Truck & Off-Highway Engineering - February 2021 - 22

'REVOLUTIONIZING'

FLUID POWER | MOTION CONTROL
FEATURE

DIGITAL
HYDRAULICS

" In electric machines [the technology] would effectively extend
the battery run-time and operating window. "
- Thomas Bitter, head of technology at Volvo CE
The NorrDigi
system is based on
Norrhydro's proven
multi-chamber
hydraulic cylinders
and patented control
system.

operation in applications with high inertia loads, both
linear and rotary, such as lowering or braking. Excess
energy can be recovered and stored in accumulators
or batteries at up to 80% efficiency, according to
Norrhydro.
Because the system uses less energy, machines
could be specced with a smaller engine to also aid fuel
efficiency and CO2 emissions, Bitter said. The companies would not divulge any more details on the patented technology at this time.

The next phase

22 February 2021

Volvo expects the electro-hydraulic technology to benefit " enormously " its
electric machines.
invest in a new multi-million euro world-class manufacturing facility in
support of the launch, and I look forward to the market introduction of
the NorrDigi system together with Volvo CE. "
Volvo CE foresees this type of advanced-algorithmic electro-hydraulic system having a significant impact on the mobile hydraulics
industry, particularly on its own future products. " The technology is
adaptable, so in theory all machines currently using hydraulic cylinders could benefit, " said Bitter. " We are exploring the potential of the
technology within the Volvo CE future product plan. "
In addition to earthmoving and material-handling machines, potential application areas for the NorrDigi system include mining, military and offshore and marine.
TRUCK & OFF-HIGHWAY ENGINEERING

FROM TOP: NORRHYDRO; VOLVO CE

After a successful proof-of-concept phase and durability tests, the technology has moved to a field-test period in which prototypes are used in real-world applications by selected customer partners. The companies
would not share where the field tests are taking place.
" The testing is going well, within expected parameters, but the validation of the system so far is encouraging, " Bitter told TOHE. " The expectations from research so far is that the NorrDigi actuators will have the
same or better durability as current hydraulic cylinders. "
Bitter said that due to the " comprehensive nature "
of introducing the new technology, the system will not
be offered as an option on existing machines. " It will
involve creating a machine designed specifically for
use with the NorrDigi technology, " he said.
" The ability to develop this radical technology in partnership with a leading player in the construction equipment industry offers many advantages, including accelerating the time to market for commercialized products, "
said Yrjö Trög, CEO of Norrhydro, in a statement. " We will

Truck & Off-Highway Engineering - February 2021

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