Based on the tooth contact simulation and the analysis of transmission errors and contact ratio on the lapping process

the lapping boundary of the tooth surface is determined:±0.25～0.3 face width and ±0.1～0.25 tooth height in the middle of tooth surface.The influences of lapping on the contact pattern

tooth form precision and dynamic performance are investigated according to the lapping experiments.It is showed that the lapping of gears may reduce the tooth form errors

improve the position and shape of contact pattern and make the contact pattern of heat treatment causing deformation return the previous fashion in a certain

and the lapping improves greatly on the gearing dynamic performance

the gearing vibration and noise in the wide range of rational speed and load reduce obviously at all.