The worm gear has the disadvantage of being easily worn out. When the worm gear is worn and the backlash becomes larger, the common worm gear uses the radial movement of the worm to adjust the meshing backlash, but the center distance of the transmission group is changed. The change of the center distance will cause the tooth surface contact to get worse, or even aggravate the wear, which is not beneficial to maintaining the accuracy of the worm gear group. The double-lead worm moves axially to adjust the meshing backlash, and the center distance of the transmission group will not be changed, so the disadvantages mentioned above can be avoided.
The double lead worm is simply the worm tooth thickness change, the left tooth surface and the right tooth surface lead length is different so that the tooth thickness formed a continuous change of tooth shape, worm gear tooth surface is also in order to cooperate with the worm, and made into different tooth surface so that you can adjust the clearance of worm gear to achieve the best state. When the user process due to worm wear, caused by worm gear clearance becomes larger, you can adjust the axial position of the worm, so that the worm gear clearance becomes smaller.