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The performance
of OilLess Bearings can be greatly effected by surface
roughness, the use of plated and non-plated surfaces and
mating materials, which form the friction between the two
solids.
Surface
Roughness In case of solid
lubricant Bearings, like OilLess # ZA 500 and ZA#1000 their
Bearing lives are determined by whether or not a lubricating
film of solid lubricants can be formed on sliding surfaces of
either mating materials or the Bearings. Surface roughness of
mating materials within 3 ~ 12 micron meter is sufficient for
proper performance of the Bearings. A mirror finish, as in the
cases of oil lubricating Bearings and plastic Bearings, is not
necessary.
Surface
Treatment.
The
three main reasons for treating mating surfaces are:
1. To improve
corrosion resistance.
2. To improve
surface hardness.
3. To improve
surface smoothness for better lubricity.
When plating is
employed to attain purpose 1 above, hard chrome plating is
highly recommended, because it prevents mating materials from
rusting and abrasive wear from developing. hard chrome plating
also contributes considerably to the lubricity improvement
.For slight oscillating motions under high loads, nitriding
treatment on shaft materials is effective. When used
under highly corrosive environments such as in seawater,
double or triple layered chromium plating is
necessary.
Role of Oiling: Periodical Oiling is
suggested for OilLess Bearing because it will reduce
co-efficient of friction and the Bearing temperature, thus
improving the Bearing life. Oiling also facilitates
performance under high load conditions and secures safety.
Other advantages of Oiling include: removal of wear particles,
sealing effect against foreign matters, prevention of rust on
the shaft material, etc.
Lubricating Oil In general, motor oil is
used. However, grease is recommended for conditions where
considerable vibration occurs which scatters oil, or a low
speed operation under a high load, which disrupts a
lubricating, oil film.
Grease Grease is superior to
lubricating oil in sealing effect, water-proofness and
adhesiveness but is inferior in its cooling effect. Grease is
often applied when Bearings are frequently splashed with water
or where there is considerable vibrating or textile machine.
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