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OMATSU
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ESIGNED
K
OMATSU
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ESIGNED
4
Gear Selections
Eight forward speeds and four reverse speeds give the
operator a wide operating range. With four gear
selections below 9.7km/h(6mph), the operator can
precisely match working speeds to job conditions for
maximum productivity in earthmoving applications. Gears
five, six and seven provide optimal speed range for snow
removal operations. When in torque converter mode,
shifting is automatic in speeds five through eight. The
operator sets the maximum gear he wishes to operate in
and the transmission will then shift automatically between
gears five through eight up to the operator selected
maximum gear.
Converter Drive:
Designed to Provide Power and Performance on the Job Site
High Performance Komatsu SAA6D102E Engine
The GD555 gets exceptional power and efficiency from the
turbocharged and air to air aftercooled engine. Output is 119
kW
160 HP
SAA6D102E (variable horsepower in higher gears)
providing excellent tractive effort with good fuel efficiency.
Komatsu Power Shift Transmission
is designed and built specifically for Komatsu graders. The
transmission provides on-the-go, full power shifting as well
as inching capability and automatic shifting in the higher
ranges.
Komatsu graders boast the industry’s most
versatile moldboard geometry. Save time
and money when pulling ditches by
throwing the windrow to the right, not into
the roadway—without narrowing the road
bed. No extra machines or crew are
needed to pick up the windrow. It’s made
possible by Komatsu’s extraordinary reach.
Plus, there is generous clearance between
the heel of the blade and main frame, even
with the toe sharply angled down.
Extra-long lift cylinders let the moldboard
reach 835 mm
2'9"
below grade
.
The Most
Versatile
Moldboard
Geometry in the
Business
GD555-3
MOTOR GRADER
5
CLSS with Proportional Flow
Hydraulic System
Power on Demand
Normally, the variable displacement pump idles at low output. When it senses a
load requirement, the pump supplies quick flow and pressure to match the
demand. The result is less hydraulic system heat, quick response and lower fuel
consumption. The bottom line is greater efficiency.
Electronic Overspeed Protection
helps prevent engine and transmission damage from
premature downshifting and grade-induced overspeeding.
Electronic Transmission Control
produces smooth shifting, which enables the operator to
maintain a uniform grading surface if shifting is required.
Smooth shifts also extend the life of the transmission by
placing less stress on transmission clutches. A single lever
controls direction, speed and parking brake.
Lock-up Torque Converter
or direct drive the operator chooses the optimum
transmission set-up for the job at hand. If power for tough
grading or low speed fine control is required, the operator
can select the torque converter mode. With the torque
converter, the operator has tremendous tractive effort.
More importantly, is the fine control at low speed without
shifting or using an inching pedal. Torque converter drive is
available in gears 1-4. If high transport speed or high
speed for snow removal is needed, the operator can select
direct drive. The operator has the best of both worlds,
torque converter or direct drive, at his fingertips.
Low Effort Inching Pedal
gives the operator, when in direct drive mode, precise
control of machine movement. This is especially
important for operators who are not familiar with
operating a torque converter drive motor grader.
Implement Control Valves
Designed and built by Komatsu specifically for motor graders. They are direct
acting and provide outstanding operator “feel” and predictable system response for
unmatched implement control. To help maintain exact blade settings, lock valves
are built into the hydraulic circuits. Relief valves are also incorporated into selected
circuits to protect the cylinders from over-pressurization.
Low Operating Effort
Implement controls are designed to reduce operator fatique. They feature short
lever throws and low effort in both directions. Properly spaced control levers and
short lever throws allow the operator to use multiple controls with one hand.
Balanced Flow
When the operator uses several controls at one time, flow is proportional to ensure
several implements can operate simultaneously.
Constant Implement Speed
Implement speed is constant regardless of
engine speed because of the large pump output
and proportional flow control function.
Blade Angle
A long wheel base allows
the operator to obtain an aggressive
moldboard angle. This large blade angle
permits material to roll more freely along
the blade, which reduces power
requirements. This is particularly helpful in
dry or clay soil and snow and ice removal.
Rugged Construction
The A-frame
drawbar u-shape welded construction. A
one-piece forged circle is built to stand up
to high stress loads. To reduce wear, teeth
are induction hardened in the front 180° of
the circle. For maximum support, the circle
is secured to the drawbar by six support
shoes.
Replaceable Metal Wear Inserts
Replaceable metal wear inserts are
located between the drawbar and circle
and the support shoes and circle. This
wear system helps keep components tight
for fine grading and allows easy
replacement. Komatsu also uses
replaceable metal wear items in the
following areas:
• Circle and moldboard tip bracket
bearings
• Moldboard slide rail
Cylinder Socket Dust Seals
• Blade Lift and Drawbar Sideshift
Cylinder sockets have dust seals to
prevent dust from entering inside the
sockets causing wear.
Optional Protection Systems
• Blade Lift Accumulators
absorb
shocks when the moldboard contacts
immovable objects. This option is
especially useful in rough grading and
rocky areas. It provides precise control
while allowing relief from vertical impact
loads.
• Circle Drive Slip Clutch
protects the
drawbar, circle and moldboard from
horizontal shocks when an object is hit
near the toe or heel of the blade.
This option is most useful in applications
where hidden objects are frequently
encountered.
