Second, the planet gear Helical Gearbox bearings need to play an active 
part in torque transfer. Planetary systems split the torque input from sunlight gear amongst the planet gears, which transfer torque to a world carrier connected to the gearbox output. The bearings that support the planets on the carrier need to bear the full brunt of that torque transfer.
Or, in acute cases, they may select angular get in touch with or tapered roller bearings, both of which are created to withstand axial loads.
In planetary gearboxes, however, it’s much more difficult to design around these axial forces for two related reasons. 1st, there is typically hardly any area in a planetary gearbox to incorporate the kind of bulky bearings that may tolerate high axial forces.
The existence of axial forces makes things completely different for the bearings that support helical gears. But it’s important to make a distinction between fixed-axis and planetary gearboxes. In fixed-axis gearboxes, the additional axial forces amount to little more than a hassle. Gearbox designers will most likely upsize the bearings to support the additional forces.
Since they won’t need to withstand any axial forces, spur gear bearings play just a supporting role in the functioning of the gearbox. The bearings should just support the rotating gear shafts, however they do not play an active role in torque transfer.
Helical Gears Place Greater Demand on Bearings