Two-dimensional ultrasonic vibration-assisted dry grinding gear: grinding force and surface characteristics

Ultrasonic vibration-assisted dry grinding has been focused on to alleviate the cutting fluids' negative impact on environment, avoid the unnecessary waste, and reduce the manufacturing costs. However, this technology has not been used for grinding gear. In order to explore its effect, this study proposes a two-dimensional (i.e., 2D or elliptical) ultrasonic vibration-assisted dry grinding gear. In this method, the form grinding wheel was designed to vibrate along the longitudinal and radial directions based on the thin disc theory. The 2D vibration can be realized under a single excitation. Then, the grain kinematics and the characteristics of grinding force and surface roughness during elliptical ultrasonic vibration-assisted dry gear grinding (EUVADGG) were theoretically substantiated. Finally, the gear grinding experiment under EUVADGG and conventional gear grinding (CGG) was conducted to verify the analytical model. It has been analytical and experimentally shown that by superimposing the two two-dimensional ultrasonic vibrations, the tangential and normal grinding forces can be reduced approximately 40 and 30%, respectively. The surface roughness of gear teeth under various rolling angles can be assessed theoretically and experimentally, and it can be reduced by up to 25.6%. These findings strongly indicate that EUVADGG can achieve a lower grinding force and higher surface quality, and provide a valuable reference for grinding gear.