Research on Compensation of Tooth Surface Twist Error in Form Grinding of Internal Helical Gears with Lead Modification

To address the issue of tooth surface twist, induced by lead modification during the form grinding of internal helical gears, this paper proposes a twist error compensation method based on tooth surface accuracy measurement and machine tool motion correction. First, the generation mechanism of the twist error is analyzed. Through the calculation of the involute helicoid and the trajectory planning for lead modification, a mathematical model of the lead-modified internal helical gear surface is established. Subsequently, a kinematic model of the grinding process is developed, grounded in the spatial structure and feed motion relationships of the CNC form gear grinding machine. Based on this, the influence of machine feed motion errors on the tooth surface topological deviation is investigated, and a corresponding compensation strategy for the twist error is formulated. Finally, experimental grinding trials on internal helical gears were conducted. The measurement results of the tooth surface deviations demonstrate the validity and effectiveness of the proposed twist error compensation method.