KOYO Spherical Roller Bearings
Spherical roller bearings feature a large load rating and
self-aligning capability. This type of bearing is suitable for low- or medium
speed applications which involve heavy or impact loading.
roller bearings are self-aligning, double-row, combination radial and thrust
bearings. They use a spherical or crowned roller as the rolling element. The
outer ring contains a spherical race which allows for some misalignment of the
shaft and housing. Spherical roller bearings are unequalled in their capacity
for high loads and tolerance to shock loads, but have limited speed
capabilities. They perform consistently, even under conditions of extreme speed,
application-specific stress, and marginal lubrication. The cage of a spherical
roller bearing provides high dimensional accuracy and functionality. According
to some estimates, spherical roller bearings have twice the running life of
Most spherical roller bearings are made of alloy steels or low-carbon steels.
Chrome-plated products are also available. Some applications require the use of
case-hardened or thorough-hardened, high-carbon, bearing-quality steel.
High-carbon grades of steel do not require carburizing and can be case-hardened
by induction heating or thorough-hardened by conventional heating methods. When
low-carbon, carburized grades of steel are used, carbon is introduced after the
spherical roller bearings are machined to a depth sufficient to produce a
hardened case that can sustain bearing loads. The addition of carbon and alloys
ensures the proper combination of a hard, fatigue-resistant case and a tough,
Bore size and outside diameter (OD) are important specifications to consider
when selecting spherical roller bearings. The bore size is the bearing's
smallest dimension. The outer diameter includes the bearing housing, but
excludes the flange. Other important specifications for spherical roller
bearings include overall width, rated speed (oil), static axial load, static
radial load, dynamic axial load, and dynamic radial load. Static axial load and
static radial load are, respectively, the maximum axial and radial loads that
bearings can withstand without permanent deformation. Dynamic axial load and
dynamic radial load are, respectively, the calculated axial and radial loads
under which a group of identical bearings with stationary outer rings can endure
for a rating life of 1 million revolutions of the inner ring.
These bearings are divided into R, RH(R) and RHA types, which differ in internal
structure. Each type can be produced with a cylindrical bore or tapered bore.
Bearings with a tapered bore can be fit and removed easily using an adapter
assembly or withdrawal sleeve. The rate of taper is equivalent among all bearing