Sprocket for roller chain drives

Abstract

A roller chain and sprocket drive includes a roller chain having multiple rollers and articulated links, the rollers being arranged with a substantially constant pitch and connected by the articulated links, and a sprocket in driving or driven engagement with the roller chain. The sprocket includes: angularly spaced sprocket teeth arranged for driving or driven engagement with the rollers wherein the spacing between at least some of the sprocket teeth is a multiple of the pitch of the rollers such that during each rotation of the sprocket at least some of the rollers pass over the sprocket and have no driving or driven connection with the sprocket; spoked portions extending radially from a sprocket axis corresponding to the sprocket, each of the spoked portions having an outer end for supporting a corresponding one of the sprocket teeth, wherein the spoked portions flex tangentially under load sufficiently to accommodate variations in the distance between adjacent rollers from the average pitch; and a support profile between adjacent ones of the sprocket teeth having an arc centered on the sprocket axis, the arc having a radius substantially equal to the root radius of the sprocket teeth, the support profile comprising resilient inserts extending towards the sprocket axis between the spoked portions.