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

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.