Turntable steering device

Abstract

Turntable steering device with a vertically extending hub carrier (1) which is rotatably mounted about a vertical steering axis (3) at its upper end region and at its lower end region a wheel shaft (2) extending transversely to the steering axis (3) with two cylindrical axial ends (4, 4') is arranged and wherein each wheel hub (14) of an individual wheel (15) with its cylindrical hub opening (13) extending coaxially to the wheel axis is rotatably mounted at each of the cylindrical axial ends (4, 4') of the wheel shaft (2) by means of a wheel bearing and the wheel bearings are concentrically opposite each other, characterized in that the hub carrier (1) is formed in one piece with the wheel shaft (2) and the wheel bearings are twin roller bearings.

Description

[0001] The invention relates to a turntable steering device with a vertically extending hub carrier, which is rotatably mounted about a vertical steering axis at its upper end region and at its lower end region a wheel shaft extending transversely to the steering axis with two cylindrical axial ends is arranged and wherein each wheel hub of an individual wheel with its cylindrical hub opening extending coaxially to the wheel axis is rotatably mounted at each of the cylindrical axial ends of the wheel shaft by means of a wheel bearing and the wheel bearings are concentrically opposite each other.

[0002] In a known turntable steering system for a vehicle, the hub carrier has a horizontal through-hole in its lower section, into which a bolt is inserted as a wheel axle and secured, for example, by welding. This design is complex to manufacture and exhibits manufacturing tolerances that lead to uneven loading of the two individual wheels, which can result, among other things, in uneven wear of the individual wheels during operation.

[0003] From DE 10 2010 045 602 A1 a turntable steering device with a vertically extending hub carrier is known, which can be rotatably driven about a vertical steering axis at its upper end region.

[0004] The object of the invention is to create a turntable steering device of the type mentioned above which avoids these disadvantages and has a simple design with few manufacturing tolerances, as well as good absorption of the forces acting on the turntable steering device during operation.

[0005] This problem is solved for a wheel drive according to the invention by the fact that the hub carrier is formed in one piece with the wheel shaft and the wheel bearings are twin roller bearings.

[0006] This training enables, for example, the production of hub carriers and wheel axles with few manufacturing tolerances and low manufacturing effort using a single clamping in a tool.

[0007] Reducing the number of components also reduces the amount of storage required for these parts.

[0008] The assembly effort required to assemble the hub carrier and wheel axle is completely eliminated.

[0009] This means that the turntable steering device can also be manufactured cost-effectively.

[0010] The turntable steering device is advantageous for industrial trucks such as three-wheeled forklifts or can also be used as portal axles for four-wheeled forklifts.

[0011] If the hub carrier and wheel axle are designed as a single-piece casting, this component can be given a weight-saving configuration that still absorbs the forces occurring during operation.

[0012] To effectively absorb the forces acting on the turntable steering mechanism during operation, the twin roller bearings can be twin tapered roller bearings.

[0013] If the twin roller bearings are arranged in an O-configuration, they can absorb not only high radial loads but also axial forces from both directions. This makes the turntable steering system robust and low-wear during operation.

[0014] If the inner ring of each twin roller bearing, which is furthest from the steering axis, is subjected to axial force towards the steering axis and its inner ring, which is closer to the steering axis, is in axial contact with a stop of the one-piece component, then the wheel bearings are not laterally displaceable and therefore have low wear.

[0015] In a simple and easily assembled manner, the free ends of the cylindrical axial ends of the wheel shaft can be provided with a thread, onto which a nut can be screwed, acting towards the steering axle on the inner ring of the twin roller bearing furthest from the steering axle.

[0016] It is understood that other suitable constructions for applying pressure to the inner ring against the stop of the one-piece component can also be used according to the invention.

[0017] The outer ring of each twin roller bearing, which is closer to the steering axis, can be axially supported on a first hub stop of the wheel hub, and the outer ring of the twin roller bearing, which is further away from the steering axis, can be axially supported on a second hub stop of the wheel hub.

[0018] It is understood that, in order to reduce the size of the product, the outer ring of each twin roller bearing that is closer to the steering axis and the outer ring of the twin roller bearing that is further away from the steering axis can be formed in one piece.

[0019] A simple and easily manufactured, largely dimensionally accurate design can consist of the inner ring closer to the steering axle being designed as a first stop shoulder on the one-piece component and / or the second hub stop of the outer ring further away from the steering axle being designed as a second stop shoulder, or the first hub stop and / or the second hub stop being a retaining ring arranged in an annular groove of the wheel hub.

[0020] To protect the wheel bearings against dirt and moisture from the outside, each wheel hub can be sealed with its hub opening against the one-piece component via a ring sealing arrangement.

[0021] An embodiment of the invention is shown in the drawing and is described in more detail below. The single figure in the drawing shows a vertical sectional view of a turntable steering device. The illustrated turntable steering device for a vehicle has a vertically extending hub carrier 1, which is formed as a one-piece cast component with a wheel axle 2 at its lower end. The hub carrier 1 is rotatably mounted about a vertical steering axis 3 by a steering drive (not shown). The wheel shaft 2 extends transversely to the steering axis 3 and has cylindrical axial ends 4, 4' at its two free end regions, on which a twin tapered roller bearing 5, 5' is arranged in an O-arrangement. The inner ring 6 of the twin tapered roller bearings 5, 5', which is closer to the steering axis 3, is designed as a first stop shoulder 7, which extends radially to the wheel shaft 2 on the one-piece cast component.

[0022] The free ends of the cylindrical axial ends of the wheel shaft 2 are provided with a thread 8, onto which a nut 9 is screwed, which presses the two inner rings 6 and 9 of the twin tapered roller bearings 5, 5' against the first stop shoulders 7 without play.

[0023] The outer rings 11, 12 of the twin tapered roller bearings 5, 5', designed as a single component, are each inserted in mutually coaxial cylindrical hub openings 13 of wheel hubs 14 and are thus rotatably mounted on the wheel shaft 2.

[0024] A single wheel 15 of the vehicle is fixedly arranged on each wheel hub 14, with the two single wheels 15 forming a twin wheel.

[0025] The hub openings 13 have radially inwardly extending second stop shoulders 16 at their end regions furthest from the steering axis 3, against which the outer ring 12 is in contact with its end face furthest from the steering axis 3.

[0026] The outer ring 11, which is closer to the steering axis 3, is axially supported on a retaining ring 17, which is inserted in a ring groove 18 formed radially around the hub opening 13.

[0027] The side of the retaining ring 17 facing the outer ring 11 extends radially to the first stop shoulder 7.

[0028] To protect against contamination, the hub openings 13 are closed to the outside by covers 19.

[0029] From the first stop shoulders 7 towards the steering axis 3, the diameter of the wheel shaft 2 corresponds to the outer diameter of the outer rings 11, 12, and the hub openings 13 have an enlarged diameter. A ring seal 21 is inserted into the resulting ring recess 20 to protect the wheel bearings against contamination. Reference sign 1 hub carrier 2 Wheel shaft 3 Steering axle 4 axial end 4' axial end 5 twin tapered roller bearings 5' Twin tapered roller bearings 6 inner ring closer to the steering axis 7 first shoulder 8 threads 9 Mother 10 inner ring furthest from the steering axle 11 outer ring closer to the steering axis 12 outer ring furthest from the steering axle 13 Hub opening 14 wheel hubs 15 single wheel 16 second shoulder strikes 17 retaining ring 18 Ring groove 19 lids 20 ring recess 21 Ring sealing arrangement

Claims

[1] Turntable steering device with a vertically extending hub carrier (1) which is rotatably mounted about a vertical steering axis (3) at its upper end region and at its lower end region a wheel shaft (2) extending transversely to the steering axis (3) with two cylindrical axial ends (4, 4') is arranged and wherein each wheel hub (14) of an individual wheel (15) with its cylindrical hub opening (13) extending coaxially to the wheel axis is rotatably mounted at each of the cylindrical axial ends (4, 4') of the wheel shaft (2) by means of a wheel bearing and the wheel bearings are concentrically opposite each other, characterized by , that the hub carrier (1) is formed in one piece with the wheel shaft (2) and the wheel bearings are twin roller bearings. [2] Turntable steering device according to claim 1, characterized by , that the hub carrier (1) is formed with the wheel shaft (2) as a one-piece cast part. [3] Turntable steering device according to one of claims 1 and 2 , characterized by , that the twin roller bearings are twin tapered roller bearings (5, 5'). [4] Turntable steering device according to one of claims 1 and 3, characterized by , that the twin roller bearings (5, 5') are each arranged in an O-arrangement. [5] Turntable steering device according to any one of claims 1 to 4, characterized by , that the inner ring (10) of each twin roller bearing furthest from the steering axis (3) is axially acted upon towards the steering axis (3) and is in axial contact with its inner ring (6) closer to the steering axis (3) against a first hub stop of the one-piece component. [6] Turntable steering device according to claim 5, characterized by, that the free ends of the cylindrical axial ends (4, 4') of the wheel shaft (2) are provided with a thread (8), onto which a nut (9) is screwed, acting towards the steering axis (3) of the inner ring (10) of the twin roller bearing which is furthest from the steering axis (3). [7] Turntable steering device according to any one of claims 1 to 6, characterized by , that the outer ring (11) of each twin roller bearing closer to the steering axis (3) is axially supported on a first hub stop of the wheel hub (14) and the outer ring (10) of the twin roller bearing further away from the steering axis (3) is axially supported on a second hub stop of the wheel hub (14). [8] Turntable steering device according to claim 7, characterized by , that the inner ring (6) closer to the steering axis (3) is designed as a first stop shoulder (7) on the one-piece component and / or the second hub stop of the outer ring (12) further away from the steering axis (3) is designed as a second stop shoulder (16). [9] Turntable steering device according to claim 7, characterized by , that the first hub stop and / or the second hub stop is a retaining ring (17) which is arranged in an annular groove (18) of the wheel hub (14). [10] Turntable steering device according to one of the preceding claims, characterized by , that each wheel hub (14) with its hub opening (13) is sealed against the one-piece component via a ring sealing arrangement (21).

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