worm wheel

Worm gears are usually used when large quickness reductions are needed. The reduction ratio depends upon the number of starts of the worm and number of teeth on the worm gear. But worm gears possess sliding contact which is silent but tends to produce heat and have relatively low transmission performance.
For the materials for production, in general, worm is made from hard metal while the worm gear is made from relatively soft metallic such as for example aluminum bronze. This is because the number of the teeth on the worm equipment is relatively high in comparison to worm with its number of begins being generally 1 to 4, by reducing the worm gear hardness, the friction on the worm tooth is reduced. Another feature of worm manufacturing may be the need of specialized machine for gear reducing and tooth worm wheel china grinding of worms. The worm gear, however, may be made with the hobbing machine utilized for spur gears. But because of the different tooth shape, it is not possible to cut many gears at once by stacking the gear blanks as can be carried out with spur gears.
The applications for worm gears include gear boxes, fishing pole reels, guitar string tuning pegs, and where a delicate speed adjustment by utilizing a sizable speed reduction is necessary. While you can rotate the worm gear by worm, it is normally not possible to rotate worm utilizing the worm gear. This is called the personal locking feature. The self locking feature cannot always be assured and a separate method is recommended for true positive reverse prevention.