Ball bearings are manufactured with four essential parts. These are the outer ring, the inner ring, the balls or rolling elements, and the separator. Low priced bearing may have the separator omitted, however this element can be very important to prevent rubbing contact between the bearing balls and side walls.
The single-row deep-groove radial contact ball bearings will take radial load well and some thrust load. The balls are inserted into the grooves by moving the inner ring to a eccentric position. The balls are separated after loading, and the separator is then installed. Sometimes manufacturers use a filling notch in the inner and outer rings to enable a greater number if balls to be inserted, increasing the bearing capacity. The rated thrust load of the bearing is decreased as the balls tend to bump against the edge of the notch when thrust loads are applied.
Angular contact ball bearings are designed for both radial and thrust loading where the thrust load maybe as much as the radial loading.