Washing machine belt pulley made of a plastic material

A belt pulley of a washing machine drum, particularly of a household washing machine, made of a plastic material, which comprises a central part of the belt pulley formed as a hub, with which the belt pulley is fastened to a drum shaft;

• a belt pulley circumference arranged concentrically with respect to the hub and receiving a belt on its outer surface;
• a substantially circular dividing rib arranged concentrically with respect to the circumference of the belt pulley so as to divide the belt pulley into two concentric sections, i.e. a first, inner section closer to the hub, and a second, outer section delimited by the circumference of the belt pulley, wherein a respective plurality of reinforcing ribs are arranged in the inner and outer sections, characterized in
• that the dividing rib is arranged on a line of a polygon having the centre in the belt pulley axis and exhibiting corners, into which, from a side facing the hub, a portion of the reinforcing ribs lying the furthest away from the hub lead, said ribs being part of a plurality of reinforcing ribs of the inner section, wherein at least a portion of the reinforcing ribs leading into the corners of the dividing rib extend along a line of polygons which are in the shape of hexagons and radially arranged in the inner section and in contact with each other along one of their sides,
• that from at least one said corner of the dividing rib on the side facing the circumference, at least one arc-shaped reinforcing rib originates, the free end of which contacts the circumference of the belt pulley.