PRODUCT FOCUS
Hybrid machinery requires additional energy
storage capacity compared to traditional
machines, and the resultant change in
powertrain configuration increases initial
costs, with the potential for hybrid excavators
to cost 20–50% more than their traditional
counterparts (Wang et al., 2016). However,
the potential reduction in operating costs,
coupled with the decreasing cost of
technology as it becomes more widely
adopted, means that this differential is
unlikely to remain so high, and also that
owners can recoup the initial costs over the
life of the machine.
Volvo’s electric excavator
One of the biggest innovators in the area
of electric excavators is Volvo CE. In May
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MARCH 2018
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2
Concept excavators
Volvo CE also has two electric concept excavators — the GaiaX
compact excavator concept and the SfinX crawler excavator
concept — developed as an exercise to examine what excavators
of the future might be like.
The fully electric, zero emission GaiaX — imagined for the year
2030 — is fitted with rechargeable batteries but can also be used
while plugged in to an external electrical power source. Most
applications can be carried out remotely using a transparent,
augmented reality tablet computer, allowing the operator to dig
and keep an eye on the surrounding environment at the same
time. The tablet will be mapped with the city’s utility systems,
showing the exact location of water pipes and electrical cables
on screen, while a ground scanner provides precise information
on obstacles to guarantee the effectiveness of auto-dig modes
and projects images onto the ground to show the worksite and
to mark safe zones for the operator and passers-by. The tablet
will also connect to other machines in the fleet to provide a more
effective way of working.
The SfinX crawler excavator concept was developed by a team
of industrial designers to answer the question, “What might a
Volvo excavator of the 2020s look like?” The answer is something
straight out of science fiction. With the central concept being a
lightweight lattice boom, operator visibility is increased, while the
reduced component weight improves efficiency, saves on steel,
and reduces fuel consumption during operation. The machine
has been designed with hydrogen fuel cells that convert a fuel’s
energy into usable electricity and heat – without combustion.
And all hydraulic systems could potentially be converted to
electric motors. The removable cab also allows for remote
operation, while the juncture between the undercarriage and
superstructure would avoid the current arrangement of a large
roller bearing by hovering on an electro-magnetic field, allowing
zero friction and better control of the speed and torque turning of
the superstructure.
last year, the company unveiled its 100%
electric compact excavator prototype, the
EX2, a concept machine that delivers zero
emissions, 10-times higher efficiency,
10-times lower noise levels, and reduced
total cost of ownership compared to its
conventional counterparts. Believed to
be the world’s first fully electric compact
excavator prototype, the EX2 is part
of a research project and is not yet
commercially available.
The EX2 stemmed from the company’s
earlier ELEXC research project, which ran from
2012 to 2015 and was partly financed by the
French government as well as various funding
bodies in France. Volvo CE worked with a team
of six partner companies, which all contributed
towards the EUR7-million project.
1&2:
Imagined for the year 2030, the GaiaX is envisaged to be
fully electric and capable of semi-automated remote
operation through an augmented reality tablet device.
the world’s first lithium ion battery-powered
hybrid excavator: the 20t Stage IV/Tier
4-compliant SK210HLC-10. “Kobelco’s original
hybrid technology has improved significantly
since we first displayed our hybrid prototype
at Intermat 2006 in Paris,” said Peter Stuijt,
Kobelco product marketing manager.
During swing acceleration, the swing
motor is only powered by electricity
accumulated in the lithium-ion battery, to
save fuel. The braking energy generated
during swing deceleration is converted into
electricity, which is stored. According to
Kobelco, the SK210HLC-10’s battery allows
greater retention of stored electricity to
provide the necessary electrical output to
a Kobelco-developed 25kW power-assist
generator motor.
The SfinX concept excavator is already influencing today’s Volvo
design.