SPROCKET FOR A CRAWLER UNDERCARRIAGE, CRAWLER UNDERCARRIAGE HAVING SUCH A SPROCKET, AND CRANE HAVING SUCH A CRAWLER UNDERCARRIAGE

Abstract

A sprocket for a crawler undercarriage comprises a plurality of sprocket teeth for engagement with a crawler track, wherein the sprocket teeth are arranged in a plurality of similar circumferential segments along the sprocket, and wherein an odd number of circumferential segments is provided.

Claims

1. A sprocket for a crawler undercarriage having a plurality of sprocket teeth for engagement with a crawler track, wherein the sprocket teeth are arranged in a plurality of similar circumferential segments along the sprocket, wherein an odd number of circumferential segments is provided.

2. A sprocket according to claim 1, wherein precisely three similar circumferential segments are provided.

3. A sprocket according to claim 1, wherein each circumferential segment has an odd number of sprocket teeth.

4. A sprocket according to claim 3, wherein each circumferential segment has precisely three sprocket teeth.

5. A sprocket according to claim 1, wherein all sprocket teeth are substantially identical in configuration.

6. A sprocket according to claim 1, wherein precisely nine sprocket teeth are provided.

7. A sprocket according to claim 1, comprising different teeth intervals between two neighbouring sprocket teeth.

8. A crawler undercarriage with a sprocket for a crawler undercarriage having a plurality of sprocket teeth for engagement with a crawler track, wherein the sprocket teeth are arranged in a plurality of similar circumferential segments along the sprocket, wherein an odd number of circumferential segments is provided.

9. A crane with a crawler undercarriage with a sprocket for a crawler undercarriage having a plurality of sprocket teeth for engagement with a crawler track, wherein the sprocket teeth are arranged in a plurality of similar circumferential segments along the sprocket, wherein an odd number of circumferential segments is provided.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0018] FIG. 1 shows a schematic partial side view of a crawler undercarriage having a sprocket in accordance with the invention and

[0019] FIG. 2 shows an enlarged detail view of the sprocket per FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020] A crawler undercarriage 1 can be used, for example, on a crane, especially on a caterpillar crane. The crawler undercarriage 1 can also serve for an excavator or other working apparatus.

[0021] The crawler undercarriage 1 is comprised of a revolving endless chain 2 having interconnected articulated chain links 3. Each chain link 3 has an engagement cam 4.

[0022] The crawler undercarriage 1, moreover, is comprised of a sprocket 5 having a total of 9 sprocket teeth 6. The sprocket 5 is able to be driven about an axis of rotation 7 by means of a drive unit (not shown) via a transmission (not shown) about the axis of rotation 7. In dependence upon the driving direction of turning about the axis of rotation 7, when the two crawler undercarriages 1 are running in the same direction travel forwards and backwards is possible, and a rotation of the crane is possible when the driving direction of the two crawler undercarriages 1 is different.

[0023] The sprocket 5 is comprised of a substantially cylindrical central disc 8. On the outer circumference of the central disc 8, the sprocket teeth 6 are formed with it as a single piece. The sprocket teeth 6 are arranged in three similar circumferential segments. This means that each time three sprocket teeth 6 are arranged in one circumferential segment.

[0024] Each circumferential segment extends across a circumferential angle of 120 in regard to the axis of rotation 7. It is clear that, with a different number n of the circumferential segments, the circumferential angle w about the axis of rotation 7 will change. In general: w=360)/n, where n is an odd number

[0025] It is essential to provide an odd number of circumferential segments. In accordance with the exemplary embodiment shown, nine sprocket teeth 6 are provided, being distributed evenly among the three circumferential segments.

[0026] The design of the sprocket 5 shall be explained more closely below with the aid of FIG. 2. The sprocket teeth 6 are essentially identical in configuration. The sprocket teeth 6 are each designed as a cam. Two neighbouring sprocket teeth 6 are separated from each other by a tooth spacing 9. The tooth spacing 9 is designed substantially as a rounded groove. Two neighbouring sprocket teeth 6 have a tooth interval z.sub.1, z.sub.2 or z.sub.3. The tooth interval z.sub.1, z.sub.2 or z.sub.3 is defined as the angle interval of rotation about the axis of rotation 7 of the respective tooth centres of neighbouring sprocket teeth 6. Within a circumferential segment with the angle of turning w about the axis of rotation 7, the tooth intervals z.sub.1, z.sub.2 and z.sub.3 add up to the circumferential angle w of the circumferential segment. We have: w=z.sub.1+z.sub.2+z.sub.3.

[0027] In accordance with the exemplary embodiment in FIG. 2, we have in regard to a direction of turning about the axis of rotation 7 in the clockwise sense: z.sub.1<z.sub.2, z.sub.2>z.sub.3. This means that, commencing with the first tooth interval of the circumferential segment in the direction of turning, i.e., in the clockwise sense, the first tooth interval z.sub.1 increases to the second tooth interval z.sub.2. From the second tooth interval z.sub.2 this is reduced to the third tooth interval z.sub.3. Conversely, this means that a maximum tooth interval is situated in a middle region of the circumferential segment. In particular, this means that even when the sprocket is turning in the opposite direction about the axis of rotation 7, i.e., in the anticlockwise sense in accordance with FIG. 2, at first a smaller tooth interval z.sub.3 is followed by a larger tooth segment z.sub.2, which is adjoined by another smaller tooth interval z.sub.1.

[0028] The first tooth interval z.sub.1 forms a minimal tooth interval. The two sprocket teeth 6 bounding the first tooth interval z.sub.1 are designated as a close gear pair.

[0029] In a drive unit of the crawler undercarriage 1, the crawler track 2 is handed off from the sprocket tooth 6 situated at roughly 2 o'clock to the sprocket tooth 6 situated at roughly 6 o'clock.