Milton CAT 321 D LCR - Manual (Page 7)

Robust Undercarriage. A solid
foundation built tough to absorb the
stresses of everyday work.
• Rollers and idlers are sealed and
lubricated to extend service life.
• Track links are assembled and sealed
with grease to decrease internal
bushing wear and increase life by
as much as 25%, when compared
to dry seal undercarriages.
• Spring recoil system stroke has been
increased to better relieve excess
track tension, which can occur when
material builds up between the track
and sprocket.
Rugged Structures. Structural
components and the undercarriage
are the backbone of the machine’s
durability. Caterpillar places a lot of
emphasis on the machine’s durability
during the designing and manufacturing
of its excavators.
• Up to 95% of the structural welds
are welded by robots, which achieve
up to three times the penetration of a
manual weld and improving overall
durability of the machine.
• The 321D LCR’s main frame
utilizes high-tensile strength steel
and a one-piece swing table, which
improves strength and reliability.
• The carbody has a X-shaped, box
section design to resist bending and
twisting forces.
• Track roller frames are press-formed
in a pentagonal shape for additional
strength.
Engine Hood. The 321D LCR features a
one-piece, flat engine hood. The engine
hood opens backwards and is located in
a place that does not obstruct access to
inspection points in the engine
compartment. Counterweight. The counterweight
is split into two pieces for improved
serviceability. The top piece weighs
approximately 2268 kg (5,000 lb), and
the bottom weighs 3832 kg (8,450 lb).
The counterweight is a rounded cast
structure that minimizes the amount
of overhang.
7
Structures
321D LCR is designed to handle the most rugged operating conditions, while providing long
life and value.