Sand casting

Model making: Based on the design drawings of the pulley, a model that matches the shape and size of the pulley is made. The materials are usually wood, metal or plastic, etc. For instance, for some large pulleys, metal models might be adopted to ensure their precision and durability.

Sand box molding: Place the model in the sand box, fill in the molding sand and compact it, then take out the model to form the casting cavity. To ensure the accuracy of the castings, it is necessary to control parameters such as the moisture content and compactness of the molding sand.

Core production: If the pulley has internal holes or complex structures, a core needs to be made to form these parts. The core is usually made of core sand and its strength is increased through the core bone.

Gating system design: Design and fabricate the gating system, including the gate cup, sprue, runner and inner runner, etc., to ensure that the molten metal can flow smoothly and evenly into the mold cavity.

Metal smelting and casting: Select metal materials (such as cast iron, cast steel, etc.) are placed in a furnace for smelting. After reaching the specified temperature and composition requirements, the molten metal is poured into the mold.

Cooling and cleaning: After the molten metal has cooled and solidified in the mold, the sand box is removed, the casting is taken out, and the surface molding sand, burrs, flash, etc. are removed to obtain the casting pulley blank.

Centrifugal casting

Mold preparation: Use a rotatable mold, and the shape of the mold should match the shape of the pulley.

our the metal liquid into a rotating mold. Under the action of centrifugal force, the metal liquid is evenly distributed on the inner wall of the mold and rapidly solidifies to form the shape.