Forging forming of gear processing

Forging forming of gear processing

Generally speaking, large bevel gears are processed on special large-tonnage hydraulic block presses, while small bevel gears are mostly formed on ordinary cold forging presses. The latter method has the characteristics of high production efficiency and low cost. Only the forging specification is affected by the blocking pressure of the die base, and the formation of large bevel gears cannot be completed.

Considering the economy of gear die manufacturing, especially for cemented carbide gear dies, the main forming process in the gear precision forging industry is still electrical discharge machining, but the forming process of tooth-shaped electrode has been completely replaced by high-speed milling CNC machining. For warm forging and hot forging forming dies with quenching hardness of about 50 degrees Rockwell, high-speed milling is far faster and more accurate than EDM, and it also shows obvious advantages in the service life of the dies. As long as the use cost of tools is solved, high-speed milling can completely replace the discharge machining of warm forging and hot forging gear dies.

Another special advantage of the extrusion process is that the mold tooth profile is obtained by CNC wire cutting. The ideal tooth profile can be obtained by programming without worrying about undercutting. When machining special tooth profile or modifying tooth profile, CNC wire cutting tooth profile is more convenient, faster and more accurate than gear unfolding or profiling.

Spline cold forging forming is a special case of gear forward extrusion forming. The formation of involute spline is equivalent to extruding a long spur gear, and the extrusion of rectangular spline is similar to the extrusion of involute spline. On the other hand, small module spur gears can be obtained by dividing the involute spline shaft.