Brake drum cooling structure

摘要

A method of manufacturing a brake drum having a plurality of axially spaced, circumferentially extending ribs provided on the exterior surface thereof. The method includes casting molten grey iron into a mold cavity formed by a plurality of axially split external mold segments spaced radially outward from an internal mold member, spacing the radially inward portions of the interfacing lateral edge surfaces of the external mold segments to form a flash base free of white iron metal at the parting line between adjacent external mold segments and, after cooling the molten iron and removing the mold members, grinding away at least a portion of the flash metal formed between the interfacing lateral edge surfaces of the external mold segments radially outward of the flash base to provide an axially extending ridge free of white iron and traversing the axially spaced ribs. The brake drum has a plurality of radially extending, heat radiating projections formed on the exterior surface thereof including a plurality of circumferentially spaced sets of helical fins with each successive set of helical fins being disposed at a helical orientation opposite to the helical orientation of the preceding set of helical fins to induce a flow of cooling air over the external surface of the brake drum regardless of the direction of rotation of the brake drum.