Schaeffler is launching a new FAG high-capacity cylindrical roller bearing for wind turbine gearboxes that offers higher load ratings and reduced friction due to a new cage design. The basic static and dynamic load ratings of the new bearings are 6 per cent higher than those of a conventional cylindrical roller bearing with solid brass cage, resulting in a 20 per cent increase in rating life.
 
These new high-capacity cylindrical roller bearings have a sheet steel cage that enables the design to be more compact than with conventional solid brass cages. This slimmer cage leaves space for at least one additional rolling element in the bearing, which increases the load rating significantly.
 
There are other advantages too. Due to the new cage, the high-capacity bearing has significantly lower friction than full-complement cylindrical roller bearings with maximum basic load rating. The 'self-retaining' cage also simplifies bearing mounting because the rolling elements are retained even when the ring is removed.
 
The cage comprises two cage rings lying one inside the other and joined together. The crosspieces of the inner cage guide the roller elements. At the same time, these retain the roller elements in the bearing, even when the bearing ring is removed. This means that the bearing is much easier to mount, as no separate device is required to help prevent the rollers from falling out. In addition, the special geometrical shape of the cage pockets improves lubricant flow, which reduces friction and prevents damage to the bearing.
 
Schaeffler's new bearings are currently undergoing trials in various customer applications, but the company plans to commence volume production .