Maintworld 1/2017

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• Say what you’re going to do
ASSET MANAGEMENT
g to do
relubrication interval of 5,333 hours and
on the other hand 6 minutes! How can a
machine manufacturer provide recommendations
that account for every operating
condition in the world?
• Say what you’re going to do
On-condition Lubrication
Using Ultrasound
Alternatively, on-condition lubrication
using ultrasound provides data that
eliminates these three problems by giving
the lube tech
1. A sound to assess
2. Condition Indicators with alarms
to measure
3. A dynamic history of the health of
every bearing in the programme
In a Planned maintenance strategy,
ultrasound will tell you when to stop
injecting grease. In the Predictive strategy,
an ultrasound measurement alerts
the lube tech when and if lubrication is
needed at all. The grease quantity and
interval calculations become only guidelines.
Measurement of friction using
ultrasound is the driving and controlling
parameter.
Ultrasound “hears” friction, so the
trained lube tech acquires valuable information
on the frictional state of that
bearing.
As a rule, “to fail to prepare is to prepare
to fail”. So many mistakes occur
before the grease gun even reaches the
lubrication point. Organizational tasks
like lubrication management, storage,
and contamination control are essential
and their need cannot be over-emphasised.
Likewise, the lubrication task
itself must also be preceded by preparation.
Preparation Information Essentials:
1. Which lubricant do I use for this
bearing?
2. What is the calculated maximum
amount?
3. How frequently should we check
this bearing?
This task is best managed with software.
Combining preparation with friction
measurement software provides a
smooth, seamless integration between
the condition assessment and the lubrication
function.
A measurement and lubricant database
is created for each bearing. The
database controls the sensor type, the
lubricant type and the calculated maximum
quantity.
How much grease does your grease
gun dispense? If the answer is, “I don’t
know”, then calibrate your grease guns.
Minimise variables that cause errors.
Ensure that the majority of grease guns
used deliver the same amount.
“Patience is a virtue” applies to lubrication.
Build in a waiting time between
each injection of grease to ensure that
the impact of that injection is detectable.
This prevents over-lubrication
and allows you to spot failures such as
blocked and broken grease tubes.
A database Tree and Lube Surveys,
similar to ones used for condition assessment,
is now created. These surveys,
loaded into your ultrasound data collector,
guide you to a precise lubrication.
In Survey Mode, the ultrasonic instrument
guides the lube tech from point to
point and measurement data is the reference
to lubricate the bearing. With the
reference stored, the detector prompts
the technician to begin adding grease.
After the waiting time, another measurement
dictates the next action.
• Say what you’re going to do
Planned vs. Predictive
Approach
To assist the lube tech, the ultrasound
meter’s built-in algorithms compare
each successive reading and suggests the
technician either add more grease at a
controlled rate, or decides to stop.
The integration of ultrasoundassisted
lubrication can be deployed in
either a Planned or Predictive strategy.
In a Planned strategy, ultrasound guides
the lube process, however the calendar
still dictates the intervals between lube
tasks. This time-based approach does
not take full advantage of ultrasonic
conditional data to trigger the lube
process. Progressive lubrication programmes
want to get to that stage.
A successful migration from Planned
to Predictive lube tasks is earmarked by
message changes. “Inspect Bearings and
Grease as Necessary” is replaced with
“Take Ultrasound Readings and Grease
ULTRASONICALLY Based on Need.”
The result becomes a history for each
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