Steering drive

Abstract

The invention relates to a steering drive for a wheel drive of a transport device that is pivotable about a vertical steering axis 3, comprising a connecting plate 2 arranged on a component of the transport device, on which a hub support plate 25 of a hub support housing 5 of a wheel 7, which is pivotably driven about the vertical steering axis 3 by a steering motor and is parallel to the connecting plate 2, is pivotably mounted by means of a bearing arrangement 4. The connecting plate 2 has one or more first rolling element raceways 11 coaxial with the steering axis 3 on its side facing the hub support plate 25, and the hub support plate 25 has second rolling element raceways 11' opposite and corresponding to the rolling element raceways 11 on its side facing the connecting plate 2, wherein a plurality of rolling elements project into and are guided in the first and second rolling element raceways 11, 11'.

Description

[0001] The invention relates to a steering drive for a wheel drive of a transport device which is pivotable about a vertical steering axis, with a connecting plate arranged on a component of the transport device, on which a hub support plate of a hub support housing of a wheel which is pivotable about the vertical steering axis and parallel to the connecting plate is pivotably mounted by means of a bearing arrangement and which can be driven pivotably by a steering motor about the vertical steering axis.

[0002] In such steering drives, it is known that the bearing arrangements are designed as radial ball bearings. In order for these bearing arrangements to withstand high forces, predominantly in a vertical direction, they must be very strong and robust, making them complex and expensive.

[0003] The object of the invention is to create a steering drive of the type mentioned above which has a simple design and can absorb high axial forces in the vertical direction.

[0004] This problem is solved according to the invention in that the connecting plate has one or more first rolling element raceways coaxial to the steering axis on its side facing the hub carrier plate and the hub carrier plate has second rolling element raceways opposite and corresponding to the first rolling element raceways on its side facing the connecting plate, wherein a plurality of rolling elements project into and are guided in the first and second rolling element raceways.

[0005] Through this design, the hub carrier plate, connection plate and rolling elements take over the function of the bearing arrangement, resulting in a simple design.

[0006] Since the rolling element raceways are optimally arranged to absorb vertical forces, significantly softer materials and surface qualities can be selected for the hub carrier plate and the connection plate, resulting in a very cost-effective design.

[0007] The rolling element raceways preferably have a semicircular cross-section and the rolling elements are spheres, which results in a particularly simple design.

[0008] If forces in unfavorable directions are introduced into the bearing arrangement via the wheel, lifting of the rolling element raceways from the rolling elements is prevented by connecting the hub support plate and the connecting plate to each other by means of an anti-lift device, allowing them to rotate around the steering axis and preventing axial movement away from each other.

[0009] To allow relative rotation between the hub support plate and the connection plate, the hub support plate can be connected to the connection plate via an axial bearing, whereby the axial bearing can be a rolling bearing.

[0010] However, for a simple design, it is also possible for the axial bearing to be a plain bearing.

[0011] For this purpose, a ring-shaped sliding surface can be arranged in a simple manner on the hub support plate or a component firmly connected to the hub support plate, perpendicular and coaxial to the steering axis, which surrounds a retaining ring arranged on the connection plate and is in axial contact with it.

[0012] To reduce friction, the sliding surface is advantageously in axial contact with the retaining ring via a ring-shaped thrust washer, whereby the thrust washer can be arranged on the connecting plate in a rotationally secured manner.

[0013] Exemplary embodiments of the invention are shown in the drawing and are described in more detail below. The drawing shows: Fig. 1. A longitudinal section of a steering drive Fig. 2 a section of the steering drive to Fig. 1.

[0014] The steering drive shown in the figures has a connecting plate 2 fixedly arranged on a vehicle frame 1 of a transport device, on which a hub carrier housing 5 is pivotably arranged about a vertical steering axis 3 by means of a bearing arrangement 4.

[0015] For this purpose, the hub carrier housing 5 has at its upper end a hub carrier plate 25 with a radially circumferential steering gear ring 6, into which a drive pinion (not shown) of a steering drive arranged on the connection plate 2 engages.

[0016] A wheel 7 is rotatably mounted on the hub carrier housing 5 about a wheel axle 8 extending at right angles to the steering axle 3, the wheel axle 8 carrying a gear 9 which can be rotatably driven by a drive motor 24 arranged on the vehicle frame 1 via a drive train 10.

[0017] The horizontal connecting plate 2 has, on its side facing the also horizontal hub support plate 25, two first rolling element raceways 11 of semicircular cross-section arranged concentrically to each other, which are opposite the corresponding second rolling element raceways 11 in the hub support plate 25. A plurality of balls 12 are arranged and guided in the rolling element raceways 11, 11'.

[0018] To prevent the rolling element raceways 11, 11' from lifting off the balls 12, the hub carrier plate 25 and the connecting plate 2 are connected to each other by a lifting protection device 13 so that they can be rotated about the steering axis 3 and are also connected to each other against axial movement away from each other.

[0019] The hub carrier plate 25 is pre-tensioned by the anti-lift device 13 via the balls 12 against the connecting plate 2.

[0020] The anti-lift device 13 has an anti-lift ring 15 which is attached to the hub carrier plate 25 concentrically to the steering axis 3 by a screw connection 14, wherein the anti-lift ring 15 has a radially inwardly projecting ring extension 16 at its end area facing the connection plate 2.

[0021] The connecting plate 2 has a pipe stub 17 on its radially inner area, which protrudes through the ring extension 16.

[0022] On its area projecting through the ring extension 16, the pipe stub 17 has a radially circumferential annular groove 18 on its outer surface, into which a retaining ring 19 is inserted.

[0023] Between the retaining ring 19 and the annular surface 20 of the ring extension 16 facing away from the connecting plate 2, a ring-shaped thrust washer 21 is arranged in such a way that an axial bearing 28 is formed and the hub support plate 25 and the connecting plate 2 cannot move axially away from each other but are rotatably clamped against each other via the balls 12.

[0024] To secure the thrust washer 21 against rotation, it has a projection 22 that extends radially inwards into an axial groove 23 in the pipe stub 17.

[0025] A drive shaft 26 of the drive motor 24 with a face gear 27 protrudes through the pipe stub 17, via which the drive train 10 and the wheel 7 of the transport device can be rotatably driven. Reference sign 1 vehicle frame 2 Connection plate 3 Steering axle 4 Storage arrangement 5 hub carrier housings 6 Steering ring 7 wheel 8 wheel axle 9 gear 10 Powertrain 11 first rolling element raceways 11' second rolling element raceways 12 balls 13 Lift-off protection 14 screw connection 15 Anti-lift ring 16 ring attachment 17 pipe stubs 18 Ring groove 19 retaining ring 20 ring area 21 Thrust washer 22 Approach 23 Axial groove 24 Drive motor 25 Hub carrier plate 26 Drive shaft 27 Front teeth 28 axial bearings

Claims

[1] Steering drive for a wheel drive of a transport device which can be pivoted about a vertical steering axis (3), with a connecting plate (2) arranged on a component of the transport device, on which a hub carrier plate (25) of a hub carrier housing (5) of a wheel (7) which can be driven by a steering motor so as to be pivotable about the vertical steering axis (3) and is parallel to the connecting plate (2) is pivotally mounted by means of a bearing arrangement (4), characterized by that the connecting plate (2) has, on its side facing the hub carrier plate (25), one or more first rolling element raceways (11) coaxial with the steering axis (3), and the hub carrier plate (25) has, on its side facing the connecting plate (2), second rolling element raceways (11') opposite and corresponding to the rolling element raceways (11), wherein a plurality of rolling elements protrude into the first and second rolling element raceways (11, 11') and are guided in these. [2] Steering drive according to claim 1, characterized bythat the rolling element raceways (11, 11') have a semicircular cross-section and the rolling elements are balls (12). [3] Steering drive according to one of the preceding claims, characterized by that the hub carrier plate (25) and the connecting plate (2) are connected to one another by a lifting lock (13) so that they can rotate relative to one another about the steering axis (3) and are prevented from moving away from one another axially. [4] Steering drive according to claim 3, characterized by that the hub carrier plate (25) is preloaded against the connecting plate (2) by the lifting device (13) via the rolling elements. [5] Steering drive according to one of the preceding claims 3 and 4, characterized by that the hub carrier plate (25) is connected to the connecting plate (2) via an axial bearing (28). [6] Steering drive according to claim 5, characterized by that the axial bearing is a rolling bearing. [7] Steering drive according to claim 5, characterized bythat the axial bearing (28) is a plain bearing. [8] Steering drive according to claim 7, characterized by that an annular sliding surface (20) is arranged on the hub carrier plate (25) or a component firmly connected to the hub carrier plate at right angles and coaxially to the steering axis (3), which sliding surface engages around a retaining ring (19) arranged on the connecting plate (2) and is in axial contact therewith. [9] Steering drive according to claim 8, characterized by that the sliding surface (20) is axially in contact with the retaining ring (19) via an annular thrust washer (21). [10] Steering drive according to claim 9, characterized by that the thrust washer (21) is arranged on the connecting plate (2) in a rotationally secured manner.

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