The sun gear is meshed around with the planet gears, which in turn are meshed with ring gear. Planet gears are connected to each other by a carrier, which helps them to rotate around the sun gear
Advantages of Planetary system over helical gearbox:
- They are compact and take less space and are light weight, as the load is shared between the planet gears.
- The noise and vibration is reduced as the load is shared. This also increases efficiency
- Since the shafts are inline and concentric, bending moment is absent.
- The manufacturing of these components is relatively cheaper due to smaller size as compared to parallel axis gearboxes.
- The gear system is complex and needs precision manufacturing
- Teeth ratios are specific and assemble is according to them.
- Calculations of efficiency are a bit difficult.