Abstract: A through study for the mechanism of the involute gear lapping with dynamic force is made in theory and test. Based on the view of using lapping instead of abrasion, the machining principle of the involute gear lapping with the dynamic force is , when two gears operate stably at high velocity (definite speed ratio, i. e, the ratio of two gears teeth) with great inertia, change their center distance periodically, the gears error can be modified by the dynamic force and grinding, so higher accuracy of the both gears can be achieved.

Key words: Dynamic force, Gear lapping, Involute gear, Manufacture processing