Worm gears are often used when large acceleration reductions are needed. The decrease ratio is determined by the number of begins of the worm and worm wheel china amount of teeth on the worm equipment. But worm gears have sliding contact which is quiet but tends to produce heat and have relatively low transmission performance.
As for the materials for production, in general, worm is made of hard metal while the worm gear is made from relatively soft steel such as aluminum bronze. That is because the number of tooth on the worm gear is relatively high compared to worm using its number of begins being generally 1 to 4, by reducing the worm equipment hardness, the friction on the worm the teeth is reduced. Another feature of worm manufacturing may be the need of specific machine for gear cutting and tooth grinding of worms. The worm gear, on the other hand, may be made out of the hobbing machine utilized for spur gears. But due to the various tooth shape, it is not possible to cut a number of gears at once by stacking the gear blanks as can be carried out with spur gears.
The applications for worm gears include equipment boxes, fishing pole reels, guitar string tuning pegs, and in which a delicate swiftness adjustment by utilizing a large speed reduction is needed. When you can rotate the worm equipment by worm, it is normally not possible to rotate worm utilizing the worm gear. This is called the self locking feature. The self locking feature cannot continually be assured and another method is preferred for accurate positive reverse prevention.