In the world of mechanical power transmission, gear drives employ a special and 
prominent place. This is actually the the majority of preferred technology if you want to transmit significant power over a short distance with a continuous velocity ratio. The mechanism of equipment drives is quite simple – one’s teeth, which are cut on the blanks of the gear wheel, mesh with each other to transmit power. To avoid slipping, the projections using one disc mesh with the recesses on other disc in equipment drives.
This technology uses different types of gears for power transmission. Actually, it could transmit power not merely between parallel shafts, but also between gear chain china nonparallel, co-planar, and intersecting etc. shafts.