GB2486572A

GB2486572A - Flat chain link for a conveyor chain

Info

Publication number: GB2486572A
Application number: GB1121542.3A
Authority: GB
Inventors: Rainer Benecke; Torsten Wirtz
Original assignee: Theile JD GmbH and Co KG; JD Theile GmbH and Co KG
Current assignee: Theile JD GmbH and Co KG; JD Theile GmbH and Co KG
Priority date: 2010-12-15
Filing date: 2011-12-15
Publication date: 2012-06-20
Anticipated expiration: 2031-12-15
Also published as: DE102010061263C5; GB2486572B; GB201121542D0; DE202010017978U1; RU2011150145A; DE102010061263A1; RU2576204C2; CN102556592B; CN102556592A; PL223019B1; PL397398A1; DE102010061263B4

Abstract

A flat chain link 2 for a link chain, in particular designed as a conveyor chain, in its legs 4, 4.1 connecting the two curves 8, 9 in a vertical orientation of the chain link 2 has a leg height H in the vertical direction which is smaller than the maximum leg width BS. The maximum leg width Bs in the vertical direction is arranged offset eccentrically and towards the leg outside 11. The maximum leg width BS is greater than the width thereof defining the nominal diameter N of the chain link 2 in the region of its curves 8, 9. The region of the curves 8, 9 defining the nominal diameter N of the chain link 2 is limited to a curve segment comprising a few angle degrees of maximum approximately 10 degrees to both sides of the centre plane 10 intersecting the curves 8,9 in cross section. Starting from the leg width BS, the width of the chain link 2 in its curves 8,9 diminishes constantly to the curve segment defining the nominal diameter N.

Description

FLAT CHAIN LINK FOR A LINKED CHAIN AND STEEL LINKED CHAIN

WITH SUCH FLAT CHAIN LINKS

The invention concerns a flat chain link for a linked chain, in particular a conveyor chain, of which the legs connecting the two curves in the vertical alignment of the chain link have a leg height in the vertical direction which is smaller than the maximum leg width, wherein the maximum leg width in the vertical direction is arranged offset eccentrically and towards outside of the leg, and the maximum leg width again is greater than the width defining the nominal diameter of the chain link in the region of its curves. Furthermore the invention concerns a steel link chain with interlinked individual chain links, of which at least every second chain link is such a flat chain link.

Such flat chain links are parts of steel link chains which are typically used as conveyor chains such as to operate scraper conveyors in underground coal mines.

Scraper conveyors or chain scraper conveyors have two circulating motorised conveyor chains, on which scrapers are attached between the chains and connecting the chains together. In corresponding use such conveyor chains can also be arranged as central chains, in particular as double central chains on a chain scraper conveyor. In operation the scraper conveyor chains are drawn over a conveyor trough, whereby the slag transported by the scrapers, for example coal, is extracted and conveyed to a loading station.

A steel link chain designed as a conveyor chain with flat chain links according to the preamble of the independent claim is known from OF 103 48 491 B3. The flat chain links of this previously known conveyor chain, to increase their breaking strength and hence to increase the performance of the steel link chain in relation to the previously known flat chain links or steel link chains produced therefrom, have a bulge in the region of the leg. This previously known flat chain link thus has a greater leg width in the region of its leg than in the region of its curves. This bulge forming the maximum leg width extends to a transition curve segment of the curves and there runs out. The transition curve segment is followed by a curve segment extending over around 80 to 1 00 with constant cross section form and cross section area. The cross section area of this curve segment is circular. Thus this curve segment with its constant cross section form and cross section area defines the nominal diameter of the previously known flat chain link. The nominal diameter of the chain link corresponds to the width of the chain link in the area of its curve, measured transverse to the longitudinal extension of the chain link. Thus the smallest diameter of the previously known flat chain link in the region of its curves defines its nominal diameter. The curve segments with constant cross section form and cross section area serve for articulation of the flat chain link in relation to a further chain link interlinked with the flat chain link which with its curve interior hinges on this curve segment of the flat chain link.

The steel link chain known from DE 103 48 491 B3 is highly valued because of its particular robustness and long service life. This is due to the fact that because of their special design, the flat chain links are relatively light despite their particular breaking strength and durability compared with other chain links of the same nominal diameter. The relatively light weight of the previously known flat chain links is due to the fact that in flat chain links of previously known steel link chains, the legs have a cross section area reduced in comparison with the cross section area in the region of the curve areas defining the nominal diameter. The cross section area in the region of the legs is just 0.55 to 0.85 of the cross section area in the curve regions.

Although the flat chain links of a steel link chain made therefrom have particular properties making this particularly safe and with a high breaking strength, there is a wish to improve these previously known flat chain links further in relation to breaking strength so that a steel link chain made from these flat chain links, in particular when used as a conveyor chain, as a whole has an even higher load-bearing capacity or meets higher load requirements. The invention is therefore based on the object of proposing such a flat chain link.

The present invention provides a flat chain link for a chain link according to claim 1.

The object of the invention is achieved by a generic flat chain link of the type cited initially in which the region of the curves defining the nominal diameter of the chain link is limited to a curve segment comprising a few angle degrees from maximum 1 0, preferably S or less to both sides of the centre plane intersecting the curves in

I

cross section, and in which the width of the chain link in its curves starting from the leg width diminishes to the curve segment defining the nominal diameter.

In this flat chain link the curve region defining the nominal diameter is limited to a few angle degrees. This means that adjacent to this curve segment defining the nominal diameter, the width of the chain link increases in the direction towards the legs.

Conversely this means that starting from the leg width of the chain link, this width diminishes constantly in the curves up to the curve segment defining the nominal diameter. The bulge formed in relation to the curve segment defining the nominal diameter has its greatest width in the legs, and then continues in the curves up to the curve segment defining the nominal diameter, with a constant decrease in bulge amount i.e. half the difference in the width difference between the bulge and the nominal diameter. Such a chain link is characterised by its waist which is identifiable when viewing the curves.

Tests have shown that flat chain links as claimed, in comparison with those known from DE 103 48 491 B3, with the same nominal diameter and same material, have an increased breaking strength of 8% to 10%. It must be emphasised in this connection that the performance increase can be achieved without significant additional material use, hence the performance increase can be achieved without a significant increase in weight of the flat chain link. This is because of the particularly suitable design of the geometry of the flat chain link and the reduction of a region in its curves which defines the nominal diameter of the chain link to virtually a minimum.

In a preferred embodiment the bulges which diminish constantly and continuously in their bulge amount towards the curve segments defining the nominal diameter transform into each other in the centre plane so that in such an embodiment, the curve segment defining the nominal diameter is reduced virtually linearly. Preferably the rate of reduction of width in the curves segments adjacent to the curve segment defining the nominal diameter of the chain link is constantly reduced in the segments adjacent to this curve segment in order to achieve a gradual transition into the curve segment forming the nominal diameter. To this extent the rate of reduction of width at least in this segment is not constant. This can be constant in the remaining curve segments. This can also diminish starting from the legs, first with a greater amount of width reduction, which reduction rate then transforms into the curve segment in which the rate of width reduction gradually reduces down to the nominal diameter.

A further performance improvement can be achieved if the diameter of the chain link in the segment defining its nominal diameter is greater than the nominal diameter in the direction transverse to the nominal diameter. This means that such a flat chain link in the curve segment defining its nominal diameter has a greater diameter in the longitudinal extent of the chain link than in the transverse direction. The consequence of this measure is an increase in the rigidity of the curve segment which in combination with the design of the chain link according to the invention leads to a further increase in breaking strength.

Instead of, or in addition to, the measure described above, the performance of the flat chain link and hence its breaking strength can also be increased in that the curvature of the segment cross section pointing towards the inside of the chain link, in each curve half adjacent to the centre plane, in a curve segment extending at least over 4O to 5O, has a curve radius which is greater than half the nominal diameter.

Particularly preferably this radius corresponds to the inner radius of the curve of a chain link interlinked with the flat chain link. The chain links lying against each other with their curve inner segments in such an embodiment then under tension load not only make contact with each other in a spot contact but also with a line or area contact.

The present invention also provides a steel link chain according to claim 9.

A steel link chain using flat chain links as described above has further chain links which each join flat chain links and preferably have an inner width which is greater, preferably greater only by a necessary movement clearance, than the maximum leg width of the flat chain link. This guarantees that the flat chain links can project sufficiently far into a chain link connecting two flat chain links, such as when these are guided over a chain wheel. Evidently it is also possible to produce a steel link chain exclusively from flat chain links as described above.

Further advantages and embodiments of the invention arise from the description below of an embodiment example with reference to the enclosed figures. These show: Fig. 1: A steel link chain with horizontal chain links and vertical chain links, with the vertical chain links formed as flat chain links, in a side view; Fig. 2: The steel link chain of Fig. 1 in a view rotated through 9O, with the horizontal chain links in a side view; Fig. 3: A flat chain link in isolated depiction from the steel link chain from Fig. 1 in a side view together with cross section depictions of the flat chain link from one of its curve halves (Figs. 3a to 3g); Fig. 4: A view of the flat chain link of figures 1 to 3 in a perspective view; and Fig. 5: A further view of the flat chain link described.

A steel link chain 1 designed as a conveyor chain for use in mining, in particular as a scraper conveyor chain in underground coal mining, comprises an alternating sequence of vertically oriented flat chain links 2 as vertical chain links and horizontal chain links 3. Figure 1 shows the steel link chain 1 in a side view to depict the vertical chain links 2. Thus the steel link chain 1 has two flat chain links 2 connected together by a horizontal chain link 3 interlinked with the flat chain links 2. The outer width B1 of the flat chain links 2 defines the height of the conveyor chain 1. The flat chain links 2 are produced in the manner of a forging process. The horizontal chain links 3 of the embodiment example shown are conventional chain links made from round wire.

The horizontal chain links 3, as evident from figure 1, have a circular cross section area all round. The inner width B2 of the flat chain links 2 is greater by the necessary movement clearance than the diameter of the horizontal chain links 3.

The depiction in figure 2 which shows the steel link chain in a top view shows that the outer width B3 of the horizontal chain link 3 is substantially larger than the outer width B1 of the flat chain links 2. In the embodiment example shown, the outer width B1 of the flat chain links 2 corresponds to approximately two-thirds of the outer width B3 of the horizontal chain links 3. In figure 2 the flat chain links 2 are shown on the upper of the two legs connecting the curves. Such a leg is marked with reference numeral 4 in figure 2. The other leg 4.1 can be seen in figure 1. The maximum width B of leg 4 is greater than the minimum width of the flat chain link 2 in the region of its curves. The nominal diameter of the flat chain link 2 is defined by this segment of minimal width of the flat chain link 2. This is marked with reference numeral N in figure 2 (nominal diameter). Thus the legs 4 bulge in relation to this segment of the curves defining the nominal diameter of the flat chain link 2, as is explained below in more detail with reference to figure 3. Width B of legs 4, 4.1 is smaller by the necessary movement clearance than the inner width B4 of a horizontal chain link 3.

Figure 3 shows a single flat chain link 2 of the steel link chain 1. The interior 5 of the flat chain link 2 is divided by a lug-like division element 6, protruding inwards from the lower leg 4.1 in figure 3, into two separate movement spaces 7, 7.1. This distance of the division element 6 from the inside of the opposite leg 4, as evident in figure 1, is smaller than the diameter of the horizontal chain link 3 interlinked with the flat chain link 2. Thus the movement space of a horizontal chain link interlinked with a movement space 7 or 7.1 is restricted to this movement space 7 or 7.1.

The curves of the flat chain link 2 connecting legs 4, 4.1 is marked with reference numeral 8 and 9 in figure 3. Each curve 8, 9 consists of two curve halves extending over 9O, which are guided against each other in the central plane 10 -the plane which intersects curves 8, 9 in cross section. The two curve halves of a curve 8 or 9 are designed mirror symmetrically to each other in relation to the centre plane 10. To characterise the curve 8 (the same applies to curve 9) therefore it is sufficient to describe one curve half. This follows below with reference to the lower half of curve 8 limiting leg 4.1 in figures. In the centre plane 10 the curve 8 has a cross section geometry as shown in this cross section of figure 3a. This cross section defines the nominal diameter of the flat chain link 2. The nominal diameter is marked with reference numeral N in figure 3a. In the embodiment example shown the nominal diameter is 52 mm. The flat chain link is therefore known as a 52 link. The diameter of the curve 8 in the longitudinal direction of the flat chain link 2 and hence transverse to the nominal diameter N is greater than the nominal diameter and in the embodiment example shown is 54 mm. The curvature of the cross section shown in figure 3.1 pointing towards the movement space 7.1 has a radius R which is greater than the radius defining the nominal diameter (here 26 mm). In the embodiment example shown the radius R corresponds to the inner radius R1 of the horizontal chain links 3 (see figure 2). Also the outer curvature of curve 8 opposite the curvature pointing towards the movement space 7.1 (see figure 3a) in the region of the centre plane 10 has a radius which is greater than the radius of the nominal diameter. In the embodiment example shown the outer radius is greater than the inner radius marked with reference numeral R. On the two mutually opposite outsides, the curve 8 is flattened as evident from the cross section view in figure 3a, whereby these sides run parallel to each other in segments. With this design and the transitions produced with tight radii, the cross section area of the flat chain link 2 as shown in figure 3 is enlarged in comparison with the cross section area of a flat chain link with curves with circular cross section. For comparison in figure 3a the cross section area of such a flat chain link with circular cross section area is drawn in dotted lines in the region of its right-hand curve.

The other end of the curve half considered is illustrated by the section in figure 3g which already shows the cross section area of the flat chain link in the region of the start of the leg 4.1. This section view is shown enlarged in comparison with the other.

The cross section view of figure 3g shows that the height H of leg 4.1 is clearly smaller than width B of leg 4.1. The maximum width B of leg 4.1 is arranged offset eccentrically towards the outside 11 of the leg 4.1 which contributes to an increase in breaking strength. The geometry of the cross section area of the leg 4.1, with the exception of the region of the division element 6, is formed trough-like or approximately semi-circular. The cross section area of leg 4 is designed like that of leg 4.1. As already evident from the top view of the flat chain links 2 in figure 2, the section view in figure 3g shows that the flat chain link 2 has its greatest width in the region of its leg and its smallest width in the region of the centre plane 10 represented by the section according to figure 3a. Between the different widths of the flat chain link 2 in the region of its leg 4, 4.1 and in the region of the centre plane 10, there is a constant reduction in width in the region of the curves 8, 9. The resulting waist, the centre of which is formed by the centre plane 1 0, is clearly evident in figure 3g.

Figures 3b to 3f show in reverse numbering, starting from figure 3g which shows the cross section region of leg 4, 4.1, how the cross section form and cross section area in this curve half of curve 8 change towards the centre plane 10 represented by the section view in figure 3a, and how the bulge A of leg 4.1 diminishes constantly in the direction towards the centre plane 10 in relation to the nominal diameter N defined by the width in the centre plane 1 0. As part of this change in cross section geometry, the ratios between width and diameter running transverse thereto in figure 3g -shown by height H -reverse in the direction towards the centre plane 10, starting from the end of the leg 4.1 or the start of the curve 8. Whereas the flat chain link 2 has its greatest width and its smallest diameter arranged transverse to this (here height H) at the start of the curve (see section view figure 3g), these ratios are reversed in the region of the centre plane 10 (see figure 3a). Here the width -the nominal diameter of the flat chain link 2 -is smaller than the diameter of the curve 8 transverse to the nominal diameter.

The individual cross section views in figure 3 (figures 3a to 3g) are each arranged at angular intervals of 15% over the curve halves. In the embodiment example shown, the segment of curve 8 which defines the nominal diameter N of the flat chain link 2 is designed virtually linear through the centre plane 10. The two curve halves forming the curve 8 taper constantly in width starting from the respective leg 4 or 4.1 towards the centre plane 10, at which point is arranged the smallest width of the flat chain link 2. This means that the rate of reduction of width also diminishes in a curve segment adjacent to the centre plane 10. This is evident from the asymptotic geometry of the bulge in figure 3g, marked A there. The nominal diameter N of the flat chain link 2 is projected into the legs 4 and 4.1 in dotted lines in figures 3a and 3g. This illustrates the size of the bulge on both sides A. The cross section area ratio between the cross section area of the curve 8, 9 in the region of centre plane 10, as illustrated by the section in figure 3a, in relation to the cross section area in the legs, as evident from the section view in figure 3g, is around 0.72 in the embodiment example shown.

Thus the cross section area of this vertical chain link in the region of its leg is around 28% smaller than in the region of the centre plane of the curves.

The radius R of curvature described above with reference to figure 3a is retained in the embodiment example shown over 6O in each curve half, before this becomes greater in the direction of the leg 4.1. This guarantees a constant articulation behaviour between the flat chain link 2 and the horizontal chain link or links 3 interlinked therein.

Figures 4 and 5 also show the flat chain link 2 described above. The figures clearly show, in particular in the view in figure 5 showing the flat chain link 2 lying, the width of chain link 2 successively diminishing from the legs to the region of the centre plane. These depictions also clearly show that there is a flowing transition of the width reductions of each leg running towards each other, over the respective curve segment towards the centre plane.

List of Reference Numerals 1 Steel link chain 2 Vertical chain link 3 Horizontal chain link 4 Leg Interior 6 Division element 7, 7.1 Movement space 8 Curve 9 Curve Centre plane 11 Outside B1 Outer width of flat chain link B2 Inner width of flat chain link B3 Outer width of horizontal chain link B4 Inner width of horizontal chain link B5 Maximum width of leg of flat chain link H Height N Nominal diameter R Radius Inner radius of horizontal link

Claims

Claims 1. Flat chain link for a link chain, in particular a conveyor chain (1), said link having legs (4, 4.1) connected by two curves (8,9) in a vertical orientation of the chain link (2) and having a leg height (H) in the vertical direction which is smaller than a maximum leg width (Be), wherein the maximum leg width (Be) in the vertical direction is arranged offset eccentrically and towards the leg outside (11), and the maximum leg width (Be) is again greater than the width thereof defining a nominal diameter (N) of the chain link (2) in the region of the curves (8, 9), characterised in that the region of the curves (8, 9) defining the nominal diameter (N) of the chain link (2) is limited to a curve segment comprising a few angle degrees of maximum approximately 1 0 to both sides of a centre plane (1 0) intersecting the curves (8, 9) in cross section, and that starting from the leg width (Be), the width of the chain link (2) in the curves (8, 9) diminishes constantly to the curve segment defining the nominal diameter (N).
2. Flat chain link according to claim 1, characterised in that the curve segment of the curves (8, 9) defining the nominal diameter (N) is limited to less than 5, in particular less than 1 to both sides of the centre plane (10) intersecting the curves (8, 9) in cross section.
3. Flat chain link according to claim 2, characterised in that the width of the curves (8, 9) in the curve halves diminishes constantly up to the centre plane (10) or approximately up to the centre plane (10).
4. Flat chain link according to any of claims 1 to 3, characterised in that the rate of reduction of width of the chain link (2) in its curves (8, 9) diminishes constantly in a region adjacent to the segment of the curves (8, 9) defining the nominal diameter (N) of the chain link (2), towards the nominal diameter seg ment.
5. Flat chain link according to any of claims 1 to 4, characterised in that the diameter of the chain link (2) in the segment defining its nominal diameter (N) is greater than the nominal diameter (N) in the transverse direction to the nominal diameter (N).
6. Flat chain link according to any of claims 1 to 5, characterised in that the curvature pointing to the inside (5) of the chain link of each curve half of the curve segment adjacent to the centre plane (10), in a segment starting from the centre plane (10) and extending over at least 4.O to SO has a radius (R) which is greater than half the nominal diameter (N).
7. Flat chain link according to any of claims 1 to 6, characterised in that the chain link (2) has a cross section area ratio between the cross section area in the region of the leg (4, 4.1) and the cross section area in the region of the curves (8, 9) defining the nominal diameter (N) of the chain link (2) which is greater than 0.55 and less than 0.85.
8. Flat chain link according to claim 7, characterised in that the cross section area ratio is between 0.6 and 0.7
9. Steel link chain with individual chain links (2, 3) interlinked with each other, of which at least every second chain link is a flat chain link (2) according to any of claims 1 to 7, characterised in that an inner width (B4) of the at least one chain link (3) interlinked with the flat chain link (2) is greater than the maximum leg width (Bs) of the flat chain link (2).
10. Steel link chain according to claim 9, characterised in that the inner width (B4) of the at least one chain link (3) interlinked with the flat chain link (2) is greater than the maximum leg width (Be) of the flat chain link (2) only by the amount of the necessary movement clearance between the two chain links (2, 3).
11. Steel link chain according to claim 9 or 10 in its reference back to claim 5, characterised in that the radius (R) of curvature of the curve cross section corresponds to the curve inner radius of a curve (8, 9) of the at least one chain link (3) interlinked with the flat chain link (2).
1 2. Flat chain link for a link chain, said link being substantially as described, with reference to the drawings, herein before.
13. Steel link chain substantially as described, with reference to the drawings, herein before.