Abstract: Based on the principal distortion issue of helical gear tooth surfaces during the grinding processing by worm-wheel machining,the contact trace equation was deduced, the evaluation scope of gear tooth profile and lead was selecteel and the distortion model was created, the deviation values of tooth profile and lead angles were calculated. The distortion optimization parameters also included the tooth profile drum and the counterpart gear tooth drum or the distortion. Through the experiment and verification,the distortion compensate methods could effectively optimize the distortion,load bearing capacity,the gear meshing impact force,the gear precision and vibration or noise level.

Key words: tooth surface distortion, micro modification, grinding, helical gear