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Introduction:
With developing
technology, speeds of rotating equipment in industry are on increase.
At such high speeds, lubrication can be a problem since grease
lubrication is not feasible and in oil sump lubrication, too much
heat is generated through fluid friction which makes its use impractical.
Oil Mist Lubrication provides a viable solution in such cases.
It is a centralized lubrication system where in the lubricating
oil is transformed into the form of oil mist using the energy
of compressed air and this oil mist generated by a single generator
can be supplied to number of locations in a plant over long distances.
This system has many advantages over conventional sump lubrication
method and hence is being used widely in recent years.
Operating life of a bearing is most of the times limited by its
failure which occurs due to contamination of lubricating oil and
so, the actual bearing life hardly reaches its fatigue life. Bearings
operating with clean uncontaminated oil run much longer before
failure than bearings operating in harsh situations. Also, with
increasing environmental regulations, it is becoming more important
to minimize oil leaks from machinery. For both of these problems,
Bearing Isolator provides the solution. As the name indicates,
it is used to isolate the bearings from the outside world. It
is meant to seal in both the directions, i.e. prevent the lubricating
oil from leaking out of the bearing housing onto the equipment
base plate and also to keep moisture, external airborne contaminants,
and dirt out of the bearing housing.
Project description:
A testing
program is being done at CeRoM on currently available bearing
isolator face materials for wear rates, coefficient of friction,
and interface temperature during both dry running and in an oil
mist environment. Testing samples of both the faces conforming
to ASTM D3702 are tested on a vertical type tribometer and real
time values of wear, friction and temperature are recorded for
different tests with different combinations of pressure and speed.
A special
attachment has been designed to provide the oil mist environment
near the contacting faces. It has two ports, one for the entry
of oil mist which is provided by the oil mist generator and the
other for the return of the condensed oil back to the reservoir
of the generator.
By studying materials, geometry,
and other design features, CeRoM hopes to advance the state of
the art for bearing isolators.
The objectives of this
research:
1. Measure wear rates of testing
samples of contacting seal faces, to predict service life.
2. Observe the effect of introduction of oil mist environment
on the performance of bearing isolator.
3. Investigate potential bearing isolator design improvements
for reduced friction, operating temperature, wear rate and for
extended service life.
Anticipated Benefits:
1. Ability to predict service life
at various conditions, for bearing isolators with contacting seal
faces.
2. Extend size and speed limits of currently available bearing
isolators.
3. Develop potential bearing isolator design improvements
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