HOW TO PREVENT A PROBLEM
THAT CAUSES 25% OF ALL FAILURES
Bearing reliability is a crucial component of productivity
and uptime in expensive machinery and
plant throughout industries such as mining, manufacturing,
bulk handling and primary production. If
a bearing fails, production can grind to a halt.
Bearing failures can be caused by a number of
factors, including:
1. Fatigue, which can occur naturally over time,
but also occurs prematurely if the incorrect bearing
is chosen for the task.
2. Incorrect installation or mounting, which can
lead to significantly higher wear and tear and
ultimately premature failure. Examples include
misalignment, incorrect fits – too loose or too tight,
out-of-roundness in shafts or housings. About
25% of bearing failures occur because of incorrect
mounting.
3. Lubrication problems, which can occur if too
little, too much or incorrect lubrication is applied
to the bearing. Incorrect or insufficient lubrication
is the single biggest cause of bearing failure,
accounting for more than 45% of problems.
4. Poor maintenance or monitoring, because
even the best precision bearings are
not ‘set-and-forget’ technologies. Their
maintenance needs change with service
and local conditions, so good monitoring
and suitable maintenance is vital.
5. Contamination, which can occur
when foreign substances enter the
bearing. It is often considered to be
the major component of lubrication
problems. Contamination is particularly
prevalent in aggressive process and
manufacturing environments, such as
mining, primary production and bulk
handling.
BEARING CONTAMINATION
CHALLENGES
“Despite it being an eminently
preventable problem, a staggering
25% of all premature bearing failures
are caused by contamination,” says
Martin Grosvenor, industrial sector
manager, Schaeffler Australia.
CLOSE-UP OF THE EFFECTS OF
BEARING CONTAMINATION
“Contaminants can include airborne dust,
dirt or any abrasive substance that finds its
way into the bearing. The main sources of
these contaminants are dirty tools, contaminated
work areas, dirty hands and foreign matter
in lubricants or cleaning solutions,” explains Mr
Grosvenor.
Symptoms of a contaminated bearing include
excessive vibration and wear, which is best
detected before it becomes expensively obvious in
the form of unscheduled maintenance, or worse,
production breakdown.
SCHAEFFLER SOLUTION
In challenging environments or operations
where the risk of contamination is high, such as
continuous casting plant, conveyor belts, elevator
plant or food industry applications, Schaeffler’s
FAG sealed spherical roller bearing (SRB) is ideally
suited to the task.
FAG SRBs are a special rolling bearing design
where the inner ring runs inside the outer ring on
two rows of rollers. The bearings have an angular
adjustment of up to 2° and are not only designed
for high load carrying capacity but can also
compensate misalignments, due to the fact that
the symmetrical barrel rollers orient themselves
freely on the concave outer ring raceway.
FAG sealed SRBs offer the same benefits as
open SRBs, but with seals typically consisting of
nitrile rubber or, high performance fluoro rubber*
depending on the application and operating
conditions.
(*Seals made from fluoro rubber comprise particularly
high performance materials that may release
vapour when heated to about. +300 °C. This
may occur if, for example, a gas torch is used in
the dismounting of a bearing. In such cases, the
appropriate safety data sheet must be observed.)
FAG sealed SRB’s are available to suit a wide
range of common applications in heavy industries
such as pulp & paper, mining, minerals processing,
wood products, power generation.
“The seals effectively close off the bearings, giving
them an increased operating life compared with
open bearings, because they are protected from
contaminants. Additionally, they require significantly
lower quantities of grease to keep them
lubricated (up to 80% less in some applications),
which means they can assist in reducing environmental
impacts too,” says Mr Grosvenor.
Other features of sealed SRBs include:
• Very high basic dynamic and static load ratings
• Environmentally friendly characteristics
• Lower grease consumption and disposal costs
• No requirement for expensive relubrication
systems
• Reduced maintenance outlay
• Simple reconditioning
X-LIFE SEALED SRBS
Schaeffler’s FAG sealed SRBs are also available
in X-life ranges, which have improved kinematics,
optimised surfaces, are made from higher
performance materials and do not have a rigid
central rib.
These enhanced characteristics of the premium
X-life range mean that under identical operating
conditions, basic dynamic and static load ratings
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