In the world of mechanical power transmission, gear drives 
employ a special and prominent place. This is the many preferred technology if you want to transmit considerable power over a brief distance with a constant velocity ratio. The system of gear drives is fairly simple – the teeth, which are cut on the blanks of the gear wheel, mesh with each other to transmit power. To avoid slipping, the projections on one disc mesh with the recesses on various other disc in gear drives.
This technology uses various kinds of gears for power transmission. Actually, it could transmit power not merely between gear chain china parallel shafts, but also between non-parallel, co-planar, and intersecting etc. shafts.