Chain drive or return arrangement and chain assembly and sprocket employed therein

1. Chain drive or return arrangement for chain-drawn winning or transport facilities, suitable for use with underground mining involving the use of plow winning systems or scraper chain conveyors, comprising:

a sprocket; and

a chain assembly returned or driven by the sprocket,

wherein the chain assembly comprises:

vertical chain links; and

horizontal chain links, and

wherein the sprocket comprises:

a plurality of sprocket teeth arranged uniformly around its circumference; and

chain link pockets between each pair of adjacent teeth, the pockets being delimited by tooth flanks of the sprocket teeth and configured for taking up a horizontal chain link of the chain assembly,

wherein the horizontal chain links include bows that form a power transmission zone when the horizontal chain links engage in the chain link pockets of the sprocket,

wherein the bows each include bow flanks linearly tapered towards each other in a first plane, the bow flanks being on opposite sides of a curved bow center section,

wherein the bow flanks of the horizontal chain links have a concave trough in a second plane, the second plane being orthogonal to the first plane the concave trough being formed at least below an equatorial line, and

wherein the tooth flanks delimiting the chain link pockets have a convex curved shape matching said bow flanks, at least in contact surfaces of the sprocket teeth with the horizontal chain links.

2. Chain drive or return arrangement according to claim 1 , wherein the vertical chain links each include two parallel legs and identical bows on each side connecting the legs.

3. Chain drive or return arrangement according to Claim 2 , wherein the bow flanks on a side of a bow centerline extend only over areas lying in an axial continuation of the legs.

4. Chain drive or return arrangement according to claim 1 , wherein the bow flanks of the horizontal chain links have concave troughs both above and below the equatorial line.

5. Chain drive or return arrangement according to claim 1 , wherein a bow centerline extends over roughly one half of a chain link width and each bow flank extends over roughly ¼ of the chain link width.

6. Chain drive or return arrangement according to claim 1 , wherein the bow flanks are troughed with a curvature corresponding roughly to a curvature of the tooth flanks of the sprockets.

7. Chain drive or return arrangement according to claim 1 , wherein a free angle between the bow flanks is roughly in a range of 48° to 56°.

8. Chain drive or return arrangement according to claim 1 , wherein the bows of the horizontal chain links exhibit a circular cross-section on a bow centerline.

9. Chain drive or return arrangement according to claim 1 , wherein the horizontal chain links include legs that are formed with surfaces on their outsides that are flat in one direction and curved in another direction and with semi-spherical surfaces on their insides.

10. Chain drive or return arrangement according to claim 1 , wherein the horizontal chain links with a chain diameter of 38 mm have a chain pitch of roughly 137 mm, an overall length of roughly 213 mm and a chain link width of roughly 97 mm.

11. Chain drive or return arrangement according to claim 1 , wherein the bow flanks enclose an angle a of less than 110°.

12. Chain drive or return arrangement according to claim 1 , wherein the horizontal chain links and the vertical chain links are of identical design.

13. Chain drive or return arrangement according to claim 1 , wherein the bow flanks exhibit a radius of curvature at least approximately corresponding to a radius of curvature of the tooth flanks in the contact surfaces.