STEERING DRIVE FOR A STEERING AXLE OF A STEERABLE VEHICLE, STEERING AXLE, AND INDUSTRIAL TRUCK

Abstract

A steering drive for a steering axle of a steerable vehicle includes an electric motor with a motor shaft. A steering lever is rotatable about a pivot axis that is parallel to the electric motor. First and second planetary stages each have a sun gear, planet gears, and a planet carrier. The steering drive is configured such that a force flow runs from the first sun gear via the first planet gears to the first planet carrier. The force flow furthermore runs via the second sun gear and via the second planet gears to the second planet carrier, and furthermore runs to the steering lever. The steering drive has a spur gear stage and is configured such that a force flow from the motor shaft to the first sun gear runs via the spur gear stage. Also disclosed is a steering axle and an industrial truck.

Claims

1. A steering drive (27) for a steering axle (1) of a steerable vehicle, comprising; an electric motor (1) with a motor shaft (2); a first planetary stage (29) with a first sun gear (31), first planet gears (16), and a first planet carrier (17); a second planetary stage (30) with a second sun gear (18), second planet gears (19), and a second planet carrier (20); and a steering lever (25) with a spur gear stage (33), the steering lever (25) rotatable about a pivot axis (15) that is parallel to the electric motor; wherein the steering drive (27) is configured such that a force flow runs from the first sun gear (31) via the first planet gears (16) to the first planet carrier (17), such that the force flow furthermore runs via the second sun gear (18) and via the second planet gears (19) to the second planet carrier (20), and such that the force flow furthermore runs to the steering lever (25), and the steering lever (25) being supported so as to be rotatable about a pivot axis (15); and wherein the steering drive (27) is configured such that a force flow from the motor shaft (2) to the first sun gear (31) runs via the spur gear stage (33).

2. The steering drive (27) as claimed in claim 1, wherein the steering drive (27) comprises a housing (4), a partial region of the housing (4) constituting a front end shield of the electric motor (1).

3. The steering drive (27) as claimed in claim 1, wherein the motor shaft (2) has a toothing (5) that meshes with an intermediate gear (6) of the spur gear stage (33).

4. The steering drive (27) as claimed in claim 3, wherein the intermediate gear (6) is supported by means of a bolt (11) that can be screwed into the housing (4).

5. The steering drive (27) as claimed in claim 3, wherein the intermediate gear (6) meshes with a further spur gear (13) that is connected rotationally conjointly to the first spur gear (31).

6. The steering drive (27) as claimed in claim 5, wherein the further spur gear (13) is supported on a first cover (26) that closes the first spur gear stage (29) and the second spur gear stage (30) in a partial region of the housing (4).

7. The steering drive (27) as claimed in claim 6, wherein the steering lever (25) has a conical receptacle (24) for the arrangement of a bearing assembly.

8. The steering drive (27) as claimed in claim 6, wherein the steering lever (25) and the second planet carrier (20) are supported on a second cover (21) by a common bearing assembly (23).

9. The steering drive (27) as claimed in claim 8, wherein the steering drive (27) comprises a ring gear (22), the ring gear (22) meshing with the first planet gears (16) and the second planet gears (19) and being arranged rotationally fixed with respect to the housing (4).

10. The steering drive (27) as claimed in claim 9, wherein the ring gear (22) is held between the first cover (26) and the second cover (21).

11. A steering axle comprising a steering drive (27) as claimed in claim 1.

12. An industrial truck comprising the steering axle as claimed in claim 11.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0039] In the drawings:

[0040] FIG. 1 shows, by way of example and schematically, a possible embodiment of a steering drive according to the invention for a steering axle of a steerable vehicle.

[0041] Identical objects, functional units and similar components are denoted by the same reference designations throughout the figures. These objects, functional units and similar components are of identical design in terms of their technical features unless explicitly or implicitly stated otherwise in the description.

DETAILED DESCRIPTION

[0042] FIG. 1 shows, by way of example and schematically, a possible embodiment of a steering drive 27 according to the invention for a steering axle (not illustrated) of a steerable vehicle.

[0043] The steering drive 27 comprises an electric motor 1 with a motor shaft 2. The electric motor 1 and the motor shaft 2 are in this case concentric with respect to an axis 3, which also constitutes the axis of rotation of the motor shaft 2. As can be seen, the motor shaft 2 is supported in a housing 4 of the steering drive by means of a bearing assembly 28. The housing 4 thus, in the region of the bearing assembly 28, constitutes a front end shield of the electric motor 1.

[0044] The steering drive 27 furthermore comprises a first planetary stage 29 with a first sun gear 31, first planet gears 16 and a first planet carrier 17 and comprises a second planetary stage 30 with a second sun gear 18, second planet gears 19 and a second planet carrier 20. The first sun gear 31 meshes with the first planet gears 19, which are held by the first planet carrier 17. The first planet carrier 17 is connected rotationally conjointly to the second sun gear 18, which in turn meshes with the second planet gears 19. The second planet gears 19 are held by the second planet carrier 20.

[0045] The first planetary stage 29 and the second planetary stage 30 are furthermore enclosed radially by a ring gear 22. Both the first planet gears 16 and the second planet gears 19 mesh with the ring gear 22. Here, the ring gear 22 is held rotationally fixedly between a first cover 26 and a second cover 21. The first cover 26 and the second cover 21 axially enclose the first planetary stage 29 and the second planetary stage 30 and thus enclose a partial region of the housing 4 which houses the first planetary stage 29 and the second planetary stage 30.

[0046] Furthermore, the steering drive 27 also comprises a steering lever 25, which is connected rotationally conjointly to the second planet carrier 20. The steering lever 25 itself has a conical receptacle 24 for the arrangement of the bearing assembly (not illustrated). As can be seen, the receptacle 24 is situated at the same level as the bearing assembly 23 which supports the second planet carrier 20 and the steering lever 25. The bearing assembly 32 can thus be kept free of tilting forces.

[0047] The steering drive 27 finally also comprises a spur gear stage 33 which, in the example, comprises a toothing 5 of the motor shaft 2, an intermediate gear 6, and a further spur gear 13. The intermediate gear 6 is supported on a bolt 11 via a bearing assembly 9. The bolt 11 has, at its lower end, a threaded region 7 by means of which it is screwed into a corresponding mating thread 12 of the housing 4. An inner ring of the bearing assembly 9 is clamped axially by means of a planar contact surface 10 and a ring 8, which is planar on both sides. The further spur gear 13 is supported, via a bearing assembly 32, on a shaft 14 on which the first sun gear 31 is also supported. The shaft 14, the first sun gear 31 and the further spur gear are rotatable about the pivot axis 15, in the same way as the steering lever 25 is pivotable about the pivot axis 15. The toothing 5 of the motor shaft 2 meshes with the intermediate gear 6, and the intermediate gear 6 meshes with the further spur gear 13.

[0048] In FIG. 1, a force flow in the steering drive runs from the electric motor 1 via the motor shaft 2, and the toothing 5 of the motor shaft 2, to the intermediate gear 6. A first speed reduction of the rotational speed occurs here. The force flow runs onward to the further spur gear 13 and via the shaft 14 to the first sun gear 31. From there, the force flow runs via the first planet gears 16 to the first planet carrier 17, and onward via the second sun gear 18 and via the second planet gears 19 to the second planet carrier 20. Since the ring gear 22 is held rotationally fixed with respect to the housing 4, the force flow runs onward from the second planet carrier 20 to the steering lever 25, such that the steering lever 25 can actuate a steering system of the steering axle.

TABLE-US-00001 Reference signs 1 Electric motor 2 Motor shaft 3 Axis 4 Housing 5 Toothing of the motor shaft 6 Intermediate gear 7 Thread region 8 Ring 9 Bearing assembly 10 Contact surface 11 Bolt 12 Mating thread 13 Further spur gear 14 Shaft 15 Axis 16 First planet gear 17 First planet carrier 18 Second sun gear 19 Second planet gear 20 Second planet carrier 21 Second cover 22 Ring gear 23 Bearing assembly 24 Receptacle 25 Steering lever 26 First cover 27 Steering drive 28 Bearing assembly 29 First planetary stage 30 Second planetary stage 31 First sun gear 32 Bearing assembly 33 Spur gear stage