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Both Caterpillar and
Komatsu are in the process of offering—from the factory—global
positioning systems (GPS) for automated blade control. Volvo’s
grader now features a more advanced cooling system. John Deere graders
now have a new hydrostatic system for six-wheel-drive machines.
And just about three years ago, Case began offering a motor grader.
That’s not all.
“The machines are becoming more sophisticated,” says Mike
Duncan, a motor grader marketing consultant at Caterpillar. “There
is a need for electronic engines to meet emission control regulations,
and we’ve used the electronic engine as a springboard to do
a lot of other things.”
For example, Caterpillar
motor graders now feature automatic engine throttle control, which
works much like cruise control in your car, and holds engine speed
at a constant level. Plus, Duncan says, “We have the third
generation of electronic monitoring systems, called EMS III.”
The system offers before-failure alerts on a host of operating parameters,
and monitors fuel consumption and safety systems.
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Photo:
Case
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Moreover, Caterpillar
offers Product Link, which allows an owner to monitor a machine’s
systems from a remote location. Product Link comes in four levels
of sophistication. At the basic level you can monitor location and
operating hours, while at the advanced level you can keep tabs on
such items as engine operating temperature, transmission oil temperature,
and many more.
“People are getting
tremendous productivity improvements with GPS systems,” Duncan
says. By June or sooner, Caterpillar will offer its AccuGrade GPS
system as a factory-installed option on motor graders. And Caterpillar
dealers will support the GPS systems. AccuGrade stems from Caterpillar’s
joint venture with Trimble, and it comes in various levels of automation.
At the basic level, AccuGrade offers automated cross-slope control.
Sonic- and laser-based systems are available, and the most sophisticated
level features a three-dimensional GPS system for automated blade
control.
Six-Wheel Drive
John Deere says the new dual-path hydrostatic propel circuits for
its six-wheel-drive machines makes them “the most efficient
and productive 6WD machines in the industry.” Six-wheel-drive
technology, Deere says, delivers 50% more blade pull. And the company
offers “unique aggressiveness settings and true inching capability
for better control during all kinds of coarse and fine grading—plus
added traction in tough conditions.”
Within the past two years,
Deere says it has introduced
- new engine side shields
and covers to provide more cooling efficiency;
- power increases in
all models; and
- Tier II emissions-certified
engines in the 670 CH Series II and the 672 CH Series II.
Deere also offers its
Powershift Plus transmission for improved shifting quality. And
the company says its graders are easy to maintain. For example,
all you need to replace circle and moldboard inserts is a nine-sixteenths-inch
wrench.
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Photo:
Volvo
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Photo:
New Holland
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More Torque
“Grader engines are more fuel-efficient than they used to be,”
says Gary Atkinson, product manager for motor graders at Volvo Construction
Equipment North America Inc. “They deliver more torque at lower
rpms, and that’s true pretty much across the board, especially
at Volvo, John Deere, and Caterpillar.”
To meet exhaust-emission
requirements, today’s engines generate more heat and therefore
demand higher-capacity cooling systems, Atkinson says. As a result,
Volvo has introduced a hydraulically driven engine cooling fan.
Instead of running linearly with engine speed, the cooling fan turns
only as fast as the engine needs, based on a given ambient air temperature.
So on cooler days especially, the engine cooling fan runs at slower
speeds.
Conventional cooling
fans can consume up to 45 horsepower of the engine’s power
output, when turning at, say, 2,500 rpm, Atkinson says. By contrast,
Volvo’s hydraulically driven fan may only turn at says 700
rpm or 800 rpm on a cool day. There are three advantages result
from the new cooling system:
- Increased fuel efficiency
- More power going
for tractive effort, if you need it
- A quieter engine,
because the fan isn’t running as fast
What’s more, Volvo
has come up with a cube system for arranging the cooling-system
cores. Normally, cooling cores are stacked, one in front of the
other. You have the radiator core, the condenser coil, and the engine
oil cooler, all stacked in a row. Debris can get between them and
cause overheating.
But with Volvo’s
cubed cooling system, heat exchangers are arranged with one on the
top, one on each side, and one in front of the cube. The back is
open, and the hydraulically driven fan draws air through all four
exchangers at the same time, Atkinson explains. To clean out the
cube, you simply open a door in the back, and blow out the debris
with a leaf blower, water hose, or air hose.
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Photo:John
Deere
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Photo:Case
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Dual-Mode Transmission
Komatsu America’s most substantive advance is the dual-mode
transmission, which allows for operation in direct-drive or in torque-converter
mode, says Bob Post, product manager for motor graders. “If
you’re in a high-speed application, such as roading or snow
plowing, you can use direct drive, because it gives you more speed,”
he says. “But in the torque-converter mode, you’ve got
a fluid coupling, so you get better fine-grading capability. You’re
not constantly declutching. You can’t stall a torque converter
machine; if you come to a stop, you won’t kill the engine.”
Post says the learning
curve is shorter on a grader with a torque converter. “The
operator can focus on using his hands to operate the blade functions,
rather than worrying about declutching and trying to prevent the
engine from stalling,” he says. “So many good motor grader
operators are retiring, so if you can shorten the learning curve
for a new operator, you’re in great shape.”
Komatsu works with Topcon
to supply GPS systems on motor graders, Post says. In the fall of
2004, he said that Komatsu would offer optional factory-mounted
GPS systems at dealers by the end of the year.
Case Construction Equipment
now offers three models of motor graders: the 140-horsepower Model
845; the dual-horsepower Model 865, which comes with 170 horsepower
for lower gears and 190 horsepower in higher gears; and the 205-horsepower
Model 885.
“We put the articulating
joint in front of the cab,” says David Wolf, Case’s marketing
manager. “Most of our competitors have the articulation joint
behind the cab. But when it’s in front, I know where the front
of the machine is in relation to the back half. The competition
needs an indicator to show where the back half is.”
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Photo:John
Deere
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Case, moreover, offers
a one-piece flip-up hood, instead of several access panels to service
points. “We have swing-out batteries for better access,”
Wolf says. “We believe that the easier maintenance is to do,
the more likely it is that the operator will do it.”
Both Case and its sister
company, New Holland Construction, offer an “involute”
curve on the moldboard. The idea is to create multiple radii on
the moldboard, so instead of focusing all of the dirt in one place,
it rolls off in all different directions, Wolf says.
“Our circle is a
little different,” he says. “Our teeth to drive the circle
are on the outside. They’re external. So the circle is easier
to clean out, and you have a larger area to engage the drive motor.
So you get extended wear life, because you have a greater surface
area to wear on.”
Richard Burckardt, New
Holland’s brand communications manager, says the company’s
RG170 is its most popular motor grader. Its 170-horsepower engine
is in a very popular horsepower class, and its price point is good
for municipalities, he says.
What’s ahead for
motor graders? Look for more manufacturers to add all-wheel drive.
“We are aggressively looking into offering that feature in
the near future,” Burckardt says.
Daniel C. Brown is
the owner of TechniComm, a communications business based in Des
Plaines, IL.
GEC
- January/February 2005
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