Elastic Deformation and Profile Deviations in Gear Shaping

In this paper, the effect of elastic tool deflection on profile errors in the gear shaping process is examined. Gear shaping is the primary method of manufacturing internal gears which are a major component in planetary gearboxes. Involute profile errors in the machined part can cause dynamic 
issues in the gear’s operation such as vibration, noise, and transmission error. Therefore, the ability to predict profile errors in a virtual environment is crucial for process planners. To predict the elastic deformation of the tool, the cutting forces are first predicted by simulating the gear shaping operation in a multi-dexel based solid modeller. From the solid modeller, the cutter-workpiece engagement is extracted and the cutting force is estimated by determining incremental forces along the cutting edge using the oblique cutting force model. Finally, the tool deflection is then calculated using an estimated static tool stiffness from impact hammer tests. Subsequently, by analyzing cross sections of the virtual gear, profile curve deviations are determined. The simulated deviations show good correlation with experimentally measured profile deviations; however, other sources of error must be researched for improved correlation.