transmit a turning motion from the spur gear 13 to the two output gears 15, 16 and provide a compensatory turning motion between the two output gears 15, 16. During straight-ahead travel 99 of the vehicle 1000 (cf. FIG. 5), the differential bevel gears 17 do not rotate, but rather revolve with the spur gear 13, and so the effect of the differential bevel gears 17 is neutral. During cornering, however, the differential bevel gears 17 rotate in opposition about the respective axes, and so the output gear 15, 16 is driven faster in the outer radius and the other output gear 16, 15 is driven more slowly.

[0033] The sideshafts 1a, 2a are connected via shaft joints 18b and 18d, respectively, to wheels 20 of the vehicle. The drive shaft 11 is connected to a rotor (not shown in greater detail) of an electric machine EM, which is the prime mover of the differential.

[0034] The axis B of the electric machine EM is situated at an angle α with respect to the output shafts 1, 2. The inclination angle α is between five degrees (5°) and ten degrees (10°) in the present case. In this way, an electric machine EM having a larger diameter than is the case from the prior art can be provided for the axle drive 100. This example embodiment provides for a bevel gearing in the form of beveloid gears having a beveloid gearwheel in order to bring about the angle.

[0035] The differential 10 is arranged essentially symmetrically with respect to the lateral distance to the wheels 20, i.e., in the center of the vehicle. The electric machine is therefore situated on one of the two sides with respect to the longitudinal axis X of the vehicle. In the present case, the electric machine is situated to the left, in a direction of travel 99, of the longitudinal axis X. The symmetrical arrangement allows for longer sideshafts and smaller deflection angles in the shaft joints.

[0036] In the example embodiment according to FIG. 2, in contrast to the example embodiment according to FIG. 1, the input shaft 11 of the electric machine EM is coupled via a shaft joint 21 to an intermediate shaft 12a, since the axis of the drive shaft is arranged at an angle with respect to the axis of the intermediate shaft. The intermediate shaft 12a is rotationally fixed to the gearwheel 12. There is no bevel gearing here, but rather an involute gearing. For the rest, this example embodiment corresponds to the example embodiment according to FIG. 2, and so reference is made to the comments presented with respect thereto.

[0037] In the example embodiment according to FIG. 3, in contrast to the example embodiment according to FIG. 2, the input shaft 11 of the electric machine EM is connected via two shaft joints 21, 22 to the gearwheel 12. The two joints 21, 22 are connected by an intermediate shaft 23. For the rest, this example embodiment corresponds to the example embodiment according to FIG. 2, and so reference is made to the comments presented with respect thereto.

[0038] One further preferred example embodiment is represented in FIG. 4. In the example embodiment of FIG. 4, in contrast to the example embodiment according to FIG. 2, the differential 10 is not symmetrically arranged with respect to the distance to the wheels 20. Instead, the differential 10 is arranged on one of the two sides of the vehicle longitudinal axis X, in the present case on the right side in the direction of travel 99. In addition, the output shaft 2, which connects the output gear 16 to the shaft joint 18c, is longer than in the example embodiment according to FIG. 2. In the present example, the output shaft 2 is longer than the length of the electric machine EM. The sideshafts 1a, 2a are designed correspondingly shorter. Due to this asymmetrical arrangement, the diameter of the electric machine EM and, thereby, also the power of the electric machine EM can be increased. The shorter sideshafts result in larger deflection angles of the shaft joints, however.

[0039] Finally, FIG. 5 shows a vehicle 1000. The vehicle 1000 can be equipped with each axle drive 100 of the type described in FIGS. 1 through 4. In FIG. 5, the drive train from FIG. 4 arranged symmetrically with respect to the vehicle axis X is shown in diagrammatic form.

[0040] The invention was comprehensively described and explained with reference to the drawings and the description. The description and the explanation are to be understood as an example and are not to be understood as limiting. The invention is not limited to the disclosed embodiments. Other embodiments or variations result for a person skilled in the art within the scope of the utilization of the present invention and within the scope of a precise analysis of the drawings, the disclosure, and the following claims.

[0041] In the claims, the words “comprise” and “comprising” do not rule out the presence of further elements or steps. The indefinite article “a” does not rule out the presence of a plurality. A single element or a single unit can carry out the functions of several of the units mentioned in the claims. The mere mention of a few measures in multiple various dependent claims is not to be understood to mean that a combination of these measures cannot also be advantageously utilized.

[0042] Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims. In the claims, reference characters corresponding to elements recited in the detailed description and the drawings may be recited. Such reference characters are enclosed within parentheses and are provided as an aid for reference to example embodiments described in the detailed description and the drawings. Such reference characters are provided for convenience only and have no effect on the scope of the claims. In particular, such reference characters are not intended to limit the claims to the particular example embodiments described in the detailed description and the drawings.

REFERENCE CHARACTERS

[0043] 1 first output shaft, axle output [0044] 1a first sideshaft [0045] 2 second output shaft, axle output [0046] 2a second sideshaft [0047] 10 bevel gear differential [0048] 11 drive shaft [0049] 12 bevel gear, gearwheel [0050] 12a intermediate shaft [0051] 13 drive element, spur gear [0052] 14 differential cage [0053] 15 first output gear [0054] 16 second output gear [0055] 17 compensating element [0056] 18a-d shaft joints [0057] 20 wheels [0058] 21 shaft joint [0059] 22 shaft joint [0060] 23 intermediate shaft [0061] EM electric machine [0062] 100 electric axle drive [0063] 1000 vehicle