Second, the planet gear bearings have to play an active part in torque transfer. Planetary systems split the torque insight from sunlight gear amongst the earth gears, which transfer torque to a planet carrier linked to the gearbox output. The bearings that support the planets on the carrier need to bear the entire brunt of this torque transfer.

Or, in extreme cases, they may select angular contact or tapered roller bearings, both of which are made to withstand axial loads.
In planetary gearboxes, however, it’s much more difficult to create around these axial Helical Gearbox forces for two related reasons. 1st, there is typically hardly any area in a planetary gearbox to include the type of bulky bearings that can tolerate high axial forces.

The presence of axial forces makes things completely different for the bearings that support helical gears. But it is important to make a distinction between fixed-axis and planetary gearboxes. In fixed-axis gearboxes, the excess axial forces total little more than an inconvenience. Gearbox designers will often upsize the bearings to accommodate the additional forces.

Since they don’t need to withstand any axial forces, spur gear bearings enjoy just a supporting function in the functioning of the gearbox. The bearings simply need to support the rotating gear shafts, however they do not play an active function in torque transfer.

Helical Gears Place Greater Demand on Bearings