Single row deep groove ball bearings
This bearing type forms the largest group because of its ability
to carry both axial and radial loads, the very low friction
and low noise and the low maintenance required. It is suitable
for high speed and light loads. Many of these bearings are
sealed or shielded for life. Most are designated and dimensioned
to the ISO standards.
Self-aligning ball bearings
This bearing has a double row of balls. Its outer ring raceway
is spherical allowing the rings to be dynamically misaligned,
making it suitable for use in applications where the misalignment
of bearings on a common shaft can occur. It can carry radial
and axial loads but is not suitable for heavy or arduous operation.
The number of balls and the contact area each ball makes with
the raceways restrict the capacity or load rating of the bearing.
Since this contact area is so small, contact stresses can
be as high as 4,000 MPa, which equates to 400 kg/mm or approximately
90 tones on an area the size of a thumbnail. This capacity
to carry such enormous loads makes the bearing the most highly
stressed component in the equipment.
Single row angular contact ball bearings
This bearing is capable of carrying high combined radial and
axial loads in one direction only. It must be used in conjunction
with a similar bearing acting in the opposite direction. This
pairing of the bearings is done in a back-to-back, load lines
diverging towards the bearing axis, or face-to-face configuration,
load lines converging towards the bearing axis, It is extremely
important that these bearings are mounted together in the
correct orientation and with the correct degree of pre-load
The Y-bearing unit is a complete unit consisting of a bearing
mounted in a bearing housing. The bearings are based on the
deep groove ball bearing but have an extended inner ring and
a spherical outer ring diameter, which allows for static misalignment
of the bearings. The bearings can be fitted in various types
of housing; cast iron being the most common but pressed steel
and plastic housings is also used.
The Y-bearing units are very robust and simple to use but
do not allow for axial displacement that may take place due
to thermally induced dimensional changes. For this reason
the bearing centres should be short or the housing supported
on a resilient material or structure, such as sheet metal.