 |
May 19, 2004
Subscribers: 35,717 |
| Today's
Tip: Advice for Keeping Gear Lube Dry |
Having problems with water contamination in outside
gearboxes? Consider the following:
-
If the gearbox runs continuously,
check for cooler leaks.
-
If it runs periodically, think
about using desiccant breathers. They will cost
a little to maintain, but less than the problems
associated with high water content.
-
Look at expansion chambers as
an option to water removing breathers. They allow
the lube to expand and contract without introducing
new (wet) air to the system.
-
Consider off-line water removal.
You can employ full-time filters or use a cart
periodically. Go ahead and filter dirt while you
are at it.
| Book
Bits: When to Regrease Motor Bearings |
From the "Lubrication Excellence
2004 Conference Proceedings"
An excerpt from the paper "How to Design an
Electric Motor Regreasing Program."
Because the bearing balls act as tiny viscosity
pumps, and the grease is less viscous when hot,
it is best to regrease a bearing while the motor
is running. If this is not practical, then regreasing
should be performed immediately after the motor
is removed from service while the grease is still
hot.
| Lube-Trivia:
Test Your Oil Metric Smarts |
Test your knowledge and prepare for ICML
lubrication and oil analysis certification.
QUESTION: What is the oil consumption
ratio?
Get
the answer.
| Q
& A: Why New Oil Color Varies |
"We notice a different color in
the lubricants we get from our lubricant supplier
in each shipment of the same product. Sometimes the
oil is lighter-colored, cloudy, darker, etc. Is this
a problem?"
For Group I mineral oils, slight changes in color
or darkness often occur due to differences in crude
stock. Color bodies in mineral oils are generally
associated with sulfur or aromatic impurities. The
darker the base oil the more of these impurities you
generally find. Dark color is more pronounced in higher
viscosity mineral oils.
Certain additives also contribute to
color, especially those containing sulfur. For instance,
detergents such as calcium sulfonate can substantial
darken a finished oil. If your lubricant supplier
has made a formulation change, this can lead to a
corresponding color change. Most responsible lubricant
suppliers disclose planned formulation changes to
their customers in advance.
Regardless of the color, with few exceptions,
a new oil should be clear and bright. If your oil
is normally clear and bright, but a new delivery reveals
a cloudy appearance, this is generally a cause of
concern. Reasons for this can vary, but those on the
list below are common:
1. Insoluble additives (blend plant or storage
stability problems)
2. Water contamination
3. Accidental cross-mixing of lubricant types
where additives or base oils have clashed
4. Solid impurities
5. High cloud point (wax crystallization)
When in doubt, retain a sample of the
oil and have it analyzed.
Jim
Fitch, Noria Corporation
Submit
a question
| Post
of the Week: Does Your Lab Know Your Goals? |
To reward the lubrication and
reliability community for its participation in the
Noria Message
Boards, we've started the Post
of the Week award. Every week, we award one lucky
member $50.
This week's award goes to:
Alan Wallace
Here's an excerpt from the post:
"An annual analysis is a bit of
a waste if you are analyzing for machinery health.
The interval between samples is too long. You could
easily have a failure between samples. If you were
analyzing with the intent of optimizing your oil change
interval then one year might be fine.
My questions to you are: what was the
lab asked to analyze? Were you specific as to what
you were trying to accomplish? Was the lab asked if
it had any background with the data interpretation
of your specific equipment? Was there an ongoing communication
with the lab when you were seeing these issues you
mentioned?" See
the entire post. |
