In the world of mechanical power transmission, gear drives have a very special and gear chain china prominent place. This 
is the the majority of preferred technology when you need to transmit considerable power over a short distance with a constant velocity ratio. The mechanism of gear drives is fairly simple – the teeth, which are cut on the blanks of the apparatus wheel, mesh with one another to transmit power. To avoid slipping, the projections on one disc mesh with the recesses on additional disc in gear drives.
This technology uses different types of gears for power transmission. In fact, it could transmit power not only between parallel shafts, but also between non-parallel, co-planar, and intersecting etc. shafts.