scope:

Gear milling cutters offer a versatile and timesaving solution for milling of high-quality gear profiles. Application methods vary. There are many ways to utilize these cutters. Machines range from traditional gear hobbing machines with single indexing capability to horizontal and vertical CNC machining centers with 4- or 5-axis capability, modern multi-task turning and milling centers, CNC lathes with live milling capability, and dedicated special-purpose machines.

Tool selection will depend on a number of factors, such as module size, work piece material, gear quality level desired, spur or helical design, tooth count, size of gear blank, and available equipment options. The desired post-milling operations needed-such as hardening, grinding, honing, and shaving-also have an influence on the milling tool design.

When planning for successful process methods, rigidity, tool holding (arbor supported vs. unsupported), and material removal rate, all must be addressed.

Power and torque requirements as related to gear material, number of passes, cutter design, and diameter, are very important in the planning phase. Tool selection has a significant impact on this. Rake angles and cutter geometry are important. Tools are designed according to rough, semi-finish, and finish requirements. Tandem, multi-cutter designs will improve productivity but bring on specific challenges to the process engineer.

Surface finish requirements are also very important. Milling methods can vary from climb cutting to conventional milling. Both methods have their place and impact surface finish and tool life. Radial infeed and reduced or increased feed rate on entry are other factors. Wet-versus-dry machining and oil-versus-water-soluble coolants impact tool life, part quality, and environmental concerns. Proper chip thickness and calculations for feed rate compensation must be considered.

This paper takes a comprehensive view of all of the above mentioned topics to assist the manufacturing engineer or process planner in successfully choosing the design of gear milling cutters to make costeffective cylindrical gears to the appropriate quality desired.