1. It can obtain a large transmission ratio, which is more compact than the staggered shaft helical gear mechanism. The meshing tooth surfaces of the two wheels are in line contact, and its bearing capacity is much higher than that of the staggered shaft helical gear mechanism.

2. Worm drive is equivalent to screw drive, which is multi tooth meshing drive, so it has stable transmission, low noise and self-locking. When the lead angle of worm is less than the equivalent friction angle between meshing teeth, the mechanism has self-locking and can realize reverse self-locking, that is, only worm drives worm gear, not worm gear

3. The transmission efficiency is low and the wear is serious. When the worm gear is meshed, the relative sliding speed between the meshing teeth is large, so the friction loss is large and the efficiency is low.