Development of large diameter v-belt pulley using coreless drag and wire-reinforced cheek

Turning of metal pulleys in lathe machines is preceded by casting of the blanks. As the diameter of the pulley increases, this method becomes more challenging due to the difficulty of taper turning grooves on the blank. Cores are used to make cavities in such pulleys to reduce their weights. The processes involved in making cores add to the cost of producing such parts. This project is aimed at reducing the machining and moulding steps and costs when producing large diameter pulleys. A wooden split pattern was moulded in a wire-reinforced cheek, then; the drag was positioned on the cheek, followed by filling of holes in the pattern with facing sand, pouring and ramming of the moulding sand in the drag; thereafter, the drag-cheek subassembly was turned upside down and the cope positioned on the cheek, filled with moulding sand and rammed. The pattern was withdrawn from the cheek by removing the bottom-half-rim, followed by the cheek and lastly the top-half-rim from the drag. Part modeling of the pattern and moulding stages was done in Pro-Engineer software. The cast pulley was made of aluminium and showed minimal deviation from dimensional specifications.