Material selection: According to the use requirements and working conditions of the sprocket, select suitable materials, such as medium carbon steel, medium carbon alloy steel, etc. Common materials include 45 steel, 40Cr, etc. For some occasions with higher requirements, carburizing steel such as 20CrMnTi will also be selected.
Forging: Forge the selected steel, and make the internal structure of the metal material denser through heating and external force, so as to improve the strength and toughness of the sprocket. The forged blank needs to be annealed to eliminate forging stress and improve cutting performance.
Machining
Turning: First, turn the blank to machine the basic outline of the sprocket, including outer diameter, inner diameter, hub thickness, etc. Ensure that the dimensional accuracy and surface roughness meet the requirements, and provide a benchmark for subsequent processing.
Milling: Use a milling machine to process the tooth shape of the sprocket. Common methods include forming milling and generating milling. Forming milling is milling with a forming tool that is the same as the sprocket tooth profile, which is suitable for single-piece small-batch production; generating milling is using a gear processing machine to generate the tooth profile through the relative movement of the tool and the workpiece. It has high processing accuracy and is suitable for mass production.
Drilling: According to the structural requirements of the sprocket, the mounting holes, keyways, etc. are processed. When drilling, the position accuracy and verticality of the holes must be ensured to ensure the matching accuracy between the sprocket and the shaft.
Heat treatment: The processed sprocket is heat treated, such as quenching and tempering, to improve the hardness, wear resistance and fatigue resistance of the sprocket. For sprockets made of carburized steel, carburizing treatment is also required to increase the hardness and wear resistance of the tooth surface.
Grinding: Grinding key parts such as the tooth surface, outer diameter, and inner diameter of the sprocket to further improve the dimensional accuracy and surface roughness, reduce the roughness value of the tooth surface, and improve the transmission efficiency and service life of the sprocket.