The RNA Series refers to a type of full complement needle roller bearing with a outer ring. The key characteristic is the "full complement" design, meaning the bearing interior is entirely filled with needle rollers without a cage to separate them. This maximizes the number of rollers in contact with the raceways, resulting in very high radial load capacity for a given cross-section. However, the absence of a cage limits the maximum permissible speed compared to caged designs. The RNA bearing includes a outer ring, simplifying housing design as the bore does not need to be hardened. It requires a hardened and ground shaft to act as the inner raceway. This design is ideal for applications with low to moderate speeds but very high radial loads and space constraints.
