Pin boss to roller flange interference
results in wear on top of roller flanges,
thus reducing the rebuildability and
strength of the flanges.
When the roller tread is worn past service
limit (100 percent worn) its weldability is
also reduced. As wear approaches 120 per-
cent worn, structural damage to the roller
shell in the form of cracking or breaking
may result due to loss of strength.
Wear Charts
Like links, roller tread wear charts have a
built in factor to account for expected
faster wear rate after the hardened case
depth is worn away. The wear rate after the
hardened case will be approximately three
times as fast as when the roller is new.
Different wear charts are provided for
different link-roller combinations where
applicable and are identified by the link
and roller group part number.
Roller Wear Patterns
Roller wear patterns may be used as indi-
cators of abnormal controllable conditions
that may affect other parts in the undercar-
riage. Most times the wear patterns shown
here are found in a combined pattern with
varying degrees of each depending on the
causes.
Tread Wear
(Normal wear pattern)
CAUSES: (1) Rolling contact with abra-
sives crushed between roller tread and rail
(top) surface. (2) Sideways sliding contact
between rail and tread.
ACCELERATORS: Weight, horsepower,
machine speed, impact, abrasiveness, and
to some extent packing. Terrain and appli-
cation often determine unbalanced inner to
outer tread and front to rear roller wear rate.
Unusual roller frame distortion problems
can accelerate selective wear rates. Turning
increases sideways sliding contact. Too
wide shoes and track snakiness tends to
accelerate rounded patterns.
EFFECT: Pin boss to roller flange interfer-
ence when link and roller combined service
limit reached or exceeded.
REMEDIES: Reduce or eliminate control-
lable accelerator variables particularly non-
productive turning and too wide shoes.
Swap rollers to balance final wear lives.
Rebuild (weld) rollers to dimensional
level.
Flange Side Wear
(Inner and/or outer sides facing tread)
CAUSES: Rolling and sliding contact
with rail sides.
ACCELERATORS: Same as “Tread Wear”
except side hill operation, uneven terrain,
turning misalignment, worn guiding guards,
snaky track and too wide shoes have greater
measurable result on flange than on tread.
EFFECT: Reduces guideability and re-
buildability of rollers.
REMEDIES: Same as “Roller Tread Wear.”
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General Information
TRACK ROLLERS