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The
Sheedy Bearing Revolution (cont'd)
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The
Effect Of Lubricants
Tribological
effects in Sheedy Bearings are extremely complex. Surface
finish, surface hardness, machining mark configuration,
the intrinsic nature of the two surfaces, temperature,
heat flow, speed, load, lubricant mobility, bulk properties
of the bearing materials in contact and a number of
less obvious factors, make it essential that you consult
your Sheedy Bearing Supplier before applying lubricants
not specifically approved by Sheedy Bearings.
Whilst
it is reasonably obvious that the presence of lubricants
will enhance the performance of bearings, it is not
always so! We had a case where a client packed a Sheedy
Bearing with graphite loaded grease to run in a baking
oven when we had specifically supplied the bearing lubricant
free - the packed bearing did not work properly - we
stripped, cleaned and rebuilt the bearing and it has
run since without any problems.
Sheedy
Bearings can be supplied in many forms and with a variety
of lubrication mechanisms. They may be absolutely devoid
of lubrication or can have extremely advanced circulating
lubricant systems, it all depends on the application.
Materials
A
number of "space age" or "lead edge"
technologies and materials are applied within the Sheedy
Concept. This section gives a brief overview of some
of these factors and features, unique developments not
otherwise applied in bearing and tribological technologies.
Metallic
Resistance
to corrosion, temperature, (erosion), wear and deformation,
coupled with good load bearing characteristics and a
low surface co-efficient of friction are the key determinants
to the selection of metallic materials for use in Sheedy
Bearings.
Control
of the surface finish is important and the surface performance
in oxidising and reducing atmospheres must be considered.
Finally,
resistance to a wide range of chemicals is important,
although a number of very specific and narrow band resistance
materials are applied in extremely difficult and unusual
cases.
Non-Metallic
Bearing Materials
The
primary needs in bearing non-metallics or plastics,
are high strength, good wear resistance, low co-efficient
of friction and good resistance to deformation at elevated
temperatures.
The Research and Development programmes supported by
Sheedy Bearings are aimed at continually pushing forward
to frontiers of performance in non-metallic bearing
elements. This ensures that the Sheedy Bearing has the
greatest possible potential to meet the needs of industry
and the ability to provide solutions to intractable
industrial problems.
The
F20 Story
Fechnerplas
20 (F20) is an exciting breakthrough in the Sheedy Bearing
concept. Our ongoing research and development programme
has resulted in this phenolic resin bonded bearing material,
embodying all of the key elements required in the bearing
field, temperature resistance, low thermal co-efficient
of expansion, high thermal conductivity, exceptional
load bearing capability, virtually no deformation within
the bearing load range, whilst retaining the great advantage
in plastic bearing elements, resistance to shock and
vibration.
Why
phenolic bonding, why is it important?
Phenolic
resins are amongst the toughest of the plastic bonding
media available to withstand the effects of heat, vibration,
shock and heavy loads, without losing strength and resilience.
They have extremely high resistance to oils, greases,
water, steam, cleaning chemicals and other common chemical
reagents. A common use of phenolics is in the moulding
and bonding of brake linings, an extremely taxing application
for any material.
Some
of the impacts
With
this new material, we now have a material to take the
Sheedy Bearing into the 1400 RPM and higher speed range.
Running this material in water or with a forced water
lubrication system, brings the Sheedy 1000 Bearing into
the world of metal bearings without the problems associated
with metal bearings.
The
internal clearances in the bearing for the 1000 Series
of bearings have been significantly reduced, resulting
in a "tighter" performance than that which
was previously possible. Given a thorough understanding
of your product or of the problems you need to overcome,
can help us to help you in reaching an optimum solution.
This
bearing material, F20, performs well in any high load
application to which the Sheedy Bearing concept is suitable.
Running environment temperatures of up to 316 degrees
Celsius in oxidising or reducing atmospheres, are readily
achieved. The dry co-efficient of friction is below
0.2 and a compressive strength of 14 000 to 20 000 Mpa
is readily achieved, with a Shore hardness of 62 to
95. The material is extremely stable, hard, tough and
slippery; it is an ideal bearing material.
One current application for this bearing is in the seal
and bearing system in water sealed vacuum pumps. The
performance is already outstripping that of the conventional
bearings applied to these machines. Other water lubricated
areas or potential applications are in drilling rig
thrust heads, special underwater plant and machinery,
submerged screw conveyors, sewage treatment plant, and
many more than can be listed.
Dry, wet or in between, F20 provides exceptional performance
in all types of atmosphere.
Let us review why you should be using the Sheedy 1000
Bearing fitted with Fechnerplas 20 (F20).
The properties which make use of this material in our
bearing are:-
It
will not weld to metal, therefore will not seize;
It
will withstand high and low temperature, with NO NEED
OF LUBRICATION;
It
will resist corrosion and therefore may be situated
within corrosive media.
Sheedy Bearings fitted with (F20) may be used in many
different types of equipment and environments where
classical bearings cannot be used.
The Sheedy 1000 Bearing is made from high grade steel
treated with a special surface conversion process
and hardened to give in excess of 1500 hours salt
spray test resistance.
The Sheedy 1000 Bearing can be made to interchange
with all conventional bearings, from self-aligning
to radial and the full range of cam followers and
rollers.
Temperature range for this bearing is minus 204 degrees
C to plus 316 degrees C and is run DRY with NO LUBRICANTS
required.
Uses for the Sheedy 1000 Bearing fitted with (F20)
are unlimited such as ovens, freezers, pumps, central
heating, air conditioners, drying ovens, boilers,
conveyors for mining and food processing and conveyor
rollers for the mining, printing, and metal processing
industries.
WHERE
AND WHEN SHOULD YOU USE THE SHEEDY BEARINGS
FITTED WITH FECHNERPLAS 20 (F20)
AT
HIGH AND LOW TEMPERATURES
Temperatures exceeding -100 degrees C to +150 degrees
C prohibit the use of standard oils and grease, the
self lubrication feature of (F20) allows its use as
a bearing material for furnaces, driers, heated mixers,
chemical installations and manufacture of paper pulp
and freezers, since they do not need to be lubricated.
IN
CORROSIVE FLUIDS OR ATMOSPHERES
Here again, classical lubricants are not recommended
and therefore Fechnerplas 20 (F20) and the Sheedy
Bearing may be used in either dry corrosive atmospheres
or immersed in corrosive liquids.
TO
AVOID CONTAMINATION BY LUBRICANTS
In some applications the presence of oil or grease
is prohibited even in vapour form. For example, this
type of contamination is undesirable in the food,
pharmaceutical and textile industries.
WHEN
LUBRICATION IS DIFFICULT OR EXPENSIVE
In many cases it is extremely difficult or expensive
to lubricate satisfactorily.
IN
ENVIRONMENTS WHERE DUST AND FLUFF IS A PROBLEM
The standard bearing attracts these particles to them
because of the oil and grease that is used, causing
bearing failure. The Sheedy Bearing using Fechnerplas
20 (F20) is not affected by these substances.
WHERE
THE MOVING PARTS ARE INACCESSIBLE
The maintenance of certain types of equipment is virtually
impossible due to the difficulty in accessing moving
parts, for example, mining conveyor rollers, marine
equipment, pumps, metering pumps and certain types
of equipment in the textile and chemical industries.
The uses of the Sheedy Bearing fitted with Fechnerplas
20 (F20) is only restricted by your imagination.
The
Sheedy Bearing (F20) can be designed to suit your
requirements. Now the customer can have the bearing
he requires not what the bearing company will sell
him. In fact, you can use the Sheedy Bearings, fitted
with F20, almost anywhere.
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P.O. Box 1192, Echuca VIC 3564, AUSTRALIA
