Efficient Plant April 2018 - 26
feature | lubrication strategies
ANYTHING WILL WORK
Cleanliness is still next to godliness. Allowing your machinery
and lubricants to get this dirty
robs it of performance and life,
increasing overall operating
warranty status if not strictly followed.
Lubrication has always been colored with the
incorrect perception that its simplicity and inexpensive nature can be successfully managed with
little or no knowledge or training. This is further
exacerbated when neglect and/or improper application do not result in any immediate bearing
or machine failure. Consequently, a number of
mistaken ideas, passed down from the early days
of industrial lubrication, persist today.
The first myth is that oil is oil, grease is grease,
and any will do the job, no matter the application.
Based on the vast array of standard and specialty lubricants available today, a red flag should go
up immediately when lubricant choice is arbitrary.
Following this edict can accelerate lubricant and
component failures for a number of reasons,
primarily involving viscosity choice, incorrect
additive packages, and cross contamination.
Today's machinery is often operated in a wide
range of environmental temperatures. Colder
temperatures require less-viscous lubricants and
hotter temperatures require thicker, more-viscous
lubricants. Choosing the correct viscosity is essential to ensure the lubricant can provide a suitable
protective film (especially in tight-tolerance
bearings) that will separate the moving surfaces
without creating excessive fluid-friction drag, in
all temperature environments. Incorrect viscosity
can also severely affect the machine energy profile
and its performance.
Combining two different lubricants will inevitably mix the additive packages. This could not only
deliver a diluted additive package, but also cause
essential additives to drop out of suspension,
leaving the bearing at risk.
Not all lubricants are made equal. Many are not
chemically compatible and can even catalyze and
harden when mixed together, essentially changing
state within the bearing cavity at the expense of
the bearing and all of its lubricant feed lines.
When in doubt, always solicit the assistance of a
reputable lubrication consultant and/or lubricant
manufacturer/supplier to facilitate an engineered
lubricant-consolidation program that will determine the most suitable lubricant selection for
all of your bearings. Choose an oil viscosity and
additive package that is designed to work in your
ambient conditions to cut down on lubricant degradation and reduce the number of oil changes.
YOU CAN NEVER HAVE ENOUGH
Our second misconception is the old adage:
"More lube is better." Many bearings are killed
with kindness when automated-delivery systems