Infrared Camera Spots Bearing Failures
The cell handling carousel at Duracell Battery was experiencing
a high failure rate of the 6,144 load bearings on which the cell racks
travel on.
The rails that these bearings travel on were quickly being worn by the
failed bearings.
Due to the high failure rate of the load bearings the predictive
maintenance team was asked to investigate the opportunity to
use any predictive technologies for early detection.
Initial scans with an infrared camera
did not detect the faulty
bearings because the machine speed is slow and
the
bearings
do
not have a significant increase in temperature. However, if the carousel
is
operated in "lube" cycle, it allows continuous running and the bearings
will heat up if a binding condition occurs.
The temperature range of the camera was lowered until
the warm bearing temperatures was noticeable. Through
trial and error, it was discovered that there was a 10 to 15 degree increase
in temperature was discovered. This is the delta T between a new bearing
and one that needs to
be replaced.
Once
a
procedure
was established, a weekly IR
route was scheduled. Adjustments on the range of the camera were performed
during each weekly scan while working with the mechanics. This was required
to
identify
the condition of the bearings that were being replaced.
The determination
for a base line and fault level was identified for the bearings. Initially,
40 to 50 binding bearings were identified at each scan and were replaced
during scheduled downtime. The rails were worn significantly and repairs
(welded and ground to shape) were performed.
Another corrective action
was to replace the rails with solid material rails. This replaced the
hollow tubing design that was originally installed. The rails were deforming
from
sheer weight, as well as the binding and wear from the worn defective
bearings. Currently there are 5 to 10 bearings detected during each weekly
scan that
require corrective action.
Benefits: Early detection of binding bearing
alerts maintenance to make repairs before breaking other components.
This reduces the rebuild costs and the unscheduled downtime. Additionally,
by
correcting the binding condition, the overall life of the rail is maximized
by reducing the wear from the rollers.
(Submitted by Mike Hammond, Predictive Maintenance Technician,
Duracell Battery.)
|
