Electromechanical Dual Steering System for a Utility Vehicle

Abstract

An electromechanical dual steering system for a utility vehicle includes two steering systems, each having a drive unit for actuating one steering linkage each for wheels of the utility vehicle. Each drive unit has an electric motor. The dual steering system has a main power supply for supplying the electric motors with energy. The electromechanical dual steering system is characterized in that the dual steering system has at least one emergency power supply for supplying at least one electric motor with energy in the event that the main power supply fails.

Claims

1-14. (canceled)

15. An electromechanical dual-circuit steering system for a utility vehicle, comprising: two steering systems, each comprising a drive unit for actuating a respective steering linkage for wheels of the utility vehicle, wherein each drive unit has a respective electric motor; a main power supply of the dual-circuit steering system for supplying the electric motors with energy; and at least one emergency power supply for supplying at least one electric motor with energy in an event of a failure of the main power supply.

16. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the dual-circuit steering system comprises one substantially independent emergency power supply per electric motor.

17. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the emergency power supply has a generator which is designed to be driven by rolling of the utility vehicle and to supply at least one of the electric motors with energy.

18. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the emergency power supply has an energy store for supplying the electric motor.

19. The electromechanical dual-circuit steering system as claimed in claim 18, wherein the energy store is a capacitor.

20. The electromechanical dual-circuit steering system as claimed in claim 18, wherein the emergency power supply is designed to charge up the energy store, in the event of a failure of the main power supply, by recuperation of restoring forces from the steering linkage.

21. The electromechanical dual-circuit steering system as claimed in claim 18, wherein the energy store has a rechargeable battery.

22. The electromechanical dual-circuit steering system as claimed in claim 21, wherein the rechargeable battery serves as an intermediate store for a generator for supplying the electric motor with energy.

23. The electromechanical dual-circuit steering system as claimed in claim 15, wherein each steering system has a dedicated, substantially closed, steering housing, and the emergency power supply and the respective drive unit are arranged in at least one steering housing.

24. The electromechanical dual-circuit steering system as claimed in claim 23, wherein an energy store of the emergency power supply is arranged in the steering housing.

25. The electromechanical dual-circuit steering system as claimed in claim 24, wherein a generator of the emergency power supply is arranged outside the steering housing.

26. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the dual-circuit steering system has an emergency power supply for supplying all of the electric motors with energy in the event of a failure of the main power supply.

27. The electromechanical dual-circuit steering system as claimed in claim 15, wherein a force for actuating the steering linkage originates solely from the respective electric motor.

28. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the dual-circuit steering system comprises a data interface for actuating the electric motor by an autonomous driving control system for driverless operation of the utility vehicle.

29. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the dual-circuit steering system has a sensor which is arranged on a direction-selecting element of the utility vehicle and which detects a desired steering angle and transmits same to a motor control module of the dual-circuit steering system, which motor control module, based on the detected desired steering angle, activates the electric motor.

30. The electromechanical dual-circuit steering system as claimed in claim 29, wherein the motor control module compares the desired steering angle with an actual steering angle.

31. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the respective electric motor for actuating the steering linkage comprises a linear actuator.

32. The electromechanical dual-circuit steering system as claimed in claim 31, wherein the linear actuator has a solenoid.

33. The electromechanical dual-circuit steering system as claimed in claim 15, wherein the respective electric motor has a rotor which is designed as a hollow shaft and is connected to a spindle nut of the drive unit for rotation therewith, which spindle nut is designed to drive a threaded spindle, which is incorporated by the drive unit, for actuating the steering linkage.

34. A utility vehicle comprising an electromechanical dual-circuit steering system as claimed in claim 15.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is a schematic overview of an electromechanical dual-circuit steering system.

[0029] FIG. 2 is a sectional illustration of a steering system of a first exemplary embodiment of an electromechanical dual-circuit steering system according to the invention.

[0030] FIG. 3 is a sectional illustration of a steering system of a second exemplary embodiment of an electromechanical dual-circuit steering system according to the invention.

[0031] FIG. 4 is a top view of a steering system of a third exemplary embodiment of an electromechanical dual-circuit steering system according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0032] The illustration of FIG. 1 shows, in an overview, the basic design of an electromechanical dual-circuit steering system for utility vehicles. The dual-circuit steering system has two steering systems 1a, 1b, specifically especially a respective steering system 1a, 1b for the front steerable axle 2a and the rear steerable axle 2b of the utility vehicle. The direction-selecting element 3 of the utility vehicle, which is designed as a steering wheel and is connected here electrically in a manner not illustrated specifically here to the steering systems 1a, 1b, the steering linkages 5a, 5b, which connect the steering systems 1a, 1b to the respective steerable axle 2a, 2b, and the wheels 6a, 6b, 6c, 6d are likewise illustrated. This design applies to all of the exemplary embodiments described below. In this case, one individual steering system 1a, 1b in each case, but also the respective other steering system 1a, 1b are formed identically.

[0033] For the first exemplary embodiment of the electromechanical dual-circuit steering system, the steering system 1a with drive unit 4 is illustrated in FIG. 2, the drive unit 4 being arranged in a substantially closed steering housing 12 of the steering system 1a. The electric motor 7 of the drive unit 4 is supplied with electrical energy from the on-board network as the main power supply 8 during regular operation. In addition, the steering system 1a has an energy store 11, which is designed as a capacitor 10, of an emergency power supply 9 for the electric motor 7, which emergency power supply 9 supplies the electric motor 7 in the event of failure of the main power supply 8. The rotor 13 of the electric motor 7 is formed with the spindle nut 14 and the threaded spindle 15 in order to actuate the respective steering linkage 5a, 5b.

[0034] The steering system 1a with the drive unit 4 of the second exemplary embodiment is illustrated in FIG. 3. The second exemplary embodiment basically corresponds to the first exemplary embodiment, but the electric motor 7 here having a linear actuator 16, which is designed as a solenoid, for actuating the respective steering linkage 5a, 5b.

[0035] Finally, the steering system 1a with the drive unit 4 of the third exemplary embodiment is reproduced in FIG. 4. In this exemplary embodiment, the emergency power supply 9 has both an energy store 11, which is designed as a capacitor 10, and a generator 17, which is arranged outside the steering housing. The generator is driven depending on the driving, supplies the electric motor 7 and charges up the capacitor 10, which acts as an intermediate store. The capacitor 10 is thereby kept charged. This exemplary embodiment of the dual-circuit steering system furthermore has a motor control module 18 to which a desired steering angle which has been detected by a sensor on the direction-selecting element 3 is transmitted. The motor control module 18 then activates the electric motor 7 in accordance with the detected desired steering angle. A steer-by-wire functionality is thereby implemented. In addition, the motor control module 18 also forms a data interface 19 for an autonomous driving control system such that driverless operation of the utility vehicle is made possible.