18 June 2019 TRUCK & OFF-HIGHWAY ENGINEERING
FROM TOP: RYAN GEHM; PERKINS
EXECUTIVE VIEWPOINTS
H
ybrid powertrains still account for a small por-
tion of the off-highway vehicle market—less
than 1%, according to Oliver Lythgoe, product
marketing executive at Perkins—but interest is
most certainly intensifying. Engine makers cannot delay
R&D activities in this area, lest they be left behind.
“Outside of forklift trucks, electrical machines are a
very small part of the market as well,” Lythgoe told
Truck & Off-Highway Engineering at the bauma 2019
trade show in Munich. But that will not always be the
case, he added. “We have to be able to
help OEMs plot out those strategies
and make sure that when the market
changes, either through economics or
regulation, that they’re ready.”
Perkins has conducted research
projects in this space for about 10
years now, Lythgoe said, focusing on
fundamental technologies such as bat-
tery ruggedization as well as on sys-
tem integration. In the past two years,
these activities have “ramped up con-
siderably,” he said, running a number
of technologies in test cells in its labs,
and creating an engineering team
dedicated to working with OEMs on
hybrid and electric solutions.
“OEMs are very pressurized, it’s not a
new thing. But the waves of regulation
coming from different governments
around the world are a constant pres-
sure on OEM R&D departments,”
Lythgoe explained. “It’s not just emissions, it’s other safety issues, light-
ing, noise, RoHS, all sorts of compliance challenges...And now with
stakeholders asking, ‘By the way, can you develop some hybrid and elec-
tric versions, please?”—that comprises a completely different skillset on
an incredibly burdened team and already-stretched resources.”
The size of Perkins’ dedicated team ultimately will be determined by
customer interest, starting at the bauma show in April. “We’ve had a lot
of decent conversations here,” he said. “If we end up running 15 projects
with customers this year, then it’s going to look very different, where
we’re running three or four [teams].”
Hybrid architectures aplenty
The duty cycles, operating conditions and packaging
constraints for off-highway machines drive the need for
specific configurations that are highly customized to the
individual application. These factors differ to such an
extent between off-highway machines and other sec-
tors such as automotive, truck and marine that there are
limited opportunities for technology transfer.
“Particularly different is the amount of g shock
that machines experience—physically the solutions
could not directly carry over, but also in terms of
performance,” Lythgoe explained. “The urban driving
cycle relies on congestion and braking at traffic
lights—that’s where the inefficiencies are that hy-
brids solve. None of those things exist off-highway.
So, the opportunities for efficiency improvement are
in some other place in an excavator or wheel loader.”
The operating cycles from one piece of equipment
to another also vary enough that one solution does
not exist for all construction machines. “The right
Power systems expert at Perkins stresses that on-highway electric solutions cannot
be directly applied to the more-rugged and varied applications in off-highway.
by Ryan Gehm, based on exclusive interview with Perkins’ Oliver Lythgoe
“We have to be
guided by what
the market wants
rather than what
we want to sell.”
Oliver Lythgoe
Unique hybrids required
Perkins showcased three different
hybrid power solutions at bauma:
the hydraulic hybrid is in the
foreground, the mechanical hybrid
in the middle, and the electric
hybrid furthest away.