Steered rigid axle of a vehicle with an axle bridge with an electric motor as drive

Abstract

A steered rigid axle of a vehicle (1) having an axle bridge (2) with at least one electric machine as a drive is proposed, which is connected to at least one output shaft (3, 4) via at least one transmission stage. A vehicle wheel (7, 8) mounted on the axle bridge (2) in a steerable manner is connected to each output shaft (3, 4). The transmission stage is designed as a bevel gear stage (9, 10) for compensating for an axle offset between a wheel axle (11) of the vehicle wheels (7, 8) and a drive axle (12) of the electric machine. A vehicle (1) having at least one rigid axle is also proposed.

Description

[0001] The present invention relates to a steered rigid axle of a vehicle having an axle bridge with at least one electric motor as the drive. Furthermore, the invention relates to a vehicle having at least one steered rigid axle.

[0002] Steered rigid axles with an axle bridge and steerable vehicle wheels are well known in automotive engineering. These rigid axles are typically mechanically driven via a cardan shaft or similar device, and power is transmitted via a differential. The differential ensures even distribution of torque to the vehicle wheels.

[0003] When using an electric motor as the drive in the axle bridge of the steered rigid axle, the problem arises that at least one gear ratio is required between the electric motor and the output shafts to increase the drive torque to the required level. This creates a corresponding axle offset between a wheel axle of the vehicle wheels and a drive axle of the electric motor, which disadvantageously increases the installation space required in the axle bridge of the rigid axle.

[0004] The present invention is based on the object of proposing a steered, electrically driven rigid axle and a vehicle with the rigid axle, which realize a sufficient gear ratio in a space-saving and efficient manner.

[0005] This object is achieved according to the invention by the features of patent claims 1 and 10, respectively. Advantageous and claimed developments emerge from the subclaims and the description as well as the drawing.

[0006] Thus, a steered rigid axle of a vehicle with an axle bridge with at least one electric machine as a drive is proposed, which is connected to at least one output shaft via at least one transmission stage, wherein a vehicle wheel mounted on the axle bridge in a steerable manner is connected to each output shaft and wherein the transmission stage is designed as a bevel gear stage for compensating an axle offset between a wheel axle of the vehicle wheels and a drive axle of the electric machine.

[0007] In this way, the electrically driven rigid axle with the output shafts arranged at a predetermined oblique axle angle achieves a sufficient final drive ratio thanks to the bevel gear stage provided on each output shaft as an angular gear. Furthermore, the additional center distance is compensated for by the oblique arrangement of the output shafts, allowing the bevel gear stages with the associated output shafts to be integrated into the existing installation space of the axle bridge. This not only achieves a sufficient drive ratio in a space-saving and efficient manner, but also enables a robust bearing arrangement for the proposed rigid axle thanks to the external gearing stage.

[0008] Within the scope of the invention, it is possible to use various types of angular gears in the claimed rigid axle. It is particularly preferred that the bevel gear stage be provided with straight-toothed, helical-toothed, and / or curved-toothed gears. Accordingly, gears with, for example, beveloid, crown, spiral bevel, zero-bevel, or hypoid gearing or the like can be used in the bevel gear stage.

[0009] To achieve an axial angle for the output shafts, it is possible within the scope of the invention for at least one gear of the bevel gear stage to be designed as a bevel gear. For example, two meshing bevel gears or tapered gears or the like can be used in the bevel gear stage to compensate for the axial offset between the wheel axle and the drive axle of the electric machine generated by the gear ratio stage.

[0010] It is also conceivable that in order to achieve the axle angle in the output shafts to compensate for the axle offset between the wheel axle and the drive axle of the electric machine, it is provided within the scope of the present invention that the bevel gear stage has a bevel gear and a spur gear meshing with the bevel gear.

[0011] In order to achieve a stable bearing arrangement in the bevel gear stage, when using two bevel gears, it can be provided that the respective bevel gear of the bevel gear stage is mounted on both sides of the associated output shaft or on a rotation axis arranged coaxially to the drive axis via rolling bearings.

[0012] When using a bevel gear and a spur gear, it can be provided that the spur gear of the bevel gear stage is mounted on both sides via rolling bearings on a rotational axis arranged coaxially to the drive axis or on the associated output shaft.

[0013] Needle roller bearings, ball bearings, tapered roller bearings, and similar types can be used. O- and X-bearing arrangements, as well as loose-fixed bearing arrangements and other adjusted bearings are possible.

[0014] To compensate for the axle angle of the obliquely arranged output shafts, a constant velocity joint or the like is provided at one end of each output shaft facing the vehicle wheel.

[0015] In an embodiment of the steered rigid axle with separately driven output shafts without a differential gear, it can be provided within the scope of the invention that each output shaft is coupled to an electric machine via at least one bevel gear stage as a transmission for the separate drive.

[0016] It is also conceivable that in an embodiment of the steered rigid axle with a common drive of the output shafts via a differential gear, it can be provided within the scope of the invention that both output shafts are each coupled via at least one bevel gear stage to a differential gear for common drive via an electric machine.

[0017] The object underlying the invention is also achieved by a vehicle with at least one steered rigid axle as described above, whereby the advantages already described and further advantages arise.

[0018] The present invention is further explained below with reference to the drawings.

[0019] The sole figure of the invention shows a schematic embodiment of a steered rigid axle according to the invention on a vehicle 1 shown only as an example.

[0020] The steered rigid axle comprises an axle bridge 2, depending on the design, with at least one electric machine (not shown in detail) as a drive, which is connected, for example, directly or via a gear ratio (likewise not shown in detail) to a differential gear (likewise not shown in detail) for jointly driving a first output shaft 3 and a second output shaft 4. However, it is also conceivable for each output shaft 3, 4 to be assigned an electric machine, wherein the output shafts 3, 4 are coupled to the respectively assigned electric machine via at least one gear ratio. In the figure, the arrangement of the at least one electric machine and, if applicable, the differential gear and possible gear ratio is merely indicated by a box.

[0021] On each output shaft 3, 4, a vehicle wheel 7, 8 is provided which is steerably connected via an associated steering knuckle 5, 6 and which is driven by the electrical machine(s) via the associated output shaft 3, 4.

[0022] To ensure sufficient final gear ratio, a bevel gear stage 9, 10 is provided on each output shaft 3, 4 as a gear ratio stage to compensate for the resulting axle offset between a wheel axle 11 and a drive axle 12 of the electric machine.

[0023] In the exemplary embodiment shown, each bevel gear stage 9, 10 comprises a bevel gear 13, 14, which meshes with a spur gear 15, 16. Each bevel gear 13, 14 of the bevel gear stage 9, 10 is mounted on the associated output shaft 3, 4 via two tapered roller bearings 17, 18, preferably in an O-arrangement, while each spur gear 15, 16 is mounted on a rotational axis arranged coaxially to the drive axis 12 via two tapered roller bearings 19, 20, preferably in an O-arrangement.

[0024] Each output shaft 3, 4 is arranged in the axle bridge 2 at a predetermined axle angle A with respect to the wheel axle 11. The axle angle A is compensated at the drive-side end of each output shaft 3, 4 by the associated bevel gear stage 9, 10. A constant velocity joint 21, 22 is provided to compensate the axle angle A at the end of each output shaft 3, 4 facing the vehicle wheel 7, 8. Reference symbol 1 vehicle 2 axle bridge 3 Output shaft 4 Output shaft 5 steering knuckles 6 steering knuckles 7 vehicle wheel 8 vehicle wheel 9 Bevel gear stage 10 bevel gear stage 11 Wheel axle of the vehicle wheels 12 Drive axle of the electrical machines 13 Bevel gear 14 Bevel gear 15 Spur gear 16 Spur gear 17 tapered roller bearings 18 tapered roller bearings 19 tapered roller bearings 20 tapered roller bearings 21 Constant velocity joint 22 Constant velocity joint A Axis angle

Claims

[1] Steered rigid axle of a vehicle (1) with an axle bridge (2) with at least one electric machine as a drive, which is connected to at least one output shaft (3, 4) via at least one transmission stage, wherein a vehicle wheel (7, 8) mounted on the axle bridge (2) in a steerable manner is connected to each output shaft (3, 4), and wherein the transmission stage is designed as a bevel gear stage (9, 10) for compensating an axle offset between a wheel axle (11) of the vehicle wheels (7, 8) and a drive axle (12) of the electric machine. [2] Steered rigid axle according to claim 1, characterized by that straight-toothed, helical-toothed and / or curved-toothed gears are provided in the bevel gear stage (9, 10). [3] Steered rigid axle according to claim 1 or 2, characterized by that at least one wheel of the bevel gear stage (9, 10) is designed as a bevel gear. [4] Steered rigid axle according to one of the preceding claims, characterized by that the bevel gear stage (9, 10) has a bevel gear (13, 14) and a spur gear (15, 16) meshing with the bevel gear (13, 14). [5] Steered rigid axle according to claim 3 or 4, characterized by that each wheel of the bevel gear stage (9, 10) is mounted on both sides of the associated output shaft (3, 4) or on a rotational axis arranged coaxially to the drive axis (12) via rolling bearings. [6] Steered rigid axle according to one of the preceding claims, characterized by that each output shaft (3, 4) is arranged in the axle bridge (2) at an axle angle (A) predetermined with respect to the wheel axle (11). [7] Steered rigid axle according to claim 6, characterized by that a constant velocity joint (21, 22) is provided at an end of each output shaft (3, 4) facing the vehicle wheel (6, 7) to compensate for the axle angle (A). [8] Steered rigid axle according to one of the preceding claims, characterized bythat each output shaft (3, 4) is coupled to an electric machine via at least one bevel gear stage as a transmission for separate drive. [9] Steered rigid axle according to one of claims 1 to 7, characterized by that both output shafts (3, 4) are each coupled via at least one bevel gear stage to a differential gear for common drive via an electric machine. [10] Vehicle (1) with at least one steered rigid axle according to one of the preceding claims.

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