The NSK bearing unit is a combination of a radial ball bearing, seal, and a housing of high-grade cast iron or pressed steel, which comes in various shapes. The outer surface of the bearing and the internal surface of the housing are spherical, so that the unit is self-aligning.
Shown in the figures, types EA, C, CD, CA, which are designed for high load capacity, are available. Types EA, C, and CD have pressed steel cages; and type CA has machined brass cages. Type EA has especially high load capacity, features low torque, and has a high-strength cage.
Bearings of this type use conical rollers guided by a back-face rib on the cone. These bearings are capable of taking high radial loads and axial loads in one direction.
In the HR series, the rollers are increased in both size and number giving it an even higher load capacity.