Electrically driveable steering axle and vehicle

Abstract

The invention relates to an electrically drivable steering axle (10) having an axle housing (11), an electric motor (12), a transmission (13), a differential (14) with a first output shaft (18) and a second output shaft (18), a first wheel head (15), a second wheel head (16) and a steering linkage (17, 17, 17). The electric motor (12) is drive-connected to the first wheel head (15) and to the second wheel head (16) via the transmission (13) and the differential (14). The steering axle (10) according to the invention is distinguished by the fact that the electric motor (12), the transmission (13), and the differential (14) are arranged coaxially with the first output shaft (18) and the second output shaft (18). The invention additionally relates to a corresponding vehicle.

Claims

1. An electrically drivable steering axle, comprising: an axle housing; an electric motor; a shiftable transmission configured as an at least two-stage transmission and having at least two shiftable transmission ratios for converting torque from the electric motor, the transmission having a sole transmission input shaft through which torque from the electric motor is fed-into the transmission; a differential having a first output shaft and a second output shaft; a first wheel head; a second wheel head; a steering linkage, wherein the electric motor is drive-connected to the first wheel head and to the second wheel head via the transmission and the differential, and wherein the electric motor, the transmission and the differential are arranged coaxially with the first output shaft and the second output shaft; and wherein the first and the second output shafts of the differential connect the differential to the first and the second wheel heads, respectively; and the first and the second output shafts of the differential are entirely enclosed within the axle housing from the differential to first and the second wheel heads, respectively.

2. The steering axle according to claim 1, wherein the electric motor has a motor shaft, the transmission has an input shaft and an output shaft, and the differential has an input shaft, wherein the motor shaft, the input shaft and the output shaft of the transmission, and the input shaft of the differential are configured as hollow shafts.

3. The steering axle according to claim 2, the first output shaft and the second output shaft of the differential are arranged in the hollow shafts.

4. The steering axle according to claim 1, wherein the axle housing has a common housing centrally located between the first and the second wheel heads, wherein the electric motor, the transmission, and the differential are arranged in the common housing.

5. The steering axle according to claim 4, wherein the common housing is a constituent part of the axle housing such that from the first wheel head to the second wheel head the steering axle is a beam axle or a rigid axle.

6. The steering axle according to claim 1, further comprising a first disc brake assigned to the first wheel head, and a second disc brake assigned to the second wheel head.

7. The steering axle according to claim 1, wherein the transmission is configured as a planetary gear train and the electric motor is a three-phase electric motor that is connected to an electric battery via an inverter which converts direct current from the battery to alternating current for controlling operation of the electric motor.

8. The steering axle according to claim 1, further comprising a differential lock assigned to the differential, wherein rotational speed and torque directed from the transmission to the differential are distributed to the first and the second output shafts of the differential based on a rotational resistance of the first and the second output shafts of the differential.

9. A vehicle comprising the steering axle according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows, by way of example and in schematic form, a possible embodiment of an electrically drivable steering axle according to the invention.

(2) FIG. 2 shows a schematic view of the electrical drivable steering axle of FIG. 1.

DETAILED DESCRIPTION

(3) Identical objects, functional units and comparable components are designated by the same references across the FIGURE. These objects, functional units and comparable components are identical with regard to their technical features, unless the description explicitly or implicitly states otherwise.

(4) FIGS. 1 and 2 show, by way of example and in schematic form, a possible embodiment of an electrically drivable steering axle 10 according to the invention. The steering axle 10 comprises an axle housing 11, an electric motor 12, a transmission 13, a differential 14 having a first output shaft 18 and a second output shaft 18, a first wheel head 15, a second wheel head 16, and a steering linkage 17, 17, 17. The steering axle 10 is a beam axle 10.

(5) The electric motor 12, the transmission 13 and the differential 14 in this case are arranged in a common housing 11 that constitutes an axially central constituent part of the axle housing 11. In the common housing 11, the electric motor 12 is arranged on the far left in the representation in the figures, and its motor shaft 25 points to the right. Via the motor shaft 25 of the electric motor 12, or via an input shaft 26 of the transmission 13, the electric motor 12 feeds a torque and a rotational speed into the transmission 13. As an example, the motor shaft 25 of the electric motor 12 and the input shaft 26 of the transmission 13 are identical or are realized in one piece. In the representation in the figures, the transmission 13 is arranged immediately to the right of the electric motor 12 and is realized as a two-stage planetary gear train 13. The transmission 13 converts the torque and rotational speed and delivers them into the differential 14 via an output shaft 28 of the transmission 13 and an input shaft 29 of the differential 14. The output shaft 28 of the transmission 13 and the input shaft 29 of the differential 14 are also, by way of example, identical, or realized in one piece. The differential 14 comprises, by way of example, a differential lock 27 and distributes the fed-in torque, as well as the fed-in rotational speed, via the first output shaft 18 and the second output shaft 18 to the first wheel head 15 and to the second wheel head 16. In the representation in FIG. 1, the first output shaft 18 and the second output shaft 18 are concealed by the axle housing 11. Thus, the electric motor 12 is drive-connected to the first and the second wheel head 15, 16 via the transmission 13, the differential 14 and the first and the second output shaft 18, 18.

(6) In order to save installation space and weight, and to improve the efficiency of the steering axle 10, the electric motor 12, the transmission 13 and the differential 14 are arranged coaxially with the first output shaft 18 and the second output shaft 18 in the axle housing 11. To enable the electric motor 12, the transmission 13 and the differential 14 to be arranged coaxially around the first output shaft 18 and the second output shaft 18, the motor shaft 25 of the electric motor 12, the input shaft 26 of the transmission 13, the output shaft 28 of the transmission 13 and the input shaft of the differential 14 are each realized as hollow shafts through which respectively the first output shaft 18 and the second output shaft 18 are routed.

(7) The first wheel head 15 and the second wheel head 16 each have a pivot bearing assembly to enable a steering movement. The steering linkage 17, 17, 17 connects the first wheel head 15 to the second wheel head 16 in such a manner that a steering movement of the first wheel head 15 is transmitted to the second wheel head 16 in compliance with the Ackermann condition. Specifically, the steering linkage 17, 17, 17 is composed of a track rod 17, two track levers 17 and a steering lever 17. The steering lever is actuated, on the basis of a steering angle of a steering wheel, by an electric steering motor (not represented in the FIGURE).

(8) There is a first disc brake 19 assigned to the first wheel head 15, and there is a second disc brake 20 assigned to the second wheel head 16. The first disc brake 19 comprises a first brake-fluid reservoir 21, and the second disc brake 20 comprises a second brake-fluid reservoir 22. In addition, there is a first rotational-speed sensor 23 assigned to the first wheel head 15, and there is a second rotational-speed sensor 24 assigned to the second wheel head 16.

REFERENCES

(9) 10 steering axle, beam axle 11 axle housing 11 common housing 12 electric motor 13 transmission, planetary gear train 14 differential 15 first wheel head 16 second wheel head 17 track rod, steering linkage 17 track lever, steering linkage 17 steering lever, steering linkage 18 first output shaft 18 second output shaft 19 first disc brake 20 second disc brake 21 first reservoir 22 second reservoir 23 first rotational-speed sensor 24 second rotational-speed sensor 25 motor shaft 26 transmission input shaft 27 differential lock 28 transmission output shaft 29 differential input shaft