scope:

A new jobbing system for manufacturing bevel and hypoid gears was developed during the past three years. In spite of the existing old European jobbing systems, the new system uses a simple one-part cutter head with stick blades. A range of gears with an outer diameter of 3 to 35 inches can be covered with three cutter head sizes. The cutter heads only have five starts, each start having one inside and one outside blade. This configuration enables the manufacturer of industrial gear boxes the flexibility to produce bevel gears of any size and specification with an extremely low investment. The calculation of tooth contact analysis, ease off and machine settings are done with a PC program which gives the manufacturer flexibility and independence. The gears produced with this method can be matched to existing old gearsets produced on old equipment with different cutting methods. A special software package was created, which allows the modeling of a new gearset in order to duplicate old gearsets. Productivity and accuracy of the new method is remarkably high. Noise optimizations are easily possible by using computerized optimization tools. To account for the needs and requirements of gear box manufacturers, a skiving process using carbide tools was developed as a finishing operation after heat treatment. The presented paper explains the gear theoretical basics of the new jobbing method. In addition, it tells about machines, tools and processes and reports about three realized examples out of the daily praxis of gear box manufacturers.