Cylindrical Bearings
Cylindrical
roller bearings have high radial capacity and low friction, which permits
operation at high speed. A certain amount of thrust loads may be carried.
The cylindrical rollers are either end relieved or crowned to avoid stress
concentrations at the ends of the roller-race contact.
They are suitable for high-speed applications and made in precision grades.
Cylindrical roller bearings are generally lubricated with oil that serves as
a coolant. To avoid the bearings kid, a common problem in cylindrical
bearings an out-of-round raceway or two preloaded hollow rollers may be
used.
Non locating Bearings have a separable outer ring or the
inner ring that allow considerable axial movement of the shaft. They are
used with an axially locating bearing such as ball bearings. Non locating
bearings have high radial and load capacity, high stiffness, and the highest
speed capability.
One-direction locating Bearings also have separable outer
or inner rings. The separable ring has a single flange that prevents the
bearing shaft going in one direction. Roller guidance is provided by the
double-flanged race. They have a slightly lower limiting speed caused by the
flange.
Two-direction locating bearings may be self-contained or
have a two-piece inner ring. They have a lower roller complement and lower
roller capacity, but a much higher load capacity. They are rather complex
bearings.
Full-complement Bearings use two snap rings in the
nonlocating race to retain the rollers. They have a 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 are used where alignment between shaft
and housing is very good and high loads are to be handled at moderate
speeds. The bearings are nonlocating. Another class of double-row bearings
is the journal roller bearing, which has two nonlocating races.
