IN-WHEEL MOTORS
“Over the next few years we
will see a mix of fuel systems,
but we will see more requests
for electric buses”
Dr Sacha Klett, technical managing director, Ziehl-Abegg
www.electrichybridvehicletechnology.com // January 2020 // 47
in-wheel systems’ ability to be integrated into
hybrid and fuel cell applications.
Hilton confi rms in-wheel technology lends
itself well for those demanding hybridization.
“It’s a good system for the hybridization of an
existing platform because it’s relatively
undisruptive.” Gotovac agrees. “Hybrid
applications benefi t more in terms of time-tomarket,
due to major packaging issues that
OEMs are experiencing with hybridization
of in-production vehicles.” Because the
technology fi ts around mass production parts,
retro-fi tting to IC vehicles is also appealing.
“Our in-wheel technology integrates with
other components, so it fi ts with existing
platforms and future vehicles designed more
around the user than powertrain,” he states.
Increased unsprung mass generated as
a result of the in-hub motor weight was
a potential challenge in the past, but
it has now been solved. “Most OEMs
see this as a completely manageable
task,” states Gotovac. “We did
work in the early days with Lotus
to establish what you would do to
mitigate the eff ects,” says Hilton.
“Essentially, you end up stiff ening
the suspension to cope and the
impact is very small.” According to
Klett, the answer is also similar for
larger-sized vehicles. “You can optimize
the suspension so there’s no critical situation,”
he reports.
Readiness and risk
When it comes to the mainstream adoption of
in-wheel solutions, the long-standing question
of market maturity remains. With OEMs such
as Lexus reported to be considering in-hub
technology, could it fi nally be on the brink of a market
breakthrough? Japanese supplier Nidec announced its fi rst
in-hub system in 2019 with mass production expected to
begin in 2023. Hilton explains that market readiness and
risk have been key drivers until now.
“With all disruptive technology you develop it to the
extent that the market will take it at a time. It would have
been pointless for us to have been producing hundreds of
thousands of these fi ve years ago because there was no one
ready to take them. The technology develops
alongside the customer willingness to adopt it.
However mature it is, until the technology’s
been adopted by somebody and it’s run
millions of miles on the road, the customer
will always consider it as a risk compared to
traditional drive systems.
“We have a product that I would describe
as mature. It’s been through comprehensive
testing to prove its durability and design, and
our main push is to get it to high volume
5. Ziehl-Abegg’s ZAwheel
is a single in-wheel
electric hub drive for
commercial vehicles
6. Buses benefi t from
noiseless and 100%
emission-free driving
5
6
/www.electrichybridvehicletechnology.com