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ADVANCED PLASTICS
LM-Tarbell has a long history in the selection, design and
manufacture of plastic bearing materials. We are well versed on a
myriad
of these materials. Here a just a few:
Delrin® Acetal
Celcon®
Acetal Copolymer
Nylatron MC901
Fluorosint 500
Thordon
PTFE
Polymides/amides
PET-P
FDA/USDA Plastics
PPG APPLICATION
Shelbyville, NC
PPG is one of the largest glass manufacturing companies
in the world. On one their production lines they were employing
bronze bearings/rollers on a take-out assembly. Although the linear
speed was moderate, these rollers would see a 1280Lbs. overturning
moment along axis of the |
shafting for several seconds. The rollers would take a mechanical
set and score the shafting. These systems run 24/7 and breakdowns
coast 10's of thousands of dollars. PPG asked an engineering
consulting company to find an answer...fast! They called LM-Tarbell.
We took the engineering application data and selected a high
strength
plastic, Intech Power Core™ material. We also purchased a
McGill cam roller which we inserted in the machined roller -
providing a one stop assembly. After several months, PPG has had no
failures.
ABB Automation
New Berlin, WI
ABB engineers were working with Good Year Tire and
Rubber trying to find a bearing material that would work
successfully in a robotic application where the robot was taking
truck tires from a press and placing them on ancillary equipment.
The issues with this " wrist" action were
several fold:
1. 180º oscillation with varying moment loading
throughout the articulation of the robotic arm and the
shifting load of a translating tire that weighs 150lbs.
2. Moment Loading
3. Contamination
4. Required Self lubrication
5. Elevated temp
6. 24/7 Operation
LM-Tarbell engineers considered
several materials which
we commonly engineer: MELDIN®, Intech Power Core™
and WearComp®.
LM-Tarbell chose MELDIN®
for its excellent oscillatory load, temperature and self lubricating
qualities. ABB engineering reports that after 1 year, their customer
has not experienced any downtime.
CATERPILLAR
Peoria, Illinois
One of Caterpillar's vendors called LM-Tarbell about
failures
he was experiencing with a product he supplied to
Caterpillar. He manufactured ladder assemblies for a
special earth moving vehicle. Due to the vehicle's size, it
was necessary to have ladders for climbing to the top of the
vehicle. The ladder assembly had to fold down
- or un-stow - so it could be positioned. Because the assembly was exposed
to the elements, impact and
vibration, the original cast bronze ( 660 ) bearings took mechanical
sets, grease evacuated and the ladder
assembly failed. LM-Tarbell
engineers designed a special fiberglass composite shell with a self
lubricating, PTFE
Composite liner for self lubrication. This bearing is made
for shock
loading, grit and outdoor enviromemnts.
US COAST
GUARD/ DIRECKTOR Ship Yard
Middletown, RI
Robert Direcktor Ship Yard won a contract to build 10,
110 foot Coast Guard Cutters. Each cutter had twin, cantilevered
rudders. The Coast Guard designed Thordon
Composite Rudder Bearings into these assemblies.
LM-Tarbell was chosen by Coast Guard and Direcktor
engineers to supply finished Thordon SXL machined
bearings. These bearings were 44" in diameter.
LM-Tarbell was chosen because we have vast experience
in machining this temperature sensitive material. We
also have several Navy Vessels under our belt.
Thordon is an interesting material because it is a mixture
of plastic and rubber. This is like mixing water and oil. It has the
dimensional stability of plastic with the toughness of rubber. A
Thordon bearing can be totally compressed upon itself and return to
90% of its original shape in several minutes. Thus, as a rudder
bearing it is fantastic: it is self lubricating ( SXL ), will not
imbed particles ( sand, solids ),
will absorb shock without pounding the rudder housing out
of roundness, and is shock resistant. It is employed in
cement, waste water and marine applications.
NOTE: Thordon has to be machined in a constant temperature
environment. LM-Tarbell is a prime source
for machined Thordon.
Got a plain bearing problem? Call the plain
bearing
experts at LM-Tarbell.
To learn more about these products, please call our product
specialist, John Tarbell at 1-800-628-8332 or email your
requirements to:
jtarbell@lm76.com
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