28
CONSTRUCTION EUROPE
OCTOBER 2013
EXCAVATORS
selected and the work being undertaken.
Doosan said the overall reduction of fuel
consumption was connected to the machine’s
improved cooling efficiency, resulting from
the fitting of a new fan clutch with electrically-
controlled fan speed.
Meanwhile, there is also a growing move
towards augmenting traditional power
sources. The most talked-about is hybrid
technology, and this is an area where Komatsu
has been a clear leader.
HYBRID SALES
Its first hybrid excavators were launched in
2008, and since then the company said it had
sold more than 2,000 such 20 tonne class
excavators, logging more than 1 million hours
of work.
The latest version, the 21.2 tonne HB215LC-1,
was on display at Bauma and the company
said it offered 25% less fuel consumption and
CO
2
emissions than a traditional excavator.
The machine achieves this by capturing
energy that would otherwise be wasted in
braking slewing movements of the upper
structure. A generator is used to convert this
energy to electricity, which is stored in a
capacitor. This is available to rotate the upper
structure back again or to assist the engine
in other ways, as dictated by the on-board
computer.
Komatsu is the only manufacturer to have
an electrical hybrid excavator in production
today, although other manufacturers
including Doosan, Hitachi and Hyundai have
exhibited prototype 20 tonne class hybrid
excavators at various exhibitions over the last
few years.
Liebherr also exhibited an interesting
concept machine at Bauma incorporating
numerous systems into a 40 tonne package.
The R 9XX concept crawler features both
electrical and hydraulic systems to capture
and store waste energy, and Liebherr said it
would make a 160kW diesel engine viable,
whereas a standard power unit for a 40 tonne
machine would normally be well over 200kW.
As well as capturing slew brake energy,
Liebherr has devised a system to grab waste
energy used to lower the boom and stick.
But there has not been a great flood of such
machines into full production. Part of the
reason for this may lie in the fact that global
sales of excavators remain sluggish in the
wake of the 2008 financial crisis.
Another issue that excavator buyers have
to weigh-up is how quickly buying such a
machine will pay off. Fuel consumption is
lower, but the extra on-board technology
inevitably means a higher purchase price.
COST BALANCE
This balance is something manufacturers are
highlighting. For example, Volvo CE president
Pat Olney said any machine the company
produced would have to provide a strong
business case for its customers.
“Our focus is on fuel efficiency and viability
for the customer. We continue to research
hybrids and we have a lot of experience in the
group through Volvo Bus,” said Olney.
He added, “When we bring something to
the market, we want to make sure it is viable
for our customers. We think we have some
Attachment
versatility
Contractor Garten- und Landschaftsbau
Olaf Krause is using a Terex TW110
wheeled excavator for preparatory
clearing work for a utility company in the
Bielefeld district of Heepen, Germany.
Driver Michael Boehne used the 11
tonne machine with a Beha stone and
recycling grab. “The TW110 can also work
with sizes from 200mm for cable lines
up to a 2.3m wide trench dipper. This
means a formation level can be created,
which serves as the basis of work for our
colleagues,” he said.
The machine features independent
travel drive and working hydraulics,
forming a closed hydraulic circuit, as well
as a standard additional control circuit for
work attachments.
Liebherr’s concept R9XX 40 tonne class
hybrid features both electrical and hydraulic
energy recovery systems
The 19 tonne class MX18 from Hydrema,
part of a new Stage IIIB-compliant wheeled
excavator range
