Drive assembly for a web spreading roll.

摘要

Spreading rolls are used in conjunction with, e.g., finishing equipment of paper mills to assure sufficient and constant cross-machine tension for the web running over guide rolls. Spreading is required due to web width variations caused by the coating, drying and calendering steps. A spreading roll comprises a curved shaft with its radius of curvature vector aligned in the machine direction and rotary driven roll segments mounted in bearings on the shaft. The roll segments are coupled to each other and they are driven about the shaft by a synchronous belt drive. The curvedness of the shaft complicates the design of a synchronous belt drive, and hence, the present invention concerns such a synchronous belt drive assembly for a web spreading roll that is free from angular nonalignment between the driving and the driven toothed pulley. The invention is based on mounting the driven toothed pulley in bearings on the bearing housing of the curved spreading roll shaft and then coupling the pulley with the outermost roll segment using a flexible coupling. <IMAGE>