Planetary Gearboxes is an old mechanics fundamental that is still being used for new leading innovative technology like 3D printing, and new methods of transport. The planetary gearbox is one in which the output and input shafts are aligned. Its basic function is to transfer the maximum amount of torque with the least amount of space. The gear system consists of a reduction state, an acceleration mode, and coupling. No one knows who invented the planetary gearbox, but it has been in use since the 15th century. The planetary gear gets its name from the way it looks while it functions. There is a sun gear in the middle attached to ring gears. As the sun gear rotates, it also moves the ring gears. The sun gears are called input shaft, whereas the carrier and ring gears are called output.
The planetary gearbox works in the ratios from 1.5:1 to 12000:1. In a 3:1 system, there are three ring gears and one sun gear and is called a one-stage planetary gearbox. In ratios of above 5:1, a two-stage planetary gearbox is used. In a 3:1 system, the sun gear is very big, compared to the ring gear, and in the 10:1 system, the sun gear is much smaller than the ring gears. The ratios are in absolute integers. The planetary gearbox system is very precisely placed together, but it still creates friction due to the moving parts inside – sun gear and ring gear. These need lubrication from time to time from oil, gel, or grease. This requirement is present in most moving mechanical machines.