26
JULY-AUGUST 2013
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EXCAVATORS
Hyundai’s latest generation
of excavators is the Robex
9A series, which feature a
new ergonomic cab design
as well as the latest
low emission engines as
required in Europe and
the USA
This year has seen Hitachi update its range of wheeled
excavators
expect to see on some of its other excavator
models in the near future – components
suppliers to the industry are starting to offer
off-the-shelf packages that include similar
fuel-saving elements.
Bosch Rexroth’s new Virtual Bleed Off
(VBO) system for example, is designed to
provide just the right amount of hydraulic
flow to a hydraulic circuit. Not only does this
save fuel, but the company said it also makes
for more comfortable operation and faster
response.
Doosan has already adopted VBO for
its DX340LC-3 and DX380LC-3 Stage IIIB
compliant crawler excavators, where it is
branded as D-Ecopower technology. A 26%
improvement in productivity and up to
12% in fuel savings is being claimed for the
electronic pressure-controlled pump and
closed centre hydraulic system, depending on
the mode selected.
HYBRID FUTURE?
Although it is early days now, hybrid
technology looks to have a place in the
excavator designs of the future. Clearly there
are competing technologies, and the market
will decide which is best. It may be that
different technologies work better in different
applications.
As a final note on the hybrid question,
Liebherr 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 says it would make a
160 kW diesel engine viable, whereas a
standard power unit for a 40 tonne machine
would normally be well over 200 kW.
As well as capturing slew brake energy,
Liebherr has devised a system to grab waste
energy used to lower the boom and stick.
Hybrids will become more attractive
options if fuel prices go up because fuel
efficiency will become a bigger part of the
equation when it comes to working out the
whole-life cost of a machine, and Liebherr’s
concept R 9XX demonstrates that there are
more areas on an excavator where waste
energy can be caught and re-used.
But as hybrids become more and more
available, it is always going to be a wise move
to weigh up the increase in purchase cost
against the fuel savings that can be achieved
to work out how soon the pay-back will come
(if at all).
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