Heavy Duty Needle Roller Bearings are bearings with a low sectional height and large load ratings. The outer ring has high rigidity and can easily be used even for light alloy housings. In addition, there are bearings with and without an inner ring.
As the type without inner ring uses a shaft as the raceway surface, a compact design is possible.  

The outer ring has a lubricating groove and a lubricating hole for convenient lubrication of the bearing. However, smaller bearings of this series