Bearings and Lubricants

Cylindrical Bearings

One-direction locating Bearings - These bearings also have separable outer or inner rings. But in these bearings the separable ring has a single flange that prevents the bearing shaft wandering in one direction. Roller guidance is provided by the double-flanged race. Characteristics are similar to the nonlocating bearings, except for a slightly lower limiting speed caused by the flange.

Two-direction locating bearings may be self-contained or have a two-piece inner ring. Self-contained bearings also have a lower roller complement and lower roller capacity, because it must be filled by displacing the rings and filling the remaining space. These two-piece bearings have a much higher load capacity, but are more complex.

Full-complement Bearings - These bearings use two snap rings in the nonlocating race to retain the rollers. Usually the outer race is the nonlocating race. Their advantage is high load capacity, their disadvantage is low speed. The speed limitation results from the high rubbing velocity between adjacent rollers and limits the bearing to low-speed or oscillatory applications.

Double-row Bearings - These bearings are used where alignment between shaft and housing is very good and high loads are encountered at moderate speeds. The bearings are nonlocating, and usually have roller-piloted retainers.

Another class of double-row bearings is the journal roller bearing, which usually has two nonlocating races. In some cases, the shaft becomes the inner race. When that is done, the shaft must be hardened and ground to tolerances equivalent to those of a bearing race.

Cylindrical Bearings